CHEMOSPHERE
·
2024
·
IF 8.1
Junling Li,Jingsi Chen,Jiafu Li
Amino acids (AAs) account for about 15–35% of dissolved organic nitrogen (DON), and are known as the important precursors of nitrogenous disinfection by-products (N-DBPs). Determining the formation potential (FP) of AAs to DBPs is used to reveal the key precursors of DBPs for further control, while the ideal method for N-DBPs FP of AAs during chlorination is not revealed. In this study, the ideal FP test models for five classes of priority DBPs during chlorination of four representative AAs (accounted for about 35% of total AAs) were analyzed. For haloaldehydes (HALs), haloketones (HKs), haloacetonitriles (HANs), haloacetamides (HAMs), and halonitromethanes (HNMs), their FPs during chlorination of four AAs were 0.1–13.0, 0.01–1.1, 0.1–104, not detectable (nd)-173, and nd-0.4 μg/mg, respectively. The FPs of priority DBPs had significant deviations between different FP test models and different tested AAs. For HALs, the model, whose chlorine dosage was determined by 15 × molar concentration of AAs [Cl (mM) = 15 × M](named: model II), was the ideal model. For HKs, model II was also the ideal FP test model for AAs with ≤3 carbons, while for AAs with 4 carbons, the model, whose chlorine dosage was determined by keeping the residual chlorine at 1 ± 0.2 mg/L after 24 h of reaction (named: model 4), was the ideal model. For HANs and HNMs, model 4 was the ideal FP test model for most of the studied AAs. The performance of HAMs during chlorination of amino acids was totally different from other P-DBPs, and model 3 was recommended to be the ideal model, in which chlorine dosage was determined by 3 × mass concentration of AAs [Cl (mg/L) = X × DOC]. This study is a reference that helps researchers select an ideal model for N-DBPs FP study of AAs.
研究领域:
环境科学
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水处理
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化学工程
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PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Jiayu Du,Decai Liu,Zhiyong Zhang,Huiying Ai,Ming-Lai Fu,Wenjie Sun,Baoling Yuan
The widespread use of chlorine during disinfection has led to the problems of disinfection by-products (DBPs). Recently, the combination of ultraviolet (UV, 254 nm) and vacuum ultraviolet (VUV, 185 nm) with chlorine has been considered a promising strategy to mitigate the formation of DBPs. This study systematically evaluated the efficacy of six different disinfection methods in abating humic acid (HA), a common precursor of DBPs (UV-Chlorine, VUV/UV-Chlorine, Chlorine-UV, Chlorine-VUV/UV, UV/Chlorine, and VUV/UV/Chlorine). Under 40 mJ/cm 2 UV fluence and 3 mg/L chlorine dose, the synergistic processes yielded DBP levels below 20 μg/L, whereas sequential disinfection resulted in DBP levels exceeding 100 μg/L. Additionally, there was no significant difference in the formation of DBPs between the two methods of chlorination followed by irradiation. However, for irradiation followed by chlorination, the addition of VUV led to an increase of 50 μg/L in trihalomethanes (THMs). As the irradiation time increased, the inclusion of VUV demonstrated enhanced control of DBP levels in the sequential disinfection process. Moreover, compared to UV/Chlorine, at 13 mg/L chlorine dose in VUV/UV/Chlorine process, the inclusion of VUV expedited the appearance of peak DBPs by two minutes and reduced the peak value by 25.6 %, but the DBP yield was 12.9 times higher than that at a chlorine dose of 3 mg/L. This study, comparing six combination disinfection methods, will provide deeper insights into precursor abatement and DBP control during drinking water disinfection.
研究领域:
环境科学
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公共卫生
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DOI
高影响因子
CHEMOSPHERE
·
2022
·
IF 8.943
Hanxuan Zeng,Shuwen Shen,Anhong Cai,Qian Sun,Lei Wang,Shijun Zhu,Xueyan Li,Jing Deng
As a widely produced and used antibiotic, tetracycline (TC) has been frequently found in rivers, soil and drinking water . In this study, the degradation of TC was investigated by UV/Fe 3+ /persulfate (PS) coupled process. The degradation behavior was well fitted with pseudo-first-order model. Hydroxyl radicals (·OH), sulfate radicals (SO 4 − ·) and superoxide radical (O 2 − ·) were identified as the primary reactive oxygen species (ROS) in UV/Fe 3+ /PS process, the contribution to TC degradation were found to be 41.94%, 33.94% and 17.44% at pH 3.0, respectively. Fe(IV) generated from the system also played a crucial role in TC removal. The effects of process parameters (PS/Fe 3+ dosages, pH, humic acid , Cl − , HCO 3 − , NO 3 − and CO 3 2− ) on degradation were investigated. It was found that the degradation of TC was highly pH-dependent, and the optimal performance was obtained at pH 3.0. Except for Cl − , the presence of HA, HCO 3 − , NO 3 − and CO 3 2− inhibited TC degradation. The possible transformation pathway involving the hydroxylation, N -demethylation, hydrogenation and dehydroxylation was proposed. Furthermore, the toxicity and mutagenicity of TC and transformation products (TPs) were estimated using ECOSAR and TEST softwares, demonstrating that the toxicity level of most TPs was lower/equal to their precursors. The evaluation of DBPs showed that UV/Fe 3+ /PS process could reduce the potential of DBPs formation, especially for TCAA and TCM. Microbial community composition was analyzed by 16 S rDNA sequencing, and the relative abundance of ARG-carrying opportunistic pathogens was significantly declined after UV/Fe 3+ /PS treatment. In general, this study provides an economical, efficient and safe strategy for TC removal.
研究领域:
环境科学
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化学工程
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生物学
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DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2026
·
IF 12.2
Yao Lu,Pin Wang,Hui-Xian Hu,Yu-En Guo,Shu-Xi Guo,Hua Li,Ye Du
The prechloramination followed by ozonation (NH2Cl–O3) process effectively mitigates bromate (BrO3–) formation in bromide-containing waters but inadvertently enhances the production of halogenated and nitrogenous disinfection byproducts (DBPs). Cytotoxicity assays revealed that the presence of precursors such as L-tyrosine (Tyr), L-tryptophan (Trp) and tannic acid during the NH2Cl–O3 process contributed to this increase in nitrogenous and halogenated DBPs and resulted in elevated overall toxicity. Nontargeted ultrahigh performance liquid chromatography-Orbitrap tandem mass spectrometry identified diverse halogenated DBPs, with NH2Cl–O3 yielding up to 5-fold more structures and higher abundances than NH2Cl or O3 alone. Taking Tyr as an example, proposed DBP (4-bromophenol, 4-hydroxyphenylacetamide, etc.) formation pathways, involving haloamine-mediated N-halogenation, O3-driven oxidation, decarboxylation, and deamination, were supported by density functional theory (DFT) calculations, confirming both thermodynamic and kinetic feasibility. Matrix-dependent quantitative validation in Suwannee River humic acid (SRHA) and wastewater effluents showed that concentrations of some identified DBPs reached tens of μg/L, dominated by aromatic halo-phenolics and brominated derivatives. In silico quantitative structure–activity relationship (QSAR) models and cytotoxicity assays indicated that these aromatic halo-DBPs exhibited comparable toxicities to conventional DBPs (e.g., dichloroacetonitrile, N-nitrosodimethylamine), but had a higher toxicity index than BrO3–. These findings highlight trade-offs in water disinfection, underscoring the need for optimized strategies to co-control BrO3– and toxic organic DBPs.
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高影响因子
Journal of Environmental Chemical Engineering
·
2026
·Vol. 14
·期 1
·121114
·
IF 7.2
Qing Wang,Lin Deng,Changbo Zhang,Rajendra Prasad Singh,Gongde Wu
Para-nitrophenol (PNP), a highly toxic compound widely detected in water bodies, was investigated as the target contaminant during the UV/chlor(am)ine/Fe(III) processes to evaluate its degradation kinetics model, and disinfection byproducts (DBPs) formation and pathways. The incorporation of Fe(III) introduced a oxidation-reduction cycle of Fe(II) and Fe(III), which can generate additional hydroxyl radicals, reactive chlorine species, and reactive nitrogen species, thereby accelerating PNP degradation by 21.85 % in the UV/chlorine system and 31.08 % in the UV/chloramine system. PNP degradation followed pseudo-first-order kinetics, with observed rate constants ( k obs ) calculated as 0.0938 and 0.0604 min −1 , in the UV/chlorine/Fe(III) and UV/chloramine/Fe(III) systems, respectively. Radical quenching experiments confirmed the dominant reactive species in each system, supporting the mechanistic interpretation. In the UV/chlorine/Fe(III) system, DBP yields ranked as follows: Halonitromethanes (HNMs) > trihalomethanes (THMs) > haloacetamides (HAcAms) > haloacetonitriles (HANs), while the order was HNMs > THMs > HANs > HAcAms, in the UV/chloramine/Fe(III) system. Factors influencing DBP formation, including Fe(III) dosage, initial pH, and chlor(am)ine dosage, were systematically investigated. The cytotoxicity index (CTI) contributions of each DBP in the UV/chlor(am)ine/Fe(III) systems were ranked as follows: HNMs > HANs > THMs > HAcAms. Based on detected transformation products (TPs) and radical contribution analysis, plausible pathways for PNP transformation and DBPs formation were proposed. These findings provide valuable insights into PNP degradation behavior and the mechanisms of DBPs formation in the UV/chlor(am)ine/Fe(III) systems, supporting their future practical applications.
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高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2024
·
IF 12.2
Shengnan Chen,Zhiwei Zhao,Chuang Wang,Fuyi Cui
Ultrafiltration (UF) is widely used in drinking water plants; however, membrane fouling is unavoidable. Natural organic matter (NOM) is commonly considered as an important pollutant that causes membrane fouling. Herein, we proposed VUV/H 2 O 2 as a UF pretreatment and used UV/H 2 O 2 for comparison. Compared to UV/H 2 O 2 , the VUV/H 2 O 2 system presented superior NOM removal. In the VUV/H 2 O 2 system, the steady-state concentration of HO• was approximately twice that in the UV/H 2 O 2 system, which was ascribed to the promoting effect of the 185 nm photons. Specifically, 185 nm photons promoted HO• generation by decomposing mainly H 2 O at a low H 2 O 2 dose or by decomposing mainly H 2 O 2 at a high H 2 O 2 dose. The VUV/H 2 O 2 pretreatment also demonstrated better membrane fouling mitigation performance than did UV/H 2 O 2 . An increase in the H 2 O 2 dose promoted HO• generation, thereby enhancing the performance of NOM degradation and membrane fouling alleviation and shifting the major membrane fouling mechanism from cake filtration to standard blocking. The VUV/H 2 O 2 (0.60 mM) pretreatment effectively reduced disinfection byproducts (DBPs) formation during chlorine disinfection. Additionally, the oxidant H 2 O 2 affected the membrane surface morphology and performance but had no evident effect on the mechanical properties. In actual water treatment, the VUV/H 2 O 2 pretreatment exhibited better performance than the UV/H 2 O 2 pretreatment in easing membrane fouling, ameliorating water quality, and reducing DBPs formation and acute toxicity.
研究领域:
环境科学
·
水处理工程
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DOI
PubMed
高影响因子
Environmental Science & Technology Letters
·
2018
·
IF 5.869
Di Zhang,Wenhai Chu,Yun Yu,Stuart W. Krasner,Yang Pan,Jun Shi,Daqiang Yin,Naiyun Gao
2-Chlorophenylacetonitrile (2-CPAN) and 3,4-dichlorophenylacetonitrile (3,4-DCPAN), representatives of a new class of nitrogenous aromatic disinfection byproducts, were first identified and quantified in chlorinated and chloraminated drinking waters. The impacts of pH, disinfectant residuals, and quenching agents on the stability of two chlorophenylacetonitriles (CPANs) were investigated. The two CPANs slightly degraded with increasing pH (5–9) and chlorination doses (0–4 mg/L) after 5 days, and NH2Cl did not cause degradation of CPANs. Among the commonly used quenching agents, the reaction between sodium sulfite and CPANs was negligible, whereas the others reduced CPANs by varying extents after 7 days. Notably, the two CPANs in finished water collected from seven drinking water treatment plants were quantified. 2-CPAN was detected between 170 and 530 ng/L with a median concentration of 220 ng/L, whereas 3,4-DCPAN ranged from below method detection limit (100 ng/L) up to 320 ng/L with a median concentration of 130 ng/L. Moreover, cytotoxicity of the CPANs and their aliphatic counterparts was determined using Chinese hamster ovary cells. The LC50 values are 133, 83, 436, 260, 905, 4150, and 8900μM for 2-CPAN, 3,4-DCPAN, chloroacetonitrile, dichloroacetonitrile, chloroacetic acid, dichloroacetic acids, and trichloromethane, respectively. Because of the relatively high stability and high toxic potencies of CPANs, the occurrence of CPANs in drinking water deserves attention.
研究领域:
环境科学
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水处理
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毒理学
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产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2023
·
IF 13.6
Shengnan Chen,Zhiwei Zhao,Fuyi Cui,Bingyan Liu
Membrane fouling , primarily resulting from natural organic matter (NOM) widely existing in water sources, has always been a chief hindrance for the prevalent application of ultrafiltration (UF). Thus, vacuum ultraviolet (VUV)/chlorine process was proposed as a strategy for UF membrane fouling control and ultraviolet (UV)/chlorine process was used for comparison. VUV/chlorine process exhibited more excellent performance on NOM removal than UV/chlorine process. [HO•]ss and [Cl•]ss were calculated as 1.26 × 10 −13 and 3.06 × 10 −14 M, respectively, and ClO• might not exist under the conditions of 0.08 mM chlorine and 30 min VUV irradiation. [HO•]ss, [Cl•]ss and [ClO•]ss were not available and the formation of reactive radicals was unsustainable in UV/chlorine system. Moreover, VUV/chlorine pretreatment also showed better performance on the reversible and irreversible membrane fouling control than UV/chlorine pretreatment. The dominated fouling mechanism in the final stage of filtration was cake filtration. Additionally, the amount of detected disinfection by-products (DBPs) in VUV/chlorine system was significantly lower than that in UV/chlorine system. During subsequent chlorination disinfection, the yield of DBPs with VUV/chorine pretreatment was higher than that with UV/chlorine pretreatment. VUV/chlorine pretreatment could effectively control DBPs formation when the pretreatment time was extended to 120 min. In summary, VUV/chlorine system presented a most excellent performance on membrane fouling control, NOM degradation and DBPs control.
研究领域:
环境科学
·
水处理工程
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DOI
PubMed
高影响因子
WATER RESEARCH
·
2022
·
IF 13.4
Shaoyang Hu,Han Yeong Kaw,Lizhong Zhu,Wei Wang
Halogenated aromatic disinfection byproducts (DBPs) exhibited similar total organic halogen levels in chlorinated drinking water samples as compared with aliphatic ones, and they predominantly accounted for the overall toxicity of the samples. Among the reported halogenated aromatic DBPs, halonitrophenols (HNPs) have received particular attention in recent years due to the relatively high risk in drinking water. In this study, a new group of halogenated aromatic DBPs were detected and then proposed to be halohydroxybenzonitriles (HHBNs) by employing the ultra-performance liquid chromatography/tandem mass spectrometers. Thereafter, the specific HHBN species in drinking water were theoretically speculated and then thoroughly identified with standard compounds. Their occurrence in drinking water was investigated, their cytotoxicity was evaluated, and their stability in the presence of chlorine was assessed. Seven newly identified HHBNs, including 3,5-dichloro-4-hydroxybenzonitrile, 3,5-dichloro-2-hydroxybenzonitrile, 5-bromo-3-chloro-4-hydroxybenzonitrile, 5-bromo-3-chloro-2-hydroxybenzonitrile, 3,5-dibromo-4-hydroxybenzonitrile, 3,5-dibromo-2-hydroxybenzonitrile, and 3,5-diiodo-4-hydroxybenzonitrile, showed 100% detection frequency in the collected drinking water samples with concentrations up to 36 ng/L. HHBNs exhibited significantly higher cytotoxicity in Chinese hamster ovary cells than regulated DBPs (e.g., trihalomethanes and haloacetic acids), which might be contributed by their cellular uptake efficiency and nucleophilicity. The seven HHBNs were proved to undergo transformation during chlorination following pseudo-first-order decay with half-lives in the range of 9–63 h. More importantly, in comparison to HNPs, which showed relatively high toxicity and strong stability among the halogenated aromatic DBPs, HHBNs presented comparable concentration-cytotoxicity contribution (50%) and slightly weaker stability (43%), suggesting that HHBNs should be a new group of DBPs of concern in drinking water.
研究领域:
环境科学
·
毒理学
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公共卫生
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DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2025
·
IF 11.3
Jiafu Li,Tian Qiu,Wenshan Shi,Caroline O. Granger,Md. Tareq Aziz,Patrick T. Justen,Susan D. Richardson
Aromatic disinfection byproducts (DBPs) can account for up to 36% of total organic halogen (TOX) in chlorinated drinking water and may be key drivers of developmental toxicity. However, aromatic DBPs reported to date cannot fully explain the observed TOX or developmental toxicity of drinking water. In this study, 17 chlorobenzenediols were identified in chlor(am)inated drinking water using gas chromatography–high resolution mass spectrometry (GC-HRMS). Total concentrations of chlorobenzenediols in tap water from seven cities ranged from 15 to 116 ng/L, with a mean of 54 ng/L. These levels are higher than previously reported for eight classes of aromatic DBPs and halobenzoquinones. Eleven chlorobenzenediols also formed during chlor(am)ination of Suwannee River natural organic matter (NOM), indicating that NOM is an important precursor. Five chlorobenzenediols have a reported LC50 and/or EC50 of less than 1 mg/L for various organisms, indicating that they are classified as very toxic chemicals and are likely to be among the most developmentally toxic aromatic DBPs discovered. Considering that the chlorobenzenediol concentrations in drinking water were higher than eight classes of reported aromatic DBPs and halobenzoquinones, they are likely to have a much more significant impact on drinking water developmental toxicity than other known aromatic DBPs.
研究领域:
环境毒理学
·
分析化学
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环境卫生学
·
分子毒理学
·
水质安全
·
发育生物学
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PubMed
高影响因子
ENVIRONMENTAL GEOCHEMISTRY AND HEALTH
·
2019
·Vol. 41
·期 3
·1545-1557
·
IF 3.252
Ye Bin,Cang Yan,Li Ji,Zhang Xiaolei
Chlorine dioxide (ClO 2 ) has been widely used in the process of preoxidation and disinfection as an excellent water treatment reagent. However, the inorganic by-products produced by ClO 2 , such as chlorite (ClO 2 − ) and chlorate (ClO 3 − ) are harmful to human health, and this has become a potential problem when using ClO 2 in drinking water treatment. In this study, ClO 2 alone and a ClO 2 /NaClO combination process were carried out to evaluate the algae removal efficiency of the treatment and the formation of disinfection by-products (DBPs: chlorite, chlorate, trihalomethanes and haloacetic acids) for high algae-laden water with 124.16 µg L −1 chlorophyll a (Chl.a) content. The results show that disinfection with 1.5 mg L −1 ClO 2 alone results in a ClO 2 − concentration exceeding 0.7 mg L −1 . ClO 2 preoxidation/ClO 2 disinfection is applicable for the control of effluent quality, but the ClO 2 − concentration still has an excessive risk when using 0.8 mg L −1 and 0.6 mg L −1 ClO 2 for the two process, respectively. In the ClO 2 /NaClO combination process, the ClO 2 − concentration is below 0.6 mg L −1 , and trihalomethane (THM) and haloacetic acid (HAA) concentrations are lower than 60% of the maximum contaminant levels (MCLs) set by the World Health Organization (WHO). Further, the formation of ClO 2 − is more effectively controlled by NaClO preoxidation/ClO 2 disinfection than ClO 2 preoxidation/NaClO disinfection.
研究领域:
环境科学
·
水处理工程
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DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2021
·
IF 9.028
Haiyang Tang,Hongli Zhong,Yang Pan,Qing Zhou,Zongli Huo,Wenhai Chu,Bin Xu
pH adjustment prior to extraction is an important step in water sample pretreatment processes for exploration of new/unknown disinfection byproducts (DBPs) in drinking water. To achieve a better extraction efficiency, the pH of a water sample is usually adjusted to a low level (e.g., < 0.5) to ensure that target DBPs are in their neutral forms. However, such a practice may elude some amphoteric DBPs (especially those nitrogenous DBPs with multiple functional groups), which can accept protons at a low pH and lose protons at a high pH. In this study, with careful extraction pH selection and optimization, we first report the detection and identification of a new group of heterocyclic nitrogenous DBPs, halogenated pyridinols, in simulated drinking water using ultra performance liquid chromatography/electrospray ionization-triple quadrupole mass spectrometry and time-of-flight mass spectrometry, including 5-chloro-3-pyridinol, 2-bromo-3-pyridinol, 2,6-dichloro-4-pyridinol, 2,6-dibromo-3-pyridinol, 3-bromo-2-chloro-5-pyridinol, 5-bromo-2-chloro-3-pyridinol, 3,5,6-trichloro-2-pyridinol, and 2,4,6-tribromo-3-pyridinol. On the basis of the speciation of dissociated chemical species and recovery tests at different extraction pH values, it was found that, only at a pH of 3.0, all the eight new DBPs could achieve recoveries of >50%. With subsequent instrumental parameter optimization, the method detection and quantitation limits of the eight new DBPs were determined to be 0.04–1.58 and 0.15–4.11 ng/L, respectively. The optimized method enabled an accurate detection of the eight new DBPs in two real drinking water samples. Further aided with in vivo developmental and acute toxicity assays using zebrafish embryos, the developmental and acute toxicity of the new DBPs were found to be slightly lower than those of halogenated benzoquinones but dozens of times higher than those of commonly known DBPs such as tribromomethane and iodoacetic acid.
研究领域:
环境科学
·
分析化学
·
毒理学
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DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）