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Wu L, Liu S, Liu H. Dichloramine Hydrolysis in Membrane Desalination Permeate: Mechanistic Insights and Implications for Oxidative Capacity in Potable Reuse Applications. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:13157-13167. [PMID: 38996057 PMCID: PMC11270831 DOI: 10.1021/acs.est.4c04547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2024] [Revised: 06/25/2024] [Accepted: 06/25/2024] [Indexed: 07/14/2024]
Abstract
Dichloramine (NHCl2) naturally exists in reverse osmosis (RO) permeate due to its application as an antifouling chemical in membrane-based potable reuse treatment. This study investigated mechanisms of background NHCl2 hydrolysis associated with the generation of oxidative radical species in RO permeate, established a kinetic model to predict the oxidative capacity, and examined its removal efficiency on trace organic contaminants in potable reuse. Results showed that NHCl2 hydrolysis generated transient peroxynitrite (ONOO-) and subsequently dissociated into hydroxyl radical (HO•). The maximal HO• exposure was observed at an RO permeate pH of 8.4, higher than that from typical ultraviolet (UV)-based advanced oxidation processes. The HO• exposure during NHCl2 hydrolysis also peaked at a NH2Cl-to-NHCl2 molar ratio of 1:1. The oxidative capacity rapidly degraded 1,4-dioxane, carbamazepine, atenolol, and sulfamethoxazole in RO permeate. Furthermore, background elevated carbonate in fresh RO permeate can convert HO• to carbonate radical (CO3•-). Aeration of the RO permeate removed total carbonate, significantly increased HO• exposure, and enhanced the degradation kinetics of trace organic contaminants. The kinetic model of NHCl2 hydrolysis predicted well the degradation of contaminants in RO permeate. This study provides new mechanistic insights into NHCl2 hydrolysis that contributes to the oxidative degradation of trace organic contaminants in potable reuse systems.
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Affiliation(s)
- Liang Wu
- Environmental
Toxicology Program, University of California, Riverside, California 92521, United States
- Department
of Chemical and Environmental Engineering, University of California, Riverside, California 92521, United States
| | - Sitao Liu
- Department
of Chemical and Environmental Engineering, University of California, Riverside, California 92521, United States
| | - Haizhou Liu
- Environmental
Toxicology Program, University of California, Riverside, California 92521, United States
- Department
of Chemical and Environmental Engineering, University of California, Riverside, California 92521, United States
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2
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Bhattacharjee L, Xia C, Krouse E, Yang H, Liu J. Degradation of 1,4-dioxane by heterogeneous photocatalysis and a photo-Fenton-like process under fluorescent light. ENVIRONMENTAL TECHNOLOGY 2024; 45:2879-2890. [PMID: 36924262 DOI: 10.1080/09593330.2023.2192367] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 03/08/2023] [Indexed: 06/18/2023]
Abstract
The overall objective of this study was to develop cost-effective treatment processes for 1,4-dioxane removal that were safe and easy to scale up. Degradation of 1,4-dioxane was conducted and compared for the first time by heterogeneous photocatalysis and a photo-Fenton-like process under cool white fluorescent light in mild conditions, using two types of commercial nanoparticles-titanium dioxide (TiO2) and nanoscale zero-valent iron (nZVI), respectively. Both types of nanoparticles removed >99.9% of 1,4-dioxane in a short period of time. Hydroxyl radicals (·OH), superoxide radicals (·O2-), and hydrogen peroxide (H2O2) were detected in both degradation processes; photogenerated holes (h+) were critical in the degradation of 1,4-dioxane by the photocatalytic process using TiO2. 1,4-Dioxane can be degraded at pH 7 in TiO2/light system and at pH 3 in nZVI/light system, and faster degradation of 1,4-dioxane at even higher concentration was achieved in the former system. Increase in light intensity accelerated 1,4-dioxane degradation, which followed first order kinetics in both systems. In wastewater effluent, the removal of 1,4-dioxane was slower than that in deionised water, which likely reflected the complex compositions of the wastewater effluent. Under combined UVA and visible light illumination, a two-stage degradation process was proposed for 1,4-dioxane for the first time by TiO2 nanoparticles; this study also demonstrated for the first time 1,4-dioxane degradation by the photo-Fenton-like process using nZVI. The cost-effective solutions using commercial nanoparticles under fluorescent light developed in this study can be potentially applied to treat water contaminated by high concentrations of 1,4-dioxane in large-scale.
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Affiliation(s)
- Linkon Bhattacharjee
- School of Civil, Environmental and Infrastructure Engineering, Southern Illinois University Carbondale, Carbondale, IL, USA
| | - Chunjie Xia
- School of Civil, Environmental and Infrastructure Engineering, Southern Illinois University Carbondale, Carbondale, IL, USA
- Paul H. O'Neill School of Public and Environmental Affairs, Indiana University Bloomington, Bloomington, IN, USA
| | - Ethan Krouse
- Department of Mechanical Engineering, University of Evansville, Evansville, IN, USA
| | - Haoran Yang
- School of Civil, Environmental and Infrastructure Engineering, Southern Illinois University Carbondale, Carbondale, IL, USA
| | - Jia Liu
- School of Civil, Environmental and Infrastructure Engineering, Southern Illinois University Carbondale, Carbondale, IL, USA
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3
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Cochran KH, Westerman DC, Montagner CC, Coffin S, Diaz L, Fryer B, Harraka G, Xu EG, Huang Y, Schlenk D, Dionysiou DD, Richardson SD. Chlorination of Emerging Contaminants for Application in Potable Wastewater Reuse: Disinfection Byproduct Formation, Estrogen Activity, and Cytotoxicity. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:704-716. [PMID: 38109774 DOI: 10.1021/acs.est.3c05978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2023]
Abstract
With increasing water scarcity, many utilities are considering the potable reuse of wastewater as a source of drinking water. However, not all chemicals are removed in conventional wastewater treatment, and disinfection byproducts (DBPs) can form from these contaminants when disinfectants are applied during or after reuse treatment, especially if applied upstream of advanced treatment processes to control biofouling. We investigated the chlorination of seven priority emerging contaminants (17β-estradiol, estrone, 17α-ethinylestradiol, bisphenol A (BPA), diclofenac, p-nonylphenol, and triclosan) in ultrapure water, and we also investigated the impact of chlorination on real samples from different treatment stages of an advanced reuse plant to evaluate the role of chlorination on the associated cytotoxicity and estrogenicity. Many DBPs were tentatively identified via liquid chromatography (LC)- and gas chromatography (GC)-high resolution mass spectrometry, including 28 not previously reported. These encompassed chlorinated, brominated, and oxidized analogs of the parent compounds as well as smaller halogenated molecules. Chlorinated BPA was the least cytotoxic of the DBPs formed but was highly estrogenic, whereas chlorinated hormones were highly cytotoxic. Estrogenicity decreased by ∼4-6 orders of magnitude for 17β-estradiol and estrone following chlorination but increased 2 orders of magnitude for diclofenac. Estrogenicity of chlorinated BPA and p-nonylphenol were ∼50% of the natural/synthetic hormones. Potential seasonal differences in estrogen activity of unreacted vs reacted advanced wastewater treatment field samples were observed.
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Affiliation(s)
- Kristin H Cochran
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Danielle C Westerman
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Cassiana C Montagner
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
- Institute of Chemistry, University of Campinas, São Paulo 13083-970, Brazil
| | - Scott Coffin
- Department of Environmental Sciences, University of California, Riverside, California 92521, United States
| | - Lorivic Diaz
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Benjamin Fryer
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Gary Harraka
- Department of Environmental Sciences, University of California, Riverside, California 92521, United States
| | - Elvis Genbo Xu
- Department of Environmental Sciences, University of California, Riverside, California 92521, United States
| | - Ying Huang
- Environmental Engineering and Science Program, Department of Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, Ohio 45221, United States
- School of the Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310024, China
| | - Daniel Schlenk
- Department of Environmental Sciences, University of California, Riverside, California 92521, United States
| | - Dionysios D Dionysiou
- Environmental Engineering and Science Program, Department of Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, Ohio 45221, United States
| | - Susan D Richardson
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
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Lei Y, Yu Y, Lei X, Liang X, Cheng S, Ouyang G, Yang X. Assessing the Use of Probes and Quenchers for Understanding the Reactive Species in Advanced Oxidation Processes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:5433-5444. [PMID: 36930043 DOI: 10.1021/acs.est.2c09338] [Citation(s) in RCA: 119] [Impact Index Per Article: 59.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Advanced oxidation processes (AOPs) are increasingly applied in water and wastewater treatment. Understanding the role of reactive species using probes and quenchers is one of the main requirements for good process design. However, much fundamental kinetic data for the reactions of probes and quenchers with reactive species is lacking, probably leading to inappropriate probe and quencher selection and dosing. In this work, second-order rate constants for over 150 reactions of probes and quenchers with reactive species such as •OH, SO4•-, and Cl• and chemical oxidants such as free chlorine and persulfate were determined. Some previously ill-quantified reactions (e.g., furfuryl alcohol and methyl phenyl sulfoxide reactions with certain chemical oxidants, nitrobenzene and 1,4-dioxane reactions with certain halogen radicals) were found to be kinetically favorable. The selection of specific probes can be guided by the improved kinetic database. The criteria for properly choosing dosages of probes and quenchers were proposed along with a procedure for quantifying reactive species free of interference from probe addition. The limitations of probe and quencher approaches were explicated, and possible solutions (e.g., the combination with other tools) were proposed. Overall, the kinetic database and protocols provided in this work benefit future research in understanding the radical chemistry in AOPs as well as other radical-involved processes.
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Affiliation(s)
- 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, P. R. China
- Key Laboratory of Photochemistry, Institute of Chemistry Chinese Academy of Sciences, Beijing National Laboratory for Molecular Sciences, Beijing 100190, P. R. China
| | - Yafei Yu
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, P. R. 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, P. R. China
| | - Xi Liang
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, P. R. China
| | - ShuangShuang Cheng
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, P. R. China
| | - Gangfeng Ouyang
- School of Chemistry, Sun Yat-sen University, Guangzhou 510275, P. R. 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, P. R. 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. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:11111-11131. [PMID: 35797184 DOI: 10.1021/acs.est.2c01017] [Citation(s) in RCA: 139] [Impact Index Per Article: 46.3] [Reference Citation Analysis] [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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Efficacy of Continuous Flow Reactors for Biological Treatment of 1,4-Dioxane Contaminated Textile Wastewater Using a Mixed Culture. FERMENTATION-BASEL 2022. [DOI: 10.3390/fermentation8040143] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The goal of this study was to evaluate the biodegradation of 1,4–dioxane using a mixed biological culture grown in textile wastewater sludge with 1,4–dioxane as the sole carbon source. The conditions for the long-term evaluation of 1,4–dioxane degradation were determined and optimized by batch scale analysis. Moreover, Monod’s model was used to determine the biomass decay rate and unknown parameters. The soluble chemical oxygen demand (sCOD) was used to determine the concentration of 1,4–dioxane in the batch test, and gas chromatography/mass spectrometry (GC/MS) was used to measure the concentrations via long-term wastewater analysis. Two types of reactors (continuous stirred reactor (CSTR) and plug flow reactor (PFR)) for the treatment of 1,4–dioxane from textile wastewater were operated for more than 120 days under optimized conditions. These used the mixed microbial culture grown in textile wastewater sludge and 1,4–dioxane as the sole carbon source. The results indicated efficient degradation of 1,4–dioxane by the mixed culture in the presence of a competitive inhibitor, with an increase in degradation time from 13.37 h to 55 h. A specific substrate utilization rate of 0.0096 mg 1,4–dioxane/mg MLVSS/h was observed at a hydraulic retention time of 20 h for 20 days of operation in a biomass concentration of 3000 mg/L produced by the mixed microbial culturing process. In the long-term analysis, effluent concentrations of 3 mg/L and <1 mg/L of 1,4–dioxane were observed for CSTR and PFR, respectively. The higher removal efficacy of PFR was due to the production of more MLVSS at 4000 mg/L compared to the outcome of 3000 mg/L in CSTR in a competitive environment.
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Guo K, Wu Z, Chen C, Fang J. UV/Chlorine Process: An Efficient Advanced Oxidation Process with Multiple Radicals and Functions in Water Treatment. Acc Chem Res 2022; 55:286-297. [PMID: 35025201 DOI: 10.1021/acs.accounts.1c00269] [Citation(s) in RCA: 96] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Because of the deterioration of global water quality, the occurrence of chemical and microbial contaminants in water raises serious concerns for the health of the population. Identifying and developing effective and environmentally friendly water treatment technologies are critical to obtain clean water. Among the various technologies for the purification of water, ultraviolet photolysis of chlorine (UV/chlorine), an emerging advanced oxidation process (AOP), has multiple functions for the control of contaminants via the production of hydroxyl radicals (HO·) and reactive chlorine species (RCS), such as Cl·, ClO·, and Cl2·-.This Account centers around the radical chemistry of RCS and HO· in different water matrices and their roles and mechanisms in the abatement of contaminants. The concentrations of Cl·, ClO·, and Cl2·- are comparable to or higher than those of HO· (10-14 to 10-13 M). The reactivities of RCS are more selective than HO· with a broader range of second-order rate constants (k). The k values of Cl· toward most aromatics are higher or similar as compared to those of HO·, while those of Cl2·- and ClO· are less reactive but more selective toward aromatics containing electron-donating functional groups. Their major reaction mechanisms with Cl· are electron transfer and addition, while those with ClO· and Cl2·- primarily involve electron transfer. As for aliphatics, their reactivities with both HO· and RCS are much lower than those of aromatics. The reaction mechanisms for most of them with Cl· and Cl2·- are hydrogen abstraction, except for olefins, which are addition. In addition, RCS greatly contribute to the inactivation of microbial contaminants.Toward future application, the UV/chlorine process has both pros and cons. Compared with the traditional HO·-based AOP of UV/H2O2, UV/chlorine is more efficient and energy-saving for oxidation and disinfection, and its efficiency is less affected by water matrix components. However, the formation of toxic byproducts in UV/chlorine limits its application scenarios. In dissolved organic matter (DOM)-rich water, the formation of halogenated byproducts is enhanced in UV/chlorine. In the presence of ammonia, reactive nitrogen species (RNS) (e.g., ·NO and ·NO2) are involved, and highly toxic nitro(so) products such as nitro(so)-phenolics and N-nitrosodimethylamine are generated. For a niche application, the UV/chlorine process is recommended to be utilized in water with low levels of DOM and ammonia.Strategies should be developed to make full use of highly reactive species (RCS and HO·) for the abatement of target contaminants and to reduce the formation of toxic byproducts. For example, the UV/chlorine process can be used in tandem with other treatments to create multiple barriers for the production of safe water. In addition, halogen radicals are very important in ecosystems as well as other areas such as medical therapy and organic synthesis. UV/chlorine is the most efficient homogeneous system to generate halogen radicals, and thus it provides a perfect system to investigate the fates of halogen radicals for interdisciplinary research.
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Affiliation(s)
- Kaiheng Guo
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, P. R. China
| | - Zihao Wu
- Advanced Institute of Natural Sciences, Beijing Normal University at Zhuhai Zhuhai 519087, P. R. China
| | - Chunyan Chen
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, P. R. China
| | - Jingyun Fang
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, P. R. China
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Suh MJ, Mitch WA. Sunlight-Driven Chlorate Formation during Produce Irrigation with Chlorine- or Chloramine-Disinfected Water. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:14876-14885. [PMID: 34652150 DOI: 10.1021/acs.est.1c04994] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The increasing use of chlorine- or chloramine-containing irrigation waters to minimize foodborne pathogens is raising concerns about the formation and uptake of disinfection byproducts into irrigated produce. Chlorate has received particular attention in the European Union. While previous research demonstrated the formation of chlorate from dark disproportionation reactions of free chlorine and uptake of chlorate into produce from roots, this study evaluated chlorate formation from solar irradiation of chlorine- and chloramine-containing irrigation droplets and uptake through produce surfaces. Sunlight photolysis of 50 μM (3.6 mg/L as Cl2) chlorine significantly enhanced the formation of chlorate, with a 7.2% molar yield relative to chlorine. Chlorate formation was much less significant in sunlit chloramine solutions. In chlorinated solutions containing 270 μg/L bromide, sunlight also induced the conversion of bromide to 280 μg/L bromate. Droplet evaporation and the resulting increase in chlorine concentrations approximately doubled sunlight-induced chlorate formation relative to that in the bulk solutions in which evaporation is negligible. When vegetables (broccoli, cabbage, chicory, lettuce, and spinach) were sprayed with chlorine-containing irrigation water in a sunlit field, sunlight promoted chlorate formation and uptake through vegetable surfaces to concentrations above maximum residue levels in the European Union. Spraying with chloramine-containing waters in the dark minimized chlorate formation and uptake into the vegetables.
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Affiliation(s)
- Min-Jeong Suh
- Department of Civil and Environmental Engineering, Stanford University, 473 Via Ortega, Stanford, California 94305, United States
| | - William A Mitch
- Department of Civil and Environmental Engineering, Stanford University, 473 Via Ortega, Stanford, California 94305, United States
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Yin R, Blatchley ER, Shang C. UV Photolysis of Mono- and Dichloramine Using UV-LEDs as Radiation Sources: Photodecay Rates and Radical Concentrations. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:8420-8429. [PMID: 32501682 DOI: 10.1021/acs.est.0c01639] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
UV-LEDs with four characteristic wavelengths (255, 265, 285, and 300 nm) were used to investigate the wavelength-dependence of the photolysis of two inorganic chloramines (NH2Cl and NHCl2) and their subsequent radical formation. The fluence-based photodecay rates of NH2Cl decreased with increasing wavelength from 255 to 300 nm, while NHCl2 photodecay rates exhibited the opposite wavelength-dependence. The fluence-based photodecay rate of NH2Cl was comparable to that of NHCl2 at 255 nm, but was lower than NHCl2 at other tested wavelengths. The wavelength-dependence was more influenced by the molar absorption coefficient than the apparent/innate quantum yield and the lower photosensitivity was mainly attributed to the higher bond (N-Cl) dissociation energy (BDE) of NH2Cl than NHCl2. The steady-state concentrations of HO• and reactive chlorine species (e.g., Cl2•-, ClO•, and Cl•) that were generated from the photolysis of NH2Cl and NHCl2 at different wavelengths were determined experimentally and compared with the simulated results by a kinetic model. UV photolysis of NHCl2 at 265, 285, and 300 nm generated higher concentrations of radicals (e.g., HO•, ClO•, Cl•, and Cl2-•) than NH2Cl, while UV photolysis of NH2Cl at 255 nm generated higher concentrations of HO•, ClO•, and Cl• but not Cl2-• than NHCl2. The findings of this study provide fundamental information to be used in selecting specific wavelengths of UV radiation for enhancing/optimizing NH2Cl/NHCl2 photodecay in swimming pools and radical generation for micropollutant abatement in drinking water treatment or potable water reuse.
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Affiliation(s)
- Ran Yin
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
- Lyles School of Civil Engineering, Purdue University, 550 Stadium Mall Drive, West Lafayette, Indiana 47907, United States
- Division of Environmental & Ecological Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Ernest R Blatchley
- Lyles School of Civil Engineering, Purdue University, 550 Stadium Mall Drive, West Lafayette, Indiana 47907, United States
- Division of Environmental & Ecological Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Chii Shang
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
- Hong Kong Branch of Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
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10
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Santos Andrade T, Papagiannis I, Dracopoulos V, César Pereira M, Lianos P. Visible-Light Activated Titania and Its Application to Photoelectrocatalytic Hydrogen Peroxide Production. MATERIALS 2019; 12:ma12244238. [PMID: 31861190 PMCID: PMC6947256 DOI: 10.3390/ma12244238] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 12/11/2019] [Accepted: 12/16/2019] [Indexed: 11/16/2022]
Abstract
Photoelectrochemical cells have been constructed with photoanodes based on mesoporous titania deposited on transparent electrodes and sensitized in the Visible by nanoparticulate CdS or CdS combined with CdSe. The cathode electrode was an air–breathing carbon cloth carrying nanoparticulate carbon. These cells functioned in the Photo Fuel Cell mode, i.e., without bias, simply by shining light on the photoanode. The cathode functionality was governed by a two-electron oxygen reduction, which led to formation of hydrogen peroxide. Thus, these devices were employed for photoelectrocatalytic hydrogen peroxide production. Two-compartment cells have been used, carrying different electrolytes in the photoanode and cathode compartments. Hydrogen peroxide production has been monitored by using various electrolytes in the cathode compartment. In the presence of NaHCO3, the Faradaic efficiency for hydrogen peroxide production exceeded 100% due to a catalytic effect induced by this electrolyte. Photocurrent has been generated by either a CdS/TiO2 or a CdSe/CdS/TiO2 combination, both functioning in the presence of sacrificial agents. Thus, in the first case ethanol was used as fuel, while in the second case a mixture of Na2S with Na2SO3 has been employed.
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Affiliation(s)
- Tatiana Santos Andrade
- Department of Chemical Engineering, University of Patras, 26500 Patras, Greece; (T.S.A.); (I.P.)
- Institute of Science, Engineering, and Technology, Universidade Federal dos Vales do Jequitinhonha e Mucuri, Campus Mucuri, 39803–371 Teófilo Otoni, Minas Gerais, Brazil;
| | - Ioannis Papagiannis
- Department of Chemical Engineering, University of Patras, 26500 Patras, Greece; (T.S.A.); (I.P.)
| | | | - Márcio César Pereira
- Institute of Science, Engineering, and Technology, Universidade Federal dos Vales do Jequitinhonha e Mucuri, Campus Mucuri, 39803–371 Teófilo Otoni, Minas Gerais, Brazil;
| | - Panagiotis Lianos
- Department of Chemical Engineering, University of Patras, 26500 Patras, Greece; (T.S.A.); (I.P.)
- Correspondence: ; Tel.: +30-2610-997513
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Mangalgiri KP, Patton S, Wu L, Xu S, Ishida KP, Liu H. Optimizing Potable Water Reuse Systems: Chloramines or Hydrogen Peroxide for UV-Based Advanced Oxidation Process? ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:13323-13331. [PMID: 31635452 DOI: 10.1021/acs.est.9b03062] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
The tapping of municipal wastewater for potable reuse significantly enhances drinking water supply in drought-stricken regions worldwide. Membrane-based potable reuse treatment trains commonly employ ultraviolet-based advanced oxidation processes (UV-AOPs) to degrade trace organic contaminants in water to produce high-quality recycled water. Hydrogen peroxide (H2O2) is used as the default photo-oxidant. Meanwhile, chloramines, which are added to prevent biofouling, pass through the membranes and impact the treatment efficiency of UV-AOP. Water reuse facilities therefore face the dilemma of optimizing H2O2 (an added photo-oxidant) and chloramines (a carry-over photo-oxidant) doses. Utilizing a uniquely designed pilot-scale reactor and real-time recycled water, we evaluated treatment efficiencies of UV-AOP on six important indicator contaminants, with monochloramine (NH2Cl) and H2O2 as photo-oxidants. Hydroxyl radical (HO•) and reactive chlorine species, such as the chlorine atom (Cl•) and chlorine dimer (Cl2•-), were the major reactive species. Overall, radicals generated from photolysis of NH2Cl alone achieved removal of indicator compounds, which can be further improved by optimizing UV fluence, i.e., the UV dose. Furthermore, the addition of H2O2 enhanced HO• formation and improved contaminant removal. However, the addition of H2O2, when the background NH2Cl level was above 2 mg L-1 (as Cl2), provided limited improvement in treatment efficiency. These trade-offs between chloramine and H2O2 as oxidants, and the recommended optimization of the associated effective UV fluence, are critical for energy-efficient and cost-effective potable reuse to address the challenges of global water scarcity.
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Affiliation(s)
- Kiranmayi P Mangalgiri
- Department of Chemical and Environmental Engineering , University of California , Riverside , California 92521 , United States
| | - Samuel Patton
- Department of Chemical and Environmental Engineering , University of California , Riverside , California 92521 , United States
- Program of Environmental Toxicology , University of California , Riverside , California 92521 , United States
| | - Liang Wu
- Department of Chemical and Environmental Engineering , University of California , Riverside , California 92521 , United States
- Program of Environmental Toxicology , University of California , Riverside , California 92521 , United States
| | - Shanhui Xu
- Department of Chemical and Environmental Engineering , University of California , Riverside , California 92521 , United States
| | - Kenneth P Ishida
- Research & Development Department , Orange County Water District , Fountain Valley , California 92708 , United States
| | - Haizhou Liu
- Department of Chemical and Environmental Engineering , University of California , Riverside , California 92521 , United States
- Program of Environmental Toxicology , University of California , Riverside , California 92521 , United States
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Wu Z, Chen C, Zhu BZ, Huang CH, An T, Meng F, Fang J. Reactive Nitrogen Species Are Also Involved in the Transformation of Micropollutants by the UV/Monochloramine Process. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:11142-11152. [PMID: 31411457 DOI: 10.1021/acs.est.9b01212] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The UV/monochloramine (NH2Cl) process is an emerging advanced oxidation process (AOP) in water treatment via radicals produced from the UV photolysis of NH2Cl. This study investigated the degradation of micropollutants by the UV/NH2Cl AOP, with ibuprofen (IBP) and naproxen (NPX) selected as representative micropollutants. Hydroxyl radical (HO•) and chlorine atom (Cl•) were identified in the process, and unexpectedly, we found that reactive nitrogen species (RNS) also played important roles in the transformation of micropollutants. The electron paramagnetic resonance (EPR) analysis proved the production of •NO as well as HO•. The concentrations of HO•, Cl•, and •NO in UV/NH2Cl remained constant at pH 6.0-8.6, resulting in the slightly changed UV fluence-based pseudo-first-order rate constants (k') of IBP and NPX, which were about 1.65 × 10-3 and 2.54 × 10-3 cm2/mJ, respectively. For IBP, the relative contribution of RNS to k' was 27.8% at pH 7 and 50 μM NH2Cl, which was higher than that of Cl• (6.5%) but lower than that of HO• (58.7%). For NPX, the relative contribution of RNS to k' was 13.6%, which was lower than both Cl• (23.2%) and HO• (46.9%). The concentrations of HO•, Cl•, and •NO increased with the increasing NH2Cl dosage. Water matrix components of natural organic matter (NOM) and bicarbonate can scavenge HO•, Cl•, and RNS. The presence of 5 mg/L NOM decreased the k' of IBP and NPX by 66.9 and 57.6%, respectively, while 2 mM bicarbonate decreased the k' of IBP by 57.4% but increased the k' of NPX by 10.5% due to the contribution of CO3•- to NPX degradation. Products containing nitroso-, hydroxyl-, and chlorine-groups were detected during the degradation of IBP and NPX by UV/NH2Cl, indicating the role of nitrogen oxide radical (•NO) as well as HO• and Cl•. Trichloronitromethane formation was strongly enhanced in the UV/NH2Cl-treated samples, further indicating the important roles of RNS in this process. This study first demonstrates the involvement of RNS in the transformation of micropollutants in UV/NH2Cl.
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Affiliation(s)
- Zihao Wu
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering , Sun Yat-Sen University , Guangzhou 510275 , China
| | - Chunyan Chen
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering , Sun Yat-Sen University , Guangzhou 510275 , China
| | - Ben-Zhan Zhu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences and University of Chinese Academy of Sciences , Chinese Academy of Sciences , Beijing 100085 , P. R. China
| | - Chun-Hua Huang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences and University of Chinese Academy of Sciences , Chinese Academy of Sciences , Beijing 100085 , P. R. China
| | - Taicheng An
- Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control , Guangdong University of Technology , Guangzhou 510006 , China
| | - Fangang Meng
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering , Sun Yat-Sen University , Guangzhou 510275 , China
| | - Jingyun Fang
- Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, School of Environmental Science and Engineering , Sun Yat-Sen University , Guangzhou 510275 , China
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Sun P, Meng T, Wang Z, Zhang R, Yao H, Yang Y, Zhao L. Degradation of Organic Micropollutants in UV/NH 2Cl Advanced Oxidation Process. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:9024-9033. [PMID: 31282670 DOI: 10.1021/acs.est.9b00749] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Monochloramine (NH2Cl) can be irradiated by UV to create an advanced oxidation condition (i.e., UV/NH2Cl) for the elimination of organic micropollutants (OMPs) from source water. However, information in retrospective studies was scarce on how UV/NH2Cl performance would be affected by the water matrix and OMP molecular structures. In this study, the degradation of five representative OMPs, including triclosan, carbamazepine, sulfamethoxazole, estradiol (E2), and ethinylestradiol (EE2), was examined in different water matrices. All OMPs were rapidly removed by UV/NH2Cl but exhibited different degradation mechanisms. Although •OH, •Cl, and direct photolysis mainly contributed to the overall degradation of OMPs in buffered nanopure water, the contribution of reactive nitrogen species (RNS) generated from the photolysis of NH2Cl was not negligible in the degradation of E2 and EE2. A phenolic group was identified as the moiety reactive toward RNS. Based on quantitative analysis of the impact on OMP degradation from cosolutes (including Cl-, HCO3-, NOM) as well as pH and NH2Cl doses, we developed a kinetic model for the prediction of OMP degradation in complex water matrices. In environmental water matrices, the performance and radical contributions in UV/NH2Cl and UV/H2O2 systems were taken into comparison, which showed faster degradation of OMPs and a more significant contribution of CO3•- in the UV/NH2Cl process.
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Affiliation(s)
- Peizhe Sun
- School of Environmental Science and Engineering , Tianjin University , Tianjin 300072 , China
| | - Tan Meng
- School of Environmental Science and Engineering , Tianjin University , Tianjin 300072 , China
| | - Zijian Wang
- School of Environmental Science and Engineering , Tianjin University , Tianjin 300072 , China
| | - Ruochun Zhang
- Institute of Surface-Earth System Science , Tianjin University , Tianjin 300072 , China
| | - Hong Yao
- School of Civil Engineering , Beijing Jiaotong University , Beijing 100044 , China
| | - Yongkui Yang
- School of Environmental Science and Engineering , Tianjin University , Tianjin 300072 , China
| | - Lin Zhao
- School of Environmental Science and Engineering , Tianjin University , Tianjin 300072 , China
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Abstract
Increasing demand for fresh water in extreme drought regions necessitates potable water reuse. However, current membrane-based water reclamation approaches cannot effectively remove carcinogenic 1,4-dioxane. The current study reports on the solar-driven removal of 1,4-dioxane (50 mg L−1) using a homemade WO3/nγ-Al2O3 nano-catalyst. Characterization methods including scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and X-ray fluorescence (XRF) analyses are used to investigate the surface features of the catalyst. The 1,4-dioxane mineralization performance of this catalyst under various reaction conditions is studied. The effect of the catalyst dosage is tested. The mean oxidation state carbon (MOSC) values of the 1,4-dioxane solution are followed during the reaction. The short chain organic acids after treatment are measured. The results showed that over 75% total organic carbon (TOC) removal was achieved in the presence of 300 mg L−1 of the catalyst with a simulated solar irradiation intensity of 40 mW cm−2. Increasing the dose of the catalyst from 100 to 700 mg L−1 can improve the treatment efficiency to some extent. The TOC reduction curve fits well with an apparent zero-order kinetic model and the corresponding constant rates are within 0.0927 and 0.1059 mg L−1 s−1, respectively. The MOSC values of the 1,4-dioxane solution increase from 1.3 to 3 along the reaction, which is associated with the formation of some short chain acids. The catalyst can be effectively reused 7 times. This work provides an oxidant-free and energy saving approach to achieve efficient removal of 1,4-dioxane and thus shows promising potential for potable reuse applications.
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Zhang Z, Chuang YH, Huang N, Mitch WA. Predicting the Contribution of Chloramines to Contaminant Decay during Ultraviolet/Hydrogen Peroxide Advanced Oxidation Process Treatment for Potable Reuse. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:4416-4425. [PMID: 30889356 DOI: 10.1021/acs.est.8b06894] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Chloramines applied to control membrane biofouling in potable reuse trains pass through reverse osmosis membranes, such that downstream ultraviolet (UV)/H2O2 advanced oxidation processes (AOPs) are de facto UV/H2O2-chloramine AOPs. Current models for UV/chloramine AOPs, which use inaccurate chloramine quantum yields and ignore the fate of •NH2, are unable to simultaneously predict the loss of chloramines and contaminants, such as 1,4-dioxane. This study determined quantum yields for NH2Cl (0.35) and NHCl2 (0.75). Incorporating these quantum yields and the formation from •NH2 of the radical scavengers, •NO and NO2-, was important for simultaneously modeling the loss of chloramines, H2O2, and 1,4-dioxane in the UV/H2O2-chloramine AOP. Although the level of radical production was higher for the UV/H2O2-chloramine AOP than for the UV/H2O2 AOP, the UV/H2O2 AOP was at least 2-fold more efficient with respect to 1,4-dioxane degradation, because chloramines efficiently scavenged radicals. At low chloramine concentrations, the UV/chloramine AOP efficiency increased with an increase in chloramine concentration, as the level of radical production increased relative to that of radical scavenging by the dissolved organic carbon in RO permeate. However, the efficiency leveled out at higher chloramine concentrations as radical scavenging by chloramines offset the increased level of radical production. The level of 1,4-dioxane degradation was ∼30-50% lower for the UV/chloramine AOP than for the UV/H2O2-chloramine AOP when the concentration of residual chloramines in RO permeate was ∼50 μM (3.3 mg/L as Cl2). Initial cost estimates indicate that the UV/chloramine AOP using the residual chloramines in RO permeate could be a cost-effective alternative to the current UV/H2O2-chloramine AOP in some cases, because the savings in reagent costs offset the ∼30-50% reduction in 1,4-dioxane degradation efficiency.
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Affiliation(s)
- Zhong Zhang
- Department of Civil and Environmental Engineering , Stanford University , 473 Via Ortega , Stanford , California 94305 , United States
| | - Yi-Hsueh Chuang
- Department of Civil and Environmental Engineering , Stanford University , 473 Via Ortega , Stanford , California 94305 , United States
| | - Nan Huang
- Environmental Simulation and Pollution Control State Key Joint Laboratory, State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC), School of Environment , Tsinghua University , Beijing 100084 , P. R. China
| | - William A Mitch
- Department of Civil and Environmental Engineering , Stanford University , 473 Via Ortega , Stanford , California 94305 , United States
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Huang Y, Kong M, Westerman D, Xu EG, Coffin S, Cochran KH, Liu Y, Richardson SD, Schlenk D, Dionysiou DD. Effects of HCO 3- on Degradation of Toxic Contaminants of Emerging Concern by UV/NO 3. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:12697-12707. [PMID: 30284820 DOI: 10.1021/acs.est.8b04383] [Citation(s) in RCA: 93] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
This study investigated the significant influence of HCO3- on the degradation of contaminants of emerging concern (CECs) during nitrate photolysis at 254 nm for water reuse applications. The second-order rate constants for the reactions between selected contaminants with carbonate radical (CO3•-) were determined at pH 8.8 and T = 20 °C: estrone ((5.3 ± 1.1) × 108 M-1 s-1), bisphenol A ((2.8 ± 0.2) × 108 M-1 s-1), 17α-ethynylestradiol ((1.6 ± 0.3) × 108 M-1 s-1), triclosan ((4.2 ± 1.4) × 107 M-1 s-1), diclofenac ((2.7 ± 0.7) × 107 M-1 s-1), atrazine ((5.7 ± 0.1) × 106 M-1 s-1), carbamazepine ((4.2 ± 0.01) × 106 M-1 s-1), and ibuprofen ((1.2 ± 1.1) × 106 M-1 s-1). Contributions from UV, reactive nitrogen species (RNS), hydroxyl radical (•OH), and CO3•- to the CEC decomposition in UV/NO3- in the presence and absence of HCO3- were investigated. In addition, possible transformation products and degradation pathways of triclosan, diclofenac, bisphenol A, and estrone in UV/NO3-/HCO3- were proposed based on the mass (MS) and MS2 spectra. Significant reduction in the cytotoxicity of bisphenol A was observed after the treatment with UV/NO3-/HCO3-.
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Affiliation(s)
- Ying Huang
- Environmental Engineering and Science, Department of Chemical and Environmental Engineering , University of Cincinnati , Cincinnati , Ohio 45221 , United States
| | - Minghao Kong
- Environmental Engineering and Science, Department of Chemical and Environmental Engineering , University of Cincinnati , Cincinnati , Ohio 45221 , United States
| | - Danielle Westerman
- Department of Chemistry and Biochemistry , University of South Carolina , Columbia , South Carolina 29208 , United States
| | - Elvis Genbo Xu
- Department of Environmental Sciences , University of California , Riverside , California 92521 , United States
| | - Scott Coffin
- Department of Environmental Sciences , University of California , Riverside , California 92521 , United States
| | - Kristin H Cochran
- Department of Chemistry and Biochemistry , University of South Carolina , Columbia , South Carolina 29208 , United States
| | - Yiqing Liu
- Environmental Engineering and Science, Department of Chemical and Environmental Engineering , University of Cincinnati , Cincinnati , Ohio 45221 , United States
- Faculty of Geosciences and Environmental Engineering , Southwest Jiaotong University , Chengdu 611756 , China
| | - Susan D Richardson
- Department of Chemistry and Biochemistry , University of South Carolina , Columbia , South Carolina 29208 , United States
| | - Daniel Schlenk
- Department of Environmental Sciences , University of California , Riverside , California 92521 , United States
| | - Dionysios D Dionysiou
- Environmental Engineering and Science, Department of Chemical and Environmental Engineering , University of Cincinnati , Cincinnati , Ohio 45221 , United States
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