ACS ES&T Water
·
2020
·
IF 0
Huihui Zhao,Linyan Yang,Xueming Chen,Lankun Cai,Yejin Li,Mei Sheng,Guomin Cao,Qianhong She
The co-presence of haloacetic acids (HAAs) and Mg2+ in swimming pool waters and the potential interaction among Mg2+, HAAs, and membranes prompted a systematic investigation of membrane performance affected by Mg2+. The rejection behavior of the tight NF90 was not significantly affected by Mg2+ due to the predominant role of size exclusion. For loose NF270, HAA rejection and water flux were reduced by 27% and 12%, respectively, after the addition of 5 mM Mg2+. The notable magnesium content in NF270 exposed in Mg2+ indicated the binding of Mg2+ to membranes. The interaction between Mg2+ and membranes resulted in a less negatively charged and hydrophilic surface and a smaller effective pore radius for membranes. The reduction of the effective pore size by Mg2+ was verified as a result of competing effects between “-COO–-induced conformational change” and “cation-induced pore shielding”. The increased permeability for charged HAAs and NaCl in the presence of Mg2+ was mainly attributed to charge neutralization, while the reduced permeability for neutral surrogates and water was due to the reduced effective pore size and hydrophilicity. The underlying mechanism for resolving the interaction among different divalent cations, trace contaminants, and polyamide membranes may have significant implications for practical water purification by membrane technologies.
研究领域:
环境科学
·
膜技术
·
水处理工程
✓ 已验证
产品关联
DOI
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2025
·
IF 5.4
Xiaoyan Ma,Kunming Wei,Hongwei Liu,Qi Zheng,Wenqing Cao,Liang Zhang,Liangjie Tang,Stefanos Giannakis,Jing Deng,Su Jiang,Daniel L. Gallagher,Andrea M. Dietrich
Haloacetic acids (HAAs) are prevalently occurred in drinking water after disinfection by chlorine or chloramine, classified as the non-volatile and thermally stable disinfection byproducts (DBPs). To minimize the existed HAAs, catalytical electrolysis based on effective cathode was employed. Dehalogenation of HAAs were improved by vitamin B12 (VB12) coating on the stainless steel (SS), iron, copper, and aluminum electrodes. The VB12/SS composite electrode proved to be the optimal for the synergistic effect of VB12 and metal substrate on the DCAA degradation. Target chloro-, bromo-, and iodo-HAAs were catalytically decomposed, and their dehalogenation efficiency and mechanistic pathway were compared. The results show that HAAs electrolytic dehalogenation rates were significantly related with both the degree of halogenation (tri > di > mono) and the halogen atomic weight (I > Br > Cl). Dehalogenation of HAAs follows a first-order kinetic model, and kinetic variations were well described by a linear model. The logarithm base 10 of the dehalogenation rate constant k was proportional to its HAA molecular weight: log 10 (k) =0.00237 MW -0.85. The intermediate dehalogenation products were identified as less-halogenated acetic acids, and the final were acetic acid and halide ions. No mineralization occurred according to carbon conservation analysis. ESR detection and quenching experiments confirmed that HAAs dehalogenation was mainly an indirect reduction mediated by atomic H*. The synergistic effect between atomic H* and VB12 occurred through the electron transfer. This comparative study of various HAAs dehalogenation provides a mechanism of dehalogenation and a predictive linear model for electrolysis of HAAs.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
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
·
2017
·
IF 6.216
Lei Wang,Ruilan Niu,Baiyang Chen,Liwei Wang,Guan Zhang
In order to better understand the haloacetic acid (HAA) photodegradation process, this study investigated the kinetics, mechanisms, and products of seven chlorinated (Cl-), brominated (Br-), and iodinated (I-) HAAs irradiated with 254 nm ultraviolet light (UV 254 ). The photodegradation rates of HAAs by UV 254 alone were found to increase with increasing halogenation degrees (i.e., tri > di > mono) and molecular weights (i.e., I > Br > Cl), and the kinetic trends from both literature and this study were well captured by a quantitative structure activity relationship model, which reveals that molar absorptivity of compound is the most important property of HAAs in defining its photo-susceptibility. Interestingly, although direct photolysis was dominant for all HAAs removal, indirect photolysis via generation of hydroxyl radicals due to photodecomposition of degradation intermediates such as formic acid also contributes partially (26–47%) to the losses of Cl-HAAs. Degradation products and pathways varied significantly among HAAs too. While Cl-HAAs mainly underwent mineralization with carbon dioxide being the major product, Br- and I-HAAs experienced stepwise dehalogenation and decarboxylation processes, which resulted in substantial halogen-free organic compounds. The common products of HAAs photolysis are halide(s), formic acid, formaldehyde, and halomethanes, symbolizing three concurrent pathways. Overall, the findings clearly demonstrated the dramatic differences between Cl- and Br-/I-HAAs, and indirectly evidenced the presence of hydroxyl radical during HAA irradiation even without addition of catalyst.
研究领域:
环境科学
·
化学
·
水处理工程
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL RESEARCH
·
2021
·
IF 6.498
Xiaoyi Lou,Zhiyuan Liu,Changling Fang,Yunyu Tang,Jie Guan,Yaoguang Guo,Xuan Zhang,Yongfu Shi,Dongmei Huang,Youqiong Cai
There exist two common processes in fishery culture, i.e. antibiotic addition to reduce disease in fishery, and chlorination disinfection to inhibit infectious pathogenic microorganisms . However, antibiotic residues might play important reverse side roles for both aquaculture water pollution and potential formation of chlorination side products. Herein, the transformation behaviour, intermediates analyses and conversion pathway of antibiotic sulfamethoxazole (SMX), and potential generation of halogenated acetic acids (HAAs) in the process of chlorination in fishery water were examined, and the results revealed that the decomposing of SMX satisfied a pseudo first-order kinetic equation . Both the addition of available chlorine and high temperature had affirmative influences on the decontamination of SMX and production of HAAs, and the near-neutral pHs promoted the removal of SMX and generation of HAAs. Br − was favorable for the removal of SMX and yields of brominated acetic acids (Br-AAs). Based on the identified intermediate products, the transformation path of SMX in chlorination process was propounded, to wit, the C–S and S–N bonds in the SMX molecules were firstly cracked, and the primeval intermediate groups are then transformed to form chloroanilines, chlorophenols , etc., and subsequently, chlorophenols were chlorinated and ring-opened to generate toxic HAAs. This study might be meaningful to evaluate the effective removal of sulfonamide antibiotic residues and the potential generation of halogenated DBPs (H-DBPs) when chlorinated in aquaculture water.
研究领域:
环境科学
·
化学
·
生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMOSPHERE
·
2021
·
IF 7.086
Hongyan Zhai,Jun Zhao,Rumeng Wang,Yuwei Yan,Shanshan Yu,Yingxin Zhao
As a typical aromatic disinfection byproduct (DBP), 2,6-dichloro-1,4-benzoquinone (2,6-DCBQ) attracts much concern due to the potential toxicity. To further evaluate the role of 2,6-DCBQ as an intermediate DBP in water with or without chlorine, their decomposition characteristics and transformation potential to the regulated DBPs (i.e., trihalomethanes (THMs) and haloacetic acids (HAAs)) were investigated under different chlorine doses, pH values, temperatures, contact times, and bromide levels. The decomposition of 2,6-DCBQ under different conditions all fit apparent first-order kinetics. The hydrolysis rate constants of 2,6-DCBQ significantly increased with pH. The half-live values of 2,6-DCBQ were 108.3–568.7 h at pH 6.0–6.5, and 1.8–31.1 h at pH 7.0–8.5. During the hydrolysis of 2,6-DCBQ, there was no THMs and HAAs generated. During chlorination, 2,6-DCBQ decayed rapidly accompanied by the fast formation of trichloromethane (TCM) and the gradual generation of dichloroacetic acid and trichloroacetic acid. The molar conversion rates of 2,6-DCBQ-to-THMs (i.e., TCM) and 2,6-DCBQ-to-HAAs were 2.9–10.0% and 0.1–2.2% under different conditions. The presence of bromide increased the conversion rates of 2,6-DCBQ-to-THMs and caused the generation of brominated THMs and HAAs. According to the decomposition characteristics of 2,6-DCBQ and the formation trends of THMs and HAAs under different conditions, multiple formation pathways from 2,6-DCBQ to THMs and HAAs were proposed.
研究领域:
环境科学
·
水处理工程
·
化学动力学
✓ 已验证
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
JOURNAL OF MOLECULAR LIQUIDS
·
2022
·
IF 6.633
Wenxin Li,Shuji Chen,Xu Hong,Mengke Fang,Wansong Zong,Xiaokang Li,Jing Wang
As typical disinfection byproducts, monohaloacetic acids (monoHAAs) were reported to be cytotoxic and genotoxic with the order of iodoacetic acid (IAA) > bromoacetic acid (BAA) ≫ chloroacetic acid (CAA). However, it remains unknown for the toxicity of monoHAAs to biomacromolecules and the detailed molecular mechanisms. Consequently, the structural and functional responses of bovine serum albumin (BSA) to three monoHAAs (CAA, BAA and IAA) were compared by investigating their interactions using multi-spectroscopic methods, esterase-like activity assays and molecular docking simulations. Results found that monoHAAs stimulated the esterase-like activity of BSA to different levels with the order of CAA > IAA > BAA. The binding of monoHAAs affected the secondary structures, peptide skeleton and aggregation state of BSA. The interactions of BSA with CAA, BAA and IAA are dominated by van der Waals forces and hydrogen bonds, hydrophobic forces and electrostatic forces, respectively. The binding of CAA directly interferes the key residues Arg 254 and Tyr 147 to the activity but BAA and IAA do not. BAA and IAA interacted with Tyr residues by static and dynamic quenching, respectively. The binding constant suggested a relatively weak binding affinity for the interaction of BSA with BAA and with IAA. While CAA barely changed the fluorescence of BSA with the increase of exposure concentrations. Accordingly, this study provides a comprehensive view on the molecular toxicity of monoHAAs interacting with BSA.
研究领域:
环境科学
·
生物化学
·
毒理学
✓ 已验证
产品关联
DOI
高影响因子
WATER RESEARCH
·
2022
·
IF 13.4
Menglin Wu,Shunke Ding,Zhongqi Cao,Zhenqi Du,Yuyang Tang,Xiaoyan Chen,Wenhai Chu
Iodinated disinfection by-products (I-DBPs) have attracted extensive interests because of their higher cytotoxicity and genotoxicity than their chlorinated and brominated analogues. Our recent studies have firstly demonstrated that cooking with seaweed salt could enhance the formation of I-DBPs with several tens of μg/L level. Here, I-DBP formation and mitigation from the reaction of disinfectant with Laminaria japonica (Haidai), an edible seaweed with highest iodine content, upon simulated household cooking process was systematically investigated. The total iodine content in Haidai ranged from 4.6 mg-I/g-Haidai to 10.0 mg-I/g-Haidai, and more than 90% of iodine is soluble iodide. During simulated cooking, the presence of disinfectant simultaneously decreased iodide by 15.0–32.8% to 2.7–5.8 mg/L and increased total organic iodine by 1.3–10.9 times to 0.5–1.8 mg/L in Haidai soup, proving I-DBP formation. The concentrations of iodinated trihalomethanes and haloacetic acids were at the levels of several hundreds of μg/L and several μg/L, respectively, which are 2–3 orders and 1–2 orders of magnitude more than those in drinking water . Effects of key factors including disinfectant specie, disinfectant dose, temperature and time on I-DBP formation were also ascertained, and temperature and disinfectant specie played a decisive role in the formation and speciation of I-DBPs. In order to avoid the potential health risk from the exposure of I-DBPs in Haidai soup, it is prerequisite to soak and wash dry Haidai sample over 30.0 min before cooking, which could effectively remove major soluble iodide. In general, this study provided the new insight into I-DBP formation from daily household cooking with Haidai and the corresponding enlightenment for inhabitants to eat Haidai in daily life.
研究领域:
环境科学
·
食品安全
·
毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Saber A.S. Ahmed,Hongyan Zhai,Soon-Thiam Khu
Haloacetic acids (HAAs) constitute a critical concern in drinking water safety due to their high toxicity, persistence, and potential carcinogenicity. The activated carbon-chitosan (CS/CAC) was synthesized and used to eliminate HAAs from drinking water, including monobromoacetic acid (MBAA), bromochloroacetic acid (BCAA), dichloroacetic acid (DCAA), and dibromoacetic acid (DBAA). CS/CAC was described using FTIR, BET, SEM, and XRD techniques. The effects of adsorption time, CS/CAC dosage, pH, initial concentration, temperature, and coexisting anions of HAA adsorption on CS/CAC by batch adsorption mode were studied. Compared with coconut shell activated carbon (CAC), the removal efficiency of MBAA, DCAA, BCAA, and DBAA on CS/CAC was increased by 28 %, 37 %, 35 %, and 49 %, respectively. The adsorption of HAA by CS/CAC was consistent with the Langmuir isotherm (R 2 = 0.985–0.992) and pseudo-second-order kinetic models (R² = 0.991–0.998), indicating a monolayer adsorption mechanism involving both physisorption and chemisorption. Thermodynamic parameters confirmed the spontaneity and endothermic nature of the process. For column experiments, increasing the empty bed contact time (EBCT) enhanced HAA removal performance, achieving up to 94 %, 74 %, 78 %, and 94 % for MBAA, DCAA, BCAA, and DBAA, respectively (EBCT 15 min). The CS/CAC composite exhibited strong reusability after four adsorption/desorption cycles. These findings highlight CS/CAC as a promising adsorbent for HAA removal in water systems.
研究领域:
环境科学
·
水处理
·
材料科学
·
吸附技术
✓ 已验证
产品关联
DOI
高影响因子
Analytical Methods
·
2017
·Vol. 9
·期 16
·2425-2432
·
IF 1.9
Zhixiong Zhong,Gongke Li,Yijuan Shao,Binghui Zhu,Zhe Liu,Jianchao Deng,Jingtian Mo
An efficient solid-phase extraction strategy was developed for the extraction and enrichment of ten haloacetic acids from drinking water. An amino-functionalized graphene oxide nanocomposite was synthesized and used as a sorbent. The factors affecting extraction efficiency were optimized by means of the Box–Behnken design. The extracts were analyzed by ion chromatography coupled with electrospray ionization mass spectrometry (IC-ESI-MS). The combination of extensive sample pretreatment and excellent background suppression was used to effectively eliminate matrix effects that enhanced or suppressed electrospray ionization of analytes. The limits of detection and quantification for ten target compounds were in the range of 0.16–0.61 μg L−1 and 0.55–2.0 μg L−1, respectively. The self-assembled solid-phase extraction cartridge was successfully applied to the enrichment of iodinated, chlorinated and brominated haloacetic acids in sixteen disinfected drinking water samples before detection. Recoveries were between 83.1% and 106.7%, and relative standard deviations ranged from 0.5% to 5.2%. This laboratory-made nanocomposite was proved to be a promising sorbent for the extraction of trace haloacetic acids in water samples.
研究领域:
环境科学
·
分析化学
✓ 已验证
产品关联
DOI
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
危险品化学品经营许可证（带存储）