WATER RESEARCH
·
2024
·
IF 11.4
Yang Deng,Shansheng Mo,Gregory V. Korshin,Mingquan Yan
Differential absorption spectroscopy (DAS) quantifies changes in the UV–Visible absorbance of dissolved organic matter (DOM) caused by reactions of its chromophores. As a result of its precision and sensitvity, DAS serves as a powerful tool for characterizing the formation of disinfection by-products (DBPs) in generated in DOM chlorination reactions. However, the nonlinear relationship between the intensity of DAS and DBP concentrations as well as the need to develop site-specific fitting parameters limit its practical applications. This study investigated the physico-chemical nature of DAS of chlorinated DOM through experimental measurements and theoretical calculations. Results of this study provide molecular-level evidence that electrophilic substitution reactions involving DOM reactive sites result in the emergence of DAS feaures ascribed to the "fast" chromophores. The ring opening in the cyclic enones-like structures which can be present either in the original DOM or are generated as intermediates in its chlorination, leads to the emergence of DAS features associated with the "slow" chromophores and high yields of DBPs. The kinetic study of chlorination of real waters reveals a strong linear relationship (R 2 > 0.91) between ln([DBP]) and the long-wavelength (λ > 325 nm) parameter of the DAS, notably (ln(-DA 350 )). This relationship varies among different water sources due to the differences in the heterogeneity of Band A 3 whose maximum is near 350 nm. Band A 3 is one of the Gaussian bands that comprise the overall UV–Visible spectrum of DOM. A new function ( f ( − D A 350 ) ) is proposed in this study to quantify DBP formation. This function, which is determined by the Band A 3 's area, allows establishing a universal linear relationship between f ( − D A 350 ) and ln([THMs]), as well as f ( − D A 350 ) and ln([HAAs]), across various water sources. The findings of this study will stimulate further development of spectroscopy-based DBP monitoring technology for monitoring and optimization of water disinfection processes.
研究领域:
环境科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Water
·
2025
·Vol. 17
·期 17
·2563
·
IF 3
Chao Feng,Tongyu Liu,Yongping Shi,Jimin Shen,Lei Yuan,Yuanqing Guo
The interaction of disinfectants with bromide/iodide ions and natural organic matter (NOM) generates brominated/iodinated disinfection byproducts (Br/I-DBPs), known for their heightened cytotoxicity and genotoxicity relative to chlorinated DBPs. This study investigated Br/I-DBP formation during sodium hypochlorite (NaClO) disinfection of lignin-containing synthetic water by quantifying adsorbable organic halogens (AOX) and trihalomethanes (THMs). Disinfection of bromide-containing water yielded a bromide ion (Br−) to adsorbable organic bromine (AOBr) conversion rate of approximately 60%, with bromine within THMs accounting for about 30% of the total AOBr, indicating significant brominated DBP formation where THMs represent a major fraction. Conversely, iodide ion (I−) conversion to adsorbable organic iodine (AOI) is minimal, suggesting negligible iodinated DBP formation under NaClO disinfection. Examination of key parameters revealed that brominated THM (Br-THM) formation decreased with increasing lignin concentration, while iodinated THM (I-THM) formation increased. The effect of chlorine dose differed: Br-THM formation exhibited an initial increase followed by a decrease at higher doses, whereas I-THM formation consistently decreased. Both Br-THM and I-THM formation increased with higher bromide or iodide ion concentration and with increasing pH. These results highlight the distinct pathways and influencing factors governing brominated versus iodinated DBP formation in lignin-containing waters disinfected with hypochlorite.
研究领域:
环境科学
·
水处理
·
消毒副产物
·
毒理学
·
天然有机物化学
✓ 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
CHEMICAL ENGINEERING JOURNAL
·
2016
·
IF 5.31
Changjun Li,Naiyun Gao,Wenhai Chu,Tom Bond,Xingya Wei
Trihalomethane (THMs) and haloacetonitriles (HANs) are typical and frequently detected carbonaceous (C–) and nitrogenous (N–) disinfection by-products (DBPs) in water treatment , and amine acids (AAs) are important precursors of DBPs. However, previous researches mainly focused on free AAs and few investigations evaluated the DBPs formation potential of combined AAs, especially combined histidine . The formation of THMs and HANs from free and combined histidine and glycine during chlorination was firstly examined and compared in this study with an emphasis on their differences. The impacts of chlorine dose, pH, ammonia nitrogen and bromide were evaluated and mechanistic formation pathways were proposed. In comparison with free AAs, combined AAs generated more chloroform (CF, 125%–671%) but less dichloroacetonitrile (DCAN, 4.66%–87.5%) at all chlorine doses. The effect of solution pH on combined AAs was slighter than that on free AAs. During chloramination, both free AAs and combined AAs generated much smaller amounts of DBPs, especially DCAN (<9.01%), compared with chlorination. At any bromide dose, there was more bromine merging into THMs than DHANs, especially for combined AAs. At the beginning of chlorination, the combined AAs decomposed in three different ways: hydrolysis, decarboxylation and scission , leading to differing amounts of CF and DCAN compared with the free AAs.
研究领域:
环境科学
·
水处理工程
·
化学
✓ 已验证
DOI
高影响因子
Environmental Science-Water Research & Technology
·
2022
·Vol. 8
·期 10
·2207-2215
·
IF 5.819
Jie Ji,Changjie Shi,Luo Xu,Kai Zhang,YunShu Zhang,Cong Li,Eric Lichtfouse
Sulfonamides (SAs) have been proved to damage organisms if the contact time last over the long term. Therefore, sulfapyridine (SPD), as typical one, was chosen as a target to be investigated. For the study, the degradation kinetic of SPD in the chlorination stage of a pilot-scale water distribution system (WDS) was studied. The result showed that the degradation of SPD simultaneously followed the first-order and pseudo second-order kinetic model. In the beakers tests or WDS, the reaction rate reaches maximum value when the pH is about 7. The degradation rate of SPD would be higher with the increase of water velocity in the WDS. Different pipe materials were studied and the degradation effect of SPD was in the following order: stainless-steel pipe > ductile iron pipe > polyethylene (PE) pipe. There was a significant increase in the content of trihalomethanes (THMs) when chlorination of tap water containing SPD in both the WDS and the beakers system were performed. The mechanism of this process was analyzed in combination with the intermediate products degraded by SPD in the process. In addition, density functional theory (DFT) calculations were performed to assist in the identification of 6 intermediates and possible degradation pathways.
研究领域:
环境科学
·
化学
·
生物学
✓ 已验证
DOI
高影响因子
CHEMOSPHERE
·
2020
·
IF 5.778
Chao Fang,Tian Ou,Xingyu Wang,Min Rui,Wenhai Chu
Ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO) are widely used in drinking water treatment and wastewater recycling. However, limited information was available regarding their performance in removing trihalomethanes (THMs). The present study investigated the effect of feed solution characteristics and membrane fouling on THM removal by UF/NF/RO membranes. The results indicated that THMs were poorly removed by UF membrane, and the removal was dominated by hydrophobic adsorption. In contrast, high removal of THMs was observed for NF/RO membranes, which was contributed by both size exclusion and hydrophobic adsorption. By comparing the adsorption of THMs on NF/RO membranes at different feed concentration, it was found that the role of hydrophobic adsorption was more important at lower feed concentration. The removal of THMs by UF/NF/RO membranes increased with increasing feed concentration, which can be ascribed to the enhanced diffusion at higher concentration gradient. With increasing ionic strength, THM removal was decreased significantly for UF membrane, but the removal by NF/RO membranes remained largely unchanged. By comparing THM removal by clean and fouled membranes, the effect of membrane fouling was examined. The removal of most THMs (except trichloromethane) decreased after fouling for UF membrane, whereas decreased removal was only observed for iodinated THMs for fouled NF/RO membranes.
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
SCIENCE OF THE TOTAL ENVIRONMENT
·
2020
·
IF 6.551
Xiaochao Duan,Xiaobin Liao,Jianfei Chen,Shuguang Xie,Huan Qi,Fei Li,Baoling Yuan
Disinfection is an indispensable process to inactivate pathogens , while unexpected disinfection by-products (DBPs) would also be formed between the reaction of residual disinfectants and microorganisms in the water distribution system (WDS). However, there are few studies referring to the formation of DBPs and DBPs-associated toxicity under various disinfection methods based on microorganisms in the real WDS. In addition, the main contributors of bacterial communities or components that generate DBPs are unclear. In this study, the formation of trihalomethanes (THMs), halo-acetic acids (HAAs), nitrosamines (NAs) from culturable microorganisms in pipeline network by ozonation(O 3 ), chlorination (Cl 2 ), chloramination (NH 2 Cl) and joint disinfection methods were compared, meanwhile, their calculated toxicities under different oxidation scenarios were also discussed. Moreover, 16S ribosomal ribonucleic acid (rRNA) gene sequencing was used to identify the main microbial communities . The results demonstrated that THMs and HAAs increased with increasing disinfectant dosages, while the quantity of NAs (mainly nitroso dimethylamine (NDMA)) was not significantly related to disinfectant dosages for each disinfection strategy. Chloroform (TCM) and dichloroacetic acid (DCAA) were the dominant THMs and HAAs species, respectively. NDMA existed in the samples before disinfections, which may due to the metabolic activity of microorganisms. Pre-O 3 increased THMs formation during subsequent Cl 2 and NH 2 Cl treatment. However, pre-O 3 effectively reduced HAAs produced by subsequent chlorination. O 3 /Cl 2 disinfection had the highest DBPs formation potential (DBPFP) (883.6 nM), while its calculated toxicity was similar to that in Cl 2 disinfection treatment. Pseudomonas was the most abundant bacterial genus in biofilm of WDS pipeline. This study can aid in an optimal disinfection strategy for water treatment plants to reduce the toxicity of DBPs caused by biomass in pipelines and ensure water quality safety.
研究领域:
环境科学
·
微生物学
✓ 已验证
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Hailan Wang,Weiye Shi,Defang Ma,Yanan Shang,Yan Wang,Baoyu Gao
Antibiotics are widespread in water and wastewater, which could react with chlorine to produce disinfection byproducts (DBPs) during disinfection process. Activation of permanganate by bisulfite generates a permanganate/bisulfite (PM/BS) ultra-fast oxidation system, which exhibits more complete oxidation of refractory organics than conventional advanced oxidation processes. This study explored the formation and speciation of trihalomethanes (THMs), haloacetic acids (HAAs), haloacetonitriles, haloketones and trichloronitromethane during chlorination of antibiotics (chloramphenicol, ciprofloxacin and sulfamerazine), as well as the impact of Br - . PM/BS pre-oxidation was further applied to control DBP formation from antibiotics. Only THMs and HAAs were quantifiable. Trichloromethane was dominant in THMs. HAAs derived from ciprofloxacin and sulfamerazine were mostly constituted by monochloroacetic acid, while trichloroacetic acid was dominate in chlorinated chloramphenicol. Sulfamerazine exhibited the highest DBP formation potential (DBPFP), of which trihalomethane formation potential (THMFP) was 997.14 ± 13.96 μg L −1 and haloacetic acid formation potential (HAAFP) was 3767.86 ± 325.09 μg L −1 . Chloramphenicol had very low THMFP, but high HAAFP (1560.29 ± 56.55 μg L −1 ), which was six times higher than that of ciprofloxacin. Adding Br - increased DBPFP and yields of brominated species. PM/BS pre-oxidation (KMnO 4 /HSO 3 − was 1.0/2.5 mM/mM) significantly reduced the DBPFP and chlorine reactivity, and inhibited the utilization of bromine into DBPs with the presence of Br - . After PM/BS treatment, over 50% of the ciprofloxacin in real drug manufacturing wastewater were degraded, and the THMFP decreased by about 50%. Overall. PM/BS process is a promising advanced oxidation technology for antibiotic wastewater treatment and control of DBP formation.
研究领域:
环境科学
·
水处理
·
高级氧化过程
✓ 已验证
产品关联
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
CHEMOSPHERE
·
2023
·
IF 8.8
Jiafu Li,Jingsi Chen,Zhiyong Hu,Xinyu Li,Mei Li,Yuan Wang,Zengli Zhang,Xiaojun Liang
Trichloroisocyanuric acid (TCCA) is a popular disinfectant for swimming pools in China. However, the occurrence and importance of regulated disinfection byproducts (DBPs) in TCCA-disinfected swimming pools are less understood. This study analyzed 12 regulated DBPs (4 trihalomethanes (THMs), 5 haloacetic acid (HAAs), bromate , chlorate, and chlorite) in 85 swimming pool water samples and 17 input tap water samples from one swimming pool for 17 days continuously. Considering water temperature, pH, free chlorine, total chlorine, and urea, most of swimming pool water samples were within the water quality limits for China. Total concentrations of THMs, HAAs, and inorganic DBPs of 20.4–42.2, 82.0–229, and 100–729 μg/L in the swimming pool, and 16.6–28.3, 8.2–12.8, and 64.4–95.6 μg/L in the tap water, indicating inorganic DBPs are the dominant swimming pool and drinking water pollutants. Cancer risk values of regulated DBPs in swimming pools and input tap water are 2.7E-05 and 8.1E-05, respectively, and exceed the US EPA's threshold (1.0E-06). The non-cancer risk is below the US EPA's threshold. Following TCCA disinfection, the concentration and calculated cytotoxicity of regulated DBPs had a 3.6-fold and 1.9-fold increase, respectively. Inorganic DBPs contribute to the calculated concentration and cancer risks of DBPs in swimming pools and tap water at sufficient concentrations warranting regulation. This study provides data on 12 regulated DBPs in TCCA-disinfected indoor swimming pools, highlighting the importance of inorganic DBPs from evidences of concentration, cytotoxicity, and cancer risk for the first time.
研究领域:
环境科学
·
公共卫生
·
水质
·
毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2020
·
IF 6.551
Guiqiao Wang,Weiye Shi,Defang Ma,Baoyu Gao
Bisulfite-activated permanganate (PM/BS) oxidation process can oxidize ciprofloxacin in complex water matrices rapidly. However, effects of PM/BS pre-oxidation on the formation of disinfection byproducts (DBPs) during post-chlorination of ciprofloxacin-contaminated waters need to be addressed. This study investigated the formation of trihalomethanes (THMs), haloacetonitriles (HANs), haloketones and trichloronitromethane during chlorination of ciprofloxacin-contaminated humic acid (HA), bovine serum albumin (BSA) and alginate solutions, and revealed the effects of PM/BS pre-oxidation on ciprofloxacin degradation and DBP formation during post-chlorination, considering the presence of Br − . Only THMs and HANs were quantifiable. THMs were the most abundant. Ciprofloxacin-contaminated HA exhibited the highest formation potential of DBPs and integrated toxic risk value (ITRV). In the absence of Br − , PM/BS pre-oxidation reduced or hardly affected the toxicity risks derived from DBPs formed from the post-chlorination. However, the presence of Br − greatly reduced the degradation of ciprofloxacin (30–50%) in various waters. In the ciprofloxacin-contaminated waters containing Br − , the total ITRVs of DBPs formed from post-chlorination increased by 60%–800% with PM/BS pre-oxidation, attributing to the enhanced formation of DBPs especially bromochloroacetonitrile and dibromoacetonitrile. Overall, PM/BS is a potential pre-oxidation technology for the treatment of ciprofloxacin-contaminated waters without bromide.
研究领域:
环境科学
·
水处理
·
化学工程
·
毒理学
✓ 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）