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Dai C, Li K, Liu Y, Teng B, Chen Q, Jin X, Xu D, Hong R. Unveiling the directional dynamics: Hydrated electron driven defluorination in PFOA⁻ and PFOS⁻ through ab Initio molecular dynamics and quantum chemistry. WATER RESEARCH 2025; 280:123486. [PMID: 40101503 DOI: 10.1016/j.watres.2025.123486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2024] [Revised: 03/04/2025] [Accepted: 03/11/2025] [Indexed: 03/20/2025]
Abstract
Hydrated electrons (e-(aq)) are recognized for their potent reducing capabilities, making them significant in environmental engineering, particularly in the degradation of persistent pollutants like perfluoroalkyl compounds (PFCs). This study investigates the influence of attack direction of e-(aq) on the degradation mechanisms of PFCs, addressing a critical gap in understanding due to experimental limitations. Utilizing ab initio molecular dynamics and quantum chemical calculations, we systematically simulated the attack direction of e-(aq) on PFCs, focusing on the formation of anionic radicals and their excited-state reactivity. Our results indicate that the attack direction is pivotal for C-F bond cleavage: e-(aq) targeting the carboxyl end promotes effective bond cleavage, while approaches from the carbon-fluorine chain are hindered by molecular orbital shielding effects. Furthermore, we demonstrate that employing micellar systems to maintain PFCs in an unsolvated anionic state significantly reduces excitation energy, enhances red-shifted absorption, and increases excitation probability. Importantly, the excited-state electronic structure of PFCs closely mirrors that of their anionic radicals. These findings provide a novel strategy for improving the degradation of PFCs, thereby advancing treatment processes for persistent environmental pollutants and contributing to the broader understanding of water quality management.
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Affiliation(s)
- Chencheng Dai
- School of Chemical and Environmental Engineering, Anhui Polytechnic University, Wuhu 241000, Anhui Province, PR China
| | - Kaixin Li
- School of Chemical and Environmental Engineering, Anhui Polytechnic University, Wuhu 241000, Anhui Province, PR China
| | - Yazi Liu
- School of Chemical and Environmental Engineering, Anhui Polytechnic University, Wuhu 241000, Anhui Province, PR China
| | - BoChen Teng
- Zhejiang Zhonghuan Detection CO., LTD, Wenzhou 325003, Zhejiang Province, PR China
| | - Qi Chen
- School of Chemical and Environmental Engineering, Anhui Polytechnic University, Wuhu 241000, Anhui Province, PR China
| | - Xin Jin
- School of the Environment, Nanjing Normal University, Nanjing 210093, PR China
| | - Dayong Xu
- School of Chemical and Environmental Engineering, Anhui Polytechnic University, Wuhu 241000, Anhui Province, PR China.
| | - Ran Hong
- School of Chemical and Environmental Engineering, Anhui Polytechnic University, Wuhu 241000, Anhui Province, PR China; National local joint engineering laboratory to functional adsorption material technology for the environmental protection, Jiangsu, Suzhou, 215123, China.
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2
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Wang L, Chen B, Liao G, Wang J, Chen W, Li X, Tang Y, Wang X, Li L. Selective oxidation of ammonium to nitrogen with VUV/UV/Cl ⁻ process: Efficiency, pathway and mechanism. JOURNAL OF HAZARDOUS MATERIALS 2025; 492:138257. [PMID: 40233459 DOI: 10.1016/j.jhazmat.2025.138257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2025] [Revised: 03/19/2025] [Accepted: 04/10/2025] [Indexed: 04/17/2025]
Abstract
Conversion of chloride ions (Cl⁻) into reactive chlorine species (RCS) is an effective strategy for ammonium (NH4⁺-N) selective oxidation to nitrogen (N2) under high salinity conditions. Herein, vacuum ultraviolet (VUV) irradiation was introduced for NH4⁺-N removal in simulated recirculating mariculture systems (RMS) water treatment. Complete oxidation of NH4⁺-N and 88.3 % N2 selectivity were achieved for VUV/UV/Cl⁻ process. Mechanism analysis revealed that Cl⁻ were effectively converted into RCS under VUV irradiation and chlorine oxide radical (ClO•) was the predominant RCS responsible for NH4+-N removal. The pathway of NH4+-N oxidation was proposed as chlorination because chloramine was identified as the main intermediate. Influence factor investigation indicated that Cl⁻ and bicarbonate (HCO3⁻) could significantly promote the removal of NH4+-N in VUV/UV/Cl⁻ process due to acceleration of ClO• generation. Ultimately, the NH4+-N removal performance of VUV/UV/Cl⁻ process in practical application was also investigated. The results showed that not only NH4+-N in actual seawater or RMS could be converted effectively to N2, but also nitrite (NO2⁻-N) and partial nitrate (NO3⁻-N) could be removed efficiently by VUV/UV/Cl⁻ process. Hence, the VUV/UV/Cl⁻ process has promising potential in NH4+-N and total nitrogen (TN) removal for RMS water treatment.
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Affiliation(s)
- Lingdan Wang
- School of Environment, South China Normal University, Guangdong Provincial Engineering Technology Research Center for Drinking Water Safety, Guangdong Provincial Key Lab of Functional Materials for Environmental Protection, China
| | - Bing Chen
- School of Environment, South China Normal University, Guangdong Provincial Engineering Technology Research Center for Drinking Water Safety, Guangdong Provincial Key Lab of Functional Materials for Environmental Protection, China
| | - Gaozu Liao
- School of Environment, South China Normal University, Guangdong Provincial Engineering Technology Research Center for Drinking Water Safety, Guangdong Provincial Key Lab of Functional Materials for Environmental Protection, China.
| | - Jing Wang
- School of Environment, South China Normal University, Guangdong Provincial Engineering Technology Research Center for Drinking Water Safety, Guangdong Provincial Key Lab of Functional Materials for Environmental Protection, China
| | - Weirui Chen
- School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Xukai Li
- School of Environment, South China Normal University, Guangdong Provincial Engineering Technology Research Center for Drinking Water Safety, Guangdong Provincial Key Lab of Functional Materials for Environmental Protection, China
| | - Yiming Tang
- School of Environment, South China Normal University, Guangdong Provincial Engineering Technology Research Center for Drinking Water Safety, Guangdong Provincial Key Lab of Functional Materials for Environmental Protection, China
| | - Xi Wang
- School of Environment, South China Normal University, Guangdong Provincial Engineering Technology Research Center for Drinking Water Safety, Guangdong Provincial Key Lab of Functional Materials for Environmental Protection, China
| | - Laisheng Li
- School of Environment, South China Normal University, Guangdong Provincial Engineering Technology Research Center for Drinking Water Safety, Guangdong Provincial Key Lab of Functional Materials for Environmental Protection, China
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3
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Wu H, Wang J, Du E, Liu T, Liu M, Guo H, Chu W. Concurrent redox reactions for perfluorocarboxylic acids decontamination via UV-activated tryptophan/carbon nanotubes. WATER RESEARCH 2025; 279:123499. [PMID: 40112736 DOI: 10.1016/j.watres.2025.123499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2025] [Revised: 02/25/2025] [Accepted: 03/13/2025] [Indexed: 03/22/2025]
Abstract
The contamination and persistence of Perfluorooctanoic Acid (PFOA) in aquatic environments have escalated environmental concerns, driving extensive research into effective decontamination strategies. To enhance the removal efficiency of PFOA via Advanced Reduction Processes (ARP) utilizing UV irradiation of tryptophan (Trp), carbon nanotubes (CNT) were incorporated, resulting in the development of a UV-Trp/CNT system. This novel process demonstrated a significant improvement in PFOA removal kinetics, as well as defluorination and Total Organic Carbon (TOC) reduction, and was effective across a broad spectrum of perfluoroalkyl carboxylic acids (PFCAs). In addition to the advanced reduction mechanism driven by hydrated electrons (eaq-), quenching experiments, material characterization, and chemical calculations indicated that CNTs facilitated the enrichment of Trp and PFOA, enabling electron transfer from PFOA to Trp via the CNT surface. This established a novel reaction pathway for PFOA oxidation coupled with ARP. The sequential defluorination of -CF₂- groups was facilitated by eaq-, while the electron transfer mechanism enabled oxidative decarboxylation, electron rearrangement, CC bond cleavage, and carbon chain shortening. These oxidative and reductive processes alternated systematically, advancing the development of a synergistic redox approach for the removal of PFCAs and inspiring further exploration into the use of carbon materials to construct confined domains and catalyze the degradation of PFASs.
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Affiliation(s)
- Han Wu
- State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering, College of Architecture and Environment, Sichuan University, Chengdu 610065, China; Key Laboratory of Leather Chemistry and Engineering (Sichuan University), Ministry of Education, Chengdu 610065, China
| | - Jingquan Wang
- State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering, College of Architecture and Environment, Sichuan University, Chengdu 610065, China
| | - Erdeng Du
- School of Environmental and Safety Engineering, Changzhou University, Changzhou 213164, China
| | - Tao Liu
- Shimadzu (China) Co., Ltd., Chengdu 610023, China
| | - Min Liu
- State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering, College of Architecture and Environment, Sichuan University, Chengdu 610065, China
| | - Hongguang Guo
- State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering, College of Architecture and Environment, Sichuan University, Chengdu 610065, China; Key Laboratory of Leather Chemistry and Engineering (Sichuan University), Ministry of Education, Chengdu 610065, China.
| | - Wenhai Chu
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
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4
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Xiong X, Luo Z, Luo S, Bai L, Shang Y, Junker AL, Wei Z. Sustained hydrated electron production for enhanced reductive defluorination of PFAS in groundwater. WATER RESEARCH 2025; 279:123401. [PMID: 40081177 DOI: 10.1016/j.watres.2025.123401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2024] [Revised: 02/25/2025] [Accepted: 02/26/2025] [Indexed: 03/15/2025]
Abstract
Hydrated electrons (eaq‒; ‒2.9 V) are effective at defluorinating per- and polyfluoroalkyl substances (PFAS), but production of eaq‒ often requires excess source chemicals, anoxic environment, and harsh pH conditions. To improve the feasibility of the reductive process, we harnessed phenol as a source chemical yielding four eaq‒ stoichiometrically and utilized dithionite (DTN) to catalyze phenol cycle for sustained eaq‒ yields. The added DTN not only scavenges dissolved oxygen, the eaq‒ trap, but also reductively transforms phenol degradation product, p-benzoquinone, to hydroquinone which yields more eaq‒ upon UV irradiation. In the UV/phenol/DTN system, up to 70 % defluorination of PFOA solution was achieved while the impact of groundwater matrix was minor on the degradation performance of PFOA, PFOS and GenX. Especially in acidic conditions, •H, the conjugate acid of eaq‒, is the dominant radical for decomposing the three tested PFAS. Density functional theory calculations reveal hydrogen bonding and van der Waals interactions between PFAS and phenol, facilitating both decarboxylation and fluorine elimination in PFAS structures. The combined experimental and theoretical evidence demonstrated the capability of the new UV/phenol/DTN method to sustain eaq‒ production for effective defluorination of PFAS in the groundwater matrix.
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Affiliation(s)
- Xingaoyuan Xiong
- Centre for Water Technology (WATEC) & Department of Biological and Chemical Engineering, Aarhus University, Ole Worms Alle 3 Aarhus C, 8000, Denmark
| | - Zirui Luo
- Centre for Water Technology (WATEC) & Department of Biological and Chemical Engineering, Aarhus University, Ole Worms Alle 3 Aarhus C, 8000, Denmark
| | - Shuang Luo
- Centre for Water Technology (WATEC) & Department of Biological and Chemical Engineering, Aarhus University, Ole Worms Alle 3 Aarhus C, 8000, Denmark; College of Environment and Ecology, Hunan Agricultural University, Changsha 410128, China
| | - Lu Bai
- Centre for Water Technology (WATEC) & Department of Biological and Chemical Engineering, Aarhus University, Ole Worms Alle 3 Aarhus C, 8000, Denmark
| | - Yanan Shang
- Centre for Water Technology (WATEC) & Department of Biological and Chemical Engineering, Aarhus University, Ole Worms Alle 3 Aarhus C, 8000, Denmark; School of Safety and Environmental Engineering, Shandong University of Science and Technology, Qingdao 266590, China
| | - Allyson L Junker
- Centre for Water Technology (WATEC) & Department of Biological and Chemical Engineering, Aarhus University, Ole Worms Alle 3 Aarhus C, 8000, Denmark
| | - Zongsu Wei
- Centre for Water Technology (WATEC) & Department of Biological and Chemical Engineering, Aarhus University, Ole Worms Alle 3 Aarhus C, 8000, Denmark.
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5
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Wang X, Chen H, Wang W, Shen X, Wang J, Chen S, Yu X, Lee CT, Chen Z, Gu C. Highly efficient removal of per- and polyfluoroalkyl substances by extrusion-regenerated aminated polyurethane sponges. WATER RESEARCH 2025; 275:123189. [PMID: 39881473 DOI: 10.1016/j.watres.2025.123189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2024] [Revised: 01/19/2025] [Accepted: 01/21/2025] [Indexed: 01/31/2025]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are a class of persistent organic compounds widely detected in the environments. Due to their chemical stability, physical adsorption has emerged as one of the most promising techniques for remediating PFAS-containing wastewater, while some newly synthesized functional absorbents in powder form suffer from separation issues. Inspired by mussel biology, we have successfully synthesized a porous spongy absorbent termed aminated polyurethane (PU-PDA-PANI) with over 99.5% removal efficiency for initial 10 mg L-1 perfluorooctanoic acid (PFOA), corresponding to the maximum adsorption capacity of 1.42 g g-1, which was superior to the ion exchange resin (Purolite® PFA694E, 0.764 g g-1). In addition to PFOA, PU-PDA-PANI also showed excellent removal efficiencies for other typical PFAS (i.e. perfluorooctane sulfonates, perfluorobutyric acid, perfluorooctane-1,8-dioic acid, hexafluoropropylene oxide trimer acid, etc), and the adsorption processes resistant to pH changes and co-existing environmental matrixes. Furthermore, PU-PDA-PANI can be readily reused and regenerated by coupling extrusion and elution procedures. The adsorption mechanism of electrostatic, hydrogen bond and hydrophobic synergistic interaction was further proposed with the support of theoretical calculation. In conclusion, this study develops an efficient and recyclable PFAS adsorbent and proposes some new insights for the design of PFAS-selective adsorbents.
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Affiliation(s)
- Xinhao Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, China
| | - Hanyang Chen
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, China
| | - Wenran Wang
- Jiangsu Environmental Engineering Technology Co.Ltd, Jiangsu Provincial Environmental Protection Group Co., Ltd, Nanjing, 210019, China
| | - Xiufang Shen
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing 210042, China
| | - Jiabao Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, China
| | - Sen Chen
- Solid Waste Technology Center, Nanjing Institute of Environmental Sciences, Nanjing 210013, China
| | - Xueru Yu
- Solid Waste Technology Center, Nanjing Institute of Environmental Sciences, Nanjing 210013, China
| | - Chew Tin Lee
- Faculty of Chemical and Energy Engineering, Universiti Teknologi Malaysia, 81310, Skudai, Johor, Malaysia
| | - Zhanghao Chen
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, China.
| | - Cheng Gu
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, China
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6
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Wang X, Qiu L, Chen Z, Chen H, Wang J, Zhang Y, Xu Y, Kong D, Zhang M, Gu C. New Insights into the Reductive Destruction of Per- and Polyfluoroalkyl Substances in Hydrated Electron-Based Systems. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2025; 59:5786-5795. [PMID: 40080663 DOI: 10.1021/acs.est.4c08548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/15/2025]
Abstract
Per- and polyfluoroalkyl substances (PFAS) make up a class of highly toxic and persistent chemicals that have been widely detected in different environmental matrices. Recently, various hydrated electron-based techniques have been developed to destroy these compounds. However, the molecular mechanisms controlled by different hydrated electron photosensitizers are still unclear. Herein, we investigated the PFAS transformation processes in different hydrated electron-based systems, i.e., UV/Na2SO3, UV/indole, and UV/3-indoleacetic acid (IAA), using different perfluorocarboxylic acids (PFCA) as model compounds. By monitoring the production and decay of hydrated electrons, molecular interactions, and the generated intermediates, we systematically revealed the structure-property-performance mechanism of different systems. In the UV/Na2SO3 system, the disordered attack of hydrated electrons induced rapid destruction for either long or short-chain PFCA. However, the lower hydrated electron efficiency limited the final defluorination ratio. In the UV/indole system, the interaction between indole and PFCA promoted the directed transfer of hydrated electrons, resulting in a significantly higher destruction efficiency for long-chain PFCA than for short-chain PFCA. However, the self-quenching of hydrated electrons in the UV/IAA system led to the ineffective decomposition for all PFCA. This study provides mechanistic insights into the hydrated electron-induced PFAS decomposition processes, which would expand the designing strategies for improving PFAS destruction efficiency.
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Affiliation(s)
- Xinhao Wang
- State Key Laboratory of Water Pollution Control and Green Resource Recycling, Nanjing University, Nanjing 210023, P. R. China
| | - Longlong Qiu
- State Key Laboratory of Water Pollution Control and Green Resource Recycling, Nanjing University, Nanjing 210023, P. R. China
| | - Zhanghao Chen
- State Key Laboratory of Water Pollution Control and Green Resource Recycling, Nanjing University, Nanjing 210023, P. R. China
- Quanzhou Institute for Environmental Protection Industry, Nanjing University, Quanzhou 362000, P. R. China
| | - Hanyang Chen
- State Key Laboratory of Water Pollution Control and Green Resource Recycling, Nanjing University, Nanjing 210023, P. R. China
| | - Jiabao Wang
- State Key Laboratory of Water Pollution Control and Green Resource Recycling, Nanjing University, Nanjing 210023, P. R. China
| | - Yueqing Zhang
- Key Laboratory of Pesticide Environmental Assessment and Pollution Control, Nanjing Institute of Environmental Sciences, Ministry of Environment and Ecology of China, Nanjing 210042, China
| | - Yichen Xu
- State Key Laboratory of Water Pollution Control and Green Resource Recycling, Nanjing University, Nanjing 210023, P. R. China
| | - Deyang Kong
- Key Laboratory of Pesticide Environmental Assessment and Pollution Control, Nanjing Institute of Environmental Sciences, Ministry of Environment and Ecology of China, Nanjing 210042, China
| | - Ming Zhang
- State Key Laboratory of Water Pollution Control and Green Resource Recycling, Nanjing University, Nanjing 210023, P. R. China
- Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, Nanjing 210037, P. R. China
| | - Cheng Gu
- State Key Laboratory of Water Pollution Control and Green Resource Recycling, Nanjing University, Nanjing 210023, P. R. China
- Quanzhou Institute for Environmental Protection Industry, Nanjing University, Quanzhou 362000, P. R. China
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7
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Liu X, Shu Y, Pan Y, Zeng G, Zhang M, Zhu C, Xu Y, Wan A, Wang M, Han Q, Liu B, Wang Z. Electrochemical destruction of PFAS at low oxidation potential enabled by CeO 2 electrodes utilizing adsorption and activation strategies. JOURNAL OF HAZARDOUS MATERIALS 2025; 486:137043. [PMID: 39754874 DOI: 10.1016/j.jhazmat.2024.137043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2024] [Revised: 11/22/2024] [Accepted: 12/29/2024] [Indexed: 01/06/2025]
Abstract
The persistence and ecological impact of per- and poly-fluoroalkyl substances (PFAS) in water sources necessitate effective and energy-efficient treatment solutions. This study introduces a novel approach using cerium dioxide (CeO2) electrodes enhanced with oxygen vacancy (Ov) to catalyze the defluorination of PFAS. By leveraging the unique affinity between cerium and fluorine-containing species, our approach enables adsorptive preconcentration and catalytic degradation at low oxidation potentials (1.37 V vs. SHE). Demonstrating high removal and defluorination efficiencies of perfluorooctanoic acid (PFOA) at 94.0 % and 73.0 %, respectively, our approach also proves effective in the environmental matrix. It minimizes the impacts of co-existing natural organic matter and chloride ions, crucial benefits of operating at lower oxidation potentials. The role of Ov in CeO2 is validated by both experimental results and density functional theory modeling, demonstrating that these sites can activate the C-F bond and substantially reduce the energy barriers for defluorination. Consequently, our CeO2-based method not only achieves defluorination efficiencies comparable to more energy-intensive techniques but does so while requiring less than 0.62 kWh/m3 per order. This positions our approach as a promising, cost-effective alternative for the remediation of PFAS-contaminated waters, emphasizing its relevance and effectiveness in environmental remediation scenarios.
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Affiliation(s)
- Xun Liu
- School of Environment, Harbin Institute of Technology, Harbin 150086, PR China; School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, PR China
| | - Yufei Shu
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, PR China
| | - Yu Pan
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, PR China
| | - Guoshen Zeng
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, PR China
| | - Meng Zhang
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, PR China
| | - Chaoqun Zhu
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, PR China
| | - Youmei Xu
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, PR China
| | - Aling Wan
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, PR China
| | - Mengxia Wang
- School of Environment, Harbin Institute of Technology, Harbin 150086, PR China; School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, PR China
| | - Qi Han
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, PR China
| | - Bei Liu
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, PR China
| | - Zhongying Wang
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, PR China; Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control, Southern University of Science and Technology, Shenzhen 518055, PR China.
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8
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Srivastava P, Mazhar H, Redington M, Crossley Q, Miller DP, Morgenstern K. Size-Dependent Effects of Electron Solvation on the Kinetics of Ammonia Revealed on the Molecular Scale. J Phys Chem Lett 2025:2265-2272. [PMID: 39988852 DOI: 10.1021/acs.jpclett.4c03656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2025]
Abstract
The high relevance of electron solvation in several branches of physics, chemistry, and environmental science arises from its efficient electron transfer mechanism. The effect of solvated electrons on solvent structure has been considered local and transient due to a lack of real-space studies. An experiment was designed to study the impact of solvated electrons on the ammonia structure while adsorbed to Cu(110) using low-temperature scanning tunneling microscopy with an adjoined femtosecond laser. The enhanced molecular kinetics induced by the solvated electrons are explained using density functional theory and first-principles molecular dynamics. The electrons have a substantially different impact on the kinetics of ammonia within clusters below and above a cluster size threshold, reflecting hydrogen bond rearrangement (mass transport) and hydrogen bond cleavage (desorption), respectively. This size-dependent effect has implications on the efficiency of processes that involve solvated electrons. Altering the solvent structure more than transiently demands the subsequent solvation of two electrons.
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Affiliation(s)
- Prashant Srivastava
- Physical Chemistry I, Department of Chemistry and Biochemistry, Ruhr-Universität Bochum, Universitätsstrasse 150, D-44801 Bochum, Germany
| | - Hussain Mazhar
- Physical Chemistry I, Department of Chemistry and Biochemistry, Ruhr-Universität Bochum, Universitätsstrasse 150, D-44801 Bochum, Germany
| | - Morgan Redington
- Department of Chemistry, State University of New York at Buffalo, 359 Natural Sciences Complex, Buffalo, New York 14260, United States
| | - Quinlan Crossley
- Department of Chemistry, Hofstra University, 106 Berliner Hall, Hempstead, New York 11549, United States
| | - Daniel P Miller
- Department of Chemistry, Hofstra University, 106 Berliner Hall, Hempstead, New York 11549, United States
| | - Karina Morgenstern
- Physical Chemistry I, Department of Chemistry and Biochemistry, Ruhr-Universität Bochum, Universitätsstrasse 150, D-44801 Bochum, Germany
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9
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Fennell BD, Chavez S, McKay G. Destruction of Per- and Polyfluoroalkyl Substances in Reverse Osmosis Concentrate Using UV-Advanced Reduction Processes. ACS ES&T WATER 2024; 4:4818-4827. [PMID: 39539762 PMCID: PMC11555674 DOI: 10.1021/acsestwater.4c00458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2024] [Revised: 10/09/2024] [Accepted: 10/10/2024] [Indexed: 11/16/2024]
Abstract
UV-advanced reduction processes (UV-ARP), characterized by the strongly reducing aqueous electron (eaq -), have been shown to degrade perfluoroalkyl and polyfluoroalkyl substances (PFAS). Due to the high cost of PFAS destruction technologies, concentrated waste streams derived from physical treatment processes, such as ion exchange or membrane concentrates, are promising targets for implementation of these technologies. However, there are limited studies on the application of UV-ARP for PFAS destruction in concentrated waste streams. This study evaluates the effectiveness of the UV/sulfite ARP in reverse osmosis concentrate (ROC) containing high concentrations of dissolved organic carbon (DOC), nitrate, and carbonate species, spiked with mg/L concentrations of perfluorooctanesulfonic acid, perfluorobutanesulfonic acid, perfluorooctanoic acid, and perfluorobutanoic acid. We demonstrate that hardness removal and preoxidation of ROC with UV/persulfate enables >90% PFAS defluorination within 24 h of subsequent UV/sulfite treatment, a 3-fold enhancement in defluorination % compared to UV/sulfite treatment without preoxidation. This enhancement is shown to result from abatement of the light shielding and eaq - scavenging capacity of DOC during UV/persulfate oxidation. Collectively, these results demonstrate that appropriate pretreatment steps increase the effectiveness of PFAS destruction using UV-ARP, supporting the application of UV-ARP for PFAS destruction in ROC and other concentrated waste streams.
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Affiliation(s)
- Benjamin D. Fennell
- Zachry
Department of Civil & Environmental Engineering Texas A&M
University, College
Station, Texas 77845, United States
- Department
of Civil & Environmental Engineering, University of Tennessee, Knoxville, Tennessee 37916, United States
| | - Shawnee Chavez
- Zachry
Department of Civil & Environmental Engineering Texas A&M
University, College
Station, Texas 77845, United States
| | - Garrett McKay
- Zachry
Department of Civil & Environmental Engineering Texas A&M
University, College
Station, Texas 77845, United States
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10
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Chen Z, Zhang S, Mi N, Wang X, Xu Y, Qiu L, Gu C, Zeng G. Synergistic adsorption and UV degradation of perfluorooctanoic acid by amine-functionalized A-center sphalerite. WATER RESEARCH 2024; 265:122277. [PMID: 39167974 DOI: 10.1016/j.watres.2024.122277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Revised: 07/30/2024] [Accepted: 08/13/2024] [Indexed: 08/23/2024]
Abstract
Perfluorinated alkylated substances (PFAS), as a category of persistent organic pollutants, have garnered extensive concern due to their resilience against environmental degradation. Herein, we developed an amine-functionalized sphalerite (ZnS) with adjustable surface amine functional groups and Zn defects (ZnS-X%[N]) by in situ coprecipitation and simple hydrothermal method in the presence of cetyltrimethylammonium bromide (CTAB). This material demonstrated efficient PFAS adsorption and subsequent photo-induced degradation under UV irradiation. The characterization results by TEM, BET, FTIR, XPS and EPR revealed that CTAB primarily influences ZnS by modulating surface amine functionalities, zinc defect density, and enhancing its photoreductive capacity. Adsorption and kinetic degradation experiments further showed that a medium CTAB concentration in ZnS-40%[N] achieves highest PFAS adsorption capacity (Cmax: 0.201 mol kg-1), and the corresponding decomposition rate was the fastest (kde: 1.53; kdf: 1.19). This efficacy is attributed to the ZnS-40%[N]'s ideal adsorptive sites and surface shallow defects. Moreover, theoretical simulation also supports the above experimental inference. Overall, ZnS-X%[N] exhibits a synergistic effect on PFAS adsorption and degradation, showcasing its potential for environmental adaptability and practical application.
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Affiliation(s)
- Zhanghao Chen
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, PR China
| | - Shuoqi Zhang
- Kuang Yaming Honors School, Nanjing University, Nanjing, Jiangsu 210023, PR China
| | - Na Mi
- State Environmental Protection Key Laboratory of Soil Environmental Management and Pollution Control, Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing 210046, China
| | - Xinhao Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, PR China
| | - Yichen Xu
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, PR China
| | - Longlong Qiu
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, PR China
| | - Cheng Gu
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, PR China
| | - Guixiang Zeng
- Kuang Yaming Honors School, Nanjing University, Nanjing, Jiangsu 210023, PR China.
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11
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Arima Y, Okayasu Y, Yoshioka D, Nagai Y, Kobayashi Y. Multiphoton-Driven Photocatalytic Defluorination of Persistent Perfluoroalkyl Substances and Polymers by Visible Light. Angew Chem Int Ed Engl 2024; 63:e202408687. [PMID: 38896058 DOI: 10.1002/anie.202408687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2024] [Revised: 06/08/2024] [Accepted: 06/19/2024] [Indexed: 06/21/2024]
Abstract
Perfluoroalkyl substances (PFASs) and fluorinated polymers (FPs) have been extensively utilized in various industries, whereas their extremely high stability poses environmental persistence and difficulty in waste treatment. Current decomposition approaches of PFASs and FPs typically require harsh conditions such as heating over 400 °C. Thus, there is a pressing need to develop a new technique capable of decomposing them under mild conditions. Here, we demonstrated that perfluorooctanesulfonate (PFOS), known as a "persistent chemical," and Nafion, a widely utilized sulfonated FP for ion-exchange membranes, can be efficiently decomposed into fluorine ions under ambient conditions via the irradiation of visible LED light onto semiconductor nanocrystals (NCs). PFOS was completely defluorinated within 8-h irradiation of 405-nm LED light, and the turnover number of the C-F bond dissociation per NC was 17200. Furthermore, 81 % defluorination of Nafion was achieved for 24-h light irradiation, demonstrating the efficient photocatalytic properties under visible light. We revealed that this decomposition is driven by cooperative mechanisms involving light-induced ligand displacements and Auger-induced electron injections via hydrated electrons and higher excited states. This study not only demonstrates the feasibility of efficiently breaking down various PFASs and FPs under mild conditions but also paves the way for advancing toward a sustainable fluorine-recycling society.
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Affiliation(s)
- Yuzo Arima
- Department of Applied Chemistry, College of Life Sciences, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga, 525-8577, Japan
| | - Yoshinori Okayasu
- Department of Applied Chemistry, College of Life Sciences, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga, 525-8577, Japan
| | - Daisuke Yoshioka
- Department of Applied Chemistry, College of Life Sciences, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga, 525-8577, Japan
| | - Yuki Nagai
- Department of Applied Chemistry, College of Life Sciences, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga, 525-8577, Japan
| | - Yoichi Kobayashi
- Department of Applied Chemistry, College of Life Sciences, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga, 525-8577, Japan
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12
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Wei X, Zhu N, Li F, Li X, Wu P. Efficient low-strength diclofenac elimination via adsorption-concentration and peroxydisulfate activation mineralization by distinct pretreated biocarbon composites. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 369:122393. [PMID: 39226810 DOI: 10.1016/j.jenvman.2024.122393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2024] [Revised: 08/21/2024] [Accepted: 08/31/2024] [Indexed: 09/05/2024]
Abstract
Sodium diclofenac (DCF) widely exists in actual water matrices, which can negatively impact ecosystems and aquatic environments even at low-strength. Herein, the adsorption-concentration-mineralization process was innovatively constructed for low-strength DCF elimination by freeze-dried biocarbon and oven-dried biocarbon coupled with cobalt oxide composites derived from the same waste biomass. Surprisingly, low-strength DCF of 0.5 mg/L was adsorbed rapidly and enriched to high-strength DCF under light with a concentration efficiency of 99.67 % by freeze-dried biocarbon. Subsequently, the concentrated DCF was economically mineralized by bifunctional oven-dried biocarbon coupled with cobalt oxide composites for peroxydisulfate (PDS) activation with full PDS activation and 76.11 % mineralization efficiency. Compared with direct low-strength DCF oxidation, adsorption-concentration-mineralization consumed less energy and none PDS residues. Mechanisms confirmed that DCF was adsorbed by freeze-dried biocarbon through hydrogen bonds and π-π stacking interactions, which were switched on due to electron-induced effect by light in DCF desorption-concentration. Furthermore, nonradical pathway (electron transfer) and radical pathway (SO4•-) were involved in efficient PDS activation by oven-dried biocarbon coupled with cobalt oxide composites for concentrated DCF mineralization, and the former was more prominent, in which graphitic carbon, cobalt redox cycle and carboxy groups were the main active sites. Overall, an energy-efficient strategy was proposed for elimination of low-strength DCF in real water matrices.
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Affiliation(s)
- Xiaorong Wei
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, PR China.
| | - Nengwu Zhu
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, PR China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Cluster, Ministry of Education, Guangzhou, 510006, PR China; Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling, Guangzhou, 510006, PR China; Guangdong Environmental Protection Key Laboratory of Solid Waste Treatment and Recycling, Guangzhou, 510006, PR China.
| | - Fei Li
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, PR China
| | - Xinyu Li
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, PR China
| | - Pingxiao Wu
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, PR China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Cluster, Ministry of Education, Guangzhou, 510006, PR China; Guangdong Provincial Key Laboratory of Solid Wastes Pollution Control and Recycling, Guangzhou, 510006, PR China; Guangdong Environmental Protection Key Laboratory of Solid Waste Treatment and Recycling, Guangzhou, 510006, PR China
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13
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Santiago-Cruz HA, Lou Z, Xu J, Sullivan RC, Bowers BB, Molé RA, Zhang W, Li J, Yuan JS, Dai SY, Lowry GV. Carbon Adsorbent Properties Impact Hydrated Electron Activity and Perfluorocarboxylic Acid (PFCA) Destruction. ACS ES&T ENGINEERING 2024; 4:2220-2233. [PMID: 39296420 PMCID: PMC11406532 DOI: 10.1021/acsestengg.4c00211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2024] [Revised: 07/15/2024] [Accepted: 07/19/2024] [Indexed: 09/21/2024]
Abstract
Carbon-based adsorbents used to remove recalcitrant water contaminants, including perfluoroalkyl substances (PFAS), are often regenerated using energy-intensive treatments that can form harmful byproducts. We explore mechanisms for sorbent regeneration using hydrated electrons (eaq -) from sulfite ultraviolet photolysis (UV/sulfite) in water. We studied the UV/sulfite treatment on three carbon-based sorbents with varying material properties: granular activated carbon (GAC), carbon nanotubes (CNTs), and polyethylenimine-modified lignin (lignin). Reaction rates and defluorination of dissolved and adsorbed model perfluorocarboxylic acids (PFCAs), perfluorooctanoic acid (PFOA) and perfluorobutanoic acid (PFBA), were measured. Monochloroacetic acid (MCAA) was employed to empirically quantify eaq - formation rates in heterogeneous suspensions. Results show that dissolved PFCAs react rapidly compared to adsorbed ones. Carbon particles in solution decreased aqueous reaction rates by inducing light attenuation, eaq - scavenging, and sulfite consumption. The magnitude of these effects depended on adsorbent properties and surface chemistry. GAC lowered PFOA destruction due to strong adsorption. CNT and lignin suspensions decreased eaq - formation rates by attenuating light. Lignin showed high eaq - quenching, likely due to its oxygenated functional groups. These results indicate that desorbing PFAS and separating the adsorbent before initiating PFAS degradation reactions will be the best engineering approach for adsorbent regeneration using UV/sulfite.
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Affiliation(s)
- Hosea A Santiago-Cruz
- Department of Civil and Environmental Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Zimo Lou
- Department of Civil and Environmental Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
- Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, Zhejiang University of Technology, Hangzhou 310014, China
| | - Jiang Xu
- Department of Civil and Environmental Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Ryan C Sullivan
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15217, United States
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15217, United States
| | - Bailey B Bowers
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15217, United States
- Department of Chemistry and Biochemistry, Oberlin College, Oberlin, Ohio 44074, United States
| | - Rachel A Molé
- Department of Civil and Environmental Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Wan Zhang
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas 77843, United States
| | - Jinghao Li
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas 77843, United States
- Department of Energy, Environmental, and Chemical Engineering, McKelvey School of Engineering, Washington University in St. Louis, St. Louis, Missouri 63130-4899, United States
| | - Joshua S Yuan
- Department of Energy, Environmental, and Chemical Engineering, McKelvey School of Engineering, Washington University in St. Louis, St. Louis, Missouri 63130-4899, United States
| | - Susie Y Dai
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas 77843, United States
| | - Gregory V Lowry
- Department of Civil and Environmental Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
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14
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Wang W, Guo X, Liu Z, Dong S, Liu H, Wu Y, Cao Z. Micro-nano H 2 bubbles enhanced hydrodehalogenation of 3-chloro-4-fluoroaniline: Mass transfer and action mechanism. CHEMOSPHERE 2024; 363:142816. [PMID: 38986787 DOI: 10.1016/j.chemosphere.2024.142816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 06/18/2024] [Accepted: 07/08/2024] [Indexed: 07/12/2024]
Abstract
3-chloro-4-fluoraniline (FCA) is an important intermediate for the synthesis of antibiotics, herbicides and insecticides, and has significant environmental health hazards. Catalytic hydrogenation technology is widely used in pretreatment of halogenated organics due to its simple process and excellent performance. However, compared with the research of high activity hydrogenation catalyst, the research of efficient utilization of hydrogen source under mild conditions is not sufficient. In this work, micro-nano H2 bubbles are produced in situ by electrolytic water and active metal replacement, and their apparent properties are studied. The result show that the H2 bubbles have a size distribution in the range of 150-900 nm, which can rapidly reduce the REDOX potential of the water and maintain it in a hydrogen-rich state for a long time. Under the action of Pd/C catalyst, atomic hydrogen (H•) produced by dissociative adsorption can sequentially hydrogenate FCA to aniline. The H• utilization ratios of the above two hydrogen supply pathways reach 6.20% and 4.94% respectively, and H2 consumption is reduced by tens of times (≥50 → ≈1.0 mL/min). The research provides technical support for the efficient removal of halogenated refractory pollutants in water and the development of hydrogen economy.
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Affiliation(s)
- Weilai Wang
- Ministry of Education Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, School of Environment, Henan Normal University, Xinxiang, Henan, 453007, China.
| | - Xinting Guo
- Ministry of Education Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, School of Environment, Henan Normal University, Xinxiang, Henan, 453007, China
| | - Zekun Liu
- Ministry of Education Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, School of Environment, Henan Normal University, Xinxiang, Henan, 453007, China
| | - Shuang Dong
- Ministry of Education Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, School of Environment, Henan Normal University, Xinxiang, Henan, 453007, China
| | - Haijin Liu
- Ministry of Education Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, School of Environment, Henan Normal University, Xinxiang, Henan, 453007, China
| | - Yuandong Wu
- Center for Child Care and Mental Health, Shenzhen Children's Hospital, Shenzhen, 518000, Guangdong, China.
| | - Zhiguo Cao
- Ministry of Education Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, School of Environment, Henan Normal University, Xinxiang, Henan, 453007, China.
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15
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Song Z, He J, Kouzehkanan SMT, Oh TS, Olshansky Y, Duin EC, Carroll KC, Wang D. Enhanced sorption and destruction of PFAS by biochar-enabled advanced reduction process. CHEMOSPHERE 2024; 363:142760. [PMID: 38969229 DOI: 10.1016/j.chemosphere.2024.142760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2024] [Revised: 07/02/2024] [Accepted: 07/02/2024] [Indexed: 07/07/2024]
Abstract
The biochar-enabled advanced reduction process (ARP) was developed for enhanced sorption (by biochar) and destruction of PFAS (by ARP) in water. First, the biochar (BC) was functionalized by iron oxide (Fe3O4), zero valent iron (ZVI), and chitosan (chi) to produce four biochars (BC, Fe3O4-BC, ZVI-chi-BC, and chi-BC) with improved physicochemical properties (e.g., specific surface area, pore structure, hydrophobicity, and surface functional groups). Batch sorption experimental results revealed that compared to unmodified biochar, all modified biochars showed greater sorption efficiency, and the chi-BC performed the best for PFAS sorption. The chi-BC was then selected to facilitate reductive destruction and defluorination of PFAS in water by ARP in the UV-sulfite system. Adding chi-BC in UV-sulfite ARP system significantly enhanced both degradation and defluorination efficiencies of PFAS (up to ∼100% degradation and ∼85% defluorination efficiencies). Radical analysis using electron paramagnetic resonance (EPR) spectroscopy showed that sulfite radicals dominated at neutral pH (7.0), while hydrated electrons (eaq-) were abundant at higher pH (11) for the efficient destruction of PFAS in the ARP system. Our findings elucidate the synergies of biochar and ARP in enhancing PFAS sorption and degradation, providing new insights into PFAS reductive destruction and defluorination by different reducing radical species at varying pH conditions.
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Affiliation(s)
- Ziteng Song
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Jianzhou He
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | | | - Tae-Sik Oh
- Department of Chemical Engineering, Auburn University, Auburn, AL, 36849, USA
| | - Yaniv Olshansky
- Department of Crop, Soil, and Environmental Sciences, Auburn, AL, 36849, USA
| | - Evert C Duin
- Department of Chemistry and Biochemistry, Auburn, AL, 36849, USA
| | - Kenneth C Carroll
- Department of Plant and Environmental Sciences, New Mexico State University, NM, 88003, USA
| | - Dengjun Wang
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA.
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16
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Wu H, Wang J, Du E, Guo H. Comparative analysis of UV-initiated ARPs for degradation of the emerging substitute of perfluorinated compounds: Does defluorination mean the sole factor? JOURNAL OF HAZARDOUS MATERIALS 2024; 474:134687. [PMID: 38805816 DOI: 10.1016/j.jhazmat.2024.134687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 04/25/2024] [Accepted: 05/20/2024] [Indexed: 05/30/2024]
Abstract
Due to the increasing attention for the residual of per- and polyfluorinated compounds in environmental water, Sodium p-Perfluorous Nonenoxybenzenesulfonate (OBS) have been considered as an alternative solution for perfluorooctane sulfonic acid (PFOS). However, recent detections of elevated OBS concentrations in oil fields and Frontal polymerization foams have raised environmental concerns leading to the decontamination exploration for this compound. In this study, three advanced reduction processes including UV-Sulfate (UV-SF), UV-Iodide (UV-KI) and UV-Nitrilotriacetic acid (UV-NTA) were selected to evaluate the removal for OBS. Results revealed that hydrated electrons (eaq-) dominated the degradation and defluorination of OBS. Remarkably, the UV-KI exhibited the highest removal rate (0.005 s-1) and defluorination efficiency (35 %) along with the highest concentration of eaq- (K = -4.651). Despite that nucleophilic attack from eaq- on sp2 carbon and H/F exchange were discovered as the general mechanism, high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (HPLC/Q-TOF-MS) analysis with density functional theory (DFT) calculations revealed the diversified products and routes. Intermediates with lowest fluorine content for UV-KI were identified, the presence nitrogen-containing intermediates were revealed in the UV-NTA. Notably, the nitrogen-containing intermediates displayed the enhanced toxicity, and the iodine poly-fluorinated intermediates could be a potential-threat compared to the superior defluorination performance for UV-KI.
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Affiliation(s)
- Han Wu
- MOE Key Laboratory of Deep Earth Science and Engineering, College of Architecture and Environment, Sichuan University, Chengdu 610065, China
| | - Jingquan Wang
- MOE Key Laboratory of Deep Earth Science and Engineering, College of Architecture and Environment, Sichuan University, Chengdu 610065, China
| | - Erdeng Du
- School of Environmental and Safety Engineering, Changzhou University, Changzhou 213164, China
| | - Hongguang Guo
- MOE Key Laboratory of Deep Earth Science and Engineering, College of Architecture and Environment, Sichuan University, Chengdu 610065, China.
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17
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Zhai Z, Zhang C, Chu L, Zhao Y, Zhou X, Zhang Y. Effective defluorination of novel hexafluoropropylene oxide oligomer acids under mild conditions by UV/sulfite/iodide: mechanisms and ecotoxicity. WATER RESEARCH 2024; 258:121804. [PMID: 38781621 DOI: 10.1016/j.watres.2024.121804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 04/08/2024] [Accepted: 05/18/2024] [Indexed: 05/25/2024]
Abstract
It has recently been discovered that HFPO-TA (a processing aid in the production of fluoropolymers) has high levels of bioaccumulation and biotoxicity. Hydrated electrons (eaq-) have been proposed to be potent nucleophiles that may decompose PFAS. Unlike previous studies in which the generation of eaq- was often restricted to anaerobic or highly alkaline environments, in this study, we applied the UV/SO32-/I- process under mild conditions of neutrality, low source chemical demand, and open-air, which achieved effective degradation (81.92 %, 0.834 h-1) and defluorination (48.99 %, 0.312 h-1) of HFPO-TA. With I- as the primary source of eaq-, SO32- acting as an I- regenerator and oxidizing substances scavenger, UV/SO32-/I- outperformed others under mild circumstances. The eaq- were identified as the main active species by quenching experiments and electron paramagnetic resonance (EPR). During degradation, the first site attacked by eaq- was the ether bond (C6-O7), followed by the generation of HFPO-DA, TFA, acetic and formic acid. Degradation studies of other HFPOs have shown that the defluorination of HFPOs was accompanied by a clear chain-length correlation. At last, toxicological experiments confirmed the safety of the process. This study updated our understanding of the degradation of newly PFASs and the application of eaq- mediated photoreductive approaches under mild conditions.
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Affiliation(s)
- Zhenyu Zhai
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China
| | - Chaojie Zhang
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China.
| | - Liquan Chu
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China
| | - Yunmeng Zhao
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China
| | - Xuefei Zhou
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China
| | - Yalei Zhang
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China.
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18
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Fang X, Jin L, Sun X, Huang H, Wang Y, Ren H. A data-driven analysis to discover research hotspots and trends of technologies for PFAS removal. ENVIRONMENTAL RESEARCH 2024; 251:118678. [PMID: 38493846 DOI: 10.1016/j.envres.2024.118678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 02/24/2024] [Accepted: 03/09/2024] [Indexed: 03/19/2024]
Abstract
The frequent detection of persistent per- and polyfluoroalkyl substances (PFAS) in organisms and environment coupled with surging evidence for potential detrimental impacts, have attracted widespread attention throughout the world. In order to reveal research hotspots and trends of technologies for PFAS removal, herein, we performed a data-driven analysis of 3975 papers and 436 patents from Web of Science Core Collection and Derwent Innovation Index databases up to 2023. The results showed that China and the USA led the way in the research of PFAS removal with outstanding contributions to publications. The progression generally transitioned from accidental discovery of decomposition, to experimentation with removal effects and mechanisms of existing methods, and finally to enhanced defluorination and mechanism-driven design approaches. The keywords co-occurrence network and technology classification together revealed the main knowledge framework, which was constructed and correlated through contaminants, substrates, materials, processes and properties. Moreover, adsorption was demonstrated to be the dominant removal process among the current studies. Subsequently, we concluded the principles, advances and drawbacks of enrichment and separation, biological methods, advanced oxidation and reduction processes. Further exploration indicated the hotspots such as alternatives and precursors for PFAS ("genx": 1.258, "f-53b": 0.337), degradable mineralization technologies ("photocatalytic degrad": 0.529, "hydrated electron": 0.374), environment-friendly remediation technologies ("phytoremedi": 0.939, "constructed wetland": 0.462) and combination with novel materials ("metal-organic framework": 1.115, "layered double hydroxid": 0.559) as well as computer science ("molecular dynamics simul": 0.559, "machine learn"). Furthermore, the future direction of technological innovation might lie in high-performance processes that minimize secondary pollution, the development of recyclable and renewable treatment agents, and collaborative control strategies for multiple pollutants. Overall, this study offers comprehensive and objective review for researchers and industry professionals in this field, enabling rapid access to knowledge guidance and insights into research frontiers.
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Affiliation(s)
- Xiaoya Fang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, Jiangsu, PR China
| | - Lili Jin
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, Jiangsu, PR China
| | - Xiangzhou Sun
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, Jiangsu, PR China
| | - Hui Huang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, Jiangsu, PR China.
| | - Yanru Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, Jiangsu, PR China
| | - Hongqiang Ren
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, Jiangsu, PR China
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19
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Liu S, Chen G, Shi Q, Gan J, Jin B, Men Y, Liu H. Promotive Effects of Chloride and Sulfate on the Near-Complete Destruction of Perfluorocarboxylates (PFCAs) in Brine via Hydrogen-tuned 185-nm UV Photolysis: Mechanisms and Kinetics. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:10347-10356. [PMID: 38808621 PMCID: PMC11171456 DOI: 10.1021/acs.est.3c10552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 05/01/2024] [Accepted: 05/03/2024] [Indexed: 05/30/2024]
Abstract
Hydrogen-tuned 185 nm vacuum ultraviolet (VUV/H2) photolysis is an emerging technology to destroy per- and polyfluoroalkyl substance (PFAS) in brine. This study discovered the promotive effects of two major brine anions, i.e., chloride and sulfate in VUV/H2 photolysis on the hydrated electron (eaq-) generation and perfluorocarboxylates (PFCAs) destruction and established a kinetics model to elucidate the promotive effects on the steady-state concentration of eaq- ([eaq-]ss). Results showed that VUV/H2 achieved near-complete defluorination of perfluorooctanoic acid (PFOA) in the presence of up to 1000 mM chloride or sulfate at pH 12. The defluorination rate constant (kdeF) of PFOA peaked with a chloride concentration at 100 mM and with a sulfate concentration at 500 mM. The promotive effects of chloride and sulfate were attributed to an enhanced generation of eaq- via their direct VUV photolysis and conversion of additionally generated hydroxyl radical to eaq- by H2, which was supported by a linear correlation between the predicted [eaq-]ss and experimentally observed kdeF. The kdeF value increased from pH 9 to 12, which was attributed to the speciation of the H·/eaq- pair. Furthermore, the VUV system achieved >95% defluorination and ≥99% parent compound degradation of a concentrated PFCAs mixture in a synthetic brine, without generating any toxic perchlorate or chlorate.
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Affiliation(s)
- Sitao Liu
- Department
of Chemical and Environmental Engineering, University of California, Riverside, California 92521, United States
| | - Gongde Chen
- Department
of Chemical and Environmental Engineering, University of California, Riverside, California 92521, United States
| | - Qingyang Shi
- Department
of Environmental Sciences, University of
California, Riverside, California 92521, United States
| | - Jay Gan
- Department
of Environmental Sciences, University of
California, Riverside, California 92521, United States
| | - Bosen Jin
- Department
of Chemical and Environmental Engineering, University of California, Riverside, California 92521, United States
| | - Yujie Men
- Department
of Chemical and Environmental Engineering, University of California, Riverside, California 92521, United States
| | - Haizhou Liu
- Department
of Chemical and Environmental Engineering, University of California, Riverside, California 92521, United States
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20
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Yang J, Fan Y, Lu Z, Guo Y, Huang J, Cai K, Sun Q, Wang F. Positive profile of natural small molecule organic matters on emerging antivirus pharmaceutical elimination in advance reduction process: A deep dive into the photosensitive mechanism of triplet excited state compounds. WATER RESEARCH 2024; 256:121611. [PMID: 38640567 DOI: 10.1016/j.watres.2024.121611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2024] [Revised: 03/05/2024] [Accepted: 04/12/2024] [Indexed: 04/21/2024]
Abstract
Natural small molecular organic matter (NSOM), ubiquitous in natural waters and distinct from humic acid or fulvic acid, is a special type of dissolved organic matter (DOM) which is characterized as strong photosensitivity and simple molecular structure. However, little study had been directed on the role of NSOM in eliminating emerging contaminants in advanced reduction process (ARP). This study took three small molecular isomeric organic acids (p-hydroxybenzoic acid, pHBA; salicylic acid, SA; m-hydroxybenzoic acid, mHBA) as the representative substances of NSOM to explore these mechanisms on promoting Ribavirin (RBV, an anti COVID-19 medicine) degradation in ultraviolet activated sulfite (UV/Sulfite) process. The results demonstrated that the observed degradation rate constant of RBV (kobs-RBV) was 7.56 × 10-6 s-1 in UV/Sulfite process, indicating that hydrated electron (eaq-) from UV/Sulfite process could not effectively degrade RBV, while it increased by 178 and 38 times when pHBA and SA were introduced into UV/Sulfite process respectively, suggesting that pHBA and SA strongly promoted RBV degradation while mHBA had no promotion on RBV abatement in UV/Sulfite process. Transient absorption spectra and reactive intermediates scavenging experiment indicated that the triplet excited state pHBA and SA (3pHBA* and 3SA*) contributed to the degradation of RBV through non-radical process. Notably, eaq- played the role of key initiator in transforming pHBA and SA into their triplet states. The difference of kobs-RBV in UV/Sulfite/pHBA and UV/Sulfite/SA process was attributed to different generation pathways of 3pHBA* and 3SA* (high molar absorptivity at the wavelength of 254 nm and photosensitive cycle, respectively) and their second order rate constants towards RBV (kRBV-3pHBA* = 8.60 × 108 M-1 s-1 and kRBV-3SA* = 6.81 × 107 M-1 s-1). mHBA could not degrade RBV for its lack of intramolecular hydrogen bond and low molar absorptivity at 254 nm to abundantly transform into its triplet state. kobs-RBV increased as pH increased from 5.0 to 11.0 in UV/Sulfite/SA process, due to the high yield of eaq- in alkaline condition which promoted the generation of 3SA* and the stable of the absorbance of SA at 254 nm. By contrast, kobs-RBV underwent a process of first increasing and then decreasing in UV/Sulfite/pHBA process as the increase of pH, and its highest value achieved in a neutral condition. This lied in the exposure of eaq- increased as the increase of pH which promoted the generation of 3pHBA*, while the molar absorptivity of pHBA at 254 nm decreased as the increase of pH in an alkaline condition which inhibited the yield of 3pHBA*. The RBV degradation pathways and products toxicity assessment indicated that UV/Sulfite/pHBA had better detoxification performance on RBV than UV/Sulfite/SA process. This study disclosed a novel mechanism of emerging contaminants abatement through non-radical process in NSOM mediated ARP, and provide a wide insight into positive profile of DOM in water treatment process, instead of only taking DOM as a quencher of reactive intermediates.
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Affiliation(s)
- Jing Yang
- College of Environmental and Resource Sciences, College of Carbon Neutral Modern Industry, Fujian Key Laboratory of Pollution Control & Resource Reuse, Fujian Normal University, Fuzhou 350117, Fujian, China
| | - Yongjie Fan
- College of Environmental and Resource Sciences, College of Carbon Neutral Modern Industry, Fujian Key Laboratory of Pollution Control & Resource Reuse, Fujian Normal University, Fuzhou 350117, Fujian, China; College of the Environment & Ecology, Xiamen University, Xiamen 361102, Fujian, China
| | - Zhilei Lu
- College of Environmental and Resource Sciences, College of Carbon Neutral Modern Industry, Fujian Key Laboratory of Pollution Control & Resource Reuse, Fujian Normal University, Fuzhou 350117, Fujian, China
| | - Yuxin Guo
- College of Environmental and Resource Sciences, College of Carbon Neutral Modern Industry, Fujian Key Laboratory of Pollution Control & Resource Reuse, Fujian Normal University, Fuzhou 350117, Fujian, China
| | - Jintao Huang
- College of Environmental and Resource Sciences, College of Carbon Neutral Modern Industry, Fujian Key Laboratory of Pollution Control & Resource Reuse, Fujian Normal University, Fuzhou 350117, Fujian, China
| | - Kaicong Cai
- College of Chemistry and Materials Science, Fujian Provincial Key Laboratory of Advanced Materials Oriented Chemical Engineering, Fujian Normal University, Fuzhou 350117, China; Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Xiamen 361005, China
| | - Qiyuan Sun
- College of Environmental and Resource Sciences, College of Carbon Neutral Modern Industry, Fujian Key Laboratory of Pollution Control & Resource Reuse, Fujian Normal University, Fuzhou 350117, Fujian, China.
| | - Feifeng Wang
- College of Environmental and Resource Sciences, College of Carbon Neutral Modern Industry, Fujian Key Laboratory of Pollution Control & Resource Reuse, Fujian Normal University, Fuzhou 350117, Fujian, China.
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21
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Li M, Cen P, Huang L, Yan J, Zhou S, Yeung KL, Mo CH, Zhang H. Iron complex regulated synergistic effect between the current and peroxymonosulfate enhanced ultrafast oxidation of perfluorooctanoic acid via free radical dominant electrochemical reaction. JOURNAL OF HAZARDOUS MATERIALS 2024; 470:134155. [PMID: 38552391 DOI: 10.1016/j.jhazmat.2024.134155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 03/09/2024] [Accepted: 03/26/2024] [Indexed: 04/25/2024]
Abstract
Iron complex regulated electrochemical reaction was triggered for revealing the reaction mechanism, degradation pathway, and applied potential of perfluorooctanoic acid (PFOA). The increased PMS concentrations, electrode spacing, and current density significantly enhanced PFOA elimination, with current density exhibiting a relatively strong interdependency to PFOA complete mineralization. The synergy between PMS and electrochemical reactions greatly accelerated PFOA decomposition by promoting the generation of key reaction sites, such as those for PMS activation and electrochemical processes, under various conditions. Furthermore, density functional theory calculations confirmed that the reciprocal transformation of Fe2+ and Fe3+ complexes was feasible under the electrochemical effect, further promoting the generation of active sites. The developed electrochemical oxidation with PMS reaction (EO/PMS) system can rapidly decompose and mineralize PFOA while maintaining strong tolerance to changing water matrices and organic and inorganic ions. Overall, it holds promise for use in treating and purifying wastewater containing PFOA.
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Affiliation(s)
- Meng Li
- School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, PR China; Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, PR China.
| | - Peitong Cen
- School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, PR China
| | - Lei Huang
- School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, PR China
| | - Jia Yan
- School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, PR China
| | - Shaoqi Zhou
- College of Resources and Environmental Engineering, Guizhou University, 2708 Huaxi Road, Guiyang 550025, PR China
| | - King Lun Yeung
- Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, PR China
| | - Ce-Hui Mo
- Guangdong Provincial Research Center for Environment Pollution Control and Remediation Materials, College of Life Science and Technology, Jinan University, Guangzhou 510632, PR China
| | - Hongguo Zhang
- School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, PR China; Guangzhou University-Linköping University Research Center on Urban Sustainable Development, Guangzhou University, Guangzhou 510006, PR China.
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22
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Zhang H, Zhu L, Zhang Y, Héroux P, Cai L, Liu Y. Removal of per- and polyfluoroalkyl substances from water by plasma treatment: Insights into structural effects and underlying mechanisms. WATER RESEARCH 2024; 253:121316. [PMID: 38377926 DOI: 10.1016/j.watres.2024.121316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 02/09/2024] [Accepted: 02/13/2024] [Indexed: 02/22/2024]
Abstract
Non-thermal plasma emerges as a promising technology for per- and polyfluoroalkyl substances (PFAS) decomposition due to its notable efficacy and environmentally friendly characteristics. In this study, we demonstrated the efficacy of a falling film dielectric barrier discharge (DBD) system for the removal of 10 PFAS, including perfluoroalkyl carboxylic acids (PFCAs), perfluoroalkyl sulfonic acids (PFSAs) and hexafluoropropylene oxide (HFPO) oligomer acids. Results showed that compounds with fluoroalkyl chain length>4 were effectively decomposed within 100 min, with long-chain PFAS demonstrating more pronounced removal performance than their short-chain analogues. The superior removal but low defluorination observed in HFPO oligomer acids could be ascribed to their ether-based structural features. The integration of experimental results with density functional theory (DFT) calculations revealed that the synergistic effects of various reactive species are pivotal to their efficient decomposition, with electrons, OH•, and NO2• playing essential roles. In contrast, the degradation of PFSAs was more dependent on electron attack than that of PFCAs and HFPO oligomer acids. Significantly, the most crucial degradation pathway for HFPO oligomer acids was the cleavage of ether CO, whether through radical or electron attack. Furthermore, the demonstrated effective removal in various water matrices showed the potential of the plasma system for removing PFAS in complex aquatic environments. This study provided mechanistic insights into PFAS degradation behavior in plasma processes, and it underscored the vital influence of molecular structures on degradability, thereby contributing to the further development and regulation of plasma-based technologies for treating PFAS in water.
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Affiliation(s)
- Han Zhang
- College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China
| | - Luxiang Zhu
- College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China
| | - Yinyin Zhang
- College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China
| | - Paul Héroux
- Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, Canada
| | - Li Cai
- College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China
| | - Yanan Liu
- College of Environmental Science and Engineering, Donghua University, 2999 North Renmin Road, Shanghai 201620, China; Shanghai institute of pollution control and ecological security, Shanghai 200092, China.
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23
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Qi Y, Yang Y, Cui S, Tang X, Zhang P, Wang C, Liang Y, Sun H, Ma C, Xing B. Novel Defluorination Pathways of Perfluoroether Compounds (GenX): α-Fe 2O 3 Nanoparticle Layer Retains Higher Concentrations of Effective Hydrated Electrons. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:5567-5577. [PMID: 38488517 DOI: 10.1021/acs.est.3c09879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/27/2024]
Abstract
The development of efficient defluorination technology is an important issue because the kind of emerging pollutant of hexafluoropropylene oxide dimer acid (GenX) as an alternative to perfluorooctanoic acid (PFOA) has the higher environmental risks. In the UV/bisulfite system, we first developed a hydrophobic confined α-Fe2O3 nanoparticle layer rich in oxygen vacancies, which accelerated the enrichment of HSO3- and GenX on the surface and pores through electrostatic attraction and hydrophobic interaction, retaining more hydrated electrons (eaq-) and rapidly destroying GenX under UV excitation. Especially, under anaerobic and aerobic conditions, the degradation percentage of GenX obtain nearly 100%, defluorination of GenX to 88 and 57% respectively. It was amazed to find that the three parallel H/F exchange pathways triggered by the rapid reactions of eaq- and GenX, which were unique to anaerobic conditions, improved the efficiency of fluoride removal and weaken the interference of dissolved oxygen and H+. Therefore, this study provided an available material and mechanism for sustainable fluoride removal from wastewater in aerobic and anaerobic conditions.
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Affiliation(s)
- Yuwen Qi
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, PR China
| | - Yinbo Yang
- School of Chemical Engineering and Technology, Tianjin University, Tianjin 300354, PR China
| | - Shengyan Cui
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, PR China
| | - Xuejiao Tang
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, PR China
| | - Peng Zhang
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, PR China
| | - Cuiping Wang
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, PR China
| | - Yanna Liang
- Department of Environmental and Sustainable Engineering, University at Albany, SUNY, Albany, New York 12222, United States
| | - Hongwen Sun
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, PR China
| | - Chuanxin Ma
- Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou 510006, PR China
| | - Baoshan Xing
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, Massachusetts 01003, United States
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24
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Antonopoulou M, Spyrou A, Tzamaria A, Efthimiou I, Triantafyllidis V. Current state of knowledge of environmental occurrence, toxic effects, and advanced treatment of PFOS and PFOA. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 913:169332. [PMID: 38123090 DOI: 10.1016/j.scitotenv.2023.169332] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2023] [Revised: 12/11/2023] [Accepted: 12/11/2023] [Indexed: 12/23/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are anthropogenic synthetic compounds, with high chemical and thermal stability and a persistent, stable and bioaccumulative nature that renders them a potential hazard for the environment, its organisms, and humans alike. Perfluorooctane sulfonic acid (PFOS) and Perfluorooctanoic acid (PFOA) are the most well-known substances of this category and even though they are phased out from production they are still highly detectable in several environmental matrices. As a result, they have been spread globally in water sources, soil and biota exerting toxic and detrimental effects. Therefore, up and coming technologies, namely advanced oxidation processes (AOPs) and advanced reduction processes (ARPs) are being tested for their implementation in the degradation of these pollutants. Thus, the present review compiles the current knowledge on the occurrence of PFOS and PFOA in the environment, the various toxic effects they have induced in different organisms as well as the ability of AOPs and ARPs to diminish and/or eliminate them from the environment.
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Affiliation(s)
- Maria Antonopoulou
- Department of Sustainable Agriculture, University of Patras, 30131 Agrinio, Greece.
| | - Alexandra Spyrou
- Department of Sustainable Agriculture, University of Patras, 30131 Agrinio, Greece
| | - Anna Tzamaria
- Department of Sustainable Agriculture, University of Patras, 30131 Agrinio, Greece
| | - Ioanna Efthimiou
- Department of Biology, Section of Genetics Cell Biology and Development, University of Patras, 26500 Patras, Greece
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25
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Zhu K, Ma S, Chen N, Dai Y, Wang T, Guo X, Jia H. Robust reactive oxygen species production in interfacial reaction between organic acids and biochar: The combined effect of electron acceptance and electron conduction. JOURNAL OF HAZARDOUS MATERIALS 2024; 464:132960. [PMID: 37976848 DOI: 10.1016/j.jhazmat.2023.132960] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 10/21/2023] [Accepted: 11/07/2023] [Indexed: 11/19/2023]
Abstract
Interfacial electron transport and reactive oxygen species (ROS) generation in the redox action between biochar (BC) and low-molecular-weight organic acids (LMWOAs) have been overlooked during the utilization of BC in soil amelioration/remediation. Herein, BC and N-doped BC (NBC) with various physicochemical properties were prepared at pyrolysis temperatures of 350, 550 and 750 °C (namely BC/NBC350, 550 and 750) and their interactions with LMWOAs were systematically investigated. Results of ROS quenching and electrochemical cell experiments revealed that BC/NBC could strongly interact with LMWOAs, especially ascorbic acid (AA), and acted as an electron shuttle to mediate one electron transfer from AA to oxygen to generate O2•-, followed by the robust generation of H2O2 and •OH. Interestingly, the generation rates of •OH and H2O2 in the NBC-AA system were significantly higher than that in the BC-AA system, of which the NBC550-AA system exhibited the best performance, enabling its superior ability in bisphenol A degradation. Different from conventional wisdom, the electron shuttle capacity depended on a combined aromatization degree and electron-accepting capacity of BC/NBC. These findings complement the interfacial electron transfer mechanism during the natural BC-LMWOAs interaction and provide new inspiration for the development of green and efficient organic pollutant removal technologies.
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Affiliation(s)
- Kecheng Zhu
- Key Laboratory of Low-carbon Green Agriculture in Northwestern China, Ministry of Agriculture and Rural Affairs, College of Natural Resources and Environment, Northwest A & F University, Yangling 712100, China
| | - Sirui Ma
- Key Laboratory of Low-carbon Green Agriculture in Northwestern China, Ministry of Agriculture and Rural Affairs, College of Natural Resources and Environment, Northwest A & F University, Yangling 712100, China
| | - Na Chen
- Key Laboratory of Low-carbon Green Agriculture in Northwestern China, Ministry of Agriculture and Rural Affairs, College of Natural Resources and Environment, Northwest A & F University, Yangling 712100, China
| | - Yunchao Dai
- Key Laboratory of Low-carbon Green Agriculture in Northwestern China, Ministry of Agriculture and Rural Affairs, College of Natural Resources and Environment, Northwest A & F University, Yangling 712100, China
| | - Tiecheng Wang
- Key Laboratory of Low-carbon Green Agriculture in Northwestern China, Ministry of Agriculture and Rural Affairs, College of Natural Resources and Environment, Northwest A & F University, Yangling 712100, China
| | - Xuetao Guo
- Key Laboratory of Low-carbon Green Agriculture in Northwestern China, Ministry of Agriculture and Rural Affairs, College of Natural Resources and Environment, Northwest A & F University, Yangling 712100, China
| | - Hanzhong Jia
- Key Laboratory of Low-carbon Green Agriculture in Northwestern China, Ministry of Agriculture and Rural Affairs, College of Natural Resources and Environment, Northwest A & F University, Yangling 712100, China.
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26
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Chen Z, Dong R, Wang X, Huang L, Qiu L, Zhang M, Mi N, Xu M, He H, Gu C. Efficient Decomposition of Perfluoroalkyl Substances by Low Concentration Indole: New Insights into the Molecular Mechanisms. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024. [PMID: 38329941 DOI: 10.1021/acs.est.3c08453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2024]
Abstract
Perfluoroalkyl substances (PFAS) are a class of persistent organic pollutants known as "forever chemicals". Currently, the hydrated electron-based advanced reduction process (ARP) holds promise for the elimination of PFAS. However, the efficiency of ARP is often challenged by an oxygen-rich environment, resulting in the consumption of hydrated electron source materials in exchange for the high PFAS decomposition efficiency. Herein, we developed a ternary system constructed by indole and isopropyl alcohol (IPA), and the addition of IPA significantly enhanced the PFOA degradation and defluorination efficiency in the presence of low-concentration indole (<0.4 mM). Meanwhile, opposite results were obtained with a higher amount of indole (>0.4 mM). Further exploring the molecular mechanism of the reaction system, the addition of IPA played two roles. On one hand, IPA built an anaerobic reaction atmosphere and improved the yield and utilization efficiency of hydrated electrons with a low concentration of indole. On the other hand, IPA suppressed the attraction between indole and PFOA, thus reducing the hydrated electron transfer efficiency, especially with more indole. In general, the indole/PFAS/IPA system significantly improved the PFAS destruction efficiency with a small amount of hydrated electron donors, which provided new insights for development of simple and efficient techniques for the treatment of PFAS-contaminated wastewater.
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Affiliation(s)
- Zhanghao Chen
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, P. R. China
| | - Ruochen Dong
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, P. R. China
| | - Xinhao Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, P. R. China
| | - Liuqing Huang
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, P. R. China
| | - Longlong Qiu
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, P. R. China
| | - Ming Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, P. R. China
- Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, Nanjing 210037, P. R. China
| | - Na Mi
- Ministry of Ecology and Environment, Nanjing Institute of Environmental Science, Nanjing 210042, P. R. China
| | - Min Xu
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, P. R. China
| | - Huan He
- School of Environment, Nanjing Normal University, Nanjing 210023, P. R. China
| | - Cheng Gu
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, P. R. China
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27
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Wang Z, Jin X, Hong R, Wang X, Chen Z, Gao G, He H, Liu J, Gu C. New Indole Derivative Heterogeneous System for the Synergistic Reduction and Oxidation of Various Per-/Polyfluoroalkyl Substances: Insights into the Degradation/Defluorination Mechanism. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:21459-21469. [PMID: 38056012 DOI: 10.1021/acs.est.3c05940] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/08/2023]
Abstract
The hydrated electron (eaq-) system is typically suitable for degrading perfluoroalkyl substances (PFASs). To enhance eaq- utilization, we synthesized a new indole compound (DIHA) that forms stable nanospheres (100-200 nm) in water via a supramolecular assembly. Herein, the DIHA nanoemulsion system exhibits high degradation efficiencies toward a broad category of PFASs, regardless of the headgroup, chain length, and branching structure, under UV (254 nm) irradiation. The strong adsorption of PFAS on the DIHA surface ensures its effective degradation/defluorination. Quenching experiments further demonstrated that the reaction took place on the surface of DIHA nanospheres. This specific heterogeneous surface reaction unveiled novel PFAS degradation and defluorination mechanisms that differ from previously reported eaq- systems. First, the photogenerated surface electrons nonselectively attacked multiple C-F bonds of the -CF2- chain. This plays a dominant degrading/defluorinating role in the DIHA system. Second, abundant hydroxyl radicals (•OH) were also produced, leading to synergistic reduction (by surface electron) and oxidation (by surface •OH) in a single system. This facilitates faster and deeper defluorination of different structured PFASs through multiple pathways. The new mechanism inspires the design of innovative organo-heterogeneous eaq- systems possessing synergistic reduction and oxidation functions, thereby making them potentially effective for treating PFAS-contaminated water.
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Affiliation(s)
- Zhe Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, P. R. China
| | - Xin Jin
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, P. R. China
- School of Environment, Nanjing Normal University, Nanjing 210023, P. R. China
| | - Ran Hong
- School of Chemical and Environmental Engineering, Anhui Polytechnic University, Wuhu 241000, P. R. China
| | - Xinhao Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, P. R. China
| | - Zhanghao Chen
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, P. R. China
| | - Guandao Gao
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, P. R. China
| | - Huan He
- School of Environment, Nanjing Normal University, Nanjing 210023, P. R. China
| | - Jinyong Liu
- Department of Chemical & Environmental Engineering and Materials Science & Engineering Program, University of California, Riverside, California 92521, United States
| | - Cheng Gu
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, P. R. China
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Zhang M, Chen Z, Shao W, Tian T, Wang X, Chen Z, Qiao W, Gu C. A confined expansion pore-making strategy to transform Zn-MOF to porous carbon nanofiber for water treatment: Insight into formation and degradation mechanism. J Colloid Interface Sci 2023; 652:69-81. [PMID: 37591085 DOI: 10.1016/j.jcis.2023.08.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 07/29/2023] [Accepted: 08/04/2023] [Indexed: 08/19/2023]
Abstract
Electrospinning MOFs nanoparticles derived porous carbon nanofibers with rational structure and design are recently as environmentally friendly and highly efficient catalytic materials for wastewater treatment. However, most of the pore-making strategies are based on precursors structural shrinkage during pyrolysis, which is a challenge to create abundant large pores and open channels. Here, a confined expansion pore-making strategy with active MOF is introduced, where energetic Zn-MOF (Zn2+/triazole) and ZIF-67 (Co2+/dimethylimidazole) are utilized as pore forming additive and precursor of active sites, respectively. The high nitrogen content gives triazole the ability to puff up and realizes N-doped during pyrolysis. Moreover, degradation mechanisms and pathways of pollutants were measured by 3D EEM, LC-MS, quenching experiments, and Fukui function. This pore-making strategy via energetic MOF local contraction and expansion provides a novel method to prepare diversiform function porous carbon materials for environmental remediation.
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Affiliation(s)
- Ming Zhang
- Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, Nanjing 210037, China; State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Zhonglin Chen
- Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, Nanjing 210037, China
| | - Weizhen Shao
- Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, Nanjing 210037, China
| | - Tian Tian
- Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, Nanjing 210037, China
| | - Xinhao Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Zhanghao Chen
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Weichuan Qiao
- Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, Nanjing 210037, China.
| | - Cheng Gu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China.
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29
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Marciesky M, Aga DS, Bradley IM, Aich N, Ng C. Mechanisms and Opportunities for Rational In Silico Design of Enzymes to Degrade Per- and Polyfluoroalkyl Substances (PFAS). J Chem Inf Model 2023; 63:7299-7319. [PMID: 37981739 PMCID: PMC10716909 DOI: 10.1021/acs.jcim.3c01303] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 10/17/2023] [Accepted: 10/18/2023] [Indexed: 11/21/2023]
Abstract
Per and polyfluoroalkyl substances (PFAS) present a unique challenge to remediation techniques because their strong carbon-fluorine bonds make them difficult to degrade. This review explores the use of in silico enzymatic design as a potential PFAS degradation technique. The scope of the enzymes included is based on currently known PFAS degradation techniques, including chemical redox systems that have been studied for perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) defluorination, such as those that incorporate hydrated electrons, sulfate, peroxide, and metal catalysts. Bioremediation techniques are also discussed, namely the laccase and horseradish peroxidase systems. The redox potential of known reactants and enzymatic radicals/metal-complexes are then considered and compared to potential enzymes for degrading PFAS. The molecular structure and reaction cycle of prospective enzymes are explored. Current knowledge and techniques of enzyme design, particularly radical-generating enzymes, and application are also discussed. Finally, potential routes for bioengineering enzymes to enable or enhance PFAS remediation are considered as well as the future outlook for computational exploration of enzymatic in situ bioremediation routes for these highly persistent and globally distributed contaminants.
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Affiliation(s)
- Melissa Marciesky
- Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, United States
| | - Diana S Aga
- Department of Chemistry, State University of New York at Buffalo, Buffalo, New York 14260, United States
| | - Ian M Bradley
- Department of Civil, Structural, and Environmental Engineering, State University of New York at Buffalo, Buffalo, New York 14228, United States
- Research and Education in Energy, Environmental and Water (RENEW) Institute, University at Buffalo, The State University of New York, Buffalo, New York 14260, United States
| | - Nirupam Aich
- Department of Civil and Environmental Engineering, University of Nebraska─Lincoln, Lincoln, Nebraska 68588-0531, United States
| | - Carla Ng
- Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, United States
- Department of Civil and Environmental Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
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30
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Hou C, Deng J, Li S, Li H, Zhou Y, Zhai Y. Differences between reductive defluorination of perfluorooctanoic acid by chlorination, bromination, and iodization in the vacuum-ultraviolet/sulfite process. JOURNAL OF HAZARDOUS MATERIALS 2023; 460:132459. [PMID: 37683349 DOI: 10.1016/j.jhazmat.2023.132459] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 08/25/2023] [Accepted: 08/30/2023] [Indexed: 09/10/2023]
Abstract
The introduction of iodide (I-) has broad perspectives on the decomposition of perfluorocarboxylates (PFCAs, CnF2n+1COO-). However, the iodinated substances produced are highly toxic synthetic chemicals, hence, it is urgent to find a similar alternative with less toxicity. In this work, the defluorination of perfluorooctanoic acid (PFOA) by I-, bromide (Br-) and chlorine (Cl-) was systematically compared in the VUV/sulfite process. Results indicated that the PFOA defluorination rates increased with increasing nucleophilicity of halogens (I > Br > Cl). Meanwhile, the introduction of I-, Br-, and Cl- reduced the interference of the coexisting water matrix on the degrading influence of PFOA. The in situ produced eaq-, SO3•-, H•, and HO• were recognized, among the addition of I- maximized the relative contribution of eaq- but Br- and Cl- decreased that of H• and other radicals. Additionally, HPLC/MS analysis revealed the presence of I-, Br-, and Cl- had a vital impact on the difference in product concentrations, while they had a negligible effect on the change in the pathway of degradation. Overall, this study demonstrated the similarities and differences between I-, Br-, and Cl-, which has significant implications for further understanding VUV/sulfite degradation.
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Affiliation(s)
- Changlan Hou
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China
| | - Jiaqin Deng
- College of Environmental Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, PR China
| | - Shanhong Li
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China
| | - Hui Li
- Hunan Academy of Forestry and State Key Laboratory of Utilization of Woody Oil Resource, Changsha 410004, PR China
| | - Yin Zhou
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China
| | - Yunbo Zhai
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
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31
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Chen Z, Zhang S, Wang X, Mi N, Zhang M, Zeng G, Dong H, Liu J, Wu B, Wei S, Gu C. Amine-Functionalized A-Center Sphalerite for Selective and Efficient Destruction of Perfluorooctanoic Acid. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023. [PMID: 37406161 DOI: 10.1021/acs.est.3c01266] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/07/2023]
Abstract
Perfluorochemicals (PFCs), especially perfluorooctanoic acid (PFOA), have contaminated the ground and surface waters throughout the world. Efficient removal of PFCs from contaminated waters has been a major challenge. This study developed a novel UV-based reaction system to achieve fast PFOA adsorption and decomposition without addition of sacrificial chemicals by using synthetic photocatalyst sphalerite (ZnS-[N]) with sufficient surface amination and defects. The obtained ZnS-[N] has the capability of both reduction and oxidation due to the suitable band gap and photo-generated hole-trapping properties created by surface defects. The cooperated organic amine functional groups on the surface of ZnS-[N] play a crucial role in the selective adsorption of PFOA, which guarantee the efficient destruction of PFOA subsequently, and 1 μg L-1 PFOA could be degraded to <70 ng L-1 after 3 h in the presence of 0.75 g L-1 ZnS-[N] under 500 W UV irradiation. In this process, the photogenerated electrons (reduction) and holes (oxidation) on the ZnS-[N] surface work in a synergistic manner to achieve complete defluorination of PFOA. This study not only provides promising green technology for PFC-pollution remediation but also highlights the significance of developing a target system capable of both reduction and oxidation for PFC degradation.
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Affiliation(s)
- Zhanghao Chen
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, Jiangsu 210023, P.R. China
| | - Shuoqi Zhang
- Kuang Yaming Honors School, Nanjing University, Nanjing, Jiangsu 210023, P.R. China
| | - Xinhao Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, Jiangsu 210023, P.R. China
| | - Na Mi
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, Jiangsu 210023, P.R. China
- Ministry of Ecology and Environment, Nanjing Institute of Environmental Science, Nanjing 210042, China
| | - Ming Zhang
- Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, Nanjing, Jiangsu 210037, P. R. China
| | - Guixiang Zeng
- Kuang Yaming Honors School, Nanjing University, Nanjing, Jiangsu 210023, P.R. China
| | - Hailiang Dong
- Center for Geomicrobiology and Biogeochemistry Research, State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing 100083, China
| | - Jinyong Liu
- Department of Chemical & Environmental Engineering, University of California, Riverside, California 92521, United States
| | - Bing Wu
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, Jiangsu 210023, P.R. China
| | - Si Wei
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, Jiangsu 210023, P.R. China
| | - Cheng Gu
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, Jiangsu 210023, P.R. China
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32
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Zhang L, Liu Y, Wang J. Selective and effective oxidation of ammonium to dinitrogen in MgO/Na 2SO 3/K 2S 2O 8 system. CHEMOSPHERE 2023; 325:138401. [PMID: 36925013 DOI: 10.1016/j.chemosphere.2023.138401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 03/07/2023] [Accepted: 03/12/2023] [Indexed: 06/18/2023]
Abstract
The oxidation of ammonium (NH4+) to dinitrogen (N2) with high selectivity and high efficiency is still a challenge. Herein, a novel sunlight induced persulfate (PS)-based AOPs process (MgO/Na2SO3/PS/hv) was proposed by introducing solid base (MgO) and hydrated electron (eaq-), to selectively oxidize NH4+ to N2, with high selectivity and high efficiency at a wide range of pH value. The deprotonation of NH4+ into NH3 by MgO and the generation of •OH and SO4-• by PS activation were responsible for the high efficiency of NH4+ oxidation. The buffering capacity provided by MgO to proton released from PS activation made the NH4+ oxidation possible at a wide pH range. The eaq- from the Na2SO3/hv process was the main active specie to reduce NO2-and NO3- (NOx-) into N2, responsible for high N2 selectivity of NH4+ oxidation. 100% NH4+ could be oxidized within 30 min, and N2 selectivity exceeded 96% at the initial pH range of 3-11 and the initial concentration of NH4+ of 30 mg N/L. This work could offer an efficient AOPs process for selective NH4+ oxidation, which is promising for the chemical denitrification of wastewater ….
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Affiliation(s)
- Le Zhang
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu, 610066, China
| | - Yong Liu
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu, 610066, China
| | - Jianlong Wang
- Laboratory of Environmental Technology, INET, Tsinghua University, Beijing, 100084, China.
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33
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Fennell B, Fowler D, Mezyk SP, McKay G. Reactivity of Dissolved Organic Matter with the Hydrated Electron: Implications for Treatment of Chemical Contaminants in Water with Advanced Reduction Processes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:7634-7643. [PMID: 37141499 PMCID: PMC10862553 DOI: 10.1021/acs.est.3c00909] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 04/17/2023] [Accepted: 04/18/2023] [Indexed: 05/06/2023]
Abstract
Advanced reduction processes (ARP) have garnered increasing attention for the treatment of recalcitrant chemical contaminants, most notably per- and polyfluoroalkyl substances (PFAS). However, the impact of dissolved organic matter (DOM) on the availability of the hydrated electron (eaq-), the key reactive species formed in ARP, is not completely understood. Using electron pulse radiolysis and transient absorption spectroscopy, we measured bimolecular reaction rates constant for eaq- reaction with eight aquatic and terrestrial humic substance and natural organic matter isolates ( kDOM,eaq-), with the resulting values ranging from (0.51 ± 0.01) to (2.11 ± 0.04) × 108 MC-1 s-1. kDOM,eaq- measurements at varying temperature, pH, and ionic strength indicate that activation energies for diverse DOM isolates are ≈18 kJ mol-1 and that kDOM,eaq- could be expected to vary by less than a factor of 1.5 between pH 5 and 9 or from an ionic strength of 0.02 to 0.12 M. kDOM,eaq- exhibited a significant, positive correlation to % carbonyl carbon for the isolates studied, but relationships to other DOM physicochemical properties were surprisingly more scattered. A 24 h UV/sulfite experiment employing chloroacetate as an eaq- probe revealed that continued eaq- exposure abates DOM chromophores and eaq- scavenging capacity over a several hour time scale. Overall, these results indicate that DOM is an important eaq- scavenger that will reduce the rate of target contaminant degradation in ARP. These impacts are likely greater in waste streams like membrane concentrates, spent ion exchange resins, or regeneration brines that have elevated DOM concentrations.
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Affiliation(s)
- Benjamin
D. Fennell
- Zachry
Department of Civil & Environmental Engineering, Texas A&M University, College Station, Texas 77845, United States
| | - Douglas Fowler
- Department
of Chemistry and Biochemistry, California
State University Long Beach, Long Beach, California 90840, United States
| | - Stephen P. Mezyk
- Department
of Chemistry and Biochemistry, California
State University Long Beach, Long Beach, California 90840, United States
| | - Garrett McKay
- Zachry
Department of Civil & Environmental Engineering, Texas A&M University, College Station, Texas 77845, United States
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34
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Chen Z, Lu YL, Wang L, Xu J, Zhang J, Xu X, Cheng P, Yang S, Shi W. Efficient Recognition and Removal of Persistent Organic Pollutants by a Bifunctional Molecular Material. J Am Chem Soc 2023; 145:260-267. [PMID: 36538618 DOI: 10.1021/jacs.2c09866] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Persistent organic pollutants (POPs) exist widely in the environment and place significant impact on human health by bioaccumulation. Efficient recognition of POPs and their removal are highly challenging tasks because their specific structures interact often very weakly with the capture materials. Herein, a molecular nanocage (1) is studied as an efficient sensing and sorbent material for POPs, which is demonstrated by a representative and stable perfluorooctane sulfonate (PFOS) substrate containing a hydrophilic sulfonic group and a hydrophobic fluoroalkyl chain. A highly sensitive and unusual turn-on fluorescence response within 10 s and a 97% total removal of PFOS from water in 20 min have been achieved owing to the strong host-guest interactions between 1 and PFOS. The binding constant of 1 to PFOS is 2 orders of magnitude higher than state-of-the-art adsorbents for PFOS and thus represents a new benchmark material for the recognition and removal of PFOS. The host-guest interaction has been elucidated by solid-state NMR spectroscopy and single-crystal X-ray diffraction, which provide key insights at a molecular level for the design of new advanced sensing/sorbent materials for POPs.
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Affiliation(s)
- Zhonghang Chen
- Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry (MOE), Frontiers Science Center for New Organic Matter and Renewable Energy Conversion and Storage Center (RECAST), College of Chemistry, Nankai University, Tianjin 300071, China
| | - Yi-Lin Lu
- Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry (MOE), Frontiers Science Center for New Organic Matter and Renewable Energy Conversion and Storage Center (RECAST), College of Chemistry, Nankai University, Tianjin 300071, China
| | - Liang Wang
- State Key Laboratory of Separation Membranes and Membrane Processes, School of Environmental Science and Engineering, Tiangong University, Tianjin 300387, China
| | - Jun Xu
- Tianjin Key Lab for Rare Earth Materials and Applications, School of Materials Science and Engineering & National Institute for Advanced Materials, Nankai University, Tianjin 300350 China
| | - Jing Zhang
- Tianjin Eco-Environmental Monitoring Center, Tianjin 300191, China
| | - Xiufang Xu
- Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry (MOE), Frontiers Science Center for New Organic Matter and Renewable Energy Conversion and Storage Center (RECAST), College of Chemistry, Nankai University, Tianjin 300071, China
| | - Peng Cheng
- Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry (MOE), Frontiers Science Center for New Organic Matter and Renewable Energy Conversion and Storage Center (RECAST), College of Chemistry, Nankai University, Tianjin 300071, China.,Haihe Laboratory of Sustainable Chemical Transformations, Tianjin 300192, China
| | - Sihai Yang
- Department of Chemistry, University of Manchester, Manchester M13 9PL, U.K
| | - Wei Shi
- Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry (MOE), Frontiers Science Center for New Organic Matter and Renewable Energy Conversion and Storage Center (RECAST), College of Chemistry, Nankai University, Tianjin 300071, China.,Haihe Laboratory of Sustainable Chemical Transformations, Tianjin 300192, China
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35
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Wang Y, Li L, Huang Q. Electrooxidation of per- and polyfluoroalkyl substances in chloride-containing water on surface-fluorinated Ti 4O 7 anodes: Mitigation and elimination of chlorate and perchlorate formation. CHEMOSPHERE 2022; 307:135877. [PMID: 35931258 DOI: 10.1016/j.chemosphere.2022.135877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 07/24/2022] [Accepted: 07/26/2022] [Indexed: 06/15/2023]
Abstract
Electrooxidation (EO) has been shown effective in degrading per- and polyfluoroalkyl substances (PFASs) in water, but concurrent formation of chlorate and perchlorate in the presence of chloride is of concern due to their toxicity. This study examined EO treatment of three representative PFASs, perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA) and 6:2 fluorotelomer sulfonate (6:2 FTS), in chloride-containing solutions on pristine and surface-fluorinated Ti4O7 anodes having different percentage of surface fluorination. The experiment results indicate that surface fluorination of Ti4O7 anodes slightly inhibited PFAS degradation, while significantly decreased the formation of chlorate and perchlorate. Further studies with spectroscopic and electrochemical characterizations and density functional theory (DFT) computation reveal the mechanisms of the impact on EO performance by anode fluorination. In particular, chlorate and perchlorate formation were fully inhibited when fluorinated Ti4O7 anode was used in reactive electrochemical membrane (REM) under a proper anodic potential range (<3.0 V vs Standard Hydrogen Electrode), resulting from slower intermediate reaction steps and short residence time of the REM system. The results of this study provide a basis for design and optimization of modified Ti4O7 anodes for efficient EO treatment of PFAS while limiting chlorate and perchlorate formation.
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Affiliation(s)
- Yaye Wang
- College of Agricultural and Environmental Sciences, Department of Crop and Soil Sciences, University of Georgia, Griffin, GA, 30223, United States
| | - Lei Li
- College of Agricultural and Environmental Sciences, Department of Crop and Soil Sciences, University of Georgia, Griffin, GA, 30223, United States
| | - Qingguo Huang
- College of Agricultural and Environmental Sciences, Department of Crop and Soil Sciences, University of Georgia, Griffin, GA, 30223, United States.
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36
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Zhao Y, Zhang C, Chu L, Zhou Q, Huang B, Ji R, Zhou X, Zhang Y. Hydrated electron based photochemical processes for water treatment. WATER RESEARCH 2022; 225:119212. [PMID: 36223677 DOI: 10.1016/j.watres.2022.119212] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 10/03/2022] [Accepted: 10/04/2022] [Indexed: 06/16/2023]
Abstract
Hydrated electron (eaq-) based photochemical processes have emerged as a promising technology for contaminant removal in water due to the mild operating conditions. This review aims to provide a comprehensive and up-to-date summary on eaq- based photochemical processes for the decomposition of various oxidative contaminants. Specifically, the characteristics of different photo-reductive systems are first elaborated, including the environment required to generate sufficient eaq-, the advantages and disadvantages of each system, and the comparison of the degradation efficiency of contaminants induced by eaq-. In addition, the identification methods of eaq- (e.g., laser flash photolysis, scavenging studies, chemical probes and electron spin resonance techniques) are summarized, and the influences of operating conditions (e.g., solution pH, dissolved oxygen, source chemical concentration and UV type) on the performance of contaminants are also discussed. Considering the complexity of contaminated water, particular attention is paid to the influence of water matrix (e.g., coexisting anions, alkalinity and humic acid). Moreover, the degradation regularities of various contaminants (e.g., perfluorinated compounds, disinfection by-products and nitrate) by eaq- are summarized. We finally put forward several research prospects for the decomposition of contaminants by eaq- based photochemical processes to promote their practical application in water treatment.
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Affiliation(s)
- Yunmeng Zhao
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China
| | - Chaojie Zhang
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China.
| | - Liquan Chu
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China
| | - Qi Zhou
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China
| | - Baorong Huang
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China
| | - Ruixin Ji
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China
| | - Xuefei Zhou
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China
| | - Yalei Zhang
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China.
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37
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Jin X, Wang Z, Hong R, Chen Z, Wu B, Ding S, Zhu W, Lin Y, Gu C. Supramolecular assemblies of a newly developed indole derivative for selective adsorption and photo-destruction of perfluoroalkyl substances. WATER RESEARCH 2022; 225:119147. [PMID: 36206684 DOI: 10.1016/j.watres.2022.119147] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 08/31/2022] [Accepted: 09/16/2022] [Indexed: 06/16/2023]
Abstract
Per-/polyfluoroalkyl substances (PFASs) contamination has caused worldwide health concerns, and increased demand for effective elimination strategies. Herein, we developed a new indole derivative decorated with a hexadecane chain and a tertiary amine center (named di-indole hexadecyl ammonium, DIHA), which can form stable nanospheres (100-200 nm) in water via supramolecular assembly. As the DIHA nanospheres can induce electrostatic, hydrophobic and van der Waals interactions (all are long-ranged) that operative cooperatively, in addition to the nano-sized particles with large surface area, the DIHA nanocomposite exhibited extremely fast adsorption rates (in seconds), high adsorption capacities (0.764-0.857 g g-1) and selective adsorption for perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), outperformed the previous reported high-end PFASs adsorbents. Simultaneously, the DIHA nanospheres can produce hydrated electron (eaq-) when subjected to UV irradiation, with the virtue of constraining the photo-generated eaq- and the adsorbed PFOA/PFOS molecules entirely inside the nanocomposite. As such, the UV/DIHA system exhibits extremely high degradation/defluorination efficiency for PFOA/PFOS, even under ambient conditions, especially with the advantages of low chemical dosage requirement (μM level) and robust performance against environmental variables. Therefore, it is a new attempt of using supramolecular approach to construct an indole-based nanocomposite, which can elegantly combine adsorption and degradation functions. The novel DIHA nanoemulsion system would shed light on the treatment of PFAS-contaminated wastewater.
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Affiliation(s)
- Xin Jin
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 201123, China
| | - Zhe Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 201123, China
| | - Ran Hong
- School of Chemical and Environmental Engineering, Anhui Polytechnic University, Wuhu 241000, China
| | - Zhanghao Chen
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 201123, China
| | - Bing Wu
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 201123, China
| | - Shichao Ding
- School of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164, USA
| | - Wenlei Zhu
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 201123, China.
| | - Yuehe Lin
- School of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164, USA
| | - Cheng Gu
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 201123, China.
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38
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Liu F, Guan X, Xiao F. Photodegradation of per- and polyfluoroalkyl substances in water: A review of fundamentals and applications. JOURNAL OF HAZARDOUS MATERIALS 2022; 439:129580. [PMID: 35905606 DOI: 10.1016/j.jhazmat.2022.129580] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 07/05/2022] [Accepted: 07/09/2022] [Indexed: 06/15/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are persistent, mobile, and toxic chemicals that are hazardous to human health and the environment. Several countries, including the United States, plan to set an enforceable maximum contamination level for certain PFAS compounds in drinking water sources. Among the available treatment options, photocatalytic treatment is promising for PFAS degradation and mineralization in the aqueous solution. In this review, recent advances in the abatement of PFAS from water using photo-oxidation and photo-reduction are systematically reviewed. Degradation mechanisms of PFAS by photo-oxidation involving the holes (hvb+) and oxidative radicals and photo-reduction using the electrons (ecb-) and hydrated electrons (eaq-) are integrated. The recent development of innovative heterogeneous photocatalysts and photolysis systems for enhanced degradation of PFAS is highlighted. Photodegradation mechanisms of alternative compounds, such as hexafluoropropylene oxide dimer acid (GenX) and chlorinated polyfluorinated ether sulfonate (F-53B), are also critically evaluated. This paper concludes by identifying major knowledge gaps and some of the challenges that lie ahead in the scalability and adaptability issues of photocatalysis for natural water treatment. Development made in photocatalysts design and system optimization forges a path toward sustainable treatment of PFAS-contaminated water through photodegradation technologies.
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Affiliation(s)
- Fuqiang Liu
- School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
| | - Xiaohong Guan
- School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China.
| | - Feng Xiao
- Department of Civil Engineering, University of North Dakota, 243 Centennial Drive Stop 8115, Grand Forks, ND 58202, United States.
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39
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Mu H, Li J, Chen L, Hu H, Wang J, Gu C, Zhang XX, Ren HQ, Wu B. Distribution, source and ecological risk of per- and polyfluoroalkyl substances in Chinese municipal wastewater treatment plants. ENVIRONMENT INTERNATIONAL 2022; 167:107447. [PMID: 35940032 DOI: 10.1016/j.envint.2022.107447] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Revised: 06/23/2022] [Accepted: 07/30/2022] [Indexed: 06/15/2023]
Abstract
Municipal wastewater treatment plants (WWTPs) are sinks of per- and polyfluoroalkyl substances (PFASs) generated by human activities and are also sources of PFASs in aquatic environment. This study analyzed distribution, source and ecological risk of 14 PFASs in influent and effluent samples from 148 Chinese municipal WWTPs. Composition and concentrations of PFASs in the influents and effluents had obvious spatial differences. Fluoropolymer processing aids/wrappers and textile treatments/coatings were found to be the dominant sources in WWTP influents, which accounted for 78.34% of all sources. Consumption structure and metal and transportation equipment manufacturing affected the spatial differences of PFASs in WWTPs. Further, mean removal rate of total PFASs in all WWTPs was -5.45%. The conventional treatment processes can not effectively remove PFASs and no significant difference was found among different treatment processes. However, risk quotient values of PFASs in effluents were all below 0.1, indicating low risk or no risk to aquatic organisms. It should be noted that the composition, source and ecological risk of PFASs in east China were different from the other regions, which need more attentions. This study sheds insights into occurrencesof PFASs in municipal WWTPs, which should be helpful for their control strategy development.
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Affiliation(s)
- Hongxin Mu
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, PR China
| | - Jiahao Li
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, PR China
| | - Ling Chen
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, PR China
| | - Haidong Hu
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, PR China
| | - Jinfeng Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, PR China
| | - Cheng Gu
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, PR China
| | - Xu-Xiang Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, PR China
| | - Hong-Qiang Ren
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, PR China
| | - Bing Wu
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, PR China.
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40
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Zhang X, Li S, Yang Y, Zhao Y, Qu J, Li C. Predicting reaction rate constants of ozone with ionic/non-ionic compounds in water. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 835:155501. [PMID: 35483457 DOI: 10.1016/j.scitotenv.2022.155501] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 03/28/2022] [Accepted: 04/20/2022] [Indexed: 06/14/2023]
Abstract
Ozonation is a significant technology for the mitigation of pollutants in water. The second-order reaction rate constant (kO3) of ozone (O3) with compounds is essential for measuring their reactivity toward O3 and understanding their fate during ozonation. However, there is a huge gap between the number of existing chemicals and the available experimental kO3 values. Moreover, the reactivity of ionizable compounds with different ionization forms toward O3 may differ greatly. In this study, two quantitative structure activity relationship (QSAR) models for non-ionic and ionic species, are respectively established with partial least squares (PLS) and support vector machine (SVM) methods based on the large datasets (324 non-ionic states and 188 ionic states). These models exhibit good fitting ability (non-ionic model: R2tr > 0.760; ionic model: R2tr > 0.780), robustness (Q2CUM > 0.700), predictive performance (non-ionic model: R2ext > 0.760; ionic model: R2ext > 0.810) and wide applicability domain. The molecular parameters in two models are revealed to be significantly different, which may be attributed to the significant difference in molecular structures in two datasets and different reactivities of uncharged and charged states toward O3. Additionally, the overall kO3 for compounds at certain pH can be estimated by combining the two single QSAR models. These models and methods can become the effective tools for predicting the conversion rate of pollutants by O3 in the urban sewage and drinking water treatment.
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Affiliation(s)
- Xiao Zhang
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun 130117, China
| | - Shaochen Li
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun 130117, China
| | - Yandong Yang
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun 130117, China
| | - Yuanhui Zhao
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun 130117, China
| | - Jiao Qu
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun 130117, China
| | - Chao Li
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun 130117, China.
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41
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Qi Y, Cao H, Pan W, Wang C, Liang Y. The role of dissolved organic matter during Per- and Polyfluorinated Substance (PFAS) adsorption, degradation, and plant uptake: A review. JOURNAL OF HAZARDOUS MATERIALS 2022; 436:129139. [PMID: 35605500 DOI: 10.1016/j.jhazmat.2022.129139] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Revised: 05/08/2022] [Accepted: 05/10/2022] [Indexed: 06/15/2023]
Abstract
The negative effects of polyfluoroalkyl substances (PFAS) on the environment and health have recently attracted much attention. This article reviews the influence of soil- and water-derived dissolved organic matter (DOM) on the environmental fate of PFAS. In addition to being co-adsorped with PFAS to increase the adsorption capacity, DOM competes with PFAS for adsorption sites on the surface of the material, thereby reducing the removal rate of PFAS or increasing water solubility, which facilitates desorption of PFAS in the soil. It can quench some active species and inhibit the degradation of PFAS. In contrast, before DOM in water self-degrades, DOM has a greater promoting effect on the degradation of PFAS because DOM can complex with iron, iodine, among others, and act as an electron shuttle to enhance electron transfer. In soil aggregates, DOM can prevent microorganisms from being poisoned by direct exposure to PFAS. In addition, DOM increases the desorption of PFAS in plant root soil, affecting its bioavailability. In general, DOM plays a bidirectional role in adsorption, degradation, and plant uptake of PFAS, which depends on the types and functional groups of DOM. It is necessary to enhance the positive role of DOM in reducing the environmental risks posed by PFAS. In future, attention should be paid to the DOM-induced reduction of PFAS and development of a green and efficient continuous defluorination technology.
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Affiliation(s)
- Yuwen Qi
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China
| | - Huimin Cao
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China
| | - Weijie Pan
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China
| | - Cuiping Wang
- Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China.
| | - Yanna Liang
- Department of Environmental and Sustainable Engineering, University at Albany, SUNY, Albany, NY 12222, USA
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42
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Zhang M, Ruan J, Wang L, Zhao Z, Shao W, Li J, Chen Z, Gu C, Qiao W. MXene-like carbon sheet/ carbon nanotubes derived from metal-organic frameworks for efficient removal of tetracycline by non-radical dominated advanced oxidation processes. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2022.121851] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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43
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Li M, Jin YT, Cao DY, Yang LL, Yan JF, Zhang ZX, Liu Z, Huang LW, Zhou SQ, Cheng JL, Zhao Q, Zhao HM, Feng NX, Mo CH. Efficient decomposition of perfluorooctane sulfonate by electrochemical activation of peroxymonosulfate in aqueous solution: Efficacy, reaction mechanism, active sites, and application potential. WATER RESEARCH 2022; 221:118778. [PMID: 35752093 DOI: 10.1016/j.watres.2022.118778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 06/10/2022] [Accepted: 06/17/2022] [Indexed: 06/15/2023]
Abstract
The electrochemical oxidation method is a promising technology for the degradation of perfluorooctane sulfonate (PFOS). However, the elimination processes of PFOS are still unknown, including the electron transfer pathway, key reactive sites, and degradation mechanism. Here, we fabricated diatomite and cerium (Ce) co-modified Sb2O3 (D-Ce/Sb2O3) anode to realize efficient degradation of PFOS via peroxymonosulfate (PMS) activation. The transferred electron and the generated hydroxyl radical (•OH) can high-effectively decompose PFOS. The electron can be rapidly transferred from the highest occupied molecular orbital of the PFOS to the lowest unoccupied molecular orbital of the PMS via the D-Ce/Sb2O3 driven by a potential energy difference under electrochemical process. The active site of Ce-O in the D-Ce/Sb2O3 can greatly reduce the migration distance of the electron and the •OH, and thus improving the catalytic activity for degrading various organic micropollutants with high stability. In addition, the electrochemical process shows strong resistance and tolerance to the changing pH, inorganic ions, and organic matter. This study offers insights into the electron transfer pathway and PMS activation mechanism in PFOS removal via electrochemical oxidation, paving the way for its potential application in water purification.
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Affiliation(s)
- Meng Li
- Guangdong Provincial Research Center for Environment Pollution Control and Remediation Materials, College of Life Science and Technology, Jinan University, Guangzhou 510632, PR China; Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, PR China; College of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006, PR China.
| | - Yu-Ting Jin
- College of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006, PR China
| | - Dan-Yang Cao
- Guangdong Provincial Research Center for Environment Pollution Control and Remediation Materials, College of Life Science and Technology, Jinan University, Guangzhou 510632, PR China
| | - Ling-Ling Yang
- Guangdong Provincial Research Center for Environment Pollution Control and Remediation Materials, College of Life Science and Technology, Jinan University, Guangzhou 510632, PR China
| | - Jian-Fang Yan
- Guangdong Provincial Research Center for Environment Pollution Control and Remediation Materials, College of Life Science and Technology, Jinan University, Guangzhou 510632, PR China
| | - Zhao-Xin Zhang
- Thrust of Sustainable Energy & Environment, The Hong Kong University of Science and Technology (Guangzhou), Guangzhou 511458, PR China
| | - Zhang Liu
- Division of Environment and Sustainability, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, PR China
| | - Long-Wei Huang
- College of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006, PR China
| | - Shao-Qi Zhou
- College of Resources and Environmental Engineering, Guizhou University, 2708 Huaxi Road, Guiyang 550025, PR China.
| | - Ji-Liang Cheng
- Guangdong Provincial Research Center for Environment Pollution Control and Remediation Materials, College of Life Science and Technology, Jinan University, Guangzhou 510632, PR China
| | - Qinglan Zhao
- Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, PR China.
| | - Hai-Ming Zhao
- Guangdong Provincial Research Center for Environment Pollution Control and Remediation Materials, College of Life Science and Technology, Jinan University, Guangzhou 510632, PR China
| | - Nai-Xian Feng
- Guangdong Provincial Research Center for Environment Pollution Control and Remediation Materials, College of Life Science and Technology, Jinan University, Guangzhou 510632, PR China
| | - Ce-Hui Mo
- Guangdong Provincial Research Center for Environment Pollution Control and Remediation Materials, College of Life Science and Technology, Jinan University, Guangzhou 510632, PR China.
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44
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Fennell BD, Odorisio A, McKay G. Quantifying Hydrated Electron Transformation Kinetics in UV-Advanced Reduction Processes Using the Re-,UV Method. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:10329-10338. [PMID: 35791772 DOI: 10.1021/acs.est.2c02003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Ultraviolet advanced reduction processes (UV-ARP) have garnered significant attention recently for the degradation of several hard to treat contaminants, including recalcitrant per- and polyfluoroalkyl substances (PFAS). The rate of contaminant degradation in UV-ARP is directly related to the available hydrated electron concentration ([eaq-]). However, reports of [eaq-] and other parameters typically used to characterize photochemical systems are not widely reported in the UV-ARP literature. Deploying monochloroacetate as a probe compound, we developed a method (Re-,UV) to quantify the time-based hydrated electron concentration ([eaq]t) available for contaminant degradation relative to inputted UV fluence. Measured [eaq]t was then used to understand the impact of eaq- rate of formation and scavenging capacity on the degradation of two contaminants─nitrate and perfluorooctane sulfonate (PFOS)─in four source waters with varying background water quality. The results show that the long-term treatability of PFOS by UV-ARP is not significantly impacted by the initial eaq- scavenging conditions but rather is influenced by the presence of eaq- scavengers like dissolved organic carbon and bicarbonate. Lastly, using [eaq]t, degradation of nitrate and PFOS was modeled in the source waters. We demonstrate that the Re-,UV method provides an effective tool to assess UV-ARP treatment performance in a variety of source waters.
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Affiliation(s)
- Benjamin D Fennell
- Zachry Department of Civil & Environmental Engineering, Texas A&M University, College Station, Texas 77845, United States
| | - Adam Odorisio
- Zachry Department of Civil & Environmental Engineering, Texas A&M University, College Station, Texas 77845, United States
| | - Garrett McKay
- Zachry Department of Civil & Environmental Engineering, Texas A&M University, College Station, Texas 77845, United States
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45
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Wen Y, Rentería-Gómez Á, Day GS, Smith MF, Yan TH, Ozdemir ROK, Gutierrez O, Sharma VK, Ma X, Zhou HC. Integrated Photocatalytic Reduction and Oxidation of Perfluorooctanoic Acid by Metal-Organic Frameworks: Key Insights into the Degradation Mechanisms. J Am Chem Soc 2022; 144:11840-11850. [PMID: 35732040 DOI: 10.1021/jacs.2c04341] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The high porosity and tunability of metal-organic frameworks (MOFs) have made them an appealing group of materials for environmental applications. However, their potential in the photocatalytic degradation of per- and polyfluoroalkyl substances (PFAS) has been rarely investigated. Hereby, we demonstrate that over 98.9% of perfluorooctanoic acid (PFOA) was degraded by MIL-125-NH2, a titanium-based MOF, in 24 h under Hg-lamp irradiation. The MOF maintained its structural integrity and porosity after three cycles, as indicated by its crystal structure, surface area, and pore size distribution. Based on the experimental results and density functional theory (DFT) calculations, a detailed reaction mechanism of the chain-shortening and H/F exchange pathways in hydrated electron (eaq-)-induced PFOA degradation were revealed. Significantly, we proposed that the coordinated contribution of eaq- and hydroxyl radical (•OH) is vital for chain-shortening, highlighting the importance of an integrated system capable of both reduction and oxidation for efficient PFAS degradation in water. Our results shed light on the development of effective and sustainable technologies for PFAS breakdown in the environment.
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Affiliation(s)
- Yinghao Wen
- Department of Civil and Environmental Engineering, Texas A&M University, College Station, Texas 77843, United States
| | - Ángel Rentería-Gómez
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Gregory S Day
- Framergy Inc., 800 Raymond Stotzer Pkwy, College Station, Texas 77945, United States
| | - Mallory F Smith
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Tian-Hao Yan
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Ray Osman K Ozdemir
- Framergy Inc., 800 Raymond Stotzer Pkwy, College Station, Texas 77945, United States
| | - Osvaldo Gutierrez
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Virender K Sharma
- Program for the Environment and Sustainability, Department of Environmental and Occupational Health, Texas A&M University, College Station, Texas 77843, United States
| | - Xingmao Ma
- Department of Civil and Environmental Engineering, Texas A&M University, College Station, Texas 77843, United States
| | - Hong-Cai Zhou
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States.,Department of Materials Science and Engineering, Texas A&M University, College Station, Texas 77843, United States
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46
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Fennell B, Mezyk SP, McKay G. Critical Review of UV-Advanced Reduction Processes for the Treatment of Chemical Contaminants in Water. ACS ENVIRONMENTAL AU 2022; 2:178-205. [PMID: 37102145 PMCID: PMC10114900 DOI: 10.1021/acsenvironau.1c00042] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
Abstract
UV-advanced reduction processes (UV-ARP) are an advanced water treatment technology characterized by the reductive transformation of chemical contaminants. Contaminant abatement in UV-ARP is most often accomplished through reaction with hydrated electrons (eaq -) produced from UV photolysis of chemical sensitizers (e.g., sulfite). In this Review, we evaluate the photochemical kinetics, substrate scope, and optimization of UV-ARP. We find that quantities typically reported in photochemical studies of natural and engineered systems are under-reported in the UV-ARP literature, especially the formation rates, scavenging capacities, and concentrations of key reactive species like eaq -. The absence of these quantities has made it difficult to fully evaluate the impact of operating conditions and the role of water matrix components on the efficiencies of UV-ARP. The UV-ARP substrate scope is weighted heavily toward contaminant classes that are resistant to degradation by advanced oxidation processes, like oxyanions and per- and polyfluoroalkyl substances. Some studies have sought to optimize the UV-ARP treatment of these contaminants; however, a thorough evaluation of the impact of water matrix components like dissolved organic matter on these optimization strategies is needed. Overall, the data compilation, analysis, and research recommendations provided in this Review will assist the UV-ARP research community in future efforts toward optimizing UV-ARP systems, modeling the eaq --based chemical transformation kinetics, and developing new UV-ARP systems.
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Affiliation(s)
- Benjamin
D. Fennell
- Zachry
Department of Civil & Environmental Engineering, Texas A&M University, College Station, Texas 77843, United States
| | - Stephen P. Mezyk
- Department
of Chemistry and Biochemistry, California
State University, Long Beach, Long Beach, California 90840, United States
| | - Garrett McKay
- Zachry
Department of Civil & Environmental Engineering, Texas A&M University, College Station, Texas 77843, United States
- . Phone: 979-458-6540
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47
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Li M, Jin YT, Yan JF, Liu Z, Feng NX, Han W, Huang LW, Li QK, Yeung KL, Zhou SQ, Mo CH. Exploration of perfluorooctane sulfonate degradation properties and mechanism via electron-transfer dominated radical process. WATER RESEARCH 2022; 215:118259. [PMID: 35294910 DOI: 10.1016/j.watres.2022.118259] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 02/27/2022] [Accepted: 03/05/2022] [Indexed: 06/14/2023]
Abstract
Polyfluoroalkyl and perfluoroalkyl chemicals (PFCs) widely used in lubricants, surfactant, textiles, paper coatings, cosmetics, and fire-fighting foams can release a large deal of organics contaminants into wastewater and pose great risks to the health of humans and eco-environments. Although advanced oxidation processes can effectively deconstruct various organic contaminants via reactive radicals, the stable structure of PFCs makes it difficult to be degraded. Here, we confirm that electrochemical oxidation process coupled with peroxymonosulfate (PMS) reaction can efficiently destroy stable structure of PFCs via electron transfer and meanwhile completely degrade PFCs via generated active radicals. We further studies via capturing and scavenging radicals, and DFT calculations find that electron hydroxyl radials play a dominant role in degrading PFCs. Based on the calculations of adsorption energy and molecular orbital energy we further demonstrate that many active sites on the surface of Ti4O7 (1 0 4) plane can rapidly take part in electrochemical reaction for generating radials and removing organic contaminants. These results give a promising insight towards high-effective and deep degradation of PFCs via electrochemical reaction coupled with advanced oxidation processes, as well as providing guidance and technical support for the remove of multiple organic contaminants.
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Affiliation(s)
- Meng Li
- Guangdong Provincial Research Center for Environment Pollution Control and Remediation Materials, College of Life Science and Technology, Jinan University, Guangzhou 510632, PR China; Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, PR. China
| | - Yu-Ting Jin
- School of Environmental and Energy, Guangzhou Higher Education Mega Center, South China University of Technology, Guangzhou 510006, PR China
| | - Jian-Fang Yan
- Guangdong Provincial Research Center for Environment Pollution Control and Remediation Materials, College of Life Science and Technology, Jinan University, Guangzhou 510632, PR China
| | - Zhang Liu
- Division of Environment and Sustainability, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, PR. China
| | - Nai-Xian Feng
- Guangdong Provincial Research Center for Environment Pollution Control and Remediation Materials, College of Life Science and Technology, Jinan University, Guangzhou 510632, PR China
| | - Wei Han
- Division of Environment and Sustainability, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, PR. China
| | - Long-Wei Huang
- School of Environmental and Energy, Guangzhou Higher Education Mega Center, South China University of Technology, Guangzhou 510006, PR China
| | - Qin-Ke Li
- Guangdong Provincial Research Center for Environment Pollution Control and Remediation Materials, College of Life Science and Technology, Jinan University, Guangzhou 510632, PR China
| | - King-Lun Yeung
- Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, PR. China; Division of Environment and Sustainability, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, PR. China.
| | - Shao-Qi Zhou
- School of Environmental and Energy, Guangzhou Higher Education Mega Center, South China University of Technology, Guangzhou 510006, PR China; College of Resources and Environmental Engineering, Guizhou University, 2708 Huaxi Road, Guiyang 550025, PR China..
| | - Ce-Hui Mo
- Guangdong Provincial Research Center for Environment Pollution Control and Remediation Materials, College of Life Science and Technology, Jinan University, Guangzhou 510632, PR China.
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48
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Wacławek S, Ma X, Sharma VK, Xiao R, O'Shea KE, Dionysiou DD. Making waves: Defining advanced reduction technologies from the perspective of water treatment. WATER RESEARCH 2022; 212:118101. [PMID: 35092911 DOI: 10.1016/j.watres.2022.118101] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Revised: 12/21/2021] [Accepted: 01/16/2022] [Indexed: 06/14/2023]
Abstract
Studies related to advanced reduction technologies (ARTs) have grown exponentially since the term was first coined in 2013. Despite recent interests in ARTs, the conditions and requirements for these processes have yet to be defined and clarifed. In comparision to well defined advanced oxidation technologies/processes (AOTs/AOPs) which involve the generation of hydroxyl radical as the common characteristic, ARTs function by electron donation from a variety of reducing agents and activators. Based on an extensive literature review, we propose that ARTs be defined as processes employing strong chemical reductants with E° ≤ -2.3 V vs. normal hydrogen electrode at 25 ºC. While extensive studies have revealed critical fundamental details of AOTs/AOPs mediated processes, there are still significant gaps in elucidation of the mechanistic details of reductive degradation/transformation of highly toxic compounds by ARTs. A significant number of pollutants and toxins resistant to AOTs/AOPs treatment are effectively degraded by ARTs. A great leap is needed on understanding ARTs to fully utilize their potential to efficiently remediate recalcitrant compounds of different sources and structures.
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Affiliation(s)
- Stanisław Wacławek
- Institute for Nanomaterials, Advanced Technologies and Innovation, Technical University of Liberec, Studentská 1402/2, 461 17, Liberec 1, Czech Republic.
| | - Xingmao Ma
- Department of Civil and Environmental Engineering, Texas A&M University, College Station, TX 77843, USA.
| | - Virender K Sharma
- Department of Environmental and Occupational Health, School of Public Health, Program for the Environment and Sustainability, Texas A&M University, 212 Adriance Lab Rd., 1266 TAMU, College Station, TX 77843, USA.
| | - Ruiyang Xiao
- Institute of Environmental Engineering, School of Metallurgy and Environment, Central South University, Changsha 410083, China.
| | - Kevin E O'Shea
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, USA.
| | - Dionysios D Dionysiou
- Department of Chemical and Environmental Engineering (ChEE), Environmental Engineering and Science Program, University of Cincinnati, Cincinnati, OH 45221-0012, USA.
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49
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Liu Z, Chen Z, Gao J, Yu Y, Men Y, Gu C, Liu J. Accelerated Degradation of Perfluorosulfonates and Perfluorocarboxylates by UV/Sulfite + Iodide: Reaction Mechanisms and System Efficiencies. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:3699-3709. [PMID: 35226468 PMCID: PMC9481055 DOI: 10.1021/acs.est.1c07608] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The addition of iodide (I-) in the UV/sulfite system (UV/S) significantly accelerated the reductive degradation of perfluorosulfonates (PFSAs, CnF2n+1SO3-) and perfluorocarboxylates (PFCAs, CnF2n+1COO-). Using the highly recalcitrant perfluorobutane sulfonate (C4F9SO3-) as a probe, we optimized the UV/sulfite + iodide system (UV/S + I) to degrade n = 1-7 PFCAs and n = 4, 6, 8 PFSAs. In general, the kinetics of per- and polyfluoroalkyl substance (PFAS) decay, defluorination, and transformation product formations in UV/S + I were up to three times faster than those in UV/S. Both systems achieve a similar maximum defluorination. The enhanced reaction rates and optimized photoreactor settings lowered the EE/O for PFCA degradation below 1.5 kW h m-3. The relatively high quantum yield of eaq- from I- made the availability of hydrated electrons (eaq-) in UV/S + I and UV/I two times greater than that in UV/S. Meanwhile, the rapid scavenging of reactive iodine species by SO32- made the lifetime of eaq- in UV/S + I eight times longer than that in UV/I. The addition of I- also substantially enhanced SO32- utilization in treating concentrated PFAS. The optimized UV/S + I system achieved >99.7% removal of most PFSAs and PFCAs and >90% overall defluorination in a synthetic solution of concentrated PFAS mixtures and NaCl. We extended the discussion over molecular transformation mechanisms, development of PFAS degradation technologies, and the fate of iodine species.
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Affiliation(s)
- Zekun Liu
- Department
of Chemical & Environmental Engineering, University of California, Riverside, California 92521, United States
| | - Zhanghao Chen
- State
Key Laboratory of Pollution Control and Resource Reuse, School of
the Environment, Nanjing University, Nanjing 210023, Jiangsu, China
| | - Jinyu Gao
- Department
of Chemical & Environmental Engineering, University of California, Riverside, California 92521, United States
| | - Yaochun Yu
- Department
of Chemical & Environmental Engineering, University of California, Riverside, California 92521, United States
- Department
of Civil & Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Yujie Men
- Department
of Chemical & Environmental Engineering, University of California, Riverside, California 92521, United States
- Department
of Civil & Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Cheng Gu
- State
Key Laboratory of Pollution Control and Resource Reuse, School of
the Environment, Nanjing University, Nanjing 210023, Jiangsu, China
| | - Jinyong Liu
- Department
of Chemical & Environmental Engineering, University of California, Riverside, California 92521, United States
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50
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Gao J, Liu Z, Bentel MJ, Yu Y, Men Y, Liu J. Defluorination of Omega-Hydroperfluorocarboxylates (ω-HPFCAs): Distinct Reactivities from Perfluoro and Fluorotelomeric Carboxylates. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:14146-14155. [PMID: 34618445 DOI: 10.1021/acs.est.1c04429] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Omega-hydroperfluorocarboxylates (ω-HPFCAs, HCF2-(CF2)n-1-COO-) are commercially available in bulk quantities and have been applied in agrochemicals, fluoropolymer production, and semiconductor coating. In this study, we used kinetic measurements, theoretical calculations, model compound experiments, and transformation product analyses to reveal novel mechanistic insights into the reductive and oxidative transformation of ω-HPFCAs. Like perfluorocarboxylates (PFCAs, CF3-(CF2)n-1-COO-), the direct linkage between HCnF2n- and -COO- enables facile degradation under UV/sulfite treatment. To our surprise, the presence of the H atom on the remote carbon makes ω-HPFCAs more susceptible than PFCAs to decarboxylation (i.e., yielding shorter-chain ω-HPFCAs) and less susceptible to hydrodefluorination (i.e., H/F exchange). Like fluorotelomer carboxylates (FTCAs, CnF2n+1-CH2CH2-COO-), the C-H bond in HCF2-(CF2)n-1-COO- allows hydroxyl radical oxidation and limited defluorination. While FTCAs yielded PFCAs in all chain lengths, ω-HPFCAs only yielded -OOC-(CF2)n-1-COO- (major) and -OOC-(CF2)n-2-COO- (minor) due to the unfavorable β-fragmentation pathway that shortens the fluoroalkyl chain. We also compared two treatment sequences-UV/sulfite followed by heat/persulfate and the reverse-toward complete defluorination of ω-HPFCAs. The findings will benefit the treatment and monitoring of H-containing per- and polyfluoroalkyl substance (PFAS) pollutants as well as the design of future fluorochemicals.
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Affiliation(s)
- Jinyu Gao
- Department of Chemical & Environmental Engineering, University of California, Riverside, California 92521, United States
| | - Zekun Liu
- Department of Chemical & Environmental Engineering, University of California, Riverside, California 92521, United States
| | - Michael J Bentel
- Department of Chemical & Environmental Engineering, University of California, Riverside, California 92521, United States
| | - Yaochun Yu
- Department of Chemical & Environmental Engineering, University of California, Riverside, California 92521, United States
- Department of Civil & Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Yujie Men
- Department of Chemical & Environmental Engineering, University of California, Riverside, California 92521, United States
- Department of Civil & Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Jinyong Liu
- Department of Chemical & Environmental Engineering, University of California, Riverside, California 92521, United States
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