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von Gunten U. Oxidation processes and me. Water Res 2024; 253:121148. [PMID: 38387263 DOI: 10.1016/j.watres.2024.121148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 01/12/2024] [Accepted: 01/14/2024] [Indexed: 02/24/2024]
Abstract
This publication summarizes my journey in the field of chemical oxidation processes for water treatment over the last 30+ years. Initially, the efficiency of the application of chemical oxidants for micropollutant abatement was assessed by the abatement of the target compounds only. This is controlled by reaction kinetics and therefore, second-order rate constant for these reactions are the pre-requisite to assess the efficiency and feasibility of such processes. Due to the tremendous efforts in this area, we currently have a good experimental data base for second-order rate constants for many chemical oxidants, including radicals. Based on this, predictions can be made for compounds without experimental data with Quantitative Structure Activity Relationships with Hammet/Taft constants or energies of highest occupied molecular orbitals from quantum chemical computations. Chemical oxidation in water treatment has to be economically feasible and therefore, the extent of transformation of micropollutants is often limited and mineralization of target compounds cannot be achieved under realistic conditions. The formation of transformation products from the reactions of the target compounds with chemical oxidants is inherent to oxidation processes and the following questions have evolved over the years: Are the formed transformation products biologically less active than the target compounds? Is there a new toxicity associated with transformation products? Are transformation products more biodegradable than the corresponding target compounds? In addition to the positive effects on water quality related to abatement of micropollutants, chemical oxidants react mainly with water matrix components such as the dissolved organic matter (DOM), bromide and iodide. As a matter of fact, the fraction of oxidants consumed by the DOM is typically > 99%, which makes such processes inherently inefficient. The consequences are loss of oxidation capacity and the formation of organic and inorganic disinfection byproducts also involving bromide and iodide, which can be oxidized to reactive bromine and iodine with their ensuing reactions with DOM. Overall, it has turned out in the last three decades, that chemical oxidation processes are complex to understand and to manage. However, the tremendous research efforts have led to a good understanding of the underlying processes and allow a widespread and optimized application of such processes in water treatment practice such as drinking water, municipal and industrial wastewater and water reuse systems.
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Affiliation(s)
- Urs von Gunten
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH-8600 Duebendorf, Switzerland; ENAC, School of Architecture, Civil and Environmental Engineering, Ecole Polytechnique Fédérale, CH-1000, Lausanne, Switzerland.
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Minakata D, von Gunten U. Predicting Transformation Products during Aqueous Oxidation Processes: Current State and Outlook. Environ Sci Technol 2023; 57:18410-18419. [PMID: 37824098 PMCID: PMC10691424 DOI: 10.1021/acs.est.3c04086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Indexed: 10/13/2023]
Abstract
Water quality and its impacts on human and ecosystem health presents tremendous global challenges. While oxidative water treatment can solve many of these problems related to hygiene and micropollutants, identifying and predicting transformation products from a large variety of micropollutants induced by dosed chemical oxidants and in situ formed radicals is still a major challenge. To this end, a better understanding of the formed transformation products and their potential toxicity is needed. Currently, no theoretical tools alone can predict oxidatively induced transformation products in aqueous systems. Coupling experimental and theoretical studies has advanced the understanding of reaction kinetics and mechanisms significantly. This perspective article highlights the key progress made concerning experimental and computational approaches to predict transformation products. Knowledge gaps are identified, and the research required to advance the predictive capability is discussed.
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Affiliation(s)
- Daisuke Minakata
- Civil,
Environmental, and Geospatial Engineering, Michigan Technological University, Houghton, Michigan 49931, United States
| | - Urs von Gunten
- Eawag,
Swiss Federal Institute of Aquatic Science and Technology, Überlandstraße 133, CH-8600 Dübendorf, Switzerland
- School
of Architecture, Civil and Environmental Engineering (ENAC), Ecole Polytechnique Fédérale de Lausanne
(EPFL), Lausanne 1015, Switzerland
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3
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Meng Y, Yuan Q, Luan F. Thermodynamic considerations on the combined effect of electron shuttles and iron(III)-bearing clay mineral on Cr(VI) reduction by Shewanella oneidensis MR-1. J Hazard Mater 2023; 459:132144. [PMID: 37517234 DOI: 10.1016/j.jhazmat.2023.132144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 07/02/2023] [Accepted: 07/23/2023] [Indexed: 08/01/2023]
Abstract
Electron shuttles (ESs) and Fe-bearing clay minerals are commonly found in subsurface environments and have shown potential in enhancing the bioreduction of Cr(VI). However, the synergistic effect of ESs at different redox potentials and Fe-bearing clay minerals on Cr(VI) bioreduction, as well as the fundamental principles governing this process, remain unclear. In our study, we investigated the role of ESs and Fe(III) in Cr(VI) bioreduction. We found that the acceleration of ESs and Fe(III) are crucial factors in this process. Interestingly, the promotion of ESs on Cr(VI) and Fe(III) showed opposite trends. Electrochemical methods confirmed the limited steps are the extent of reduced ESs and the redox potential difference between ESs and Fe(III), separately. Furthermore, we investigated the combined effect of ESs and NAu-2 on Cr(VI) bioreduction. Our results revealed two segments: in the first segment, the ES (5-HNQ) and NAu-2 did not synergistically enhance Cr(VI) reduction. However, in the second segment, ESs and NAu-2 demonstrated a synergistic effect, significantly increasing Cr(VI) reduction by MR-1. These bioreduction processes all follow linear free energy relationships (LFERs). Overall, our study highlights the fundamental principles governing multivariate systems and presents a promising approach for the remediation of Cr(VI)-contaminated sites.
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Affiliation(s)
- Ying Meng
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China
| | - Qingke Yuan
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China
| | - Fubo Luan
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
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Meng X, Wang J, Xu L. Degradation of the mixed nuclear-grade cationic and anionic exchange resins using Fe 2+/H + homogeneous Fenton oxidation. Environ Res 2022; 212:113400. [PMID: 35525296 DOI: 10.1016/j.envres.2022.113400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 04/15/2022] [Accepted: 04/28/2022] [Indexed: 06/14/2023]
Abstract
To further improve the treatment capacity of actual wastes, H+ was introduced into the homogeneous Fenton system as a co-catalyst for dissolution and degradation of the mixed nuclear-grade cationic and anionic exchange resins. The effects of acid type and concentration, catalyst type and concentration, H2O2 dosage, initial temperature, antifoaming agent and resin ratio were studied. The concentration of inorganic acid, type and concentration of catalyst had significant influence on the decomposition of mixed resins. The experimental results showed that when the mixing ratio of resins was 1:1, the initial temperature was 96 ± 1 °C, the amount of H2O2 was 200 mL, and the concentration of H+/Fe2+ was 1 M/0.1 M, complete dissolution and 79% weight reduction of mixed resins were obtained. Combined with density functional theory (DFT) calculations, cationic exchange resin and anionic exchange resin showed different reactivity in the experiment. Hydroxyl radicals (•OH) tended to attack -SO3- groups with more negative charges, and the barrier energy of -SO3- ion dissociation was 8.2 kcal/mol, which caused the cationic exchange resin to be easily destroyed. According to the characterization results, the characteristic intermediates were determined, indicating that desulfonation, valence change of nitrogen atom, and cleavage of long-chain carbon skeleton existed during the reaction, but incomplete oxidation still remained.
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Affiliation(s)
- Xiang Meng
- Department of Nuclear Engineering and Technology, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan, 430074, PR China; Baosteel Central Research Institute, Baoshan Iron & Steel Co., Ltd., Shanghai, 201900, PR China
| | - Jianlong Wang
- Institute of Nuclear and New Energy Technology, Key Laboratory of Advanced Reactor Engineering and Safety of Ministry of Education, Tsinghua University, Beijing, 100084, PR China; Beijing Key Laboratory of Radioactive Wastes Treatment, Tsinghua University, Beijing, 100084, PR China
| | - Lejin Xu
- Department of Nuclear Engineering and Technology, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan, 430074, PR China.
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Yang X, Rosario-Ortiz FL, Lei Y, Pan Y, Lei X, Westerhoff P. Multiple Roles of Dissolved Organic Matter in Advanced Oxidation Processes. Environ Sci Technol 2022; 56:11111-11131. [PMID: 35797184 DOI: 10.1021/acs.est.2c01017] [Citation(s) in RCA: 68] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Advanced oxidation processes (AOPs) can degrade a wide range of trace organic contaminants (TrOCs) to improve the quality of potable water or discharged wastewater effluents. Their effectiveness is impacted, however, by the dissolved organic matter (DOM) that is ubiquitous in all water sources. During the application of an AOP, DOM can scavenge radicals and/or block light penetration, therefore impacting their effectiveness toward contaminant transformation. The multiple ways in which different types or sources of DOM can impact oxidative water purification processes are critically reviewed. DOM can inhibit the degradation of TrOCs, but it can also enhance the formation and reactivity of useful radicals for contaminants elimination and alter the transformation pathways of contaminants. An in-depth analysis highlights the inhibitory effect of DOM on the degradation efficiency of TrOCs based on DOM's structure and optical properties and its reactivity toward oxidants as well as the synergistic contribution of DOM to the transformation of TrOCs from the analysis of DOM's redox properties and DOM's transient intermediates. AOPs can alter DOM structure properties as well as and influence types, mechanisms, and extent of oxidation byproducts formation. Research needs are proposed to advance practical understanding of how DOM can be exploited to improve oxidative water purification.
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Affiliation(s)
- Xin Yang
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, China
| | - Fernando L Rosario-Ortiz
- Department of Civil, Environmental and Architectural Engineering, University of Colorado, Boulder, Colorado 80309, United States
| | - Yu Lei
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, China
| | - Yanheng Pan
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, China
| | - Xin Lei
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, China
| | - Paul Westerhoff
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, Arizona 85287-3005, United States
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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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Kirpalani DM, Nong A, Ansari R. Insights into ultrasound-promoted degradation of naphthenic acid compounds in oil sands process affected water. Part II: In silico quantum screening of hydroxyl radical initiated and propagated degradation of benzoic acid. Ultrason Sonochem 2022; 85:105983. [PMID: 35338999 PMCID: PMC8956944 DOI: 10.1016/j.ultsonch.2022.105983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 03/11/2022] [Accepted: 03/13/2022] [Indexed: 06/14/2023]
Abstract
In Part I, we outlined the importance of sustainable sonochemical treatment to intensify oil sands process affected water (OSPW) treatment empirically and hypothesized degradation pathways. Herein, we elucidate the formation of intermediate products with well-defined molecular level solutions. Proposed mechanisms describe hydroxylation, decarboxylation and bond scission which drive the degradation of intermediates towards mineralization. This comprehensive first study on in silico screening of sonochemical degradation investigates quantum methods using density functional theory to explain the postulated degradation mechanisms through a theoretical radical attack approach, based on condensed Fukui reactivity indicators. A nudged elasticity band (NEB) approach is applied to find a minimum energy path (MEP), allowing the determination of intermediate products and energy barriers associated with naphthenic acid degradation. This approach provides structures and energies of the breakdown compounds formed along the reaction pathway enabling the determination of molecular reaction kinetics. In continuation of Part 1, the focus of this study is to evaluate sonochemically-induced hydroxyl radical (OH•) reactions of benzoic acid using density functional theory. Hydroxylation and decarboxylation mechanisms of the model naphthenic acid compound and its intermediates were simulated to determine the prospective pathway to ideal mineralization. DFT was applied to calculate interaction energies, Mulliken charges, Hirshfeld population analysis, dipole moments, frontier orbitals, and polarizability. Electronic properties and frontier orbital trends were also compared to computational work by Riahi et al.[1] to confirm the transition states by Nudged Elastic Band Transition State theory (NEB-TS). In combination with Hirshfeld Population analysis, Fukui indices suggest a more linear degradation pathway narrowed down from earlier experimental work by Singla et al.[2]. The linear free energy relationship for the newly suggested computational benzoic acid degradation can be determined by lnkTST/W=-1.677ΔG-15.41 with a R2 of 0.9997 according to classic transition state theory and Wigner tunneling. This computational method can be used to explore possible degradation pathways of other NAs and bridges molecular-to-macroscale sonochemical degradation of NA's through a manifestation of molecular solutions.
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Affiliation(s)
- Deepak M Kirpalani
- National Research Council of Canada, Energy Mining and Environment Portfolio, 1200 Montreal Road, Ottawa, ON K1A 0R6, Canada.
| | - Andy Nong
- National Research Council of Canada, Energy Mining and Environment Portfolio, 1200 Montreal Road, Ottawa, ON K1A 0R6, Canada
| | - Rija Ansari
- National Research Council of Canada, Energy Mining and Environment Portfolio, 1200 Montreal Road, Ottawa, ON K1A 0R6, Canada
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Nolte TM, Hendriks AJ, Novák LA, Peijnenburg WJGM. A universal free energy relationship for both hard and soft radical addition in water. J PHYS ORG CHEM 2022. [DOI: 10.1002/poc.4317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Tom M. Nolte
- Department of Environmental Science, Institute for Water and Wetland Research Radboud University Nijmegen Nijmegen The Netherlands
| | - A. Jan Hendriks
- Department of Environmental Science, Institute for Water and Wetland Research Radboud University Nijmegen Nijmegen The Netherlands
| | - Laurie A. Novák
- Department of Environmental Science, Institute for Water and Wetland Research Radboud University Nijmegen Nijmegen The Netherlands
| | - Willie J. G. M. Peijnenburg
- Department of Environmental Science, Institute for Water and Wetland Research National Institute of Public Health and the Environment Bilthoven The Netherlands
- Institute of Environmental Sciences (CML) Leiden University Leiden The Netherlands
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Ren W, Cheng C, Shao P, Luo X, Zhang H, Wang S, Duan X. Origins of Electron-Transfer Regime in Persulfate-Based Nonradical Oxidation Processes. Environ Sci Technol 2022; 56:78-97. [PMID: 34932343 DOI: 10.1021/acs.est.1c05374] [Citation(s) in RCA: 182] [Impact Index Per Article: 91.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Persulfate-based nonradical oxidation processes (PS-NOPs) are appealing in wastewater purification due to their high efficiency and selectivity for removing trace organic contaminants in complicated water matrices. In this review, we showcased the recent progresses of state-of-the-art strategies in the nonradical electron-transfer regimes in PS-NOPs, including design of metal and metal-free heterogeneous catalysts, in situ/operando characterization/analytical techniques, and insights into the origins of electron-transfer mechanisms. In a typical electron-transfer process (ETP), persulfate is activated by a catalyst to form surface activated complexes, which directly or indirectly interact with target pollutants to finalize the oxidation. We discussed different analytical techniques on the fundamentals and tactics for accurate analysis of ETP. Moreover, we demonstrated the challenges and proposed future research strategies for ETP-based systems, such as computation-enabled molecular-level investigations, rational design of catalysts, and real-scenario applications in the complicated water environment. Overall, this review dedicates to sharpening the understanding of ETP in PS-NOPs and presenting promising applications in remediation technology and green chemistry.
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Affiliation(s)
- Wei Ren
- Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang 330063, China
- Department of Environmental Science and Engineering, School of Resource and Environmental Sciences, Wuhan University, Wuhan 430079, China
- School of Chemical Engineering and Advanced Materials, The University of Adelaide, Adelaide, SA5005, Australia
| | - Cheng Cheng
- Department of Environmental Science and Engineering, School of Resource and Environmental Sciences, Wuhan University, Wuhan 430079, China
| | - Penghui Shao
- Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang 330063, China
| | - Xubiao Luo
- Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang 330063, China
| | - Hui Zhang
- Department of Environmental Science and Engineering, School of Resource and Environmental Sciences, Wuhan University, Wuhan 430079, China
| | - Shaobin Wang
- School of Chemical Engineering and Advanced Materials, The University of Adelaide, Adelaide, SA5005, Australia
| | - Xiaoguang Duan
- School of Chemical Engineering and Advanced Materials, The University of Adelaide, Adelaide, SA5005, Australia
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Waggoner AR, Abdulrahman Y, Iverson AJ, Gibson EP, Buckles MA, Poole JS. Reaction of hydroxyl radical with arenes in solution—On the importance of benzylic hydrogen abstraction. J PHYS ORG CHEM 2021. [DOI: 10.1002/poc.4278] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
| | - Yahya Abdulrahman
- Department of Chemistry and Biochemistry St. Cloud State University St. Cloud Minnesota USA
| | - Alexis J. Iverson
- Department of Chemistry and Biochemistry St. Cloud State University St. Cloud Minnesota USA
| | - Ethan P. Gibson
- Department of Chemistry Ball State University Muncie Indiana USA
| | - Mark A. Buckles
- Department of Chemistry Ball State University Muncie Indiana USA
| | - James S. Poole
- Department of Chemistry Ball State University Muncie Indiana USA
- Department of Chemistry and Biochemistry St. Cloud State University St. Cloud Minnesota USA
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Chen B, Jiang J, Yang X, Zhang X, Westerhoff P. Roles and Knowledge Gaps of Point-of-Use Technologies for Mitigating Health Risks from Disinfection Byproducts in Tap Water: A Critical Review. Water Res 2021; 200:117265. [PMID: 34091221 PMCID: PMC8634687 DOI: 10.1016/j.watres.2021.117265] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 05/11/2021] [Accepted: 05/14/2021] [Indexed: 05/19/2023]
Abstract
Due to rising concerns about water pollution and affordability, there is a rapidly-growing public acceptance and global market for a variety of point-of-use (POU) devices for domestic uses. However, the efficiencies and mechanisms of POU technologies for removing regulated and emerging disinfection byproducts (DBPs) are still not systematically known. To facilitate the development of this field, we summarized performance trends of four common technologies (i.e., boiling, adsorption, membrane filtration, and advanced oxidation) on mitigating preformed DBPs and identified knowledge gaps. The following highest priority knowledge gaps include: 1) data on DBP levels at the tap or cup in domestic applications; 2) certainty regarding the controls of DBPs by heating processes as DBPs may form and transform simultaneously; 3) standards to evaluate the performance of carbon-based materials on varying types of DBPs; 4) long-term information on the membrane performance in removing DBPs; 5) knowledge of DBPs' susceptibility toward advanced redox processes; 6) tools to monitor/predict the toxicity and diversity of DBPs formed in waters with varying precursors and when implementing different treatment technologies; and 7) social acceptance and regulatory frameworks of incorporating POU as a potential supplement to current centralized-treatment focused DBP control strategies. We conclude by identifying research needs necessary to assure POU systems protect the public against regulated and emerging DBPs.
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Affiliation(s)
- Baiyang Chen
- State Key Laboratory of Urban Water Resource and Environment, Shenzhen Key Laboratory of Organic Pollution Prevention and Control, Harbin Institute of Technology (Shenzhen), 518055, China.
| | - Jingyi Jiang
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Xin Yang
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, China.
| | - Xiangru Zhang
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
| | - Paul Westerhoff
- NSF Nanosystems Engineering Research Center for Nanotechnology-Enabled Water Treatment, School of Sustainable Engineering and the Built Environment, Ira A. Fulton Schools of Engineering, Arizona State University, Tempe, AZ 85287-3005, United States.
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12
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Barrios B, Mohrhardt B, Doskey PV, Minakata D. Mechanistic Insight into the Reactivities of Aqueous-Phase Singlet Oxygen with Organic Compounds. Environ Sci Technol 2021; 55:8054-8067. [PMID: 34096699 DOI: 10.1021/acs.est.1c01712] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Singlet oxygen (1O2) is a selective reactive oxygen species that plays a key role for the fate of various organic compounds in the aquatic environment under sunlight irradiation, engineered water oxidation systems, atmospheric water droplets, and biomedical systems. While the initial rate-determining charge-transfer reaction mechanisms and kinetics of 1O2 have been studied extensively, no comprehensive studies have been performed to elucidate the reaction mechanisms with organic compounds that have various functional groups. In this study, we use density functional theory calculations to determine elementary reaction mechanisms with a wide variety of organic compounds. The theoretically calculated aqueous-phase free energies of activation of single electron transfer and 1O2 addition reactions are compared to the experimentally determined rate constants in the literature to determine linear free-energy relationships. The theoretically calculated free energies of activation for the groups of phenolates and phenols show excellent correlations with the Hammett constants that accept electron densities by through-resonance. The dominant elementary reaction mechanism is discussed for each group of compounds. As a practical implication, we demonstrate the fate of environmentally relevant organic compounds induced by photochemically produced intermediate species at different pH and evaluate the impact of predicting rate constants to the half-life.
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Affiliation(s)
- Benjamin Barrios
- Department of Civil and Environmental Engineering, Michigan Technological University, 1400 Townsend Drive, Houghton, Michigan 49931, United States
| | - Benjamin Mohrhardt
- Department of Civil and Environmental Engineering, Michigan Technological University, 1400 Townsend Drive, Houghton, Michigan 49931, United States
| | - Paul V Doskey
- College of Forest Resources and Environmental Science, Michigan Technological University, Houghton, Michigan 49931, United States
| | - Daisuke Minakata
- Department of Civil and Environmental Engineering, Michigan Technological University, 1400 Townsend Drive, Houghton, Michigan 49931, United States
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13
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Zhang W, Zhou S, Wu Y, Zhu S, Crittenden J. Computerized Pathway Generator for the UV/Free Chlorine Process: Prediction of Byproducts and Reactions. Environ Sci Technol 2021; 55:2608-2617. [PMID: 33522788 DOI: 10.1021/acs.est.0c07080] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The ultraviolet (UV)/free chlorine process is a very promising treatment technology to remove persistent organic contaminants (POCs, e.g., pharmaceutical and personal care products) from water. The radical chain reactions involved in the UV/free chlorine process are very complicated, and the reaction pathways for organic contaminants degradation are largely unknown. Therefore, we developed a computerized pathway generator that uses graph theory and experimentally determined reaction rules that were reported for the UV/free chlorine process. Our pathway generator predicts all possible intermediates, byproducts, and elementary reactions that are involved in the oxidation of organic contaminants. For example, the degradation of tricholoroethylene (TCE) produces 497 species (i.e., intermediates and byproducts) and 6608 elementary reactions. The predicted species from our pathway generator not only predict the major and stable byproducts that were observed in our experiments (e.g., CHCl2COOH, CHCl(OCl)COOH, etc.) but also include many other minor and toxic byproducts that were produced but not measured because they have a short lifetime. Overall, our pathway generator significantly improves our understanding of the reaction pathways that are involved in organic contaminant degradation in the UV/free chlorine process.
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Affiliation(s)
- Weiqiu Zhang
- School of Civil and Environmental Engineering and the Brook Byers Institute for Sustainable Systems, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Shiqing Zhou
- School of Civil and Environmental Engineering and the Brook Byers Institute for Sustainable Systems, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
- Key Laboratory of Building Safety and Energy Efficiency, Ministry of Education, College of Civil Engineering, Hunan University, Changsha 410082, China
| | - Yangtao Wu
- Key Laboratory of Building Safety and Energy Efficiency, Ministry of Education, College of Civil Engineering, Hunan University, Changsha 410082, China
| | - Shumin Zhu
- Key Laboratory of Building Safety and Energy Efficiency, Ministry of Education, College of Civil Engineering, Hunan University, Changsha 410082, China
| | - John Crittenden
- School of Civil and Environmental Engineering and the Brook Byers Institute for Sustainable Systems, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
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Abstract
Peracetic acid combined with UV (i.e., UV/PAA) has emerged as a novel advanced oxidation process (AOP) for water disinfection and micropollutant degradation, but kinetic modeling for this AOP was lacking. In this study, a comprehensive model was developed to elucidate the reaction mechanisms and simulate reaction kinetics of UV/PAA process. By combining radical scavenging experiments and kinetic modeling, accurate quantum yield of PAA under UV254 (Φ = 0.88 ± 0.04 mol-Einstein-1) was determined via simultaneously quenching •OH and CH3C(O)O• with 2,4-hexadiene. The comparison between experimental observations and model predictions over a wide range of conditions allowed estimation of the rate constants of PAA with •OH (k•OH/PAA = 1.3 ± 0.2 × 109 M-1 s-1) and HO2• (kHO2•/PAA ≤ 5 × 102 M-1 s-1) with good accuracy. With derived Φ, k•OH/PAA and kHO2•/PAA, the kinetic model accurately predicts PAA decay under UV254 photolysis across varying PAA and H2O2 concentrations and water pH (5.8-7.2). Meanwhile, the model reveals that UV/PAA generates a lower •OH concentration than UV/H2O2 at equivalent oxidant concentrations, with CH3C(O)OO• as the most abundant carbon-centered radical. This study significantly improves the knowledge of reactive species generation and reaction kinetics and mechanisms under UV/PAA, and provides a useful kinetic model for this AOP in water treatment.
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Affiliation(s)
- Tianqi Zhang
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Ching-Hua Huang
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
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15
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Nolte TM, Nauser T, Gubler L. Attack of hydroxyl radicals to α-methyl-styrene sulfonate polymers and cerium-mediated repair via radical cations. Phys Chem Chem Phys 2020; 22:4516-4525. [PMID: 32048646 DOI: 10.1039/c9cp05454e] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Both synthetic polymers (membranes, coatings, packaging) and natural polymers (DNA, proteins) are subject to radical-initiated degradation. In order to mitigate the deterioration of the polymer properties, antioxidant strategies need to be devised. We studied the reactions of poly(α-methylstyrene sulfonate), a model compound for fuel cell membrane materials, with different degrees of polymerization with OH˙ radicals as well as subsequent reactions. We observed the resulting OH˙-adducts to react with oxygen and eliminate H2O, the relative likelihood of which is determined by pH and molecular weight. The resulting radical cations can be reduced back to the parent molecule by cerium(iii). This 'repair' reaction is also dependent on molecular weight likely because of intramolecular stabilization. The results from this study provide a starting point for the development of new hydrocarbon-based ionomer materials for fuel cells that are more resistant to radical induced degradation through the detoxification of intermediates via damage transfer and repair pathways. Furthermore, a more fundamental understanding of the mechanisms behind conventional antioxidants in medicine, such as ceria nanoparticles, is achieved.
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Affiliation(s)
- Tom M Nolte
- Electrochemistry Laboratory, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland.
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16
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Tentscher PR, Lee M, von Gunten U. Micropollutant Oxidation Studied by Quantum Chemical Computations: Methodology and Applications to Thermodynamics, Kinetics, and Reaction Mechanisms. Acc Chem Res 2019; 52:605-614. [PMID: 30829468 DOI: 10.1021/acs.accounts.8b00610] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The abatement of organic micropollutants during oxidation processes has become an emerging issue for various urban water systems such as drinking water, wastewater, and water reuse. Reaction kinetics and mechanisms play an important role in terms of efficiency of these processes and the formation of transformation products, which are controlled by functional groups in the micropollutants and the applied oxidants. So far, the kinetic and mechanistic information on the underlying reactions was obtained by experimental studies; additionally, predictive quantitative structure-activity relationships (QSARs) were applied to determine reaction kinetics for the oxidation of emerging compounds. Since this experimental approach is very laborious and there are tens of thousands potential contaminants, alternative strategies need to be developed to predict the fate of micropollutants during oxidative water treatment. Due to significant developments in quantum chemical (QC) computations in recent years and increased computational capacity, QC-based methods have become an alternative or a supplement to the current experimental approach. This Account provides a critical assessment of the current state-of-the-art of QC-based methods for the assessment of oxidation of micropollutants. Starting from a given input structure, QC computations need to locate energetic minima on the potential energy surface (PES). Then, useful thermodynamic and kinetic information can be estimated by different approaches: Experimentally determined reaction mechanisms can be validated by identification of transition structures on the PES, which can be obtained for addition reactions, heavy atom transfer (Cl+, Br+, O·) and H atom transfer (simultaneous proton and electron transfer) reactions. However, transition structures in the PES cannot be obtained for e--transfer reactions. Second-order rate constants k for the reactions of micropollutants with chemical oxidants can be obtained by ab initio calculations or by QSARs with various QC descriptors. It has been demonstrated that second-order rate constants from ab initio calculations are within factors 3-750 of the measured values, whereas QSAR-based methods can achieve factors 2-4 compared to the experimental data. The orbital eigenvalue of the highest occupied molecular orbital ( EHOMO) is the most commonly used descriptor for QSAR-based computations of k-values. In combination with results from experimental studies, QC computations can also be applied to investigate reaction mechanisms for verification/understanding of oxidative mechanisms, calculation of branching ratios or regioselectivity, evaluation of the experimental product distribution and assessment of substitution effects. Furthermore, other important physical-chemical constants such as unknown equilibria for species, which are not measurable due to low concentrations, or p Ka values of reactive transient species can be estimated. With further development of QC-based methods, it will become possible to implement kinetic and mechanistic information from such computations in in silico models to predict oxidative transformation of micropollutants. Such predictions can then be complemented by tailored experimental studies to confirm/falsify the computations.
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Affiliation(s)
- Peter R. Tentscher
- Department of Chemistry and Bioscience, Aalborg University, 9220 Aalborg East, Denmark
| | - Minju Lee
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Urs von Gunten
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH-8600 Duebendorf, Switzerland
- School of Architecture, Civil and Environmental Engineering (ENAC), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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17
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Abstract
The regioselectivity of hydroxyl radical addition to arenes was studied using a novel analytical method capable of trapping radicals formed after the first elementary step of reaction, without alteration of the product distributions by secondary oxidation processes. Product analyses of these reactions indicate a preference for o- over p-substitution for electron donating groups, with both favored over m-addition. The observed distributions are qualitatively similar to those observed for the addition of other carbon-centered radicals, although the magnitude of the regioselectivity observed is greater for hydroxyl. The data, reproduced by high accuracy CBS-QB3 computational methods, indicate that both polar and radical stabilization effects play a role in the observed regioselectivities. The application and potential limitations of the analytical method used are discussed.
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Affiliation(s)
- Lee C Moores
- Department of Chemistry , Ball State University , Muncie , Indiana 47306 , United States
| | - Devinder Kaur
- Department of Chemistry , Ball State University , Muncie , Indiana 47306 , United States
| | - Mathew D Smith
- Department of Chemistry , Ball State University , Muncie , Indiana 47306 , United States
| | - James S Poole
- Department of Chemistry , Ball State University , Muncie , Indiana 47306 , United States
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18
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Johnson EM, Waggoner AR, Xia S, Luk HL, Hadad CM, Poole JS. Reactivity of Hydroxyl Radical in Nonaqueous Phases: Addition Reactions. J Phys Chem A 2018; 122:8326-8335. [DOI: 10.1021/acs.jpca.8b08463] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Erica M. Johnson
- Department of Chemistry, Ball State University, Muncie, Indiana 47306, United States
| | - Abygail R. Waggoner
- Department of Chemistry, Ball State University, Muncie, Indiana 47306, United States
| | - Shijing Xia
- Department of Chemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Hoi Ling Luk
- Department of Chemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Christopher M. Hadad
- Department of Chemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - James S. Poole
- Department of Chemistry, Ball State University, Muncie, Indiana 47306, United States
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19
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Kamath D, Mezyk SP, Minakata D. Elucidating the Elementary Reaction Pathways and Kinetics of Hydroxyl Radical-Induced Acetone Degradation in Aqueous Phase Advanced Oxidation Processes. Environ Sci Technol 2018; 52:7763-7774. [PMID: 29923393 DOI: 10.1021/acs.est.8b00582] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Advanced oxidation processes (AOPs) that produce highly reactive hydroxyl radicals are promising methods to destroy aqueous organic contaminants. Hydroxyl radicals react rapidly and nonselectively with organic contaminants and degrade them into intermediates and transformation byproducts. Past studies have indicated that peroxyl radical reactions are responsible for the formation of many intermediate radicals and transformation byproducts. However, complex peroxyl radical reactions that produce identical transformation products make it difficult to experimentally study the elementary reaction pathways and kinetics. In this study, we used ab initio quantum mechanical calculations to identify the thermodynamically preferable elementary reaction pathways of hydroxyl radical-induced acetone degradation by calculating the free energies of the reaction and predicting the corresponding reaction rate constants by calculating the free energies of activation. In addition, we solved the ordinary differential equations for each species participating in the elementary reactions to predict the concentration profiles for acetone and its transformation byproducts in an aqueous phase UV/hydrogen peroxide AOP. Our ab initio quantum mechanical calculations found an insignificant contribution of Russell reaction mechanisms of peroxyl radicals, but significant involvement of HO2• in the peroxyl radical reactions. The predicted concentration profiles were compared with experiments in the literature, validating our elementary reaction-based kinetic model.
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Affiliation(s)
- Divya Kamath
- Department of Civil and Environmental Engineering , Michigan Technological University , Houghton , Michigan 49931 , United States
| | - Stephen P Mezyk
- Department of Chemistry and Biochemistry , California State University , Long Beach , California 90840 , United States
| | - Daisuke Minakata
- Department of Civil and Environmental Engineering , Michigan Technological University , Houghton , Michigan 49931 , United States
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20
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Minakata D, Coscarelli E. Mechanistic Insight into the Degradation of Nitrosamines via Aqueous-Phase UV Photolysis or a UV-Based Advanced Oxidation Process: Quantum Mechanical Calculations. Molecules 2018; 23:molecules23030539. [PMID: 29495565 PMCID: PMC6017648 DOI: 10.3390/molecules23030539] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 02/21/2018] [Accepted: 02/23/2018] [Indexed: 11/16/2022] Open
Abstract
Nitrosamines are a group of carcinogenic chemicals that are present in aquatic environments that result from byproducts of industrial processes and disinfection products. As indirect and direct potable reuse increase, the presence of trace nitrosamines presents challenges to water infrastructures that incorporate effluent from wastewater treatment. Ultraviolet (UV) photolysis or UV-based advanced oxidation processes that produce highly reactive hydroxyl radicals are promising technologies to remove nitrosamines from water. However, complex reaction mechanisms involving radicals limit our understandings of the elementary reaction pathways embedded in the overall reactions identified experimentally. In this study, we perform quantum mechanical calculations to identify the hydroxyl radical-induced initial elementary reactions with N-nitrosodimethylamine (NDMA), N-nitrosomethylethylamine, and N-nitrosomethylbutylamine. We also investigate the UV-induced NDMA degradation mechanisms. Our calculations reveal that the alkyl side chains of nitrosamine affect the reaction mechanism of hydroxyl radicals with each nitrosamine investigated in this study. Nitrosamines with one- or two-carbon alkyl chains caused the delocalization of the electron density, leading to slower subsequent degradation. Additionally, three major initial elementary reactions and the subsequent radical-involved reaction pathways are identified in the UV-induced NDMA degradation process. This study provides mechanistic insight into the elementary reaction pathways, and a future study will combine these results with the kinetic information to predict the time-dependent concentration profiles of nitrosamines and their transformation products.
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Affiliation(s)
- Daisuke Minakata
- Department of Civil and Environmental Engineering, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931, USA.
| | - Erica Coscarelli
- Department of Civil and Environmental Engineering, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931, USA.
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21
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Affiliation(s)
- Frank-Dieter Kopinke
- Department of Environmental
Engineering, Helmholtz Centre for Environmental Research − UFZ, Permoserstrasse 15, D-04318 Leipzig, Germany
| | - Anett Georgi
- Department of Environmental
Engineering, Helmholtz Centre for Environmental Research − UFZ, Permoserstrasse 15, D-04318 Leipzig, Germany
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22
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Minakata D, Kamath D, Maetzold S. Mechanistic Insight into the Reactivity of Chlorine-Derived Radicals in the Aqueous-Phase UV-Chlorine Advanced Oxidation Process: Quantum Mechanical Calculations. Environ Sci Technol 2017; 51:6918-6926. [PMID: 28541663 DOI: 10.1021/acs.est.7b00507] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The combined ultraviolet (UV) and free chlorine (UV-chlorine) advanced oxidation process that produces highly reactive hydroxyl radicals (HO•) and chlorine radicals (Cl•) is an attractive alternative to UV alone or chlorination for disinfection because of the destruction of a wide variety of organic compounds. However, concerns about the potential formation of chlorinated transformation products require an understanding of the radical-induced elementary reaction mechanisms and their reaction-rate constants. While many studies have revealed the reactivity of oxygenated radicals, the reaction mechanisms of chlorine-derived radicals have not been elucidated due to the data scarcity and discrepancies among experimental observations. We found a linear free-energy relationship quantum mechanically calculated free energies of reaction and the literature-reported experimentally measured reaction rate constants, kexp, for 22 chlorine-derived inorganic radical reactions in the UV-chlorine process. This relationship highlights the discrepancy among literature-reported rate constants and aids in the determination of the rate constant using quantum mechanical calculations. We also found linear correlations between the theoretically calculated free energies of activation and kexp for 31 reactions of Cl• with organic compounds. The correlation suggests that H-abstraction and Cl-adduct formation are the major reaction mechanisms. This is the first comprehensive study on chlorine-derived radical reactions, and it provides mechanistic insight into the reaction mechanisms for the development of an elementary reaction-based kinetic model.
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Affiliation(s)
- Daisuke Minakata
- Department of Civil and Environmental Engineering, Michigan Technological University , 1400 Townsend Drive, Houghton, Michigan 49931, United States
| | - Divya Kamath
- Department of Civil and Environmental Engineering, Michigan Technological University , 1400 Townsend Drive, Houghton, Michigan 49931, United States
| | - Shaye Maetzold
- Department of Civil and Environmental Engineering, Michigan Technological University , 1400 Townsend Drive, Houghton, Michigan 49931, United States
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23
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Arnold WA, Oueis Y, O'Connor M, Rinaman JE, Taggart MG, McCarthy RE, Foster KA, Latch DE. QSARs for phenols and phenolates: oxidation potential as a predictor of reaction rate constants with photochemically produced oxidants. Environ Sci Process Impacts 2017; 19:324-338. [PMID: 27942650 DOI: 10.1039/c6em00580b] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Quantitative structure-activity relationships (QSARs) for prediction of the reaction rate constants of phenols and phenolates with three photochemically produced oxidants, singlet oxygen, carbonate radical, and triplet excited state sensitizers/organic matter, are developed. The predictive variable is the one-electron oxidation potential (E1), which is calculated for each species using density functional theory. The reaction rate constants are obtained from the literature, and for singlet oxygen, are augmented with new experimental data. Calculated E1 values have a mean unsigned error compared to literature values of 0.04-0.06 V. For singlet oxygen, a single linear QSAR that includes both phenols and phenolates is developed that predicts experimental rate constants, on average, to within a factor of three. Predictions for only 6 out of 87 compounds are off by more than a factor of 10. A more limited data set for carbonate radical reactions with phenols and phenolates also gives a single linear QSAR with prediction of rate constant being accurate to within a factor of three. The data for the reactions of phenols with triplet state sensitizers demonstrate that two sensitizers, 2-acetonaphthone and methylene blue, most closely predict the reactivity trend of triplet excited state organic matter with phenols. Using sensitizers with stronger reduction potentials could lead to overestimation of rate constants and thus underestimation of phenolic pollutant persistence.
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Affiliation(s)
- William A Arnold
- Department of Civil, Environmental, and Geo- Engineering, University of Minnesota, 500 Pillsbury Drive SE, Minneapolis, Minnesota 55455-0116, USA.
| | - Yan Oueis
- Department of Civil, Environmental, and Geo- Engineering, University of Minnesota, 500 Pillsbury Drive SE, Minneapolis, Minnesota 55455-0116, USA.
| | - Meghan O'Connor
- Department of Civil, Environmental, and Geo- Engineering, University of Minnesota, 500 Pillsbury Drive SE, Minneapolis, Minnesota 55455-0116, USA.
| | - Johanna E Rinaman
- Department of Chemistry, Seattle University, 901 12th Avenue, Seattle, WA 98122, USA.
| | - Miranda G Taggart
- Department of Chemistry, Seattle University, 901 12th Avenue, Seattle, WA 98122, USA.
| | - Rachel E McCarthy
- Department of Chemistry, Seattle University, 901 12th Avenue, Seattle, WA 98122, USA.
| | - Kimberley A Foster
- Department of Chemistry, Seattle University, 901 12th Avenue, Seattle, WA 98122, USA.
| | - Douglas E Latch
- Department of Chemistry, Seattle University, 901 12th Avenue, Seattle, WA 98122, USA.
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24
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Nolte TM, Ragas AMJ. A review of quantitative structure-property relationships for the fate of ionizable organic chemicals in water matrices and identification of knowledge gaps. Environ Sci Process Impacts 2017; 19:221-246. [PMID: 28296985 DOI: 10.1039/c7em00034k] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Many organic chemicals are ionizable by nature. After use and release into the environment, various fate processes determine their concentrations, and hence exposure to aquatic organisms. In the absence of suitable data, such fate processes can be estimated using Quantitative Structure-Property Relationships (QSPRs). In this review we compiled available QSPRs from the open literature and assessed their applicability towards ionizable organic chemicals. Using quantitative and qualitative criteria we selected the 'best' QSPRs for sorption, (a)biotic degradation, and bioconcentration. The results indicate that many suitable QSPRs exist, but some critical knowledge gaps remain. Specifically, future focus should be directed towards the development of QSPR models for biodegradation in wastewater and sediment systems, direct photolysis and reaction with singlet oxygen, as well as additional reactive intermediates. Adequate QSPRs for bioconcentration in fish exist, but more accurate assessments can be achieved using pharmacologically based toxicokinetic (PBTK) models. No adequate QSPRs exist for bioconcentration in non-fish species. Due to the high variability of chemical and biological species as well as environmental conditions in QSPR datasets, accurate predictions for specific systems and inter-dataset conversions are problematic, for which standardization is needed. For all QSPR endpoints, additional data requirements involve supplementing the current chemical space covered and accurately characterizing the test systems used.
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Affiliation(s)
- Tom M Nolte
- Department of Environmental Science, Institute for Water and Wetland Research, Radboud University Nijmegen, P.O. Box 9010, 6500 GL Nijmegen, The Netherlands.
| | - Ad M J Ragas
- Department of Environmental Science, Institute for Water and Wetland Research, Radboud University Nijmegen, P.O. Box 9010, 6500 GL Nijmegen, The Netherlands.
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25
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Paraskevas PD, Sabbe MK, Reyniers MF, Marin GB, Papayannakos NG. Group additive kinetic modeling for carbon-centered radical addition to oxygenates and β-scission of oxygenates. AIChE J 2016. [DOI: 10.1002/aic.15139] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Paschalis D. Paraskevas
- Laboratorium voor Chemische Technologie; Universiteit Gent; Technologiepark 914 9052 Gent Belgium
- School of Chemical Engineering; National Technical University of Athens; 15780 Athens Greece
| | - Maarten K. Sabbe
- Laboratorium voor Chemische Technologie; Universiteit Gent; Technologiepark 914 9052 Gent Belgium
| | - Marie-Françoise Reyniers
- Laboratorium voor Chemische Technologie; Universiteit Gent; Technologiepark 914 9052 Gent Belgium
| | - Guy B. Marin
- Laboratorium voor Chemische Technologie; Universiteit Gent; Technologiepark 914 9052 Gent Belgium
| | - Nikos G. Papayannakos
- School of Chemical Engineering, National Technical University of Athens; 15780 Athens Greece
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26
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Guo X, Minakata D, Crittenden J. On-the-Fly Kinetic Monte Carlo Simulation of Aqueous Phase Advanced Oxidation Processes. Environ Sci Technol 2015; 49:9230-9236. [PMID: 26134180 DOI: 10.1021/acs.est.5b02034] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We have developed an on-the-fly kinetic Monte Carlo (KMC) model to predict the degradation mechanisms and fates of intermediates and byproducts that are produced during aqueous-phase advanced oxidation processes (AOPs). The on-the-fly KMC model is composed of a reaction pathway generator, a reaction rate constant estimator, a mechanistic reduction module, and a KMC solver. The novelty of this work is that we develop the pathway as we march forward in time rather than developing the pathway before we use the KMC method to solve the equations. As a result, we have fewer reactions to consider, and we have greater computational efficiency. We have verified this on-the-fly KMC model for the degradation of polyacrylamide (PAM) using UV light and titanium dioxide (i.e., UV/TiO2). Using the on-the-fly KMC model, we were able to predict the time-dependent profiles of the average molecular weight for PAM. The model provided detailed and quantitative insights into the time evolution of the molecular weight distribution and reaction mechanism. We also verified our on-the-fly KMC model for the destruction of (1) acetone, (2) trichloroethylene (TCE), and (3) polyethylene glycol (PEG) for the ultraviolet light and hydrogen peroxide AOP. We demonstrated that the on-the-fly KMC model can achieve the same accuracy as the computer-based first-principles KMC (CF-KMC) model, which has already been validated in our earlier work. The on-the-fly KMC is particularly suitable for molecules with large molecular weights (e.g., polymers) because the degradation mechanisms for large molecules can result in hundreds of thousands to even millions of reactions. The ordinary differential equations (ODEs) that describe the degradation pathways cannot be solved using traditional numerical methods, but the KMC can solve these equations.
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Affiliation(s)
- Xin Guo
- †School of Civil and Environmental Engineering, Georgia Institute of Technology, 828 West Peachtree Street, Atlanta, Georgia 30332, United States
| | - Daisuke Minakata
- ‡Department of Civil and Environmental Engineering, Michigan Technological University, 1400 Townsend Drive, Houghton, Michigan 49931, United States
| | - John Crittenden
- †School of Civil and Environmental Engineering, Georgia Institute of Technology, 828 West Peachtree Street, Atlanta, Georgia 30332, United States
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27
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Minakata D, Song W, Mezyk SP, Cooper WJ. Experimental and theoretical studies on aqueous-phase reactivity of hydroxyl radicals with multiple carboxylated and hydroxylated benzene compounds. Phys Chem Chem Phys 2015; 17:11796-812. [DOI: 10.1039/c5cp00861a] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this study, we shed light on the initial addition of hydroxyl radicals (HO˙) to multiple carboxylated and hydroxylated benzene compounds in aqueous-phase advanced oxidation processes (AOPs).
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Affiliation(s)
- Daisuke Minakata
- Department of Civil and Environmental Engineering
- Michigan Technological University
- Houghton
- USA
| | - Weihua Song
- Department of Environmental Science and Engineering
- Fudan University
- Shanghai
- P. R. China
| | - Stephen P. Mezyk
- Department of Chemistry and Biochemistry
- California State University Long Beach
- Long Beach
- USA
| | - William J. Cooper
- Department of Civil and Environmental Engineering
- University of California
- Irvine
- USA
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28
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Guo X, Minakata D, Niu J, Crittenden J. Computer-based first-principles kinetic modeling of degradation pathways and byproduct fates in aqueous-phase advanced oxidation processes. Environ Sci Technol 2014; 48:5718-5725. [PMID: 24749836 DOI: 10.1021/es500359g] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In this study, a computer-based first-principles kinetic model is developed to predict the degradation mechanisms and fates of intermediates and byproducts produced during aqueous-phase advanced oxidation processes (AOPs) for various organic compounds. The model contains a rule-based pathway generator to generate the reaction pathways, a reaction rate constant estimator to estimate the reaction rate constant for each reaction generated, a mechanistic reduction module to reduce the generated mechanisms, an ordinary differential equations generator and solver to solve the generated mechanisms and calculate the concentration profiles for all species, and a toxicity estimator to estimate the toxicity of major species and calculate time-dependent profiles of relative toxicity (i.e., concentration of species divided by toxicity value). We predict concentration profiles of acetone and trichloroethylene and their intermediates and byproducts in photolysis with hydrogen peroxide (i.e., UV/H2O2) and validate with experimental observations. The predicted concentration profiles for both parent compounds are consistent with experimental data. The calculated profiles of 96-h green algae chronic toxicity show that the overall toxicity decreases during the degradation process. These generated mechanisms also provide detailed and quantitative insights into the pathways for the formation and consumption of important intermediates and byproducts produced during AOPs. Our approach is sufficiently general to be applied to a wide range of contaminants.
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Affiliation(s)
- Xin Guo
- School of Civil and Environmental Engineering, Georgia Institute of Technology , 828 West Peachtree Street, Atlanta, Georgia 30332, United States
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