ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
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2024
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IF 6.2
Dong Li,Wen Cheng,Xiaoping Zhou,Xing Zheng,Jiehui Ren,Ting Meng
Chloro-haloacetonitrile (Cl-HAN), belongs to a group of nitrogenous disinfection by-products (N-DBPs) found in surface water, and are known to pose a major risk to the safety of human drinking water. However, the exact biological toxicity mechanism and the extent of the stress response caused by Cl-HAN remain unclear, resulting in a lack of effective measures to control its presence. Thus, the quantitative toxicological genomics and bioinformatics methods were applied to explore the effects of three chloro-haloacetonitriles (Cl-HANs) on the transcription of fusion genes under varying concentrations of stress in E. coli over 2-hour period. The initial stress response and their toxic mechanism were analyzed. The study also identified the molecular toxicity endpoint, and the core genes that are responsible for the specific toxicity of different Cl-HANs. Cl-HANs exhibited concentration-dependent characteristics of toxic effects, and caused changes in gene expression related oxidative and membrane stress. The stress response results showed that dichloroacetonitrile (dCAN) still caused significant DNA damage under the lowest concentration stress. Chloroacetonitrile (CAN) and trichloroacetonitrile (tCAN) exhibited lower genetic toxicity levels at 513 μg/L and 10.7 μg/L, respectively. The toxic effects of tCAN were widespread. And there was a good correlation between the molecular endpoint (EC-TELI 1.5 ) and the phenotypic endpoint (LD50) with r p =-0.8634 ( P =0.0593). In all concentrations of stress in CAN, dCAN, and tCAN, the number of overexpressed genes shared was 15, 2, and 14, respectively. Furthermore, bioinformatics analysis demonstrated that Cl-HANs affected genes associated with general stress pathways, such as cell biochemistry and physical homeostasis, resulting in changes in biological processes. And for CAN-induced DNA damage, polA played a dominant role, while katG , oxyR , and ahpC were the core genes involved in oxidative stress induced by dCAN and tCAN, respectively. These findings provide valuable data for the toxic effect of Cl-HANs.
研究领域:
环境科学
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分子生物学
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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
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2022
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IF 10.753
Zhen Pang,Peifeng Zhang,Xinyi Chen,Feilong Dong,Jing Deng,Cong Li,Junping Liu,Xiaoyan Ma,Andrea M. Dietrich
Disinfection byproducts (DBPs) are initially formed in the process of chlorination in the drinking water treatment plants (DWTPs), then further formed in the distribution system due to the presence of residual chlorine and reactive organic matters. However, in China, DBPs are monitored in the effluent from the DWTPs, but less is known about concentrations of DBPs in tap water since they are usually monitored once per half a year. The smart water service system is establishing real-time monitoring of water indices, although DBPs are an urgent need, they are difficult to monitor in real-time due to their diversity and complicated detection methods. If the correlation between DBP concentration and routinely real-time monitored water quality parameters (e.g., pH value, residual chlorine, ammonia) can be evaluated, the concentration of DBPs can be predicted, which will strengthen the control of tap water safety. This article comprehensively assessed the physicochemical parameters and the occurrence of DBP formation in the tap water with an 18-month investigation in Z city (China). DBP formation in tap water of different seasons and different water sources were compared. Based on the relationship between DBPs and physicochemical parameters, linear prediction and nonlinear prediction models of trihalomethanes (THMs), haloacetonitriles (HANs) and haloacetic acids (HAAs) were established, and the accuracy of these models was verified by measured data. Finally, the toxicity and carcinogenic and non-carcinogenic health risk assessment of DBPs in tap water were analyzed.
研究领域:
环境科学
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公共卫生
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毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2015
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IF 4.321
Wenhai Chu,Dongmei Li,Naiyun Gao,Daqiang Yin,Yanshen Zhang,Yanping Zhu
There has been a series of research work on exploring how disinfection by-products (DBPs) are formed from free amino acids (AAs) during chlorination in drinking water. Yet there is very limited information about the formation of carbonaceous DBPs (C-DBPs) and nitrogenous DBPs (N-DBPs) from the chlorination of those AAs in combined forms which are more abundant than free AAs in source waters. In this study, we compared the differences on the formation of trihalomethanes (THMs, representing C-DBPs) and haloacetonitriles (HANs, representing N-DBPs) from free AAs and combined AAs (short oligopeptides) during chlorination. And, the influence of the selected pre-oxidation processes (permanganate, persulfate, hydrogen peroxide) on THM and HAN formation during subsequent chlorination was also examined. There were significant differences in chloroform (CF), dichloroacetonitrile (DCAN) and trichloroacetonitrile (TCAN) formation between free AAs and short oligopeptides, which was probably ascribed to the presence of peptide bond. Of note, the combined tyrosine (Tyr) in tripeptides (Tyr–Tyr–Tyr) formed more TCAN compared with free Tyr and other combined Tyr in dipeptides, and a novel possible formation pathway of TCAN from Tyr–Tyr–Tyr was proposed. In addition, the effect of three pre-oxidation on DBP formation was different, and their rank order was permanganate > persulfate > hydrogen peroxide. The permanganate is a better choice than persulfate and hydrogen peroxide for controlling AA derived HANs, but this benefit should be weighed against the potential drawback of increased regulated THMs.
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
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2025
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IF 11.3
Yan Shen,Xinyi Weng,Jingsi Chen,Jiafu Li
The aldehyde addition reaction is recognized as a key pathway in the formation of haloacetamides (HAMs) in drinking water. In particular, the reaction between monochloramine and chloroaldehydes has been reported to proceed rapidly. However, the measured concentrations of haloaldehydes (HALs) in chloraminated water are often much higher than those of HAMs. This discrepancy suggests that the role of the aldehyde pathway in HAM formation may have been overestimated. In this study, two commonly detected HALs [dichloroacetaldehyde (DCAL) and trichloroacetaldehyde (TCAL)] were selected as model compounds to investigate the transformation and formation among three classes of toxic disinfection byproducts (DBPs): HALs, HAMs, and haloacetonitriles (HANs), within a chloramination system. Theoretical calculations reveal that HALs can form HAMs via two distinct reaction pathways. Quantum-level computational analyses confirm the thermodynamic feasibility of both pathways for the studied Cl-HALs. Experimental investigations of the reaction kinetics between Cl-HALs and monochloramine, conducted at room temperature under light-shielded and catalyst-free conditions, showed that the concentrations of both DCAL and TCAL remained essentially unchanged throughout the reaction. HANs and HAMs in reaction solution were not detected. These results suggest that HALs exhibit negligible reactivity with monochloramine under ambient, uncatalyzed conditions, indicating strong kinetic hindrance in practical scenarios. In general, the reaction rate between HALs and monochloramine is not as high as that reported in the published literature (3.27–8.25 ×10 −3 h −1 ), which may help explain why much higher concentrations of HALs than HAMs were generally observed in chloraminated drinking water. This finding provides new insights into the transformation and formation of HALs, HAMs, and HANs in chloraminated drinking water systems.
研究领域:
环境化学
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水处理
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毒理学
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化学反应工程
✓ 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）