ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2019
·
IF 7.149
Shunke Ding,Yang Deng,Hongwei Li,Chao Fang,Naiyun Gao,Wenhai Chu
Iodinated disinfection byproducts (I-DBPs) are of particular concern in drinking water due to the more cytotoxic and genotoxic properties than their chlorinated and brominated analogs. Formation of I-DBP primarily results from the oxidation of iodide-containing waters with various oxidants and the chlor(am)ination of iodinated organic compounds in drinking water. This study first reports that ferric chloride (FeCl3) can lead to the formation of iodinated coagulation byproducts (I-CBPs) from iodide-containing resorcinol solution or natural waters. The unwanted I-CBP formation involved the oxidation of iodide by ferric ions to generate various reactive iodine species, which further oxidize organic compounds. Although the oxidation rate of iodide by FeCl3 was several orders of magnitude slower than that by chlorine or chloramine, most of the converted iodide under the ferric/iodide system was transformed into iodine and iodinated organic compounds rather than iodate. Formation of four aliphatic I-CBPs was observed, and four aromatic I-CBPs were identified by gas chromatography mass-spectrometry and theoretical calculation. Coagulation of iodide-containing waters with FeCl3 also produced I-CBPs ranging from 12.5 ± 0.8 to 32.5 ± 0.2 μg/L as I. These findings call for careful consideration of the formation of I-CBPs from coagulation of iodide-containing waters with ferric salts.
研究领域:
环境科学
·
公共卫生
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2024
·
IF 12.2
Xu Gao,Juan Yan,Chunyu Wang,Peizeng Yang,Junhe Lu,Yuefei Ji
Brominated and nitrated byproducts generated from bromide (Br - ) and nitrite (NO 2 - ), respectively, by sulfate radical (SO 4 •- ) oxidation have raised increasing concern. However, little is known about the concurrent generation of brominated and nitrated byproducts in the unactivated peroxymonosulfate (PMS) oxidation process. This study revealed that Br - can facilitate the transformation of NO 2 - to nitrated byproducts during unactivated PMS oxidation of phenol . In the co-existence of 0.1 mM Br - and 0.5 mM NO 2 - , the total yield of identified nitrated byproducts reached 2.316 μM in 20 min, while none was found with NO 2 - alone. Nitryl bromide (BrNO 2 ) as the primary nitrating agent was formed via the reaction of NO 2 - with free bromine in situ generated through the oxidation of Br - by PMS. BrNO 2 rapidly reacted with phenol or bromophenols , generating highly toxic nitrophenols or nitrated bromophenols, respectively. Increasing NO 2 - concentration led to more nitrated byproducts but less brominated byproducts. This study advances our understanding of the transformation of Br - and NO 2 - in the unactivated PMS oxidation process. It also provides important insights into the potentially underestimated environmental risks when PMS is applied to degrade organic contaminants under realistic environments, particularly when Br - and NO 2 - co-exist.
研究领域:
环境科学
·
化学工程
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DOI
PubMed
高影响因子
WATER RESEARCH
·
2022
·
IF 13.4
Di Zhang,Li Chen,Shengkun Dong,Jiayi Luo,Zuxin Xu,Wenhai Chu
In China, urea degradants are often used in combination with chlorine in swimming pool water to remove urea. Here we report the first study about the impacts of urea degradants on urea degradation, disinfection byproduct (DBP) formation and estimated DBP-associated cytotoxicity and genotoxicity. Firstly, four groups of typical DBPs from six real indoor swimming pools were analyzed. The concentration of DBPs in swimming pool waters was about 1-2 orders of magnitude higher than that source tap water. Notably, a rapid increase in DBPs was observed after urea degradant treatment. Simulated processes of urea removal using three commonly used urea degradants were therefore conducted in laboratory. Neither urea degradant nor chlorine alone removed urea effectively within 48 h. When applied in combination, urea degradant with sufficient chlorine rapidly removed urea by 100% within 3 h, and anti-chlorourea oligomer in urea degradants was the main contributor. Meanwhile, a remarkable increase in DBPs, especially brominated DBPs, was observed due to bromide introduction by urea degradants. For this reason, bromine incorporation factor (BIF) of DBPs dramatically increased. For instance, the BIF of dihaloacetic acids increased by 2665%-4025% after applying three urea degradants. As the highly toxic brominated DBPs were generated, attention should be paid into the potential DBP-related health risks from the use of urea degradants together with chlorine.
研究领域:
环境科学
·
公共卫生
·
毒理学
✓ 已验证
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2021
·
IF 7.963
Kejin Zhou,Sheng Ye,Qi Yu,Jingji Chen,Pang Yong,Xiaoyan Ma,Qingsong Li,Andrea M. Dietrich
Dissolved nitrogenous organic matter in water can contain precursors of disinfection by-products (DBPs), especially nitrogenous DBPs (N-DBPs). Amino acids are ubiquitous as dissolved nitrogenous organic matter in source water and can pass through drinking water treatment processes to react with disinfectants in finished water and in the distribution system. Phenylalanine (Phe) was selected as a model amino acid precursor to investigate its derived DBPs and their variations during a chlorination regime that simulated water distribution with residue chlorine. The 7-day DBPs formation potential (DBPsFP) test with chlorine revealed chlorination by-products of phenylalanine including trihalomethanes (THMs), haloacetic acids (HAAs), haloacetonitriles (HANs), and halonitromethanes (HNMs), but not trichloronitromethane (TCNM) which was a significant N-DBP detected during the first 48 h of chlorine contact. The formation of most carbonaceous DBPs (C-DBPs) increased with chlorination time; however N-DBPs and non-chlorinated byproducts of phenylacetonitrile and phenylacetaldehyde reached their highest concentration after 2 h of reaction, and then gradually decreased until below detection after 7 days. The chlorination influencing factors indicated that light enhanced the peak yield of DBPs; the pH value showed different influences associated with corresponding DBPs; and the presence of bromide ions (Br − ) generated a variety of bromine-containing DBPs. The DBPsFP test with chloramine reduced C-DBPs generation to about 1/3 of the level observed for chlorine disinfection and caused an increase in dichloroacetonitrile. Surveillance of DBPs during drinking water distribution to consumers should consider the varying contact times with disinfectants to accurately profile the types and concentrations of C-DBPs and N-DBPs present in drinking water.
研究领域:
环境科学
·
公共卫生
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2025
·
IF 11.3
Yan Shen,Xiaochen Liu,Junling Li,Jingsi Chen,Jiafu Li
Haloacetamides (HAMs) is a class of highly toxic emerging nitrogenous disinfection byproducts (N-DBPs) in drinking water, however the factors influencing the formation of HAMs by amino acids remain incompletely understood. Besides, a quantitative data regarding how many HAMs in chlorinated drinking water can attribute to amino acids in source water is lacking. To address this gap, HAMs formation during chlorination for 20 amino acids with different side-chains was analyzed. HAMs yield of 20 common amino acids during chlorination was 0.04–132 μg/mg-C. For different side-chains in amino acids, carboxyl group exhibited the highest HAM’s yield at 65.9 μg/mg-C, followed by aromatic rings (10.2 μg/mg-C), and containing nitrogen (10.1 μg/mg-C), respectively. In contrast, hydroxyl groups, sulfur-containing amino acids and those with only hydrogen and alkyl groups showed the lowest HAM’s yield (<1 μg/mg-C). HAM yields of basic and neutral amino acids were lower than that of acidic amino acids. HAM yields of nonpolar amino acids were lower than polar amino acids. The HAM formation potentials of amino acids in source water during chlorination were 14.8–5138 ng/L, with an average of 576 ng/L. Aspartic acid, asparagine, and histidine accounted for as much as 97 % of the theoretical HAMs formation. The theoretical calculation found that amino acids in source water contribute about 3.2 % of HAMs in chlorinated drinking water, which is close to that of lab-controlled experiments (4.3 %), suggesting that the role of amino acids on HAMs in chlorinated drinking water is overvalued. Our study reveals the role of precursor’s side-chains on toxic DBP formation as well their potential contribution to drinking water DBPs.
研究领域:
环境健康学
·
水处理化学
·
毒理学
·
环境污染物
·
分子结构与活性关系
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产品关联
DOI
PubMed
高影响因子
WATER SCIENCE AND TECHNOLOGY
·
2018
·Vol. 2017
·期 2
·340-350
·
IF 1.247
Ma Jie,Li Haiyan,Yang Yongqi,Li Xuening
The present study explored the influence of Cl − , Br − , CO 3 2− , HCO 3 − , PO 4 3− , HPO 4 2− , NO 3 − , SO 3 2− and natural organic matter (NOM) on the reaction kinetics and the formation of undesired degradation byproducts during phenol oxidation by heat-activated persulfate (PS). CO 3 2− and PO 4 3− promoted the phenol degradation, because the hydrolysis of CO 3 2− and PO 4 3− created basic pH conditions which were conducive to enhanced PS oxidation rate. Br − promoted the reaction by reacting with sulfate radicals (SO 4 •− ) to produce bromine radicals that can selectively react with electron-rich phenol. NOM scavenged reactive SO 4 •− , thus inhibiting the reaction. As a strong reducing agent, SO 3 2− rapidly reduced PS, thus completely suppressing the reaction. HCO 3 − , HPO 4 2− , Cl − , and NO 3 − had negligible impact on PS oxidation of phenol. Six intermediates were detected in the no anion control using gas chromatography–mass spectrometry (GC-MS). Various toxic halogenated phenols and halogenated hydroquinones were detected in the treatment containing Cl − and Br − . In contrast, in the treatment containing CO 3 2− , HCO 3 − , PO 4 3− , HPO 4 2− , and NO 3 − , no new intermediates were identified except for the intermediates already detected in the control treatment. Based on intermediates identified, reaction pathways for PS oxidation of phenol without anions and in the presence of halides were proposed respectively.
研究领域:
环境化学
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水处理技术
·
高级氧化过程
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污染物降解
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反应机理
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环境毒理学
✓ 已验证
DOI
高影响因子
Journal of Water Process Engineering
·
2024
·
IF 6.3
Yu-qiong Gao,Ke-xuan Li,Qian Zeng,Fu-xiang Tian,Ze-ning Fan,Gang-yi Xing,Nai-yun Gao
Pharmaceuticals and personal care products (PPCPs) and their disinfection by-product (DBPs) formation during the disinfection process have raised widespread concerns. In this study, the effects of common anions on the sonochemical degradation of two model PPCPs, sulfamethoxazole (SMX) and naproxen (NPX), and their DBPs formation potentials were comparatively explored. The degradation processes followed the heterogeneous kinetic models, indicating PPCPs degradation mainly occurred at the bubble/water interface via radical oxidation. Acidic conditions enhanced sonochemical degradation. Cl − and HCO 3 − have minimal effect, with HCO 3 − moderately enhancing SMX degradation, while Br − notably increased degradation of both PPCPs. Ultrasonic pretreatment reduced trichloromethane (TCM) formation but raised nitrogenous disinfection by-products (N-DBPs) level due to the formed intermediates. Cl − has little effect on DBPs formation, while HCO 3 − obviously diminished N-DBPs formation from both PPCPs. The increase of Br − concentration increased the formation of brominated DBPs (Br-DBPs), while the formation of chlorinated DBPs were inhibited both in direct chlorination and ultrasonic pretreatment followed by postchlorination. Ultrasonic pretreatment also elevated Br incorporation and utilization factors of trihalomethanes (THMs). Of note, although ultrasonic treatment can effectively degrade PPCPs in real environmental matrices, the increase in trichloronitromethane (TCNM) formation potential should be carefully monitored.
研究领域:
环境科学
·
水处理工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Huiming Xiang,Naiyun Gao,Xian Lu,Yuanquan Xiang,Wenhai Chu
Ultraviolet combined monochloramine (UV/NH 2 Cl) process is a promising advanced oxidation process (AOP) to remove organic micropollutants effectively through the generation of various reactive species e.g., hydroxyl radicals (HO • ), reactive chlorine species (RCS), and reactive nitrogen species (RNS). This study investigated the kinetics, transformation pathways, DBPs formation, and toxicity alternation in the degradation of sulfamethazine (SMT). Based on the calculation of degradation kinetic models, RNS was proved to be the most important reactive species in the degradation of SMT in UV/NH 2 Cl. The contribution of RNS, HO • and RCS were approximately 56.6%, 38.8%, and 4.5%, respectively. With the NH 2 Cl dosage increased from 100 to 800 µmol L -1 , degradation rate increased from 37% to 73% in 10 min. Significantly alternation was not observed with the changing of pH. Natural organic matter (NOM) remarkably inhibited the degradation rate to 48.6% and 32.8% in the presence of 1 and 2 mg L -1 NOM. Degradation reactions of SMT in UV/NH 2 Cl system primarily comprised of hydroxylation, nitrosation, and ring opening reactions. The total theoretical toxicity of degradation system increased in the first 20 min and decreased eventually. Comparing with UV/free chlorine (UV/Cl 2 ) process, less disinfection by-products (DBPs) generated in UV/NH 2 Cl treatment. Thus, the theoretical toxicity of DBPs formed in UV/NH 2 Cl was much lower than UV/Cl 2 . Within 40 min degradation, the theoretical toxicity value reached maximum at pH 7.1 due to the mass production of dicloroacetonitrile (DCAN). Bromide ions (10 µmol L -1 ) significantly promoted the formation of brominated DBPs especially dibromoacetonitrile (DBAN). This study provided insight into the important role of RNS in the SAs’ transformation in UV/NH 2 Cl process and reference to benefits and disadvantages when selecting the process for disinfection in drinking water treatment.
研究领域:
环境科学
·
水处理
·
高级氧化工艺
·
水中的药物
·
毒理学
✓ 已验证
产品关联
DOI
高影响因子
WATER RESEARCH
·
2021
·
IF 11.236
Yangrui Huang,Shunke Ding,Lei Li,Qingying Liao,Wenhai Chu,Huaizheng Li
Ultrasound techniques have gained increased interest in environmental remediation because of their promising performance and reagent-free nature. This study investigated the effects of ultrasound-coagulation on Microcystis aeruginosa removal, disinfection by-product (DBP) formation during subsequent chlorination, and acute toxicity and DBP-associated toxicity variations in chlorinated effluents. Compared with coagulation using polymeric aluminum chloride (5 mg-Al/L) alone, ultrasound-coagulation showed significantly enhanced turbidity removal, with the removal ratio increasing from 51% to 87%–96%. Although the addition of ultrasound may not substantially improve and even deteriorate the coagulation removal of DOC following the leakage of intracellular organic matter, the significantly improved DBP control was achieved as the cells dominated DBP formation. With the addition of ultrasound, the chlorine demand, aggregate DBP concentration and total organic halogen concentration reductions in the chlorinated M. aeruginosa solution increased from 15%, 47% and 52% (coagulation alone), respectively, to 56%–78%, 56%–80% and 68%–89%. The enhanced DBP mitigation was mainly attributed to the enhanced algal removal. Similarly, the acute toxicity and DBP-associated toxicity of chlorinated effluents further decreased from 100% and 0.0092 (coagulation alone) to 30%–88% and 0.0029–0.0060. Therefore, ultrasound-enhanced coagulation is a promising strategy for urgent algal removal, DBP mitigation and toxicity abatement.
研究领域:
环境科学
·
水处理工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
WATER RESEARCH
·
2020
·
IF 9.13
Simiao Li,Xiuwei Ao,Chen Li,Zedong Lu,Wenfeng Cao,Fangfang Wu,Shuming Liu,Wenjun Sun
The UV/NH 2 Cl process is an emerging advanced oxidation process (AOP) that is greatly effective in degrading pharmaceuticals and personal care products (PPCPs). However, detailed information regarding the process is lacking. The degradation of ibuprofen (IBP, an electron-withdrawing PPCP) and naproxen (NPX, an electron-donating PPCP) in UV/NH 2 Cl and UV/NaClO processes was performed to investigate the applicability and security of the UV/NH 2 Cl process and compare with those of UV/NaClO. UV/NH 2 Cl was effective in degrading both IBP and NPX and the degradation followed pseudo-first order kinetics (k IBP = 0.0037 cm 2 /mJ and k NPX = 0.0044 cm 2 /mJ). This indicated the broad applicability of UV/NH 2 Cl to different kinds of PPCPs. Ranges of values of UV intensity (0.3–1.0 mW/cm 2 ) and pH (6.0–8.0) showed little effect on the degradation of PPCPs by UV/NH 2 Cl based on UV Dose but HCO 3 − (2–8 mM), natural organic matter (NOM, 2–8 mg/L), and the natural water matrixes were inhibitory. Increasing the dosage of NH 2 Cl from 0.15 mM to 0.75 mM, resulted in an even increase of k IBP ; however, k NPX increased slowly after 0.3 mM NH 2 Cl. Mechanism experiments involving nitrobenzene showed that •OH was the major radical involved in degrading IBP and NPX via UV/NH 2 Cl. The electron spin resonance spectroscopy and kinetic modeling results also indicated the larger amount of •OH and weaker reactive chlorine species (mainly ClO• and ClO 2 •) in UV/NH 2 Cl compared with UV/NaClO. Compared to UV/NaClO in synthetic and natural water, UV/NH 2 Cl was a more stable degrader with little pH- and substrate-dependence, while UV/NaClO preferred degrading the electron-donating PPCP and at low pH. The UV/NH 2 Cl produced less halogenated disinfection byproducts (DBPs) (even nitrogenous DBPs) and was less cytotoxic theoretically than UV/NaClO based on the DBPs included in this study. Thus UV/NH 2 Cl process may be an effective AOP for water treatment .
研究领域:
环境科学
·
水处理工程
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产品关联
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2024
·
IF 8.2
Shengnan Chen,Zhiwei Zhao,Li Li,Fuyi Cui
Ultrafiltration (UF) is widely used in drinking water plants, nevertheless, it still encounters challenges stemming from inevitable membrane fouling caused by natural organic matter (NOM). Herein, this work applied VUV/PS as UF membrane pretreatment and used UV/PS for comparison. VUV/PS system exhibited superior ability in removing NOM compared to UV/PS system. HO and SO 4 − played crucial roles in the degradation. [SO 4 − ]ss was notably higher than [HO ]ss in the systems, yet HO was of greater significance. [HO ]ss and [SO 4 − ]ss in the VUV/PS process were remarkably higher than those in the UV/PS process, due to the function of 185 nm photons. VUV/PS pretreatment basically recovered flux and effectively reduced fouling resistance, with better performance than UV/PS. Fouling mechanism was dominated by multiple mechanisms after UV/PS pretreatment, whereas it was transformed into pore blockage after VUV/PS pretreatment. Moreover, the UF effluent quality after VUV/PS pretreatment outperformed that of UV/PS but fell short of that without pretreatment, possibly due to the generation of abundant low MW substances under the action of HO and SO 4 − . After chlorine disinfection, UV/PS and VUV/PS pretreatments increased the DBPs production and cytotoxicity. Specifically, oxidant PS affected the membrane surface morphology and fouling behaviors, and had no obvious effect on interception performance and mechanical properties. In actual water treatment, VUV/PS and UV/PS pretreatments exhibited excellent performance in alleviating membrane fouling, improving water quality, and reducing DBPs formation and acute toxicity.
研究领域:
环境科学
·
水处理工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
WATER ENVIRONMENT RESEARCH
·
2020
·Vol. 92
·期 12
·2049-2059
·
IF 1.369
Mengyi Wu,Yulin Tang,Qianhong Liu,Zhenjiao Tan,Mu Wang,Bin Xu,Shengji Xia,Shun Mao,Naiyun Gao
In this study, UV-LED was employed as a novel light source to investigate the degradation of a representative antibiotic compound, chloramphenicol (CAP), in the absence or presence of H 2 O 2 . The UV-LED irradiation showed a higher capability for degradation of CAP than conventional UV-Hg vapor lamps. Effects of the initial CAP concentration, UV wavelength, and light intensity on the degradation of CAP by UV-LED were evaluated. Introduction of H 2 O 2 evidently enhanced the degradation efficiency of CAP due to the production of reactive hydroxyl radicals. Results showed that the UV-LED/H 2 O 2 removed CAP by up to 95% within 60 min at pH 5.0, which was twice as that achieved by the UV-LED alone. The degradation products were identified to propose plausible degradation pathways. Moreover, the formation potentials of typical carbonaceous disinfection by-products (C-DBPs) and nitrogenous disinfection by-products (N-DBPs) were assessed for the CAP polluted water treated by the UV-LED alone and UV-LED/H 2 O 2 processes. Results indicate unintended formation of certain DBPs, thereby highlighting the importance of health risk assessments before practical application. This study opens a new avenue for developing environment-friendly and high-performance UV-LED photocatalytic reactors for abatement of CAP pollution in water. Practitioner points UV-LED bore higher capability to degrade CAP than low-pressure Hg lamp. The optimal performance to degrade CAP can be achieved at the UV wavelength of 280 nm. The degradation efficiency under UV-LED/H 2 O 2 process was double of that under UV-LED process. TCM, DCAN, and TCNM formation were higher under the existence of UV-LED radiation. The addition of H 2 O 2 had greater influence on the formation of DCAcAm than the introduction of UV-LED.
研究领域:
环境科学
·
水处理技术
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）