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Ma J, Li Y, Zhang X, Li J, Lin Q, Zhu Y, Ruan Z, Ni Z, Qiu R. Modified nano zero-valent iron coupling microorganisms to degrade BDE-209: Degradation pathways and microbial responses. JOURNAL OF HAZARDOUS MATERIALS 2024; 465:133378. [PMID: 38160554 DOI: 10.1016/j.jhazmat.2023.133378] [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: 08/14/2023] [Revised: 12/24/2023] [Accepted: 12/25/2023] [Indexed: 01/03/2024]
Abstract
Polybrominated diphenyl ethers (PBDEs) in soil and groundwater have garnered considerable attention owing to the significant bioaccumulation potential and toxicity. Currently, the coupling treatment method of nano zero-valent iron (nZVI) with dehalogenation microorganisms is a research hotspot in the field of PBDE degradation. In this study, various systems were established within anaerobic environments, including the nZVI-only system, microorganism-only system, and the nZVI + microorganisms system. The aim was to investigate the degradation pathway of BDE-209 and elucidate the degradation mechanism within the coupled system. The results indicated that the degradation efficiency of the coupled system was better than that of the nZVI-only or microorganism-only system. Two modified nZVI (carboxymethyl cellulose and polyacrylamide) were prepared to improve the coupling degradation efficiency. CMC-nZVI showed the highest stability, and the coupled system consisting of microorganisms and CMC-nZVI showed the best degradation effect among all of the systems in this study, reaching 89.53% within 30 days. Furthermore, 22 intermediate products were detected in the coupling systems. Notably, changing the inoculation time did not significantly improve the degradation effect. The expression changes of the two reductive dehalogenase genes, e.g. TceA and Vcr, reflected the stress response and self-recovery ability of the dehalogenating bacteria, indicating such genes can be used as biomarker for evaluating the degradation performance of the coupling system. These findings provide a better understanding about the mechanism of coupling debromination process and the direction for the optimization and on-site repair of coupled systems.
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Affiliation(s)
- Jing Ma
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
| | - Yingping Li
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
| | - Xing Zhang
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
| | - Jingjing Li
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
| | - Qingqi Lin
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
| | - Yanping Zhu
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
| | - Zhepu Ruan
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
| | - Zhuobiao Ni
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China.
| | - Rongliang Qiu
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China; School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China.
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2
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Liang J, Liu H, Zou M, Tao X, Zhou J, Dang Z, Lu G. Degradation efficiency and mechanism of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) by thermally activated persulfate system. CHEMOSPHERE 2023; 325:138396. [PMID: 36931399 DOI: 10.1016/j.chemosphere.2023.138396] [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: 01/08/2023] [Revised: 02/27/2023] [Accepted: 03/11/2023] [Indexed: 06/18/2023]
Abstract
Polybrominated diphenyl ethers (PBDEs) as a typical brominated flame retardant (BFR) have attracted worldwide attention due to the high environmental risk and resistance to conventional remediation processes. In this study, thermally activated persulfate (TAP) process was applied to degrade 2,2',4,4'-tetrabromodiphenyl ether (BDE-47), which is the most toxic and representative PBDEs in e-waste dismantling sites. Impact factors such as PDS dosage, heating temperature, and initial pH were evaluated. Results showed that BDE-47 can be 100% degraded within 180 min under the condition of PDS:BDE-47 = 1000:1, 60 °C, and pH = 7. Quenching experiments combined with EPR analysis further proved the important role of SO4·- in oxidating BDE-47. According to high-resolution mass spectrometry (HRMS) analysis, only one oxidation product of low toxicity was detected during the oxidation process. Theoretical calculations further revealed that the oxidation process mainly involved radical attack at C-Br bond, cleavage of C-Br bond, and fission of ether bond, and HSO4· may also play an important role in BDE-47 degradation in TAP system. In addition, TAP system exhibited universality as all selected PBDE congeners can be degraded, and the degradation rate of PBDEs was greatly affected by the number of substituted Br atoms in a negative trend. Overall, these findings indicate that TAP can be applied as an effective method for removal of PBDEs, and we provide a new insight for the practical application of TAP technology in BDE-47 degradation from experimental and theoretical aspects.
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Affiliation(s)
- Jiahao Liang
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China
| | - He Liu
- South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, 510655, China.
| | - Mengyao Zou
- College of Resources and Environment, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China
| | - Xueqin Tao
- College of Resources and Environment, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China
| | - Jiangmin Zhou
- College of Life and Environmental Sciences, Wenzhou University, Wenzhou, 325035, China
| | - Zhi Dang
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, South China University of Technology, Guangzhou, 510006, China; Guangdong Provincial Key Lab of Solid Wastes Pollution Control and Recycling, South China University of Technology, Guangzhou, 510006, China
| | - Guining Lu
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, South China University of Technology, Guangzhou, 510006, China.
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3
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Lei M, Tang Y, Zhu L, Tang H. Chemical reductive technologies for the debromination of polybrominated diphenyl ethers: A review. J Environ Sci (China) 2023; 127:42-59. [PMID: 36522073 DOI: 10.1016/j.jes.2022.05.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 05/06/2022] [Accepted: 05/10/2022] [Indexed: 06/17/2023]
Abstract
Polybrominated diphenyl ethers (PBDEs) are widely used as brominated flame retardants, which had attracted amounts of attention due to their harmful characteristics of high toxicity, environmental persistence and potential bioaccumulation. Many chemical reductive debromination technologies have been developed for the debromination of PBDEs, including photolysis, photocatalysis, electrocatalysis, zero-valent metal reduction, chemically catalytic reduction and mechanochemical method. This review aims to provide information about the degradation thermodynamics and kinetics of PBDEs and summarize the degradation mechanisms in various systems. According to the comparative analysis, the rapid debromination to generate bromine-free products in an electron-transfer process, of which photocatalysis is a representative one, is found to be relatively difficult, because the degradation rate of PBDEs depended on the Br-rich phenyl ring with the lowest unoccupied molecular orbital (LUMO) localization. On the contrary, the complete debromination occurs easily in other systems with active hydrogen atoms as the main reactive species, such as chemically catalytic reduction systems. The review provides the knowledge on the chemical reductive technique of PBDEs, which would greatly help not only clarify the degradation mechanism but also design the more efficient system for the rapid and deep debromination of PBDEs in the future.
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Affiliation(s)
- Ming Lei
- College of Resources and Environmental Science, South-Central Minzu University, Wuhan 430074, China
| | - Yao Tang
- College of Resources and Environmental Science, South-Central Minzu University, Wuhan 430074, China
| | - Lihua Zhu
- School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
| | - Heqing Tang
- College of Resources and Environmental Science, South-Central Minzu University, Wuhan 430074, China.
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Ighalo JO, Yap PS, Iwuozor KO, Aniagor CO, Liu T, Dulta K, Iwuchukwu FU, Rangabhashiyam S. Adsorption of persistent organic pollutants (POPs) from the aqueous environment by nano-adsorbents: A review. ENVIRONMENTAL RESEARCH 2022; 212:113123. [PMID: 35339467 DOI: 10.1016/j.envres.2022.113123] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 03/07/2022] [Accepted: 03/11/2022] [Indexed: 06/14/2023]
Abstract
The intensification of urbanisation and industrial activities significantly exacerbates the distribution of toxic contaminations into the aqueous environment. Persistent organic pollutants (POPs) have received considerable attention in the past few decades because of their persistence, long-distance migration, potential bioaccumulation, latent toxicity for humans and wildlife. There is no doubt that POPs cause serious effects on the global ecosystem. Therefore, it is necessary to develop a simple, safe and sustainable approach to remove POPs from water bodies. Among other conventional techniques, the adsorption process has proven to be a more effective method for eliminating POPs and to a larger extent meet discharge regulations. Nanomaterials can effectively adsorb POPs from aqueous solutions. For most POPs, a >70% adsorptive removal efficiency was achieved. The major mechanisms for POPS uptake by nano-adsorbents includes electrostatic interaction, hydrophobic (van der Waals, π-π and electron donor-acceptor) interaction and hydrogen bonding. Nano-adsorbent can sustain a >90% POPs adsorptive removal for about 3 cycles and reuseable for up to 10 cycles. Challenges around adsorbent ecotoxicity and safe disposal were also discussed. The present review evaluated recent research outcomes on nanomaterials that are employed to remove POPs in water systems.
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Affiliation(s)
- Joshua O Ighalo
- Department of Chemical Engineering, Nnamdi Azikiwe University, P. M. B., 5025, Awka, Nigeria; Department of Chemical Engineering, University of Ilorin, P. M. B., 1515, Ilorin, Nigeria.
| | - Pow-Seng Yap
- Department of Civil Engineering, Xi'an Jiaotong-Liverpool University, Suzhou, 215123, China.
| | - Kingsley O Iwuozor
- Department of Pure and Industrial Chemistry, Nnamdi Azikiwe University, P. M. B., 5025, Awka, Nigeria
| | - Chukwunonso O Aniagor
- Department of Chemical Engineering, Nnamdi Azikiwe University, P. M. B., 5025, Awka, Nigeria
| | - Tianqi Liu
- Department of Civil Engineering, Xi'an Jiaotong-Liverpool University, Suzhou, 215123, China
| | - Kanika Dulta
- Faculty of Applied Sciences and Biotechnology, Shoolini University, Solan, 173229, India
| | - Felicitas U Iwuchukwu
- Department of Chemical Engineering, Nnamdi Azikiwe University, P. M. B., 5025, Awka, Nigeria
| | - Selvasembian Rangabhashiyam
- Department of Biotechnology, School of Chemical and Biotechnology, SASTRA Deemed University, Thanjavur, 613401, Tamil Nadu, India.
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5
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Nair KM, Kumaravel V, Pillai SC. Carbonaceous cathode materials for electro-Fenton technology: Mechanism, kinetics, recent advances, opportunities and challenges. CHEMOSPHERE 2021; 269:129325. [PMID: 33385665 DOI: 10.1016/j.chemosphere.2020.129325] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 12/10/2020] [Accepted: 12/13/2020] [Indexed: 06/12/2023]
Abstract
Electro-Fenton (EF) technique has gained significant attention in recent years owing to its high efficiency and environmental compatibility for the degradation of organic pollutants and contaminants of emerging concern (CECs). The efficiency of an EF reaction relies primarily on the formation of hydrogen peroxide (H2O2) via 2e─ oxygen reduction reaction (ORR) and the generation of hydroxyl radicals (●OH). This could be achieved through an efficient cathode material which operates over a wide pH range (pH 3-9). Herein, the current progresses on the advancements of carbonaceous cathode materials for EF reactions are comprehensively reviewed. The insights of various materials such as, activated carbon fibres (ACFs), carbon/graphite felt (CF/GF), carbon nanotubes (CNTs), graphene, carbon aerogels (CAs), ordered mesoporous carbon (OMCs), etc. are discussed inclusively. Transition metals and hetero atoms were used as dopants to enhance the efficiency of homogeneous and heterogeneous EF reactions. Iron-functionalized cathodes widened the working pH window (pH 1-9) and limited the energy consumption. The mechanism, reactor configuration, and kinetic models, are explained. Techno economic analysis of the EF reaction revealed that the anode and the raw materials contributed significantly to the overall cost. It is concluded that most reactions follow pseudo-first order kinetics and rotating cathodes provide the best H2O2 production efficiency in lab scale. The challenges, future prospects and commercialization of EF reaction for wastewater treatment are also discussed.
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Affiliation(s)
- Keerthi M Nair
- Centre for Precision Engineering, Materials and Manufacturing Research (PEM), Institute of Technology, Sligo, F91 YW50, Ireland; Nanotechnology and Bio-Engineering Research Group, Department of Environmental Science, Institute of Technology, Sligo, F91 YW50, Ireland
| | - Vignesh Kumaravel
- Centre for Precision Engineering, Materials and Manufacturing Research (PEM), Institute of Technology, Sligo, F91 YW50, Ireland; Nanotechnology and Bio-Engineering Research Group, Department of Environmental Science, Institute of Technology, Sligo, F91 YW50, Ireland
| | - Suresh C Pillai
- Centre for Precision Engineering, Materials and Manufacturing Research (PEM), Institute of Technology, Sligo, F91 YW50, Ireland; Nanotechnology and Bio-Engineering Research Group, Department of Environmental Science, Institute of Technology, Sligo, F91 YW50, Ireland.
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6
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Yao B, Luo Z, Zhi D, Hou D, Luo L, Du S, Zhou Y. Current progress in degradation and removal methods of polybrominated diphenyl ethers from water and soil: A review. JOURNAL OF HAZARDOUS MATERIALS 2021; 403:123674. [PMID: 33264876 DOI: 10.1016/j.jhazmat.2020.123674] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 08/04/2020] [Accepted: 08/06/2020] [Indexed: 06/12/2023]
Abstract
The widespread of polybrominated diphenyl ethers (PBDEs) in the environment has caused rising concerns, and it is an urgent endeavor to find a proper way for PBDEs remediation. Various techniques such as adsorption, hydrothermal and thermal treatment, photolysis, photocatalytic degradation, reductive debromination, advanced oxidation processes (AOPs) and biological degradation have been developed for PBDEs decontamination. A comprehensive review of different PBDEs remediation techniques is urgently needed. This work focused on the environmental source and occurrence of PBDEs, their removal and degradation methods from water and soil, and prospects for PBDEs remediation techniques. According to the up-to-date literature obtained from Web of Science, it could be concluded that (i) photocatalysis and photocatalytic degradation is the most widely reported method for PBDEs remediation, (ii) BDE-47 and BDE-209 are the most investigated PBDE congeners, (iii) considering the recalcitrance nature of PBDEs and more toxic intermediates could be generated because of incomplete degradation, the combination of different techniques is the most potential solution for PBDEs removal, (iv) further researches about the development of novel and effective PBDEs remediation techniques are still needed. This review provides the latest knowledge on PBDEs remediation techniques, as well as future research needs according to the up-to-date literature.
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Affiliation(s)
- Bin Yao
- Hunan International Scientific and Technological Cooperation Base of Agricultural Typical Pollution Remediation and Wetland Protection, College of Resources and Environment, Hunan Agricultural University, Changsha, 410128, China
| | - Zirui Luo
- Hunan International Scientific and Technological Cooperation Base of Agricultural Typical Pollution Remediation and Wetland Protection, College of Resources and Environment, Hunan Agricultural University, Changsha, 410128, China
| | - Dan Zhi
- Hunan International Scientific and Technological Cooperation Base of Agricultural Typical Pollution Remediation and Wetland Protection, College of Resources and Environment, Hunan Agricultural University, Changsha, 410128, China
| | - Dongmei Hou
- Hunan International Scientific and Technological Cooperation Base of Agricultural Typical Pollution Remediation and Wetland Protection, College of Resources and Environment, Hunan Agricultural University, Changsha, 410128, China
| | - Lin Luo
- Hunan International Scientific and Technological Cooperation Base of Agricultural Typical Pollution Remediation and Wetland Protection, College of Resources and Environment, Hunan Agricultural University, Changsha, 410128, China
| | - Shizhi Du
- Hunan International Scientific and Technological Cooperation Base of Agricultural Typical Pollution Remediation and Wetland Protection, College of Resources and Environment, Hunan Agricultural University, Changsha, 410128, China
| | - Yaoyu Zhou
- Hunan International Scientific and Technological Cooperation Base of Agricultural Typical Pollution Remediation and Wetland Protection, College of Resources and Environment, Hunan Agricultural University, Changsha, 410128, China.
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7
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Maddela NR, Venkateswarlu K, Kakarla D, Megharaj M. Inevitable human exposure to emissions of polybrominated diphenyl ethers: A perspective on potential health risks. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 266:115240. [PMID: 32698055 DOI: 10.1016/j.envpol.2020.115240] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Revised: 07/10/2020] [Accepted: 07/10/2020] [Indexed: 05/24/2023]
Abstract
Polybrominated diphenyl ethers (PBDEs) serve as flame retardants in many household materials such as electrical and electronic devices, furniture, textiles, plastics, and baby products. Though the use of PBDEs like penta-, octa- and deca-BDE greatly reduces the fire damage, indoor pollution by these toxic emissions is ever-growing. In fact, a boom in the global market projections of PBDEs threatens human health security. Therefore, efforts are made to minimize PBDEs pollution in USA and Europe by encouraging voluntary phasing out of the production or imposing compelled regulations through Stockholm Convention, but >500 kilotons of PBDEs still exist globally. Both 'environmental persistence' and 'bioaccumulation tendencies' are the hallmarks of PBDE toxicities; however, both these issues concerning household emissions of PBDEs have been least addressed theoretically or practically. Critical physiological functions, lipophilicity and toxicity, trophic transfer and tissue specificities are of utmost importance in the benefit/risk assessments of PBDEs. Since indoor debromination of deca-BDE often yields many products, a better understanding on their sorption propensity, environmental fate and human toxicities is critical in taking rigorous measures on the ever-growing global deca-BDE market. The data available in the literature on human toxicities of PBDEs have been validated following meta-analysis. In this direction, the intent of the present review was to provide a critical evaluation of the key aspects like compositional patterns/isomer ratios of PBDEs implicated in bioaccumulation, indoor PBDE emissions versus human exposure, secured technologies to deal with the toxic emissions, and human toxicity of PBDEs in relation to the number of bromine atoms. Finally, an emphasis has been made on the knowledge gaps and future research directions related to endurable flame retardants which could fit well into the benefit/risk strategy.
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Affiliation(s)
- Naga Raju Maddela
- Instituto de Investigación, Universidad Técnica de Manabí, Portoviejo, 130105, Ecuador; Facultad la Ciencias la Salud, Universidad Técnica de Manabí, Portoviejo, 130105, Ecuador
| | - Kadiyala Venkateswarlu
- Formerly Department of Microbiology, Sri Krishnadevaraya University, Anantapuramu, 515003, India
| | - Dhatri Kakarla
- University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Mallavarapu Megharaj
- Global Centre for Environmental Remediation (GCER), Cooperative Research Centre for Contamination Assessment and Remediation of the Environment (CRC CARE), The University of Newcastle, Callaghan, NSW, 2308, Australia.
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Seo YD, Oh SY, Rajagopal R, Ryu KS. FeS-biochar and Zn(0)-biochar for remediation of redox-reactive contaminants. RSC Adv 2020; 10:30203-30213. [PMID: 35518218 PMCID: PMC9056297 DOI: 10.1039/d0ra05571a] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 08/06/2020] [Indexed: 01/26/2023] Open
Abstract
To enhance the removal of redox-reactive contaminants, biochars including FeS and Zn(0) were developed via pyrolysis. These biochars significantly promoted the removal of 2,4-dichlorophenol (DCP) by means of sorption and reduction. Compared to direct reduction with FeS and Zn(0), the formation of reduction intermediates and product was enhanced from 21% and 22% of initial DCP concentration to 41% and 52%, respectively. 2,4-Dinitrotoluene (DNT), chromate (CrO42−) and selenate (SeO42−) were also reductively transformed to reduction products (e.g., 2,4-diaminotoluene [DAT], Cr3+, and selenite [SeO32−]) after they sorbed onto the biochars including FeS and Zn(0). Mass recovery as DAT, Cr3+ and selenite was 4–20%, 1–3%, and 10–30% under the given conditions. Electrochemical and X-ray analyses confirmed the reduction capability of the biochars including FeS and Zn(0). Fe and S in the FeS–biochar did not effectively promote the reductive transformation of the contaminants. Contrastingly, the stronger reducer Zn(0) yielded faster reductive transformation of contaminants over the Zn(0)-containing biochar, while not releasing high concentrations of Zn2+ into the aqueous phase. Our results suggest that biochars including Zn(0) may be suitable as dual sorbents/reductants to remediate redox-reactive contaminants in natural environments. To enhance the removal of redox-reactive contaminants, biochars including FeS and Zn(0) were developed via pyrolysis.![]()
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Affiliation(s)
- Yong-Deuk Seo
- Department of Civil and Environmental Engineering, University of Ulsan 93 Daehak-ro, Nam-gu Ulsan 44610 South Korea +82-52-259-2629 +82-52-259-2752
| | - Seok-Young Oh
- Department of Civil and Environmental Engineering, University of Ulsan 93 Daehak-ro, Nam-gu Ulsan 44610 South Korea +82-52-259-2629 +82-52-259-2752
| | - Rajesh Rajagopal
- Department of Chemistry, University of Ulsan Ulsan 44610 South Korea
| | - Kwang-Sun Ryu
- Department of Chemistry, University of Ulsan Ulsan 44610 South Korea
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9
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Xu Y, Liang C, Zhang T, Tao X, Wang R, Huang K, Pan Z, Dang Z, Yin H, Lu G. Debromination of polybrominated diphenyl ethers (PBDEs) by palladized zerovalent zinc particles: Influence factors, pathways and mechanism. CHEMOSPHERE 2020; 253:126726. [PMID: 32302906 DOI: 10.1016/j.chemosphere.2020.126726] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 02/26/2020] [Accepted: 04/05/2020] [Indexed: 06/11/2023]
Abstract
We synthesized a novel material, namely palladized zero-valent zinc (Pd/ZVZ), and investigated its efficiency for the degradation of polybrominated diphenyl ethers (PBDEs). The plated Pd significantly enhances the degradation rate of PBDEs by ZVZ at the optimum loading of 1% by weight. In the Pd/ZVZ system, very few lower BDEs were accumulated during the degradation of 2,2',4,4'- tetrabromodiphenyl ether (BDE-47) and the final product is diphenyl ether, whereas the ZVZ system only debrominates BDE-47 to di-BDE and further debromination becomes very difficult. The degradation rates of BDEs by ZVZ greatly decreased with decreased bromination level, while in Pd/ZVZ system, the degradation rates of PBDEs did not show a significant difference. These indicate different mechanisms. This was confirmed by investigating the debromination pathways of the PBDEs in both systems. We determined that a H-transfer was the dominant mechanism in the Pd/ZVZ system. In addition, the reactivity of Pd/ZVZ to BDE-47 is pH-independent, which has a great advantage for various applications over ZVZ alone. Our study provides a new approach for the remediation of the PBDEs pollution.
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Affiliation(s)
- Yongye Xu
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China
| | - Chenghao Liang
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China
| | - Taiping Zhang
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou, 510006, China.
| | - Xueqin Tao
- School of Environmental Science and Engineering, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China
| | - Rui Wang
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China
| | - Kaibo Huang
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China
| | - Zhaoxi Pan
- School of Environmental Science and Engineering, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China
| | - Zhi Dang
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou, 510006, China
| | - Hua Yin
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou, 510006, China
| | - Guining Lu
- School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou, 510006, China.
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10
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Ranjbar Jafarabadi A, Dashtbozorg M, Raudonytė-Svirbutavičienė E, Riyahi Bakhtiari A. First report on polybrominated diphenyl ethers in the Iranian Coral Islands: Concentrations, profiles, source apportionment, and ecological risk assessment. CHEMOSPHERE 2020; 251:126397. [PMID: 32169708 DOI: 10.1016/j.chemosphere.2020.126397] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 02/28/2020] [Accepted: 02/29/2020] [Indexed: 06/10/2023]
Abstract
Coral reefs are challenged by multiple stressors due to the growing industrialization. Despite that, data on their environment are still scarce, and no research is yet performed on polybrominated diphenyl ethers in the Persian Gulf area. Seeking to fill in this gap, the present study aims to determine spatio-vertical distributions, source apportionment and ecological risk of polybrominated diphenyl ethers in the sediment cores and seawater samples from ten coral reef Islands in the Persian Gulf, Iran. Σ12PBDEs concentrations ranged from 0.42 ± 0.04 to 47.14 ± 1.35 ng g-1 dw in sediments, and from 1.17 ± 0.06 to 7.21 ± 1.13 ng L-1 in seawater. The vertical polybrominated diphenyl ethers distribution varied significantly among the sampling stations and different depths with a decreasing trend towards the surface and peaks around 12-20 cm. Both in the seawater and sediment samples, elevated polybrominated diphenyl ethers loadings were observed in highly industrialized areas. Deca-bromodiphenyl ether-209 was the predominant congener along the sediment cores, whereas Tetra-bromodiphenyl ether-47 and Penta-bromodiphenyl ether-100 dominated in seawater samples. Commercial Deca-bromodiphenyl ether mixture was found to be the major source of polybrominated diphenyl ethers. Penta-bromodiphenyl ether was revealed to be the major ecological risk driver in the study area: it posed medium to high-risk quotient to sediment dwelling organisms. This study indicated that coral reefs are playing an important role in retaining polybrominated diphenyl ethers and highlighted the need to manage polybrominated diphenyl ethers contamination in the coral reef environment.
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Affiliation(s)
- Ali Ranjbar Jafarabadi
- Department of Environmental Sciences, Faculty of Natural Resources and Marine Sciences, Tarbiat Modares University, Noor, Mazandaran, Iran
| | - Mehdi Dashtbozorg
- Young Researchers and Elites Club, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | | | - Alireza Riyahi Bakhtiari
- Department of Environmental Sciences, Faculty of Natural Resources and Marine Sciences, Tarbiat Modares University, Noor, Mazandaran, Iran.
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Gao R, Liu B, Zhan L, Guo J, Zhang J, Xu Z. In-situ debromination mechanism based on self-activation and catalysis of Ca(OH) 2 during pyrolysis of waste printed circuit boards. JOURNAL OF HAZARDOUS MATERIALS 2020; 392:122447. [PMID: 32193111 DOI: 10.1016/j.jhazmat.2020.122447] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 02/29/2020] [Accepted: 02/29/2020] [Indexed: 06/10/2023]
Abstract
Completely and deeply removed bromide from waste printed circuit boards (WPCBs) is necessary due to their toxicity and carcinogenicity. To achieve this purpose, calcium hydroxide (Ca(OH)2) as a debromination agent was added during pyrolysis process of WPCBs. The results showed that hydrogen bromide (HBr), 4-bromophenol, 2-bromophenol and 2,4-dibromophenol were the main bromide species in pyrolysis products. The Ca(OH)2 plays a significant role for removing HBr and organic bromide, but not affects products yield. Optimal removal efficiency for 4-bromophenol, 2-bromophenol and 2,4-dibromophenol reached 87.5 %, 74.6 % and 54.5 %, respectively. And debromination efficiency was related to the steric hindrance caused by bromide atoms. The Ca(OH)2 can be activated by captured HBr and its thermal decomposition. And the newly-generated calcium bromide and calcium oxide significantly facilitate debromination due to their high surface energy and reactivity. The debromination mechanism was clarified by experiments coupled with computational chemistry: the coordination of bromide and calcium to form [Ph-Br···Ca2+] or [Ph-Br···Caatom]. Then, electrons were delivered form bromide atom to Ca2+ or Caatom, which resulted in the stretch and weaken the C-Br bond. Hence, the C-Br bond was more easily to break. This work can provide support for designing novel and efficient debromination agents applied for high-temperature system.
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Affiliation(s)
- Ruitong Gao
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, PR China
| | - Binyang Liu
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, PR China
| | - Lu Zhan
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, PR China
| | - Jie Guo
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, PR China
| | - Jie Zhang
- Instrumental Analysis Center, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, PR China
| | - Zhenming Xu
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, PR China.
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12
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Wei L, Zhou B, Xiao K, Yang B, Yu G, Li J, Zhu C, Zhang J, Duan H. Highly efficient degradation of 2,2',4,4'-tetrabromodiphenyl ether through combining surfactant-assisted Zn 0 reduction with subsequent Fenton oxidation. JOURNAL OF HAZARDOUS MATERIALS 2020; 385:121551. [PMID: 31708290 DOI: 10.1016/j.jhazmat.2019.121551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 10/13/2019] [Accepted: 10/24/2019] [Indexed: 06/10/2023]
Abstract
2,2',4,4'-tetrabromodiphenyl ether (BDE47) was difficult to be rapidly degraded by common reductive debromination or oxidative decomposition. In this study, the debromination via surfactant-assisted zero valent zinc (Zn0) reduction and subsequent Fenton oxidation was combined to completely degrade BDE47. Firstly, Zn0 integrated with surfactants including cetyltrimethylammonium chloride (CTAC), polyethylene glycol dodecyl ether (Brij35), or 1-dodecanesulfonic acid sodium salt (SDS) were evaluated for their reactivity to debrominate BDE47. CTAC-assisted Zn0 system presented the highest removal efficiency of 98.6% for BDE47 (C0 = 5 mg/L) under the optimized conditions including 0.3 g/L of Zn0 particles and 0.05 g/L of CTAC at 25 °C and pH 4.0 during 1-h reaction. Subsequently, the debromination products as low-brominated BDEs were attacked by hydroxyl radicals (•OH) from Fenton reagent, which were decomposed into short-chain carboxylic acids and even mineralized within 2-h oxidation. In addition, HPLC, GC-MS, LC-MS/MS, and IC were employed to detect intermediates during this reaction/oxidation process and the pathways of debromination and oxidation were proposed according to carbon and bromine balance. The above combination achieved the complete degradation of BDE47 via a relative low-cost method to rapidly remove PBDEs, which provide a new approach for the effective treatment of halogenated organic pollutants.
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Affiliation(s)
- Liyan Wei
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, PR China
| | - Biao Zhou
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, PR China
| | - Ke Xiao
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, PR China
| | - Bo Yang
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, PR China.
| | - Gang Yu
- School of Environment, POPs Research Center, Tsinghua University, Beijing 100084, PR China
| | - Juying Li
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, PR China
| | - Caizhen Zhu
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, PR China
| | - Junmin Zhang
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, PR China
| | - Huabo Duan
- Smart City Research Institute, College of Civil Engineering, Shenzhen University, Shenzhen 518060, PR China
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He F, Gong L, Fan D, Tratnyek PG, Lowry GV. Quantifying the efficiency and selectivity of organohalide dechlorination by zerovalent iron. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2020; 22:528-542. [PMID: 32124893 DOI: 10.1039/c9em00592g] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The efficiency and selectivity of zerovalent iron-based treatments for organohalide contaminated groundwater can be quantified by accounting for redistribution of electrons derived from oxidation of Fe0. Several types of efficiency are reviewed, including (i) the efficiency of Fe(0) utilization, εFe(0), (ii) the electron efficiency of target contaminant reduction, εe, and (iii) the electron efficiency of natural reductant demand (NRD) involving H2O, O2, and co-contaminants such as nitrate, εNRD. Selectivity can then be calculated by using εe/εNRD. Of particular interest is εe and the key to its determination is measuring the total quantity of electrons provided by Fe0 oxidation, which can be based on either the loss of Fe(0), the formation of Fe(ii)/Fe(iii), or the composition of the total reaction products. Recently, many data have accumulated on εe for the treatment of various chlorinated solvents (esp. trichloroethylene, TCE) by zerovalent iron (ZVI), and analysis of these data shows that ZVI particle properties (e.g., stabilization with polymers, bimetallic modification, sulfidation, etc.) and other operational factors have variable effects on εe. Of particular interest is that pre-exposure of ZVI to reduced sulfur species (i.e., sulfidation) consistently improves the εe of contaminant reduction, mainly by suppressing the reduction of water.
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Affiliation(s)
- Feng He
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China.
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Zhou Q, Wang Y, Xiao J, Zhan Y. Preparation of magnetic core-shell Fe 3O 4@polyaniline composite material and its application in adsorption and removal of tetrabromobisphenol A and decabromodiphenyl ether. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2019; 183:109471. [PMID: 31377520 DOI: 10.1016/j.ecoenv.2019.109471] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 07/12/2019] [Accepted: 07/22/2019] [Indexed: 06/10/2023]
Abstract
Present study described a magnetic adsorption and removal method with prepared magnetic core-shell Fe3O4@polyaniline microspheres for the removal of two typical BFRs, tetrabromobisphenol-A (TBBPA) and decabromodiphenyl ether (BDE-209) from water samples. Magnetic core-shell Fe3O4@polyaniline microspheres were prepared by a hydrothermal and two step polymerization method with cheap iron salts and aniline, which were characterized with transmission electron microscopic (TEM) and scanning electron microscopy (SEM). The results showed that the Fe3O4@polyaniline microspheres earned a clear thickness shell of polyaniline (about 50 nm) and a saturation magnetization of 40.4 emu g-1. The Magnetic core-shell Fe3O4@polyaniline exhibited excellent adsorption capability and removal rate to TBBPA and BDE 209. The adsorption of TBBPA and BDE 209 all followed pseudo-second order kinetics and agreed well to the Freundlich adsorption isotherms model. The negative Gibbs free energy change (ΔG0) and positive standard enthalpy change (ΔH0) for TBBPA and BDE-209 suggested that the adsorption was spontaneous and endothermic in nature. These results demonstrated that Fe3O4@PANI was a good adsorbent and would have a good application prospect in the removal of pollutants from environmental water.
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Affiliation(s)
- Qingxiang Zhou
- State Key Laboratory of Heavy Oil Processing, State Key Laboratory of Petroleum Pollution Control, China University of Petroleum (Beijing), Beijing 102249, China.
| | - Yuqin Wang
- State Key Laboratory of Heavy Oil Processing, State Key Laboratory of Petroleum Pollution Control, China University of Petroleum (Beijing), Beijing 102249, China; College of Chemistry and Bioengineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Junping Xiao
- College of Chemistry and Bioengineering, University of Science and Technology Beijing, Beijing 100083, China
| | - Yali Zhan
- State Key Laboratory of Heavy Oil Processing, State Key Laboratory of Petroleum Pollution Control, China University of Petroleum (Beijing), Beijing 102249, China.
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15
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Wang R, Tang T, Wei Y, Dang D, Huang K, Chen X, Yin H, Tao X, Lin Z, Dang Z, Lu G. Photocatalytic debromination of polybrominated diphenyl ethers (PBDEs) on metal doped TiO 2 nanocomposites: Mechanisms and pathways. ENVIRONMENT INTERNATIONAL 2019; 127:5-12. [PMID: 30889398 DOI: 10.1016/j.envint.2019.03.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 02/28/2019] [Accepted: 03/04/2019] [Indexed: 06/09/2023]
Abstract
Nanoparticles of four noble metal doped titanium dioxide (i.e., Pd/TiO2, Ag/TiO2, Pt/TiO2 and Cu/TiO2) were synthesized and investigated for their effectiveness to degrade polybrominated diphenyl ethers (PBDEs) under UV light. All the investigated noble metal additives can greatly enhance the performance of TiO2 to degrade 2,2',4',4'-tetrabromodiphenyl ether (BDE-47). However, the debromination pathways of BDE-47 in Ag/TiO2 and Cu/TiO2 systems are just contrary to those in Pd/TiO2 and Pt/TiO2 systems, and there was an induction period in the former systems but not in the latter systems. The hydrogenation experiment suggests a direct H-atom transfer mechanism in Pd/TiO2 and Pt/TiO2 systems, while in Ag/TiO2 and Cu/TiO2 systems, electron transfer is still the dominant mechanism. Electronic method was applied to explain why BDE-47 exhibit different debromination pathways based on different degradation mechanism. In addition, oxygen was proved to be able to capture both electrons and H atoms, and thus can greatly inhibit the degradation of PBDEs in all investigated systems. Finally, the merit and demerit of each metal doped TiO2 were discussed in detail, including the reactivity, stability and the generation of byproducts. We proposed our study greatly enhance our understanding on the mechanisms of PBDE degradation in various metal doped TiO2 systems.
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Affiliation(s)
- Rui Wang
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Ting Tang
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Yanchun Wei
- School of Environmental Science and Engineering, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China
| | - Dai Dang
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou, Guangdong 510006, China.
| | - Kaibo Huang
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Xingwei Chen
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou, Guangdong 510006, China
| | - Hua Yin
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006, China
| | - Xueqin Tao
- School of Environmental Science and Engineering, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China
| | - Zhang Lin
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China; Guangdong Provincial Engineering and Technology Research Center for Environmental Nanomaterials, Guangzhou 510006, China
| | - Zhi Dang
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006, China
| | - Guining Lu
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006, China.
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16
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Wang R, Tang T, Lu G, Zheng Z, Huang K, Li H, Tao X, Yin H, Shi Z, Lin Z, Wu F, Dang Z. Mechanisms and pathways of debromination of polybrominated diphenyl ethers (PBDEs) in various nano-zerovalent iron-based bimetallic systems. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 661:18-26. [PMID: 30665128 DOI: 10.1016/j.scitotenv.2019.01.166] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 01/09/2019] [Accepted: 01/13/2019] [Indexed: 06/09/2023]
Abstract
This study investigated the relative significance of electron transfer (e-transfer) and H-atom transfer (H-transfer) in a nanoscale zerovalent iron (n-ZVI) system and six n-ZVI-based bimetallic systems (Fe/Cu, Fe/Ni, Fe/Pd, Fe/Ag, Fe/Pt, and Fe/Au) through a case study of the debromination of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47). The results revealed that the reactivities of these bimetallic particles to BDE-47 decreased in the following order: Fe/Pd>Fe/Ag>Fe/Cu>Fe/Ni>Fe/Au>Fe/Pt≈n-ZVI. Debromination of BDE-47 in metal-H2 systems suggested that Ni, Pd, Pt, Cu and Au can utilize H2 to debrominate BDE-47. In the H-transfer process, BDE-47 preferentially debrominated the para‑bromine substituent to generate BDE-17, whereas in the e-transfer process, BDE-47 preferentially debrominate ortho‑bromine substituent to generate BDE-28. The debromination pathways of BDE-47 in bimetallic and NaBH4-metal systems suggested that Fe/Ni, Fe/Pd and Fe/Pt debrominate polybrominated diphenyl ethers (PBDEs) through a H-transfer dominant mechanism, while Fe/Ag debrominate PBDEs through an e-transfer dominant mechanism. In the cases of Fe/Cu and Fe/Au, the e-transfer and H-transfer may be equally involved in the debromination of PBDEs. These results greatly improve our understanding of the relative significance of e-transfer and H-transfer in the dehalogenation of halogenated aromatic compounds (HACs) in various n-ZVI-based bimetallic systems.
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Affiliation(s)
- Rui Wang
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Ting Tang
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Guining Lu
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006, China.
| | - Zhiqiang Zheng
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Kaibo Huang
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Huafeng Li
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Xueqin Tao
- School of Environmental Science and Engineering, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China
| | - Hua Yin
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006, China
| | - Zhenqing Shi
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006, China
| | - Zhang Lin
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006, China; Guangdong Engineering and Technology Research Center for Environmental Nanomaterials, China
| | - Fengchang Wu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Zhi Dang
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006, China.
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17
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Wang R, Tang T, Feng S, Chen X, Dang D, Huang K, Tao X, Yin H, Dang Z, Lu G. Experimental and theoretical investigations on debromination pathways of polybrominated biphenyls (PBBs) under ultraviolet light. CHEMOSPHERE 2018; 212:1-7. [PMID: 30130655 DOI: 10.1016/j.chemosphere.2018.08.063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2018] [Revised: 07/29/2018] [Accepted: 08/13/2018] [Indexed: 06/08/2023]
Abstract
Polybrominated biphenyls (PBBs) are brominated flame retardants that are widely used in textiles and electronic products. Recently, many researches have been devoted to determining their concentrations in food and in the environment. Yet, their degradation behavior has been less investigated and is not well understood. Here, we have investigated the debromination pathways of PBBs by (UV) light in the case of 2,4,5-tribrominated biphenyl (PBB-29). Our investigation indicates that para-bromine substituent on PBB-29 was preferentially removed. By means of density functional theory (DFT), we found that the energies of the debromination products, the CBr bond length in the excited state (S1), the Mulliken charge of bromine in S1, and the lowest unoccupied molecular orbital (LUMO) in S1 correlated well with the debromination pathways of PBBs. Further, LUMO-based prediction of PBB debromination pathways in S1 suggests that the bromine substituent on all brominated positions (i.e. ortho-, meta- and para-) can be preferentially removed, as the debromination sequence is not based on the brominated position but on the specific brominated arrangement pattern. In addition, reductive debromination preferentially occurs on the benzene ring that has the highest number of bromine substituents. This study provided useful descriptors to predict the debromination pathways of PBBs, and the theoretical result greatly improve our understanding of photolytic debromination of PBBs.
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Affiliation(s)
- Rui Wang
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Ting Tang
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Siyuan Feng
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Xingwei Chen
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, China
| | - Dai Dang
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, China
| | - Kaibo Huang
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Xueqin Tao
- College of Environmental Science and Engineering, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China
| | - Hua Yin
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou, 510006, China
| | - Zhi Dang
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou, 510006, China
| | - Guining Lu
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou, 510006, China.
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18
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Li H, Wang J, Wang R, Huang K, Luo W, Tao X, Dang Z, Yin H, Guo C, Lu G. Debromination of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) by synthetic Pd/Fe 0 and Cu/Fe 0 in different protic solvents. CHEMOSPHERE 2018; 212:946-953. [PMID: 30286551 DOI: 10.1016/j.chemosphere.2018.09.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2018] [Revised: 08/30/2018] [Accepted: 09/01/2018] [Indexed: 06/08/2023]
Abstract
Polybrominated diphenyl ethers (PBDEs) belong to a class of persistent organic pollutants (POPs), with potential toxicity to the liver, reproductive system, and development of mammals. The highly toxic and concentrated congener, 2,2',4,4'-tetrabromodiphenyl ether (BDE-47), was chosen to investigate debromination mechanisms by the two synthetic iron-based bimetals (Pd/Fe0 and Cu/Fe0) in two protic solvents (water and ethanol). SEM, XPS, and BET analyses showed that the synthetic bimetals Pd/Fe0 and Cu/Fe0 were spherical with diameters of about 100 nm and loaded with ∼1% (wt%) of Pd and Cu, respectively. GC-MS was used for the analysis of degradation products and the chromatograms showed that both Pd/Fe0 and Cu/Fe0 bimetals had effective reducing properties in water solvent. In ethanol solvent, debromination of BDE-47 by Pd/Fe0 showed a similar high activity, but BDE-47 could be hardly degraded by Cu/Fe0. The dominant debromination products of BDE-47 by Pd/Fe0 and Cu/Fe0 were ortho-substituted and para-substituted BDEs, respectively. Active H-atomic transfer was found to play a key role in the debromination of BDE-47 by Pd/Fe0 in both, water and ethanol, with a preference for para-debromination along with the formation of dibenzo-p-furan (DF) as the by-product, mainly in water. In contrast, electron transfer with a preference for ortho-debromination was found to play a predominant role for Cu/Fe0 system in water. More importance should be provided to active H-atomic transfer for its high efficiency. In-depth study on the mechanism of formation of by-product DF would be significant for its higher toxicity, possibility of accumulation and migration in the environment.
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Affiliation(s)
- Huafeng Li
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Jin Wang
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Rui Wang
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Kaibo Huang
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China
| | - Wanying Luo
- College of Environmental Science and Engineering, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China
| | - Xueqin Tao
- College of Environmental Science and Engineering, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China
| | - Zhi Dang
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China; The Key Lab of Pollution and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006, China
| | - Hua Yin
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China; The Key Lab of Pollution and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006, China
| | - Chuling Guo
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China; The Key Lab of Pollution and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006, China
| | - Guining Lu
- School of Environment and Energy, South China University of Technology, Guangzhou 510006, China; The Key Lab of Pollution and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006, China; Guangdong Engineering and Technology Research Center for Environmental Nanomaterials, Guangzhou 510006, China.
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