SCIENCE OF THE TOTAL ENVIRONMENT
·
2019
·
IF 5.589
Siying Tan,Shaojie Jiang,Yangzhou Lai,Qiuhong Yuan
Cationic polymers, which are commonly used as flocculants and coagulant aids in water and wastewater treatment , have been recently reported to promote the formation of nitrosamines . Most of the findings to date are based on poly (epichlorohydrin dimethylamine) and poly (diallyldimethylammonium chloride), while few studies have considered nitrosamines formation of polyacrylamides. In this work, the nitrosamines formation from non-ionic, anionic and cationic polyacrylamides was evaluated. Moreover, the effects of chemical structures of cationic polyacrylamides (including molecular weight , charge density, and monomers) on nitrosamines formation were investigated. The results revealed that the highest amount of nitrosamines formation was formed from cationic polyacrylamide, followed by non-ionic polyacrylamide and anionic polyacrylamide. Molecular weight and various cationic monomers showed no significant effects on nitrosamines formation, but monomers generated significantly higher amount of nitrosamines formation than cationic polyacrylamides. Nitrosamines formation increased with the increasing charge density of cationic polyacrylamides, and FTIR analysis results showed that the quaternary amine groups preferentially reacted with chloramines than with amide groups. This work shed new light on the nitrosamines formation from water and wastewater treatment polymers.
研究领域:
环境科学
·
水处理工程
✓ 已验证
DOI
PubMed
高影响因子
MOLECULES
·
2024
·Vol. 29
·期 2
·396
·
IF 4.2
Zhenkun Sun,Zhenyi Chen,Marie Celine Chung Lan Mow,Xiaowen Liao,Xiaoxuan Wei,Guangcai Ma,Xueyu Wang,Haiying Yu
The unrestricted utilization of antibiotics poses a critical challenge to global public health and safety. Levofloxacin (LEV) and sulfaphenazole (SPN), widely employed broad-spectrum antimicrobials, are frequently detected at the terminal stage of water treatment, raising concerns regarding their potential conversion into detrimental disinfection byproducts (DBPs). However, current knowledge is deficient in identifying the potential DBPs and elucidating the precise transformation pathways and influencing factors during the chloramine disinfection process of these two antibiotics. This study conducts a comprehensive analysis of reaction pathways, encompassing piperazine ring opening/oxidation, Cl-substitution, OH-substitution, desulfurization, and S−N bond cleavage, during chloramine disinfection. Twelve new DBPs were identified in this study, exhibiting stability and persistence even after 24 h of disinfection. Additionally, an examination of DBP generation under varying disinfectant concentrations and pH values revealed peak levels at a molar ratio of 25 for LEV and SPN to chloramine, with LEV contributing 11.5% and SPN 23.8% to the relative abundance of DBPs. Remarkably, this research underscores a substantial increase in DBP formation within the molar ratio range of 1:1 to 1:10 compared to 1:10 to 1:25. Furthermore, a pronounced elevation in DBP generation was observed in the pH range of 7 to 8. These findings present critical insights into the impact of the disinfection process on these antibiotics, emphasizing the innovation and significance of this research in assessing associated health risks.
研究领域:
环境科学
·
公共卫生
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2021
·
IF 7.963
Si-Yu Duan,Xue Chen,Huang Huang,Xin Yang,Xin Lu
The formation of nitrogenous disinfection byproducts (N-DBPs) occurs in chloraminated water in drinking water distribution systems and may be affected by metal pipe materials and their corrosion products. The effect of copper corrosion products, including Cu 2+ , CuO, and Cu 2 O, on the formation of dichloroacetonitrile (DCAN) and dichloroacetamide (DCAcAm) was investigated during chloramination of natural organic matter (NOM), model precursors (carboxylic acids and amino acids), and real water samples. Copper corrosion products enhanced DCAN and DCAcAm formation during chloramination of NOM by 33%–72% and 11%–80%, respectively. Addition of 15 N-labeled monochloramine showed that the copper corrosion products primarily enhanced the formation of DCAN using organic nitrogen and monochloramine as nitrogen sources, and the formation of DCAcAm using monochloramine as the nitrogen source, but had a limited impact on the formation of DCAcAm using organic nitrogen as the nitrogen source. A distinct N-DBP formation pathway in the presence of Cu 2+ and CuO was observed using tyrosine as a model compound, which included the formation of 1,4-benzoquinone as a dominant intermediate. On reaction with monochloramine, the 1,4-benzoquinone greatly contributed to enhancement of DCAN and DCAcAm formation using monochloramine as the nitrogen source. During chloramination of real water samples, Cu 2+ and CuO enhanced DCAN formation by 9–40% and DCAcAm formation by 16–33%. This study increases our knowledge of copper catalyzed DCAN and DCAcAm formation in copper pipes, which will be meaningful for water safety in distribution systems using chloramine disinfection.
研究领域:
环境科学
·
公共卫生
✓ 已验证
产品关联
DOI
PubMed
高影响因子
WATER RESEARCH
·
2022
·
IF 13.4
Jing Wang,Jie Zhang,Jing Liu,Nannan Hou,Qi Li,Guannan Zhou,Kewan Li,Yang Mu
Copper water pipelines are widely used in water distribution systems, but the effects of solid copper corrosion products (CCPs) including CuO, Cu 2 O and Cu 2 (OH) 2 CO 3 on the generation of iodinated trihalomethanes (I-THMs) during chloramination remain unknown. This study found that the formation of I-THMs during chloramination of humic acid (HA) was inhibited by the presence of CuO and Cu 2 O, but promoted with the addition of Cu 2 (OH) 2 CO 3 . The negative effect of CuO and Cu 2 O is mainly exerted by promoting the decay of both NH 2 Cl and HOI. Although Cu 2 (OH) 2 CO 3 also accelerated the decomposition of NH 2 Cl and HOI, it was found that the complexes formed between Cu 2 (OH) 2 CO 3 and HA facilitated, through carboxyl functional groups, the reaction between HA and HOI, leading to an enhancement of I-THM generation during chloramination, which was further confirmed by model compound experiments. Additionally, this study demonstrated that the effects of solid CCPs on I-THM generation during chloramination were solid CCP- and HA-concentration dependent, but almost unaffected by different initial I − and Br − concentrations. This study provides new insights into the health risks caused by the corrosion of copper water pipelines, especially in areas intruded by sea water.
研究领域:
环境科学
·
公共卫生
✓ 已验证
产品关联
DOI
PubMed
高影响因子
WATER RESEARCH
·
2018
·
IF 7.051
Chao Fang,Stuart W. Krasner,Wenhai Chu,Shunke Ding,Tiantao Zhao,Naiyun Gao
Haloacetamides (HAMs), an emerging class of disinfection by-products, have received increasing attention due to their elevated cyto- and genotoxicity. However, only limited information is available regarding the iodinated analogues. This study investigated the formation and speciation of iodinated haloacetamides (I-HAMs) and their chlorinated/brominated analogues during the chloramination of bromide and/or iodide-containing waters and a model compound solution over various time periods. The rapid formation of diiodoacetamide (DIAM) was observed during chloramination of three simulated samples, whereas brominated (Br-HAMs) and chlorinated haloacetamides (Cl-HAMs) increased slowly with increasing reaction time. To further understand the differences in the formation of HAMs containing different halogens, experiments with the model compound asparagine in the presence/absence of iodide were conducted. Moreover, iodine utilisation factors and iodine incorporation factors were observed to increase significantly faster and were substantially higher than those of bromine. This implied that, compared with bromide, iodide has substantially greater potential to be transformed to the corresponding HAMs during chloramination, similar to that of other classes of DBPs. That is, I-HAMs formed faster than the other species investigated, including Cl-HAMs and Br-HAMs, in the early reaction stages (0–3 h). The effect of the bromide/iodide ratio (i.e., constant iodide, increasing bromide) on I-HAM formation was also examined. With increasing bromide/iodide ratio, the formation of Br-HAMs increased and dichloroacetamide decreased, but the formation of DIAM was largely unchanged. This was consistent with the constant level of iodide in spite of the increasing bromide. Chlorine and ammonia are applied separately during chloramination in water treatment , so the effect of pre-chlorination (before adding ammonia) on the formation and speciation of I-HAMs during in situ chloramination was also evaluated. Effective mitigation of DIAM formation with in situ chloramination was achieved, and the efficiency improved with increasing pre-chlorination time, where iodide was oxidised to iodate . The HAM-associated cytotoxicity was calculated to determine the change in toxicity at different reaction times, bromide/iodide ratios, and pre-chlorination times. A similar trend as the formation of I-HAMs was observed, which increased rapidly in the first 3 h, but decreased somewhat subsequently. When the bromide/iodide ratio and pre-chlorination time was increased, the calculated toxicity of the HAMs increased (due to more formation of Br-HAMs and less Cl-HAMs) and decreased (due to less DIAM formation), respectively.
研究领域:
环境科学
·
毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2022
·
IF 10.753
Haoyuan Zhang,Peng Gao,Yongze Liu,Ziwen Du,Li Feng,Liqiu Zhang
Nitrogenous disinfection by-products (N-DBPs) raise increasing concerns because of their high genotoxicity, cytotoxicity, and carcinogenicity compared to carbonaceous disinfection by-products (C-DBPs). Nitrogen-containing disinfectants, dissolved organic nitrogen (DON), and inorganic nitrogen may all promote the formation of N-DBPs. Therefore, it is urgent to explore the dominant nitrogen source of N-DBPs under the coexistence of multiple nitrogen sources. In this study, the effects of amino acids, nitrate, ammonia, and chloramine as different types of nitrogen sources on the formation of five N-DBPs were investigated systematically, including chloroacetonitrile (CAN), dichloroacetonitrile (DCAN), bromochloroacetonitrile (BCAN), dibromoacetonitrile (DBAN) and dichloroacetamide (DCAcAm). L-Aspartic acid (L-Asp) as the organic nitrogen source showed a high potential on the formation of N-DBPs by forming acetonitrile intermediates. Ammonia as the inorganic nitrogen source consumed oxidants and changed the existing form of chloramine, thus inhibiting the formation of N-DBPs. Instead of providing nitrogen to N-DBPs, nitrate as a salt promoted the volatilization of N-DBPs, thereby reducing the detected N-DBPs. Furthermore, an isotope labeling method was applied to clearly trace the nitrogen sources of N-DBPs via GC–MS with electron ionization. 15 N-chloramine, 15 N-amino acid, 15 N-nitrate and 15 N-ammonia were selected as the corresponding isotopic nitrogen sources. The results indicated that chloramine was the major nitrogen contributor to five N-DBPs during the chloramination of L-Asp under the coexistence of multiple nitrogen sources, ranging from 61 % to 79 %. The influence of environmental factors (reaction time, pH, and bromide) on the formation of N-DBPs during chloramination was also investigated. There was competition between brominated N-DBPs and chlorinated N-DBPs in chloramination. With the increase of reaction time or bromine, the formation potentials of chlorinated N-DBPs gradually decreased, while brominated N-DBPs gradually increased. Moreover, higher pH inhibited the generation of N-DBPs.
研究领域:
环境科学
·
公共卫生
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
WATER RESEARCH
·
2016
·
IF 5.991
Wenhai Chu,Tengfei Chu,Tom Bond,Erdeng Du,Yingqing Guo,Naiyun Gao
Persulfate oxidation processes, with and without activation using ultraviolet light (respectively UV/PS and PS) have the potential to degrade anthropogenic chemicals in water. However, little is known about the impact of PS or UV/PS pre-oxidation on downstream formation of disinfection by-products (DBPs). In this study the three antibiotic chloramphenicols (chloramphenicol and two of its analogues [thiamphenicol and florfenicol], referred to collectively as CAPs), which frequently occur in wastewater-impacted source waters used by drinking water treatment plants, were selected as model antibiotic compounds. The formation of carbonaceous and nitrogenous disinfection by-products, including halomethanes, haloacetonitriles and halonitromethanes, during chlorination and chloramination preceded by PS and UV/PS was investigated. No significant concentrations of haloacetonitriles and halonitromethanes were detected during chlorination. During chloramination chloramphenicol formed a considerable amount of dichloronitromethane (e.g., 3.44 ± 0.33% mol/mol at NH 2 Cl dose = 1 mM) and trichloronitromethane (e.g., 0.79 ± 0.07% mol/mol at NH 2 Cl dose = 1 mM), compared with THM and HAN formation. PS pre-oxidation achieved a statistically significant reduction in trichloromethane formation from chlorination, and in HAN and HNM formation from chloramination. Although UV/PS slightly increased dichloroacetonitrile formation during chloramination, it significantly decreased dichloronitromethane and trichloronitromethane formation during chloramination. Overall, the use of PS and UV/PS has the potential to have contrasting impacts on DBP formation in heavily wastewater-impacted waters, depending on the disinfection method. Hence, their application needs to be carefully balanced against the downstream effect on DBP formation.
研究领域:
环境科学
·
水处理工程
·
公共卫生
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Environmental Science-Water Research & Technology
·
2023
·Vol. 9
·期 4
·1231-1237
·
IF 5
Run Zhou,Zhifei Xu,Yukang Wu,Li Yang,Xiuzhu Li,Yuanhua Meng,Pengfei Zhu,Lingcan Kong,Xinliang Ding
Human exposure to disinfection by-products (DBPs) primarily occurs through the consumption of drinking water. Haloacetamides (HAcAms) are an emerging class of nitrogenous DBPs with higher levels of cytotoxicity and genotoxicity compared to those of regulated DBPs. Detecting ultra-trace levels of HAcAms in drinking water remains challenging despite the availability of multiple detection methods. This paper reports the first use of ultra-performance liquid chromatography–mass spectrometry/mass spectrometry (UPLC-MS/MS) to quantify 13 HAcAms in drinking water without pretreatment. Results from the analysis of water samples collected from four cities in East China showed total HAcAm concentrations of 0.21–6.12 μg L−1, which were comparable to previously reported data from other countries. Further, 11 out of 13 HAcAms were detected in 60 water samples, with diHAcAms being the predominant subclass. DCAcAm and BCAcAm were the primary HAcAms targeted for detection and two Iodo-HAcAms were detected. The average total HAcAm concentration in water samples disinfected with chloramine was significantly higher than that in water samples disinfected with chlorine. Additionally, the total HAcAm concentrations in water samples from a treatment plant (WTP) using the ozone-biological activated carbon (ozone-BAC) process were lower than those in water samples from WTPs that did not use this treatment process. The results of this study have significant implications for monitoring water quality and protecting human health.
研究领域:
环境科学
·
公共卫生
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2012
·
IF 3.286
Huachang Hong,Yujing Xiong,Mengyong Ruan,Fanglei Liao,Hongjun Lin,Yan Liang
The formations of THMs, HAAs, and HNMs from chlorination and chloramination of water from Jinlan Reservoir were investigated in this study. Results showed that monochloramine rather than chlorine generally resulted in lower concentration of DBPs, and the DBPs formation varied greatly as the treatment conditions changed. Specifically, the yields of THMs, HAAs and HNMs all increased with the high bromide level and high disinfectant dose both during chlorination and chloramination. The longer reaction time had a positive effect on the formation of THMs, HAAs and HNMs during chlorination and HNMs during chloramination. However, no time effect was observed on the formation of THMs and HAAs during chloramination. An increase in pH enhanced the levels of THMs and HNMs upon chlorination but reduced levels of HNMs upon chloramination. As for the THMs in chloramination and HAAs in chlorination and chloramination, no obvious pH effect was observed. The elevated temperature significantly increased the yields of THMs during chlorination and HNMs during chloramination, but has no effect on THMs and HAAs yields during chloramination. In the same temperature range, the formation of HAAs and HNMs in chlorination showed a first increasing and then a decreasing trend. In chloramination study, addition of nitrite markedly increased the formation of HNMs but had little impact on the formation of THMs and HAAs. While in chlorination study, the presence of high nitrite levels significantly reduced the yields of THMs, HAAs and HNMs. Range analysis revealed that the bromide and disinfectant levels were the major factors affecting THMs, HAAs and HNMs formation, in both chlorination and chloramination. Finally, comparisons of the speciation of mono-halogenated, di-halogenated, tri-halogenated HAAs and HNMs between chlorination and monochloramination were also conducted, and factors influencing the speciation pattern were identified.
研究领域:
环境科学
·
公共卫生
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL POLLUTION
·
2025
·
IF 7.3
Jialing Luo,Suling Wei,Yufeng Xie,Junlang Qiu,Xiaolin Niu,Na Luo,Yanpeng Gao,Yuemeng Ji,Taicheng An
The widespread use of chloramination as a disinfection strategy has raised concerns about the formation of harmful disinfection byproducts (DBPs), highlighting the urgent need to elucidate the underlying transformation mechanisms. In this study, we integrated non-targeted screening, organic synthesis, and quantum chemical calculations to investigate the chloramination mechanism of preservative methylparaben and assess the toxicological impacts of the resulting DBPs. In addition to chlorinated products, two novel transformation products, the coupled (C-MeP) and hydroxylated (OH-MeP) products were identified, and the structure of C-MeP was confirmed through synthesized standards. Quantum chemical calculations reveal that the formation of C-MeP is driven by electron transfer, generating radicals that promote C-C bond coupling, while OH-MeP is likely formed by an addition-hydrolysis pathway. The formation of chlorinated products occurs through electrophilic substitution, facilitated by water molecules, and may undergo coupling to form chlorinated products with a biphenyl structure. Toxicity assessments indicate that coupled products exhibit greater negative effects on the gastrointestinal and cardiovascular system compared to parent pollutant. These findings highlight the need to expand the focus of chloramination disinfection beyond traditional chlorinated DBPs, emphasizing the ecological and health implications of novel products including coupled byproducts.
研究领域:
环境科学
·
毒理学
·
计算化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMOSPHERE
·
2024
·
IF 8.1
Xuefeng Sun,Dongbin Wei,Feipeng Wang,Fan Yang,Yuguo Du,Han Xiao,Xinming Wei,Anshan Xiao
Chloramination was commonly used as disinfectant for killing pathogens in water. However, in this process, nitrogen-containing disinfection by-products (N-DBPs) would accidently form and subsequently rise toxicity. Here, we investigated acute toxicity variation and by-products formation during chloramination treatment on UV filter 2-hydroxy-4-methoxy-5-sulfonic acid benzophenone (BP-4). Under alkaline conditions, the acute toxicity of this system had significant increase. A total of 17 transformation products were tentatively identified, and for them, plausible transformation pathways were proposed. Noticeably, numerous aniline and nitrosobenzene analogs were detected, and the dramatic increase of acute toxicity in this system might be primarily attributed to the formation of benzoquinone and aniline analogs. Besides, bromophenol, iodophenol and iodobenzoquinone analogs exhibiting high toxicity were generated in the presence of bromine and iodide ions. This study indicates that chloramination treatment may significantly increase potential health risk, further management on disinfection system is reasonable.
研究领域:
环境科学
·
毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2025
·
IF 11.3
Wenyuan Yang,Tom Bond,Chao Fang,Zhenqi Du,Wenhai Chu
Iodinated DBPs (I-DBPs), many more toxic than regulated chlorinated and/or brominated DBPs, are a major challenge in the supply of safe drinking water. While over 800 DBPs have been identified, the occurrence and precursors of toxic I-DBPs remain poorly understood. Herein, natural organic matter from two raw drinking waters was fractionated using ultrafiltration membranes into different groups based on molecular weight (MW). The <1 kDa fraction exhibited the highest levels of cytotoxicity and genotoxicity after disinfection. However, in the presence of iodide, the 10–100 kDa fraction had the highest toxicity/dissolved organic carbon values. FT-ICR MS analysis showed high reactivity between hypoiodous acid and the 10–100 kDa fraction, and a shift from aromatic and unsaturated molecules to more saturated and oxidized molecules during chloramination of 10–100 kDa fraction. Based on nontarget analysis using orbitrap MS, four I-DBPs with high peak intensities during chloramination of 10–100 kDa fraction were identified and then confirmed using chemical standards: 4-hydroxy-3-iodo-5-nitrobenzonitrile, 2,4,5-triiodoimidazole, 3,5-diiodo-4-hydroxybenzonitrile, and 2,6-diiodo-4-nitrophenol. The first two have been first identified in drinking water. The concentrations of the four DBPs ranged from
CAS / MDL:
研究领域:
环境科学
·
毒理学
·
分析化学
✓ 已验证
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）