CHEMOSPHERE
·
2022
·
IF 8.943
Chuyin Qiu,Weiting He,Yu Li,Feng Jiang,Yang Pan,Meihui Zhang,Daying Lin,Kaili Zhang,Yanduo Yang,Wen Wang,Pei Hua
Chlorine disinfection is widely applied in drinking water treatment plant to inactivate pathogens in drinking water , but it unintentionally reacts with organic matter present in source waters and generates halogenated disinfection byproducts (DBPs). Sugar is one of the most commonly used seasoning in our diet. The addition of sugar could significantly improve the taste of the beverages; however, the effects of sugar on DBP formation and transformation remain unknown. In this study, the effects of sugar type and dose on the halogenated DBP formation in chlorinated boiled real tap water were evaluated during making hot beverages. We found that sugar can react with chlorine residual in tap water and generate halogenated DBPs. As the most commonly used table sugar, the addition of sucrose in the water sample at 100 or 500 mg/L as C could increase the level of total organic halogen (TOX) by ∼35%, when compared with the boiled tap water sample without sugar addition. In addition, fifteen reported and new polar brominated and chlorinated DBPs were detected and proposed from the reaction between chlorine and sucrose; accordingly, the corresponding transformation pathways were also proposed. Moreover, the DBP formation in the chlorinated boiled real tap water samples with the addition of xylose , glucose, sucrose, maltose and lactose were also investigated. By comparing with the TOX levels in the water samples with different sugar addition and their calculated TOX risk indexes, it was suggested that applying xylose as a sweetener in beverages could not only obtain a relatively high sweetness but also minimize the adverse effect inducing by halogenated DBPs during making hot beverages.
研究领域:
水处理
·
环境化学
·
食品科学
✓ 已验证
DOI
PubMed
高影响因子
ENVIRONMENTAL TECHNOLOGY
·
2023
·
IF 2.8
Tuqiao Zhang,Rongrong Jiang,Lei Fang,Xiaowei Liu,Lijie Jiang
The presence of metal ions in drinking water treatment and distribution systems may affect the disinfection process of organic matter, which had aroused people's concern. L-tyrosine can complex with metal ions through carboxyl, carbonyl, and amino groups and affect its chemical reactions. In this paper, the complexation of L-tyrosine with common metal ions was studied and the influence of complexation on chlorination with different experimental factors was investigated. It was inferred that L-tyrosine complexed with metal ions by single dentate ligand or double dentate chelation in a ratio of 2:1. The degradation of L-tyrosine-metal complex followed the pseudo-first-order reaction kinetic. TCM, DCAA, and TCAA were the main species DBPs in the chlorination of L-tyrosine. Compared with L-tyrosine, the reaction rate constants of complex increased by 5.6%, the formation of trihalomethane production decreased by 21.5% and the formation of haloacetic acids production increased by 26.9% at the state of metal complexation. The effect of metal complexation on chlorination was more obvious than that of metal coexistence. For different metal complexation, the order of inhibition on trihalomethane production was Ca2+> Fe3+> Mn2+ and the order of promotion on haloacetic acids production was Mn2+> Fe3+> Ca2+. Moreover, it was found that alkaline conditions were favorable for the formation of DBPs due to the hydroxyl radical. The combination of ultraviolet and chlorine disinfection promoted L-Tyrosine degradation and DBPs generation, and the promotion efficiency follow the order: UV/Cl2> UV-Cl2> Cl2.
研究领域:
环境科学
·
化学
·
水处理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Environmental Sciences
·
2024
·
IF 5.9
Chenyan Hu,Yihui Wu,Zhengyu Dong,Ziyi Dong,Shengjie Ji,Lili Hu,Xinyu Yang,Hao Liu
A mixed oxidant of chlorine dioxide (ClO 2 ) and NaClO was often used in water treatment. A novel UVA-LED (365 nm)-activated mixed ClO 2 /NaClO process was proposed for the degradation of micropollutants in this study. Carbamazepine (CBZ) was selected as the target pollutant. Compared with the UVA 365 /ClO 2 process, the UVA 365 /ClO 2 /NaClO process can improve the degradation of CBZ, with the rate constant increasing from 2.11×10 −4 sec −1 to 2.74×10 −4 sec −1 . In addition, the consumption of oxidants in the UVA 365 /ClO 2 /NaClO process (73.67%) can also be lower than that of UVA 365 /NaClO (86.42%). When the NaClO ratio increased, both the degradation efficiency of CBZ and the consumption of oxidants can increase in the UVA 365 /ClO 2 /NaClO process. The solution pH can affect the contribution of NaClO in the total oxidant ratio. When the pH range of 6.0-8.0, the combination process can generate more active species to promote the degradation of CBZ. The change of active species with oxidant molar ratio was investigated in the UVA 365 /ClO 2 /NaClO process. When ClO 2 acted as the main oxidant, HO• and Cl• were the main active species, while when NaClO was the main oxidant, ClO• played a role in the system. Both chloride ion (Cl – ), bicarbonate ion (HCO 3 – ), and nitrate ion (NO 3 – ) can promote the reaction system. As the concentration of NaClO in the reaction solution increased, the generation of chlorates will decrease. The UVA 365 /ClO 2 /NaClO process can effectively control the formation of volatile disinfection by-products (DBPs), and with the increase of ClO 2 dosage, the formation of DBPs can also decrease.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Water Resources and Industry
·
2023
·
IF 5.1
Jiayu Zhang,Qiongfang Wang,Lei Dong,Pinhua Rao,Xin Zhang,Naiyun Gao,Xiaoying Yin
In this paper, UV/NH 2 Cl process was used to research the degradation of sulfathiazole (STZ) and the formation of disinfection by-products (DBPs) after disinfection were detected. UV and NH 2 Cl process showed a synergistic effect on the removal of STZ. Natural organic matter and CO 3 2− inhibited the STZ degradation, NO 3 − promoted the degradation of STZ, whereas NH 2 Cl concentration, HCO 3 − and Cl − had dual effects on the removal of STZ. The removal of STZ by UV/NH 2 Cl was slightly influenced by pH. The contribution of reactive chlorine species and reactive nitrogen species to STZ degradation was significantly higher than that of HO · . Possible STZ degradation pathways were presented by analyzing intermediate products. In addition, the pretreatment of UV/NH 2 Cl significantly reduced the formation of DBPs during NH 2 Cl or NaClO disinfection. In conclusion, UV/NH 2 Cl process is an effective water treatment technology and can be well applied for practical purposes.
研究领域:
环境科学
·
水处理技术
✓ 已验证
DOI
高影响因子
CHEMOSPHERE
·
2021
·
IF 7.086
Guilin He,Tuqiao Zhang,Yunfei Li,Jinzhe Li,Feiyong Chen,Jun Hu,Feilong Dong
Fleroxacin (FLE) is a widely used fluoroquinolones to cure urinary tract infections and respiratory disease, which has been frequently detected in the aquatic environment. The reactivity kinetics of FLE by chlorine and chlorine dioxide (ClO 2 ) and transformation mechanism were investigated in this study. The results showed that FLE was degraded efficiently by chlorine and ClO 2 , and both reactions followed second-order kinetics overall. The increase of disinfectant dosage and temperature would enhance the degradation of FLE. The highest removal of FLE by chlorine was achieved at a neutral condition (pH 7.4), whereas ClO 2 reaction rates increased dramatically with the increasing pH in this study condition. The number of intermediates identified in FLE chlorination and ClO 2 oxidation was seven and ten, respectively. The piperazine ring cleavage was the principal and initial reaction in both above reactions. Then, the removal of the piperazine group was predominantly in FLE removal by chlorine, while the decarboxylation mainly occurred in FLE removal by ClO 2 . The intermediates increased first and then decreased with time, while three kinds of halogenated DBPs increased with time, indicating the above-identified intermediates were further transformed to the halogenated DBPs. Additionally, compared to chlorine reaction, the reaction of ClO 2 with FLE reduced the formation of halogenated DBPs, but it also induced the formation of chlorite. The analysis of toxicity showed that compared with chlorination, the oxidation of ClO 2 was more suitable for FLE removal.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
·
2023
·
IF 8.7
Shengnan Chen,Xin Sheng,Zhiwei Zhao,Fuyi Cui
Membrane fouling induced by natural organic matter (NOM) has seriously affected the further extensive application of ultrafiltration (UF). Herein, a simple, green and robust vacuum ultraviolet (VUV) technology was adopted as pretreatment before UF and ultraviolet (UV) technology was used for comparison. The results showed that control effect of VUV pretreatment on membrane fouling was better than that of UV pretreatment, as evidenced by the increase of normalized flux from 0.27 to 0.38 and 0.73 after 30 min UV or VUV pretreatment, respectively. This is related to the fact that VUV pretreatment exhibited stronger NOM degradation ability than UV pretreatment owing to the formation of HO•. The steady-state concentration of HO• was calculated as 3.04 × 10 −13 M and the cumulative exposure of HO• reached 5.52 × 10 −10 M s after 30 min of VUV irradiation. And the second-order rate constant between NOM and HO• was determined as 1.36 × 10 4 L mg −1 s −1 . Furthermore, fluorescence EEM could be applied to predict membrane fouling induced by humic-enriched water. Standard blocking and cake filtration were major fouling mechanisms . Moreover, extension of UV pretreatment time increased the disinfection by-products (DBPs) formation, the DBPs concentration was enhanced from 322.36 to 1187.80 μg/L after 210 min pretreatment. However, VUV pretreatment for 150 min reduced DBPs content to 282.57 μg/L, and DBPs content continued to decrease with the extension of pretreatment time, revealing that VUV pretreatment achieved effective control of DBPs. The variation trend of cytotoxicity and health risk of DBPs was similar to that of DBPs concentration. In summary, VUV pretreatment exhibited excellent effect on membrane fouling alleviation, NOM degradation and DBPs control under a certain pretreatment time.
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
RSC Advances
·
2023
·Vol. 13
·期 31
·21537-21544
·
IF 3.9
Xingya Wei,Bangjun Han,Renzheng Gu,Weimin Geng,Naiyun Gao
Disinfection by-products (DBPs) formed in chlorination and chloramination are proved to be cytotoxic and genotoxic and arouse increasing attention. However, previous studies of DBP precursors mainly focused on free amino acids (AAs) and few papers evaluated DBPs' formation potential of combined AAs. This study demonstrated that typical carbonaceous (C-) DBPs, trihalomethanes (THMs) and typical nitrogenous (N-) DBPs, dichloroacetonitrile (DCAN), trichloroacetonitrile (TCAN) and trichloronitromethane (TCNM) could be formed during chlorination and chloramination of polymyxin B sulfate (PBS), a common polypeptide antibiotic working against Gram-negative bacterial infections. The effects of major parameters, including disinfectant dose, contact time, solution pH, temperature, bromide concentration and chloramination mode were evaluated in batch experiments. Different kinds of DBPs exhibited different characteristics as disinfectant dose or contact time increased. Solution pH and temperature affected the formation of DBPs greatly. The formation pathways of different DBPs from chlor(am)ination of PBS were also proposed. Combined AAs, such as PBS, were proved to be important precursors of DBPs during disinfections.
研究领域:
环境科学
·
公共卫生
✓ 已验证
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Anhong Cai,Jing Deng,Mengyuan Xu,Tianxin Zhu,Shiqing Zhou,Jun Li,Guofang Wang,Xueyan Li
The combination of UV and monochloramine (UV/NH 2 Cl) was investigated to eliminate tetracycline (TC) in water. The results indicated that TC degradation by UV/NH 2 Cl oxidation far exceeded that by UV photolysis and dark chloramination and these processes well fitted pseudo-first-order kinetics. With the increase of NH 2 Cl dosage, the pseudo-first-order rate constant ( k obs ) value increased linearly during TC chloramination, while the growth rate of k obs presented a gradual downward trend in UV/NH 2 Cl process. TC degradation by UV photolysis, dark chloramination and UV/NH 2 Cl oxidation displayed highly pH-dependent. As solution pH increased from 5.0 to 9.0, the TC removal increased during UV photolysis, while decreased during dark chloramination. For UV/NH 2 Cl process, the TC degradation showed a decreasing trend with increasing pH from 5.0 to 7.0, but further increasing pH to 9.0 presented an increasing trend. Reactive chlorine species acted as the major contributors to TC degradation in pH range of 6.0–8.0. TC degradation was not apparently affected after the introduction of HA and chloride, but was substantially accelerated in the presence of HCO 3 − . The proposed degradation pathways involved the hydroxylation, demethylation, dehydration and chlorine substitution processes. Compared with dark chloramination, the N-Nitrosodimethylamine (NDMA) generation was enhanced during TC oxidation by UV/NH 2 Cl process. The NDMA concentration increased with increasing solution pH from 6.0 to 8.0 and also elevated in the presences of humic acid (HA), nitrite, nitrate and ammonium during TC oxidation by chloramination and UV/NH 2 Cl. The results of acute toxicity test demonstrated that the toxicity of the reacted solution exhibited similar trends during dark chloramination and UV/NH 2 Cl treatment and was found to be obviously higher than UV photolysis.
研究领域:
环境科学
·
水处理工程
·
毒理学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Huiming Xiang,Yisheng Shao,Naiyun Gao,Xian Lu,Na An,Wenhai Chu
β-cyclocitral is a taste and odor (T&O) compounds and can cause malodorous problems in drinking water. This study focused on the kinetics and disinfection by-products (DBPs) formation of β-cyclocitral degradation by UV/persulfate (UV/PS) and UV/free chlorine processes. The degradation of β-cyclocitral in the two processes well fitted the first-order kinetic model. The second-order rate constant of β-cyclocitral with SO 4 · - , OH · , and Cl · were estimated to be (8.6 ± 0.12) × 10 9 M −1 s −1 , (6.89 ± 0.42) × 10 9 M −1 s −1 , and (9.58 ± 0.38) × 10 9 M −1 s −1 at pH 7.0, respectively. For UV/PS system, SO 4 · - contributed more than OH · does, while Cl · accounted for most degradation in UV/free chlorine process. The degradation rate increased with the increasing PS and chlorine dosage. For UV/PS process, the degradation rate constant ( k obs , β - cyclocitral ) was observed to be the highest at pH 7.0. For UV/free chlorine process, k obs , β - cyclocitral was found to be the highest at pH 5.0 and decreased substantially at pH 9.0. Presence of high concentration (5 mM) anions (chloride, bicarbonate) showed inhibition effect on the β-cyclocitral degradation. Dramatic decreasing was observed in the presence of NOM in both UV/PS and UV/free chlorine process. Compared with UV/PS system, UV/free chlorine was more suitable for treating waters containing β-cyclocitral because of the serious inhibition in real water matrix. UV/PS pretreatment reduced the trichlormethane (TCM) yield after post-chlorination, while enhanced the yield of dichloro acetaldehyde (DCAL). UV/free chlorine pretreatment promoted the formation of both TCM and DCAL. The theoretical cytotoxicity UV/PS pretreatment and post-chlorination is observed to be the highest due to the great amount of DCAL generation. Although UV/PS and UV/free chlorine processes can effectively degrade the β-cyclocitral, the selection of two processes should be carefully balanced against the DBPs formation in post-chlorination.
研究领域:
环境科学
·
饮用水处理
✓ 已验证
产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2022
·
IF 10.753
Shijun Zhu,Huiming Zheng,Huihong Sun,Junping Liu,Xiaoyan Ma,Xueyan Li,Qingsong Li,Andrea M. Dietrich
Based on a one-year field investigation of disinfection by-products (DBPs) in large scale water distribution system (LSWDS), the various characteristics of DBPs together with their correlation with booster chlorination were elaborated through ArcGIS model. Furthermore, the effects of booster chlorination on DBP formation were investigated through simulated experiments. Residual chlorine showed a strong relationship with occurrence of different DBPs in LSWDS, and the yield of DBPs increased significantly after booster chlorination. The simulated chlorination experiments showed that diminution of the ratio of primary to secondary (booster) chlorination dosage, and delaying the secondary chlorine addition reduced the generation of DBPs during water conveyance. The yield concentrations of THMs and HAAs obviously increased after booster chlorination. The correlation between HAAs and chlorine dosage is weaker in the field research than in the simulation experiment while THMs had a positive correlation with the chlorine addition in both field research and simulation experiment.
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 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
·
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
危险品化学品经营许可证（带存储）