SCIENCE OF THE TOTAL ENVIRONMENT
·
2023
·
IF 9.8
Tianze Liu,Xiaobin Liao,Xinna Lin,Jing Yu,Huan Qi,Zhibin Jiang,Jing Zou,Qingsong Li
This study was to evaluate the feasibility of controlling carcinogenic nitrosodiethylamine (NDEA) formation from greenhouse gas adsorbent 3-diethylaminopropylamine (DEAPA) by pre-O 3 in subsequent chlorination/chloramination processes. The result indicated that the NDEA yields (0.4 %) during chlorination was 1.3 times of that during chloramination (0.3 %); pre-oxidation with 4 mg/L O 3 significantly cut down its formation; the reduction rates were up to 67.5 and 48.5 %, respectively. OH scavenger greatly augmented the final NDEA amount from 1.86 to 5.05 μg/L during ozonation , while its roles on subsequent processes differed with disinfection methods as well as O 3 (g) dosages. Most of co-existed substances inhibited NDEA generation, except NO 2 − , CO 3 2− and SO 4 2− , which slightly promoted during ozonation. Basing on Gaussian calculation, GC/MS and UPLC-Q-TOF-MS analysis, the influencing mechanisms of pre-O 3 on NDEA formation in subsequent disinfection processes were proposed. In addition, the calculated toxicity analysis as well as the whole toxicity was applied to evaluate the possibility of pre-O 3 on risk control.
研究领域:
环境科学
·
水处理工程
·
毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2025
·
IF 11.3
Jiacheng Ge,Xiaoyan Chen,Zhenqi Du,Yingying Zhou,Ruixin Qu,Jiangdong Cui,Shunke Ding,Wenhai Chu
Halogenated nitrophenols (HNPs) have raised significant concerns due to their extensive detection and potent toxicity. Understanding how these compounds persist and degrade over time is crucial for predicting their potential accumulation and assessing the long-term exposure risks. Kinetic studies showed that the degradation of HNPs through hydrolysis and chloramination over realistic hydraulic retention times is relatively low. The species-specific second-order rate constants for the reaction of hypochlorous acid and the acid-catalyzed reaction of hypochlorous acid with anionic HNP species, which accounted for HNP degradation during chlorination, range from 3.84 ± 1.09–363.25 ± 50.44 M⁻¹min⁻¹ and from (1.50 ± 0.091) × 10⁶ to (1.34 ± 0.36) × 10⁸ M⁻²min⁻¹ , respectively. The reactivity order of reactive species in hydrolysis, chlorination, and chloramination with HNP species has also been verified through computational modeling using density functional theory. The introduction of nitro group onto HNPs significantly diminishes the electron density of the benzene ring, thereby reducing their inherent reactivity compared with other aromatic DBPs. The hydrolysis and chlorination of HNPs primarily result in the formation of halogenated hydroquinones and various polyhaloquinones and polyhalophenols, respectively. These results suggest that HNPs and their transformation products exhibit relatively high persistence and exposure risks.
研究领域:
环境科学
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饮用水安全
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毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2024
·
IF 8.2
Rui Yu,Yunkun Qian,Yanan Chen,Yijun Shi,Jun Guo,Dong An
Dichloroacetonitrile (DCAN) is an emerging disinfection by-product (DBP) that is widespread in drinking water. However, the pathway for DCAN formation from aromatic amino acids remains unclear, leading to a lack of an understanding of its explicit fate during chloramination. In this study, we investigated the specific formation mechanism of DCAN during the chloramination of phenylalanine based on reaction kinetics and chemical thermodynamics. The reason for differences between aldehyde and decarboxylation pathways was explained, and kinetic parameters of the pathways were obtained through quantum chemistry calculations. The results showed that the reaction rate constant of the rate-limiting step of the aldehyde pathway with 1.9 × 10 −11 s −1 was significantly higher than that of decarboxylation (3.6 × 10 −16 s −1 M −1 ), suggesting that the aldehyde pathway is the main reaction pathway for DCAN formation during the chloramination of phenylalanine to produce DCAN. Subsequently, theoretical calculations were performed to elucidate the effect of pH on the formation mechanism, which aligned well with the experimental results. Dehydrohalogenation was found to be the rate-limiting step under acidic conditions with reaction rate constants higher than those of the rate-limiting step (expulsion of amines) under neutral conditions, increasing the rate of DCAN formation. This study highlights the differences in DCAN formation between the decarboxylation and aldehyde pathways during the chloramination of precursors at both molecular and kinetic levels, contributing to a comprehensive understanding of the reaction mechanisms by which aromatic free amino acids generate DCAN.
研究领域:
环境科学
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化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2019
·
IF 5.589
Jing Liu,Jing Wang,Jie Zhang,Yang Mu
In this study, the impact of Cu 2+ on the formation of iodo-trihalomethanes (I-THMs) during chlorination and chloramination of iodide-containing waters was investigated. Initially, the oxidant consumption and evolution of hypoiodous acid (HOI) were determined during disinfection in the presence of Cu 2+ and the interaction between natural organic matter humic acid (HA) and Cu 2+ was also analyzed. Subsequently, the formation of the I-THMs at various Cu 2+ concentrations was evaluated for chlorination and chloramination. Moreover, in order to explore the possible underlying mechanisms, five model compounds based on the HA structure were used to investigate the I-THMs formation with and without Cu 2+ during disinfection. The results indicated that the presence of Cu 2+ markedly affected the conformation of the HA rather than the HOI evolution during disinfection. The concentration of the I-THMs decreased from 34.5 ± 0.8 to 20.9 ± 0.8 nM as the Cu 2+ concentration increased from 0 to 20 μM during chlorination. In contrast, during chloramination, the total I-THMs concentration decreased from 320.7 ± 7.4 to 267.2 ± 10.7 nM as the Cu 2+ concentration increased from 0 to 5 μM and then increased to 315.0 ± 1.7 nM when the Cu 2+ concentration reached 20 μM. The disinfection experiments with the model compounds suggested that the impact of Cu 2+ on the I-THMs formation largely depended on the organic structures in the HA, thus leading to different results during chlorination and chloramination.
研究领域:
环境科学
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水处理工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2016
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IF 5.31
Guilin He,Cong Li,Tuqiao Zhang,Jingguo Zhao,Virender K. Sharma,Leslie Cizmas
Chloramination of bisphenol A (BPA) in a pilot-scale water distribution system (WDS) was investigated to assess factors that influence degradation rate and degradation products. In deionized water (DW) and in the WDS, complete degradation of BPA after chloramination required >9 h. At Cl/N mass ratios of 3, 4 or 6, the degradation rate was appreciably greater in the WDS than in the DW. In both the DW and WDS, the bromide ion concentration had little influence on BPA degradation. The BPA degradation rate was greatly affected by pH and temperature in both the DW and in the WDS. The rate of BPA degradation by chloramination increased with increasing flow velocity, but the increase was limited. The BPA degradation rate in different pipes followed the order: ductile iron pipe > polyethylene (PE) pipe > stainless steel pipe. Twelve specific degradation products of BPA that were produced following chloramination were tentatively identified, with 2-chloro-BPA as the main byproduct. One nitrogenous byproduct produced following chloramination was detected for the first time, and appeared at 15 min, indicating that nitrogen from the chloramine participated in the BPA degradation reaction at the beginning of the experiment. In the presence of chloramines and BPA, the formation of trihalomethanes (THMs), haloacetic acids (HAAs) and halogenated nitromethane (HNMs) occurred primarily in the initial 3 h. The intermediates of BPA that were formed during chloramination had relatively little influence on THM, HAA and HNM formation. The degradation pathways for BPA during chloramination in the WDS are proposed.
研究领域:
环境科学
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水处理工程
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化学
✓ 已验证
DOI
高影响因子
Environmental Science-Water Research & Technology
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2018
·Vol. 5
·期 2
·397-405
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IF 3.649
Yan Huang,Yangyang Zhang,Qing Zhou,Aimin Li,Peng Shi,Jingfan Qiu,Yang Pan
Disinfection of wastewater effluents could generate numerous toxic disinfection byproducts (DBPs) during wastewater reclamation owing to the complexity of their dissolved organic matter. Recently, iodinated disinfection byproducts (I-DBPs) have attracted increasing attention as a result of their higher toxicity than their brominated and chlorinated analogues. In this study, various new polar I-DBPs in chlor(am)inated wastewater effluents were detected with ultra-performance liquid chromatography/electrospray ionization-triple quadrupole mass spectrometry (UPLC/ESI-tqMS) by setting a precursor ion scan of m/z 126.9. Three new polar I-DBPs were identified as wastewater I-DBPs, including iodoacetic acid, chloroiodoacetic acid and 3,5-diiodo-4-hydroxybenzaldehyde. The remaining new polar I-DBPs were proposed with structures, nine of which were found to be aromatic halogenated DBPs, and six of which were proposed to be in a group because they share closely related m/z values, retention times, and fragmentation pathways. In addition, formation of these new polar I-DBPs with disinfectants and contact times was also studied. Compared with chlorination, chloramination generated more species and higher concentrations of new polar I-DBPs. Furthermore, control of the newly detected polar I-DBPs during chlorination by coagulation, resin adsorption, and combined processes was compared. Resin adsorption showed a higher precursor removal efficiency than coagulation, and thus achieved a better control of these new polar I-DBPs. Coagulation followed by resin adsorption was the most effective compared with single coagulation and single resin adsorption.
研究领域:
环境科学
·
毒理学
✓ 已验证
DOI
高影响因子
CHEMOSPHERE
·
2019
·
IF 5.108
Shisheng Zhang,Tao Lin,Wei Chen,Hang Xu,Hui Tao
The residues of pharmaceuticals and personal care products (PPCPs) in environmental waters have been widespread concerned. Metronidazole (MNZ), normally employed to treat inflammation and infection, was chosen as one model PPCP. The degradation of MNZ by chlorination could be fitted by pseudo-first-order kinetics as the observed pseudo-first-order rate constants increasing from 0.0302 min −1 to 0.2872 min −1 . However, the kinetics during chloramination of MNZ followed pseudo-second-order reaction, whose estimated half-live was approximately 6–8 times longer than chlorination. The chlor(am)ination of MNZ especially formed chloroform (CF), dicholoacetamide (DCAcAm), tricholoacetamide (TCAcAm) and dichloroacetonitrile (DCAN), and their yields were overall lower under chloramination than chlorination. During chlorination, the yield of CF was increased from 0.35 ± 0.02% to 2.06 ± 0.12% with 1–20 chlorine/MNZ molar ratio, whereas the formations of DCAcAm, TCAcAm and DCAN increased firstly and then decreased. Increasing chloramine dosage promoted the concentrations of scheduled disinfection byproducts (DBPs). CF and TCAcAm kept continuous generation in chlor(am)ination versus reaction time. Compared with the chlorination, the chloramination of MNZ was more dependent on pH value due to the self-degradation of chloramine. Faintly acidic condition favored N-DBPs' formation in MNZ when it was subjected to chlor(am)ination. The chloramination of MNZ produced cytotoxicity and genotoxicity by 10–15 folds lower than chlorination, and DCAN formed during chloramination dominated both DBPs' yields and toxicity contribution. Opposite to chlorination, the integrated toxicity of MNZ during chloramination varied linearly versus N-DBPs' yields.
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
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2014
·
IF 2.482
Shiqing Zhou,Yisheng Shao,Naiyun Gao,Shumin Zhu,Yan Ma,Jing Deng
Formation of disinfection by-products (DBPs) from chlorination and chloramination of tetracycline antibiotics (TCs) was comprehensively investigated. It was demonstrated that a connection existed between the transformation of TCs and the formation of chloroform (CHCl 3 ), carbon tetrachloride (CCl 4 ), dichloroacetonitrile (DCAN) and dichloroacetone (DCAce). Factors evaluated included chlorine (Cl 2 ) and chloramine(NH 2 Cl) dosage, reaction time, solution pH and disinfection modes. Increased Cl 2 /NH 2 Cl dosage and reaction time improved the formation of CHCl 3 and DCAce. Formation of DCAN followed an increasing and then decreasing pattern with increasing Cl 2 dosage and prolonged reaction time. pH affected DBPs formation differently, with CHCl 3 and DCAN decreasing in chlorination, and having maximum concentrations at pH 7 in chloramination. The total concentrations of DBPs obeyed the following order: chlorination>chloramination>pre-chlorination (0.5 h)>pre-chlorination (1 h)>pre-chlorination (2 h).
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMOSPHERE
·
2021
·
IF 7.086
Peilu Zhai,Yeming Shen,Pengxuan Xi,Minghuo Wu,Xinping Wu,Li Li,Wanxue Cao,Yu Ke,Jianye Zhang
Phenylalanine (Phe) is widely present in natural water and serves as a precursor of disinfection by-products (DBPs). We reported the identification of chloramination DBPs from Phe in drinking water using ultra-high performance liquid chromatography (UHPLC) coupled with complementary high-resolution quadrupole time-of-flight (QTOF) and triple quadrupole (tQ) tandem mass spectrometry (MS/MS). In the chloraminated Phe water solution, sixteen new DBPs in a total of seventeen were identified based on their accurate mass, MS/MS spectra and 35 Cl/ 37 Cl isotopic patterns. Three of these DBPs were verified as benzamide, phenylacetamide, and p -hydroxyphenylacetamide with their standards, while the others were chlorinated derivatives of Phe, hydrazone, amidine, amide and peroxide, in which the unique structures of these DBPs were rarely reported. Their stability and formation process were investigated as well. Furthermore, a method consisting of solid phase extraction (SPE) and UHPLC-MS/MS using dynamic multiple reaction monitoring (dMRM) was developed to investigate these DBPs in authentic waters. Phe, benzamide, phenylacetamide, and N –Cl-2-phenylacetimidamide were detected in chlorinated tap water . Compared with the other identified DBPs, these three DBPs were exceptionally stable and could be formed in wide formation conditions. Our work not only provided ideas for the identification of new chloramination DBPs, but also demonstrated that some DBPs usually generated in the chloramination disinfection process could also be found in the chlorinated drinking water.
研究领域:
环境科学
·
分析化学
✓ 已验证
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2015
·
IF 4.321
Wenhai Chu,Xin Li,Tom Bond,Naiyun Gao,Daqiang Yin
Low-molecular weight organic acids (LMWOAs) are widespread in nature, and many are recalcitrant during conventional drinking water treatment, due to their LMW and hydrophilic character. This study assessed the formation of a range of disinfection by-products (DBPs) from the chloramination of seven non-nitrogenous LMWOA precursors, with an emphasis on the contribution of N-chloramine incorporation to haloacetamide (HAcAm) formation. The other DBPs comprised chlorinated halomethanes, haloacetonitriles and haloacetic acids. Citric acid generated higher yields of trichloromethane and two chloroacetic acids than the other LMWOAs. Further, the unsaturated acids (fumaric acid and itaconic acid) formed more chloroacetic acids than saturated acids (oxalic acid, succinic acid, adipic acid). Importantly, non-nitrogenous LMWOAs formed three nitrogenous DBPs (dichloroacetamide, trichloroacetamide, and small amounts of dichloroacetonitrile) during chloramination, firstly indicating the monochloramine can supply the nitrogen in nitrogenous DBPs, and the formation of haloacetamides at least in part is independent of the hydrolysis of haloacetonitriles. To the authors’ knowledge, this is the first time formation of halogenated nitrogenous DBPs (N-DBPs) has been reported from chloramination of non-nitrogenous LMWOA precursors. This indicates that concentrations of dissolved organic nitrogen compounds in drinking water are not a reliable surrogate for formation of N-DBPs during chloramination. Bromine incorporation factor increased with increasing bromide during chloramination of citric acid, and bromine was easier to incorporate into di-HAcAms than mono- and tri-HAcAms during chloramination.
研究领域:
环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
TETRAHEDRON
·
2013
·
IF 2.803
Run-Lin Li,Gong-Qing Liu,Wei Li,Yu-Mei Wang,Lin Li,Lili Duan,Yue-Ming Li
3-Chloropiperidine compounds were obtained via Cu(II)-promoted one-pot intramolecular chloroamination of N -benzyl-4-penten-1-amines and subsequent rearrangement. The reaction conditions leading to this skeleton were studied, and the structure of the product was confirmed by NMR as well as X-ray diffraction experiments.
研究领域:
有机化学
·
药物化学
✓ 已验证
产品关联
DOI
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
危险品化学品经营许可证（带存储）