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Chen C, Zhao X, Chen H, Wang J, Wang Y, Xian Q. The investigation of quenching conditions for the analysis of total organic halogen, aliphatic and aromatic halogenated disinfection byproducts formed from chlor(am)ination. JOURNAL OF HAZARDOUS MATERIALS 2024; 475:134918. [PMID: 38878428 DOI: 10.1016/j.jhazmat.2024.134918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 05/21/2024] [Accepted: 06/13/2024] [Indexed: 06/27/2024]
Abstract
Total organic halogen (TOX) is used to describe total amount of halogenated DBPs. Typically, once a chlor(am)inated water sample is collected, it is necessary to add a quenching agent to quench the residual disinfectant so that further reactions to form more DBPs during the holding time can be prevented. In this study, we evaluated the effects of four quenching agents: ammonium chloride (NH4Cl), ascorbic acid, sodium sulfite (Na2SO3), and sodium thiosulfate (Na2S2O3) on the decomposition of TOX, aliphatic and aromatic halogenated DBPs under various quenching conditions (quenching time, pH, quenching ratio, temperature). The results showed that ascorbic acid had the least impact on TOX. Ascorbic acid appeared to be the most suitable quenching agent for aliphatic halogenated DBPs, especially since it could preserve more haloacetonitriles than other quenching agents. Both ascorbic acid and Na2SO3 could be used for the analysis of aromatic halogenated DBPs. The lower pH (pH 6.0), not excessive quenching agents and lower temperature (4 ºC) were all conducive to the preservation of TOX and halogenated DBPs. Importantly, unknown TOX (UTOX) also contained significantly toxic components. It was also found that addition of quenching agents might lead to underestimation of UTOX by researchers. SYNOPSIS: The quenching agents and quenching conditions for the analysis of total organic halogen, aliphatic and aromatic halogenated DBPs formed from chlor(am)ination were investigated.
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Affiliation(s)
- Chuze Chen
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, China
| | - Xiating Zhao
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, China
| | - Haoran Chen
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, China
| | - Junjie Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, China
| | - Yuting Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, China
| | - Qiming Xian
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, China.
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Ren J, Tang M, Wang L, Chu W, Shi W, Zhou Q, Pan Y. How to achieve adequate quenching for DBP analysis in drinking water? WATER RESEARCH 2024; 253:121264. [PMID: 38335842 DOI: 10.1016/j.watres.2024.121264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 02/01/2024] [Accepted: 02/03/2024] [Indexed: 02/12/2024]
Abstract
Quenching is an important step to terminate disinfection during preparation of disinfected water samples for the analysis of disinfection byproducts (DBPs). However, an incomplete quenching might result in continued reactions of residual chlorine, whereas an excessive quenching might decompose target DBPs. Therefore, an adequate quenching to achieve simultaneous disinfection termination and DBP preservation is of particular importance. In this study, the two-stage reaction kinetics of chlorine and three commonly used quenching agents (i.e., ascorbic acid, sodium thiosulfate, and sodium sulfite) were determined. Stopping quenching during the first stage prevented interactions of residual chlorine with natural organic matter. Complete quenching was achieved by minimizing the quenching time for ascorbic acid and sodium sulfite, while limiting the quenching time to less than 3 min for sodium thiosulfate. At the optimized quenching times, the molar ratios (MRs) of quenching agent to chlorine were 1.05, 1.10, and 0.75 for ascorbic acid, sodium sulfite, and sodium thiosulfate, respectively. The destructive effects of the three quenching agents on total organic halogen (TOX) followed the rank order of ascorbic acid (33.7-64.8 %) < sodium sulfite (41.6-72.8 %) < sodium thiosulfate (43.3-73.2 %), and the destructive effects on aliphatic DBPs also followed the rank order of ascorbic acid (29.5-44.5 %) < sodium sulfite (34.9-51.9 %) < sodium thiosulfate (46.9-53.2 %). For total organic chlorine (TOCl) and aliphatic DBPs, the quenching behavior itself had more significant destructive effect than the quenching agent type/dose and quenching time, but for total organic bromine (TOBr), the destructive effect caused by quenching agent type/dose and quenching time was more significant. High-dose, long-duration quenching enhanced the reduction of TOX, but had little effect on aliphatic DBPs. Additionally, the three quenching agents reduced the levels of halophenols (except for tribromophenol), while maintained or increased the levels of tribromophenol, halobenzoic/salicylic acids, and halobenzaldehydes/salicylaldehydes. To achieve adequate quenching for overall DBP analysis in chlorinated water samples, it is recommended to use ascorbic acid at a quenching agent-to-chlorine MR of 1.0 for a quenching time of < 0.5 h.
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Affiliation(s)
- Jiafeng Ren
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu 210023, China
| | - Mengmeng Tang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu 210023, China
| | - Leyi Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu 210023, China
| | - Wenhai Chu
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Wei Shi
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu 210023, China
| | - Qing Zhou
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu 210023, China.
| | - Yang Pan
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu 210023, China.
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Li J, Chen J, Zhang Z, Liang X. Impact of prevalent chlorine quenchers on phenolic disinfection byproducts in drinking water and potential reaction mechanisms. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 871:161971. [PMID: 36739019 DOI: 10.1016/j.scitotenv.2023.161971] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 01/22/2023] [Accepted: 01/29/2023] [Indexed: 06/18/2023]
Abstract
To prevent the reactions of disinfection byproducts (DBPs) or natural organic matters with residual chlorine in drinking water in the course of the water store, residual chlorine is quenched by chlorine quenchers, while some chlorine quenchers may result in dechlorination of DBPs. Phenolic compounds are a group of highly toxic DBPs compared to regulated aliphatic DBPs (trihalomethanes (THMs) and haloacetic acids (HAAs)), which might be a great threat to drinking water safety. Nevertheless, impact of popular chlorine quenchers on phenolic DBPs is less understanding. In this study, the influences of ammonium chloride, ascorbic acid, sodium thiosulfate, and sodium sulfite on phenolic DBPs are assessed. Total concentration of 19 phenolic DBPs in drinking water from 7 Chinese cities was 145-1821 ng/L, suggesting a widely occurrence of these pollutants. Four assessed chlorine quenchers have not impacts on mass spectra of studied phenolic DBPs. Additionally, when the storage time ≤24 h, recoveries of 19 phenolic DBPs using four assessed chlorine quenchers are within the accept levels (70-130 %). However, when the storage time increased to 168 h, ascorbic acid and sodium thiosulfate satisfied the recovery requirement of phenolic DBPs during the sample analysis, and ammonium chloride and sodium sulfite showed a unacceptable impact on bromo-chloro-phenols. In general, ascorbic acid and sodium thiosulfate are recommended to be the ideal chlorine quenchers of phenolic DBPs. Mechanism study indicated that sodium sulfite induced the dechlorination of 2-chloro-4-bromophenol via nucleophilic reaction. This study is the first attempt to provide the impact of chlorine quenchers on phenolic DBPs and corresponding reaction mechanism.
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Affiliation(s)
- Jiafu Li
- School of Public Health, Soochow University, Suzhou 215122, China.
| | - Jingsi Chen
- School of Public Health, Soochow University, Suzhou 215122, China
| | - Zengli Zhang
- School of Public Health, Soochow University, Suzhou 215122, China
| | - Xiaojun Liang
- Center for Disease Control and Prevention of Kunshan, Kunshan 215301, China.
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Fang C, Luan X, Ao F, Wang X, Ding S, Du Z, Liu S, Jia R, Chu W. Decomposition of Total Organic Halogen Formed during Chlorination: The Iceberg of Halogenated Disinfection Byproducts Was Previously Underestimated. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:1433-1442. [PMID: 36626160 DOI: 10.1021/acs.est.2c03596] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Total organic halogen (TOX) is widely used as a surrogate bulk parameter to measure the overall exposure of halogenated disinfection byproducts (DBPs) in drinking water. In this study, we surprisingly found that the level of TOX in chlorinated waters had been significantly underestimated under common analytical conditions. After the addition of quenching agent sodium thiosulfate, total organic chlorine and total organic bromine exhibited a two-phase decomposition pattern with increasing contact time, and a significant decomposition was observed for different types of quenching agents, quenching doses, and pH conditions. More importantly, the decomposed TOX closely correlated with the acute toxicity of quenched water against luminous bacteria, implying that the DBPs responsible for TOX decomposition could be of important toxicological significance. Based on nontarget analysis by using high-resolution mass spectrometry, molecular formulas for the decomposed TOX were determined. After re-examining the mass balance of TOX in the context of unintentional decomposition, it was found that both the level and percentage of unknown TOX in chlorinated waters were considerably higher than historically thought. Overall, this study brings new insights into the knowledge of TOX formed during chlorination, providing important clues on the identification of toxicity driver in drinking water.
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Affiliation(s)
- Chao Fang
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Xinmiao Luan
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Feiyang Ao
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Xingyu Wang
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Shunke Ding
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Zhenqi Du
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Shushen Liu
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Ruibao Jia
- Shandong Province Water Supply and Drainage Monitoring Centre, Jinan 250101, China
| | - Wenhai Chu
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
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Huang H, Liang X, Li Q, Deng J, Zou J, Li X, Ma X, Li G, Chen G. High-performance reductive decomposition of trichloroacetamide by the vacuum-ultraviolet/sulfite process: Kinetics, mechanism and combined toxicity risk. WATER RESEARCH 2022; 225:119122. [PMID: 36152441 DOI: 10.1016/j.watres.2022.119122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 08/26/2022] [Accepted: 09/14/2022] [Indexed: 06/16/2023]
Abstract
Trichloroacetamide (TCAcAm) is among of the nitrogenous disinfection by-products (N-DBPs) with high cytotoxicity and genotoxicity, which is usually detected at low concentration (μg/L) in drinking water. In this study, advanced reduction process (ARP) based on vacuum ultraviolet (VUV) was employed to eliminate TCAcAm. Compared with VUV, VUV/sulfide, and VUV/ferrous iron processes, VUV/sulfite process demonstrated excellent performance for TCAcAm decomposition, the higher removal of TCAcAm could be achieved by VUV/sulfite process (85.6 %) than VUV direct photolysis (13.5 %) due to the production of a great number of reactive species. The degradation of TCAcAm followed the pseudo-first-order kinetics well in VUV/sulfite process, and the pseudo-first-order rate constant (kobs) increased with increasing sulfite concentration. Reactive species quenching experiments demonstrated that eaq-, SO3·- and H· were involved in the degradation of TCAcAm. The in situ generated eaq-, SO3·- and HO· via VUV/sulfite process were identified by electron paramagnetic resonance (EPR), and the eaq- was proved to be the dominated species (relative contribution: 83.5 %) for TCAcAm decomposition. The second-order rate constant of TCAcAm with eaq- was determined to be 2.41 × 1010 M-1 s-1 for the first time based on competitive kinetic method. The complete TCAcAm degradation could be achieved at pH > 8.3, while TCAcAm degradation efficiency decreased to 11.9 % at pH 5.8. TCAcAm decay could be divided into two stages: rapid growth (sulfite dosage: 0.25-1.0 mM) and slow growth (sulfite dosage: 1.0-4.0 mM). The yield of eaq- was controlled by sulfite dosage, and the predict yield of eaq- increased from 3.69 × 10-14 to 2.58 × 10-12 M with increasing the sulfite dosage from 0.25 to 4.0 mM by Kintecus 6.80, which resulted in an increase in TCAcAm removal. Meanwhile, the presence of dissolved oxygen (DO), chloride (Cl-), bicarbonate (HCO3-) and humic acid (HA) posed negative influence on TCAcAm decomposition to various degrees. Dichloroacetamide (DCAcAm), trichloroacetic acid (TCAA), dichloroacetic acid (DCAA) and Cl- were identified as intermediate products, indicated that reductive dechlorination and hydrolysis coexisted during the degradation of TCAcAm in VUV/sulfite process.
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Affiliation(s)
- Huahan Huang
- Water Resources and Environmental Institute, Xiamen University of Technology, Xiamen 361005, China; Key Laboratory of Water Resources Utilization and Protection, Xiamen city, Xiamen 361005, China
| | - Xinrui Liang
- Water Resources and Environmental Institute, Xiamen University of Technology, Xiamen 361005, China; Key Laboratory of Water Resources Utilization and Protection, Xiamen city, Xiamen 361005, China
| | - Qingsong Li
- Water Resources and Environmental Institute, Xiamen University of Technology, Xiamen 361005, China; Key Laboratory of Water Resources Utilization and Protection, Xiamen city, Xiamen 361005, China.
| | - Jing Deng
- College of Civil Engineering and Architecture, Zhejiang University of Technology, Hangzhou 310014, China
| | - Jing Zou
- College of Civil Engineering, Huaqiao University, Xiamen 361021, China
| | - Xia Li
- College of Civil Engineering, Fuzhou University, Fuzhou 350116, China
| | - Xiaoyan Ma
- College of Civil Engineering and Architecture, Zhejiang University of Technology, Hangzhou 310014, China
| | - Guoxin Li
- Water Resources and Environmental Institute, Xiamen University of Technology, Xiamen 361005, China
| | - Guoyuan Chen
- Water Resources and Environmental Institute, Xiamen University of Technology, Xiamen 361005, China
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Hao Z, Hou W, Fang C, Huang Y, Liu X. Sulfite activation by cobaltosic oxide nanohydrangeas for tetracycline degradation: Performance, degradation pathways and mechanism. JOURNAL OF HAZARDOUS MATERIALS 2022; 439:129618. [PMID: 35870208 DOI: 10.1016/j.jhazmat.2022.129618] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 07/13/2022] [Accepted: 07/14/2022] [Indexed: 06/15/2023]
Abstract
Sulfite has been used as a classic reductant for the dehalogenation and reduction of organic compounds for a long time, it is recently deemed as a promising alternative (for persulfate) to generate sulfate radical for wastewater treatment due to its low price and eco-toxicity. In contrast with the enormous work developed in the field of tetracycline (TC) degradation via PMS activization, sulfite activization could play a important role in TC degradation but there is only very few available reports in this area. Herein, the novel and efficient CoNHs nanocatalyst is designed and developed, via immobilization of hydrangea-shaped Co3O4 nanoparticles onto graphitic carbon nanosheet (GCN), for the degradation of tetracycline via sulfite activation. The detailed characterizations have confirmed that CoNHs possesses a nanohydrangea-shaped structure with high microporosity. The comparison with other supports (such as CeO2 and MoS2), CoNHs provides the highest degradation efficiency in TC degradation, due to the synergistic effect between Co3O4 and GCN. Free radical quenching experiments and EPR analysis confirm that SO4•- and O2•- are major reactive oxygen species in the CoNHs/sulfite system. This work could provide a simple, economical and durable cobalt-based catalyst for organic wastewater treatment via sulfite activation.
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Affiliation(s)
- Zixuan Hao
- Engineering Research Center of Eco-Environment in Three Gorges Reservoir Region of Ministry of Education, College of Materials and Chemical Engineering, China Three Gorges University, Yichang, Hubei 443002 , China
| | - Wenxin Hou
- Engineering Research Center of Eco-Environment in Three Gorges Reservoir Region of Ministry of Education, College of Materials and Chemical Engineering, China Three Gorges University, Yichang, Hubei 443002 , China
| | - Chen Fang
- Engineering Research Center of Eco-Environment in Three Gorges Reservoir Region of Ministry of Education, College of Materials and Chemical Engineering, China Three Gorges University, Yichang, Hubei 443002 , China
| | - Yingping Huang
- Engineering Research Center of Eco-Environment in Three Gorges Reservoir Region of Ministry of Education, College of Materials and Chemical Engineering, China Three Gorges University, Yichang, Hubei 443002 , China; College of Hydraulic & Environmental Engineering, China Three Gorges University, Yichang, Hubei 443002 , China.
| | - Xiang Liu
- Engineering Research Center of Eco-Environment in Three Gorges Reservoir Region of Ministry of Education, College of Materials and Chemical Engineering, China Three Gorges University, Yichang, Hubei 443002 , China; Hubei Three Gorges Laboratory, 443007 Yichang, Hubei, China.
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Ding S, Wu M, Xiao R, Fang C, Wang Q, Xu B, Chu W. Evaluation of N-acetylcysteine and glutathione as quenching agents for the analysis of halogenated disinfection by-products. J Environ Sci (China) 2022; 117:71-79. [PMID: 35725091 DOI: 10.1016/j.jes.2022.01.033] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 12/24/2021] [Accepted: 01/21/2022] [Indexed: 06/15/2023]
Abstract
Disinfection by-products (DBPs), formed from the reactions of disinfectants with natural organic matter and halides in drinking water, were considered to be cytotoxic and genotoxic, and might trigger various cancers. The relatively low concentration of DBPs in finished water (low µg/L or even ng/L levels) and the interference from water matrix inhibited in situ determination of DBPs. Moreover, the further formation and degradation of DBPs by disinfectants during the holding time (several hours to several days) from sample collection to analysis could adversely affect the determination of DBPs. To obtain accurate, precise and reliable data of DBP occurrence and formation, robust and reliable sample preservation is indispensable. However, the commonly used quenching agents (e.g., sodium sulfite, sodium thiosulfate, and ascorbic acid) for sample preservation can decompose reactive DBPs by reductive dehalogenation. This study evaluated the performance of N-acetylcysteine (NAC) and glutathione (GSH) as quenching agents for the analysis of halogenated DBPs by investigating the stoichiometry of the disinfectant-quenching agent reaction, the formation of DBPs during chlor(am)ination of NAC or GSH, and the effects of NAC or GSH on the stability of 18 individual DBPs and total organic halogen (TOX). Based on the results of this study, NAC and GSH were considered to be ideal quenching agents for the analysis of most DBPs and TOX, except halonitromethanes.
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Affiliation(s)
- Shunke Ding
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Key Laboratory of Yangtze River Water Environment, Ministry of Education, Tongji University, Shanghai 200092, China
| | - Menglin Wu
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Key Laboratory of Yangtze River Water Environment, Ministry of Education, Tongji University, Shanghai 200092, China
| | - Rong Xiao
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Key Laboratory of Yangtze River Water Environment, Ministry of Education, Tongji University, Shanghai 200092, China
| | - Chao Fang
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Key Laboratory of Yangtze River Water Environment, Ministry of Education, Tongji University, Shanghai 200092, China
| | - Qi Wang
- School of Life and Environmental Science, Wenzhou University, Zhejiang 325035, China
| | - Bin Xu
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Key Laboratory of Yangtze River Water Environment, Ministry of Education, Tongji University, Shanghai 200092, China
| | - Wenhai Chu
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Key Laboratory of Yangtze River Water Environment, Ministry of Education, Tongji University, Shanghai 200092, China.
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Dong Q, Dong H, Li Y, Xiao J, Xiang S, Hou X, Chu D. Degradation of sulfamethazine in water by sulfite activated with zero-valent Fe-Cu bimetallic nanoparticles. JOURNAL OF HAZARDOUS MATERIALS 2022; 431:128601. [PMID: 35255337 DOI: 10.1016/j.jhazmat.2022.128601] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 02/24/2022] [Accepted: 02/26/2022] [Indexed: 06/14/2023]
Abstract
In this work, zero-valent Fe-Cu bimetallic nanoparticles were synthesized using a facile method, and applied to activate sulfite for the degradation of sulfamethazine (SMT) from the aqueous solution. The key factors influencing SMT degradation were investigated, namely the theoretical loading of Cu, Fe-Cu catalyst dosage, sulfite concentration and initial solution pH. The experimental results showed that the Fe-Cu/sulfite system exhibited a much better performance in SMT degradation than the bare Fe0/sulfite system. The mechanism and possible degradation pathway of SMT in Fe-Cu/sulfite system were revealed. The reactive radicals that played a dominant role in the SMT degradation process were •OH and SO4•-, while the loading of Cu induced the synergistic effect between Fe and Cu. The redox cycle between Cu(I)/Cu(II) remarkably contributed to the conversion of Fe(III) to Fe(II), greatly enhancing the catalytic performance of Fe-Cu bimetal. In real groundwater applications, the Fe-Cu/sulfite system also exhibited satisfactory SMT degradation. The 30-day aging tests of Fe-Cu particles demonstrated that the aging of catalyst was not obviously affecting the removal of SMT. Furthermore, the reusability of catalyst was evidenced by the recycling experiments. This study provides a promising application of bimetal activated sulfite for enhanced contaminant degradation in groundwater.
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Affiliation(s)
- Qixia Dong
- College of Environmental Science and Engineering, Hunan University, Changsha, Hunan 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, Hunan 410082, China
| | - Haoran Dong
- College of Environmental Science and Engineering, Hunan University, Changsha, Hunan 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, Hunan 410082, China.
| | - Yangju Li
- College of Environmental Science and Engineering, Hunan University, Changsha, Hunan 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, Hunan 410082, China
| | - Junyang Xiao
- College of Environmental Science and Engineering, Hunan University, Changsha, Hunan 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, Hunan 410082, China
| | - Shuxue Xiang
- College of Environmental Science and Engineering, Hunan University, Changsha, Hunan 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, Hunan 410082, China
| | - Xiuzhen Hou
- College of Environmental Science and Engineering, Hunan University, Changsha, Hunan 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, Hunan 410082, China
| | - Dongdong Chu
- College of Environmental Science and Engineering, Hunan University, Changsha, Hunan 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, Hunan 410082, China
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9
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Detection and Stability of Cyanogen Bromide and Cyanogen Iodide in Drinking Water. WATER 2022. [DOI: 10.3390/w14101662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This study systematically summarized the factors affecting the stability of CNXs, providing a reference for better control and elimination of CNXs. A method for the detection of CNBr and CNI in solution was established using a liquid–liquid extraction/gas chromatography/electron capture detector. Specifically, the method was used to investigate the stability of CNBr and CNI in drinking water, especially in the presence of chlorine and sulfite, and it showed good reproducibility (relative standard deviation <3.05%), high sensitivity (method detection limit <100 ng/L), and good recovery (91.49–107.24%). Degradation kinetic studies of cyanogen halides were conducted, and their degradation rate constants were detected for their hydrolysis, chlorination, and sulfite reduction. For hydrolysis, upon increasing pH from 9.0 to 11.0, the rate constants of CNCl, CNBr, and CNI changed from 8 to 155 × 10−5 s−1, 1.1 to 34.2 × 10−5 s−1, and 1.5 to 6.2 × 10−5 s−1, respectively. In the presence of 1.0 mg/L chlorine, upon increasing pH from 7.0 to 10.0, the rate constants of CNCl, CNBr, and CNI changed from 36 to 105 × 10−5 s−1, 15.8 to 49.0 × 10−5 s−1, and 1.2 to 24.2 × 10−5 s−1, respectively. In the presence of 3 μmol/L sulfite, CNBr and CNI degraded in two phases. In the first phase, they degraded very quickly after the addition of sulfite, whereas, in the second phase, they degraded slowly with rate constants similar to those for hydrolysis. Owing to the electron-withdrawing ability of halogen atoms and the nucleophilic ability of reactive groups such as OH− and ClO−, the rate constants of cyanogen halides increased with increasing pH, and they decreased in the order of CNCl > CNBr > CNI during hydrolysis and chlorination. The hydrolysis and chlorination results could be used to assess the stability of cyanogen halides in water storage and distribution systems. The sulfite reduction results indicate that quenching residual oxidants with excess sulfite could underestimate the levels of cyanogen halides, especially for CNBr and CNI.
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Ratanaphain C, Viboonratanasri D, Prompinit P, Krajangpan S, Khan E, Punyapalakul P. Reactivity characterization of SiO 2-coated nano zero-valent iron for iodoacetamide degradation: The effects of SiO 2 thickness, and the roles of dehalogenation, hydrolysis and adsorption. CHEMOSPHERE 2022; 286:131816. [PMID: 34418658 DOI: 10.1016/j.chemosphere.2021.131816] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Revised: 06/05/2021] [Accepted: 08/04/2021] [Indexed: 06/13/2023]
Abstract
The effect of SiO2-layer thickness in SiO2-coated nano zero-valent iron (nZVI) particles on the reactivity characteristics of iodoacetamide (IAcAm) degradation was evaluated. SiO2-layer thicknesses ranging from 3.6 to 27.3 nm were obtained through varying tetraethyl orthosilicate dosages of 0.001-1 M. The crystallinity, surface chemical composition, and physicochemical properties were evaluated for their effects on synergetic degradation mechanisms, dehalogenation, hydrolysis, and adsorption. At a thickness of 3.6 nm, the SiO2 layer offered the highest observed pseudo-first-order rate (kobs) and higher rates of IAcAm degradation were maintained under pH fluctuations (pH 5-7) and aerobic conditions compared to pristine nZVI. At this SiO2-layer thickness (3.6 nm), the rate of iron oxide-layer formation was reduced and the migration of reactive iron species (Fe0 and Fe2+) for the dehalogenation and hydrolysis reactions was enabled. In a single-solute solution, IAcAm elimination was greater than bromoacetamide and chloroacetamide elimination due to the weak ionic I-C bond. In mixed solute conditions, the hydrophobicity of chloroacetamide played a more significant role in competitive degradation through greater adsorption. The proportion of dehalogenation relative to hydrolysis during IAcAm degradation by pristine nZVI and SiO2-coated nZVI was approximately 0.6:0.4. Iodoacetic acid and acetic acid were detected as intermediates in the degradation pathway of IAcAm by pristine nZVI. In contrast, the SiO2 layer on nZVI can accelerate the transformation of IAcAm to acetamide and iodoacetic acid. The electrolyte background of tap water exhibited a slight inhibitory effect on the degradation of IAcAm for both nZVI and SiO2-coated nZVI.
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Affiliation(s)
- Chatkrita Ratanaphain
- Department of Environmental Engineering, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Duangkamon Viboonratanasri
- National Nanotechnology Center (NANOTEC), National Science and Technology Development Agency (NSTDA), Pathum Thani, 12120, Thailand; Research Network of NANOTEC - CU on Environment, Bangkok, 10330, Thailand
| | - Panida Prompinit
- National Nanotechnology Center (NANOTEC), National Science and Technology Development Agency (NSTDA), Pathum Thani, 12120, Thailand; Research Network of NANOTEC - CU on Environment, Bangkok, 10330, Thailand
| | | | - Eakalak Khan
- Civil and Environmental Engineering and Construction Department, University of Nevada, Las Vegas, NV, 89154-4015, USA
| | - Patiparn Punyapalakul
- Department of Environmental Engineering, Chulalongkorn University, Bangkok, 10330, Thailand; Research Network of NANOTEC - CU on Environment, Bangkok, 10330, Thailand; Center of Excellence on Hazardous Substance Management, Chulalongkorn University, Bangkok, 10330, Thailand; Research Unit Control of Emerging Micropollutants in Environment, Chulalongkorn University, Bangkok, 10330, Thailand.
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11
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Yang J, Luo Y, Fu X, Dong Z, Wang C, Liu H, Jiang C. Unexpected degradation and deiodination of diatrizoate by the Cu(II)/S(IV) system under anaerobic conditions. WATER RESEARCH 2021; 198:117137. [PMID: 33957311 DOI: 10.1016/j.watres.2021.117137] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 04/06/2021] [Accepted: 04/08/2021] [Indexed: 06/12/2023]
Abstract
Transition metal catalyzed sulfite auto-oxidation is a promising technology used in water and wastewater treatment for the elimination of contaminants. In the literature, this process has been reported to be efficient only in the presence of oxygen. However, in this study, we unexpectedly found that the degradation of diatrizoate (DTZ) by a system based on the combination of copper ion and sulfite (Cu(II)/S(IV)) reached over 95% under anaerobic conditions, but was considerably retarded under aerobic conditions at pH 7. Furthermore, it was found that Cu(I), generated from the cleavage of the CuSO3 complex, was the main reactive species responsible for the degradation of DTZ by the Cu(II)/S(IV) system under anaerobic conditions. In fact, the absence of oxygen promoted the accumulation of Cu(I). The concomitant release of the iodide ion with the degradation of DTZ indicated that the anaerobic degradation of DTZ by the Cu(II)/S(IV) system mainly proceeded through the deiodination pathway, which was also confirmed by the detection of deiodinated products. The anaerobic degradation of DTZ was favored at higher initial concentrations of Cu(II) or sulfite in this system. Since the CuSO3 complex, the precursor of Cu(I), was formed mainly at pH 7, the highest anaerobic degradation of DTZ was achieved at pH 7. An increase in reaction temperature considerably enhanced the degradation of DTZ by the Cu(II)/S(IV) system with an apparent activation energy of 119.4 kJ/mol. The presence of chloride, bicarbonate and humic acid slightly influenced the anaerobic degradation of DTZ. The experiments with real water samples also demonstrated the effectiveness of the degradation of DTZ by the Cu(II)/S(IV) system under anaerobic conditions.
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Affiliation(s)
- Jingxin Yang
- Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Institute of Environmental Research at Greater Bay,Guangzhou University, Guangzhou 510006, China
| | - Yujie Luo
- WISDRI City Construction Engineering &Research Incorporation Ltd, Xudong Street, Hongshan District,Wuhan 430223, China
| | - Xianghui Fu
- Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Institute of Environmental Research at Greater Bay,Guangzhou University, Guangzhou 510006, China
| | - Zijun Dong
- Department of Building and Environmental Engineering, Shenzhen Polytechnic, Shenzhen 518055, China.
| | - Chuan Wang
- Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Institute of Environmental Research at Greater Bay,Guangzhou University, Guangzhou 510006, China
| | - Hong Liu
- Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China
| | - Chengchun Jiang
- Department of Building and Environmental Engineering, Shenzhen Polytechnic, Shenzhen 518055, China
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12
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Induvesa P, Ratanatawanate C, Wongrueng A, Punyapalakul P. Adsorption of iodinated trihalomethanes onto thiol functionalized ZIF-8s: Active adsorption sites, adsorptive mechanisms, and dehalogenation by-products. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 754:142376. [PMID: 33254906 DOI: 10.1016/j.scitotenv.2020.142376] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 08/31/2020] [Accepted: 09/12/2020] [Indexed: 06/12/2023]
Abstract
The adsorptive mechanisms operating in, and the effect of two different thiol modification methods on, the removal of five iodinated trihalomethanes (I-THMs) by the zeolite imidazolate framework (ZIF-8) were investigated in single and mixed solutions. The direct postgrafting of dithioglycol to the zinc complex node of ZIF-8 (ZF-SH) can increase the mesopore structures that enhance inner pore accessibility; this increase is a critical property required for excellent adsorption of I-THMs. The synergetic adsorptive interactions consist of Lewis acid-base interactions via the Zn-Zn complex, ion-dipole interactions involving the protonated hydroxyl and thiol groups, and hydrophobic interactions at the imidazole ring. In contrast to ZF-SH, the (3-mercaptopropyl)-trimethoxy functionalized silica coating on ZIF-8 (ZF-Si-SH) causes a lower thiol moiety and a steric effect that is reflected in its lower adsorption capacity. In both single and mixed solutions, the small molecular size and hydrophobic nature of I-THMs can promote better adsorption capacity on all thiol-modified ZIF-8, while the minus dipole charge distribution of the I-THMs structure plays a more critical role in selective adsorption on pristine ZIF-8. Interestingly, the dehalogenation of triiodomethane to diiodomethane due to a nucleophilic substitution (SN2) reaction can be accelerated by the thiol functionalized silica layer on ZIF-8.
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Affiliation(s)
- Phacharapol Induvesa
- International Postgraduate Programs in Hazardous Substance and Environmental Management, Graduate School, Chulalongkorn University, Bangkok 10330, Thailand; Center of Excellence on Hazardous Substance Management, Chulalongkorn University, Bangkok 10330, Thailand
| | - Chalita Ratanatawanate
- National Nanotechnology Center (NANOTEC), National Science and Technology Development Agency (NSTDA), Pathum Thani 12120, Thailand; Research Network of NANOTEC, CU on Environment, Bangkok 10330, Thailand
| | - Aunnop Wongrueng
- Department of Environmental Engineering, Faculty of Engineering, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Patiparn Punyapalakul
- Center of Excellence on Hazardous Substance Management, Chulalongkorn University, Bangkok 10330, Thailand; Department of Environmental Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok 10330, Thailand; Research Unit Control of Emerging Micropollutants in Environment, Chulalongkorn University, Bangkok 10330, Thailand; Research Network of NANOTEC, CU on Environment, Bangkok 10330, Thailand.
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13
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Shen X, Xiao F, Zhao H, Chen Y, Fang C, Xiao R, Chu W, Zhao G. In Situ-Formed PdFe Nanoalloy and Carbon Defects in Cathode for Synergic Reduction-Oxidation of Chlorinated Pollutants in Electro-Fenton Process. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:4564-4572. [PMID: 31977202 DOI: 10.1021/acs.est.9b05896] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Complete dechlorination and mineralization of chlorophenols via the reduction-oxidation-mediated electro-Fenton process with a composite bulk cathode is first proposed. The in situ formation of a PdFe nanoalloy and carbon defects as key active sites is mutually induced during the formation of a carbon aerogel-based electrode. Specifically, the PdFe nanoalloy promotes the generation of [H]ads as reduction sites and improves the electron transfer via an electrical circuit, while the carbon defects selectively favor the 2e- oxygen reduction pathway. Notably, this work implies a novel electrocatalytic model for the formation of ·OH via (2 + 1)e- oxygen reduction by a consecutive reaction with carbon defects and a PdFe nanoalloy. Complete total organic carbon removal and dechlorination of 3-chlorophenol were performed after 6 h. The kinetic rate constant for removing haloacetamides (HAMs) in drinking water was 0.21-0.41 h-1, and the degradation efficiency was self-enhanced after electrolysis for 2 h because of the increased concentration of [H+]. The specific energy consumption was ∼0.55 W·h·g-1 at 100% removal of some HAMs, corresponding to a power consumption of 0.6-1.1 kW·h for complete dehalogenation per ton of drinking water in waterworks. Moreover, the PdFe alloy/CA exhibited extreme mechanical and electrochemical stability with limited iron (∼0.07 ppm) and palladium (0.02 ppm) leaching during the actual application.
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Affiliation(s)
- Xuqian Shen
- School of Chemical Science and Engineering, Shanghai Key Lab of Chemical Assessment and Sustainability, Tongji University, Siping Road 1239, Shanghai 200092, P. R. China
| | - Fan Xiao
- School of Chemical Science and Engineering, Shanghai Key Lab of Chemical Assessment and Sustainability, Tongji University, Siping Road 1239, Shanghai 200092, P. R. China
| | - Hongying Zhao
- School of Chemical Science and Engineering, Shanghai Key Lab of Chemical Assessment and Sustainability, Tongji University, Siping Road 1239, Shanghai 200092, P. R. China
| | - Ying Chen
- School of Chemical Science and Engineering, Shanghai Key Lab of Chemical Assessment and Sustainability, Tongji University, Siping Road 1239, Shanghai 200092, P. R. China
| | - Chao Fang
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, P. R. China
| | - Rong Xiao
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, P. R. China
| | - Wenhai Chu
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, P. R. China
| | - Guohua Zhao
- School of Chemical Science and Engineering, Shanghai Key Lab of Chemical Assessment and Sustainability, Tongji University, Siping Road 1239, Shanghai 200092, P. R. China
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14
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Jaichuedee J, Wattanachira S, Musikavong C. Kinetics of the formation and degradation of carbonaceous and nitrogenous disinfection by-products in Bangkok and Songkhla source waters. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 703:134888. [PMID: 31767322 DOI: 10.1016/j.scitotenv.2019.134888] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 10/06/2019] [Accepted: 10/07/2019] [Indexed: 06/10/2023]
Abstract
The kinetics of the formation and degradation of disinfection by-products (DBPs) in the treated water from the Bangkhen and Hatyai water treatment plants in Thailand were investigated. The DBPs studied included trichloromethane (TCM), bromodichloromethane (BDCM), dibromochloromethane (DBCM), trichloroacetonitrile (TCAN), dichloroacetonitrile (DCAN), bromochloroacetonitrile (BCAN), and trichloronitromethane (TCNM). When the chlorination time was increased, the levels of TCM, BDCM, DBCM, and TCNM increased, while the levels of TCAN, DCAN, and BCAN decreased. The kinetic rates of DBPs' formation were assessed based on the formation and degradation rates, which were best described by first-order kinetics. TCM had the highest formation rate with a range of rate constants from 5.5 × 10-3 to 7.3 × 10-3 h-1. TCAN had the lowest degradation rate with a range of rate constants from 0.6 × 10-3 to 2.9 × 10-3 h-1. Good correlations were observed between chlorination time and DBPs' formation normalized by LC50, lowest cytotoxicity, and lowest genotoxicity. A high formation rate of TCM and a low degradation rate of TCAN normalized by their toxicity were observed. The optimal retention time providing low DBPs' formation together with high DBPs' degradation was determined. The retention time of three days decreased the sum of the DBPs/LC50, DBPs/lowest cytotoxicity, and DBPs/lowest genotoxicity from a retention time of one day by 40-60%, 45-65%, and 25-36%, respectively.
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Affiliation(s)
- Juthamas Jaichuedee
- Environmental Assessment and Technology for Hazardous Waste Management Research Center, Department of Civil Engineering, Faculty of Engineering, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand
| | - Suraphong Wattanachira
- Department of Environmental Engineering, Faculty of Engineering, Chiang Mai University, Muang, Chiang Mai 50200, Thailand
| | - Charongpun Musikavong
- Environmental Assessment and Technology for Hazardous Waste Management Research Center, Department of Civil Engineering, Faculty of Engineering, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand; Center of Excellence on Hazardous Substance Management (HSM), Bangkok 10330, Thailand.
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15
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Chen X, Miao W, Yang Y, Hao S, Mao S. Aeration-assisted sulfite activation with ferrous for enhanced chloramphenicol degradation. CHEMOSPHERE 2020; 238:124599. [PMID: 31454743 DOI: 10.1016/j.chemosphere.2019.124599] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 08/12/2019] [Accepted: 08/15/2019] [Indexed: 06/10/2023]
Abstract
In this study, an Fe(Ⅱ)/S(IV) system was designed for the degradation of chloramphenicol (CAP). The pseudo-first-order rate constants for CAP degradation under typical conditions with and without air purging were investigated. The greatly enhanced rate of 0.0099 min-1 with air purging compared with 0.0006 min-1 with no air purging indicated that aeration was significant to the degradation of CAP in Fe(Ⅱ)/S(Ⅳ) system. Radical scavenging experiments revealed that SO4- was the primary oxidant generated from the activation of S(IV) with Fe(II), accounting for around 70% of degradation under weak acidic and neutral conditions. Increasing Fe(II) and S(IV) doses promoted the degradation of CAP, whereas the overdose of them led to a decreased degradation rate by scavenging radicals. Owing to the participation of oxygen in the formation of ferric sulfite complex and SO5-, the increase of dissolved oxygen improved the removal efficiency of CAP. The removal efficiency of CAP was also found to be pH dependent, decreasing from acid condition (initial pH = 4) to basic condition (initial pH = 8). The presence of coexisting anions and water matrix was found inhibiting CAP degradation in Fe(Ⅱ)/S(Ⅳ) system. This work provides an understanding on the working mechanism and possible applications of Fe(Ⅱ)/S(Ⅳ) system in organic compound degradation in wastewater.
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Affiliation(s)
- Xiaoyan Chen
- Biomedical Multidisciplinary Innovation Research Institute, Shanghai East Hospital, State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Wei Miao
- Biomedical Multidisciplinary Innovation Research Institute, Shanghai East Hospital, State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Yulin Yang
- Biomedical Multidisciplinary Innovation Research Institute, Shanghai East Hospital, State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Sibei Hao
- Biomedical Multidisciplinary Innovation Research Institute, Shanghai East Hospital, State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Shun Mao
- Biomedical Multidisciplinary Innovation Research Institute, Shanghai East Hospital, State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
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16
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Occurrence of Free Amino Acids in the Source Waters of Zhejiang Province, China, and Their Removal and Transformation in Drinking Water Systems. WATER 2019. [DOI: 10.3390/w12010073] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Free amino acids (FAAs) are key components of the global nitrogen cycle and important disinfection byproduct (DBP) precursors. The knowledge gap of FAA occurrence in source and engineered water is discussed in this paper. Solid phase extraction and post column derivatization was combined with gas chromatography–mass spectrometry to simultaneously detect μg/L concentrations of FAAs. This method efficiently detects alanine (Ala), threonine (Thr), serine (Ser), valine (Val), leucine (Leu), isoleucine (Ile), proline (Pro), aspartic (Asp), phenylalanine (Phe), and glutamic acid (Glu) with good linearity, accuracy, and precision. An investigation of FAAs in surface waters in Zhejiang Province found concentrations of 1.48–14.73 μg/L Ala, 0.20–2.39 μg/L Thr, 0.41–7.84 μg/L Val, 0.21–6.86 μg/L Ser, 0.11–4.16 μg/L Leu, 0.57–1.54 μg/L Ile, 0.24–8.06 μg/L Pro, 0.42–4.73 μg/L Asp, 0.30–3.01 μg/L Phe, and 0.12–3.83 μg/L Glu. Phe and tyrosine (Tyr) exhibited higher trichloromethane (TCM) formation (1029–1148 μg/mmolAA) than dichloroacetonitrile (DCAN) formation (333–347 μg/mmolAA). Asp and Glu demonstrated the opposite trend: higher DCAN (570–1106 μg/mmolAA) formation than TCM (137–506 μg/mmolAA).
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17
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Pan L, Zhang X, Yang M, Han J, Jiang J, Li W, Yang B, Li X. Effects of dechlorination conditions on the developmental toxicity of a chlorinated saline primary sewage effluent: Excessive dechlorination is better than not enough. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 692:117-126. [PMID: 31344565 DOI: 10.1016/j.scitotenv.2019.07.207] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2019] [Revised: 07/10/2019] [Accepted: 07/14/2019] [Indexed: 05/07/2023]
Abstract
Chlorine-disinfected sewage effluents are typically dechlorinated by using NaHSO3, Na2SO3, or Na2S2O3, as chlorine residual could be harmful to aquatic organisms upon discharge of sewage effluents into receiving marine water. In this study, we systematically investigated the effects of dechlorination-related factors on the developmental toxicity of a chlorinated saline primary sewage effluent, via direct exposure of the embryos of a marine polychaete to the effluent. The results showed that dechlorination ratio (i.e., the ratio of the dosed amount to the requisite stoichiometric amount of a dechlorination agent) and mixing condition were critical factors affecting the toxicity of the effluent. The toxicity of the effluent under insufficient dechlorination conditions was mainly caused by residual chlorine, especially monochloramine. Although the three dechlorination agents generally performed similarly, dechlorination with Na2S2O3 required a more vigorous mixing condition than that with NaHSO3 or Na2SO3, as the relatively high density of Na2S2O3 might affect the mixing efficiency. Under insufficient mixing conditions, a prolonged dechlorination time was beneficial to achieving complete dechlorination and thus lowered the toxicity of the effluent. Moreover, because disinfection byproducts (DBPs) may have chronic effects on aquatic organisms, the developmental toxicity of the DBP mixtures in the chlorinated effluent in different dechlorination scenarios was also evaluated. The results indicated that increasing the dechlorination ratio reduced the developmental toxicity of the DBP mixture in the chlorinated saline sewage effluent, which might be ascribed to the decrease of the levels of overall brominated and iodinated DBPs; the dechlorination agent (NaHSO3 or Na2S2O3) might act as a nucleophile in the nucleophilic substitution and cause the substitution of bromine or iodine atoms in brominated and iodinated DBPs. The results from this study might aid in the design and operation of dechlorination facilities in sewage treatment plants.
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Affiliation(s)
- Long Pan
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Xiangru Zhang
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China.
| | - Mengting Yang
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, China.
| | - Jiarui Han
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Jingyi Jiang
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Wanxin Li
- Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Bo Yang
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, China
| | - Xiaoyan Li
- Department of Civil Engineering, The University of Hong Kong, Hong Kong, China
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Qiao J, Feng L, Dong H, Zhao Z, Guan X. Overlooked Role of Sulfur-Centered Radicals During Bromate Reduction by Sulfite. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:10320-10328. [PMID: 31368696 DOI: 10.1021/acs.est.9b01783] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
In this work, the kinetics and mechanisms of the reductive removal of BrO3- by sulfite in air atmosphere were determined. BrO3- could be effectively reduced by sulfite at pHini 3.0-6.0, and the reduction rate of BrO3- increased with decreasing pH. The coexisting organic contaminants with electron-rich moieties could be degraded, accompanied with BrO3- reduction by sulfite. The reaction stoichiometries of -Δ[sulfite]/Δ[bromate] were determined to be 3.33 and 15.63 in the absence and presence of O2, respectively. Many lines of evidence verified that the main reactions in the BrO3-/sulfite system in air atmosphere included the reduction of BrO3- to HOBr and its further reduction to Br-, as well as the oxidation of H2SO3 by BrO3- to form SO3·- and its further transformation to SO4·-. Moreover, SO4·- rather than HOBr was determined to be the major active oxidant in the BrO3-/sulfite system. SO3·- played a key role in the over-stoichiometric sulfite consumption because of its rapid reaction with dissolved oxygen. However, the formed SO3·- was further oxidized by BrO3- in the N2 atmosphere. BrO3- reduction by sulfite is an alternative for controlling BrO3- in water treatment because it was effective in real water at pHini ≤ 6.0.
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Affiliation(s)
- Junlian Qiao
- Shanghai Institute of Pollution Control and Ecological Security , Shanghai 200092 , P.R. China
| | | | | | - Zhiwei Zhao
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, State Ministry of Education , Chongqing University , Chongqing 400045 , P.R. China
| | - Xiaohong Guan
- Shanghai Institute of Pollution Control and Ecological Security , Shanghai 200092 , P.R. China
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19
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Zhang A, Wang F, Chu W, Yang X, Pan Y, Zhu H. Integrated control of CX 3R-type DBP formation by coupling thermally activated persulfate pre-oxidation and chloramination. WATER RESEARCH 2019; 160:304-312. [PMID: 31154128 DOI: 10.1016/j.watres.2019.05.047] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 05/15/2019] [Accepted: 05/16/2019] [Indexed: 06/09/2023]
Abstract
The alternative disinfectant chloramine can lower the formation of carbonaceous DBPs (C-DBPs) but promote the formation of nitrogenous DBPs (N-DBPs), which are more cytotoxic and genotoxic. In this study, the combination of thermally activated persulfate pre-oxidation and post-chloramination (TA/PS-NH2Cl) was proposed to control the formation and reduce the toxicity of both C-DBPs and N-DBPs. The formation, speciation and toxicity of trihalomethanes, haloacetic acids, haloaldehydes, haloacetonitriles, halonitromethanes and haloacetamides, collectively defined as CX3R-type DBPs, under TA/PS-NH2Cl process were compared with processes of chlorination alone (Cl2), chloramination alone (NH2Cl) and coupled thermally activated persulfate pre-oxidation with post-chlorination (TA/PS-Cl2). Results showed that chloramination could reduce formation of C-DBPs and total organic halogen (TOX) while increase N-DBP formation, and the introduction of TA/PS pretreatment process slightly increased the formation of C-DBPs and TOX but sharply reduced the formation of N-DBPs with higher toxicity as well as brominated CX3R-type DBPs that are more toxic than their chlorinated analogues. By comprehensive toxicity calculation, an outright decline of both cytotoxicity and genotoxicity risk of CX3R-type DBPs was observed during TA/PS-NH2Cl process compared with Cl2, NH2Cl, and TA/PS-Cl2 processes. In summary, TA/PS-NH2Cl process was a potential effective method for integrally controlling the formation of CX3R-type DBPs and their toxicity and is suggested to be used to treat raw waters containing no bromide or low levels of bromide considering bromate caused by TA/PS pre-oxidation. The study may provide a feasible and economical method for DBP control on the background of global warming.
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Affiliation(s)
- Aihong Zhang
- State Key Laboratory of Pollution Control and Resources Reuse, International Joint Research Center for Sustainable Urban Water System, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Key Laboratory of Yangtze River Water Environment, Ministry of Education, Shanghai, 200092, China
| | - Feifei Wang
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, China
| | - Wenhai Chu
- State Key Laboratory of Pollution Control and Resources Reuse, International Joint Research Center for Sustainable Urban Water System, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Key Laboratory of Yangtze River Water Environment, Ministry of Education, Shanghai, 200092, China.
| | - Xu Yang
- State Key Laboratory of Pollution Control and Resources Reuse, International Joint Research Center for Sustainable Urban Water System, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Key Laboratory of Yangtze River Water Environment, Ministry of Education, Shanghai, 200092, China
| | - Yang Pan
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, Jiangsu, China
| | - Huifeng Zhu
- Shanghai Municipal Water Supply Dispatching and Monitoring Center, Shanghai, 200002, China
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