CHEMOSPHERE
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2021
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IF 7.086
Yiya Wei,Yang Yang,Baiyang Chen,Bingcheng Yang
Chlorinated cyanurates (CCAs) are a type of disinfectants currently used worldwide for fight of Coronavirus. However, CCAs upon dosed into water can release not only free chlorine (FC), a strong disinfectant, but also cyanurate (CYA), a persistent compound potentially harmful to human and environment. Therefore, detecting CYA and FC in water are very important not only for ensuring sufficient disinfection but also for monitoring the impacts of FC and CYA on receiving watershed. However, conventional analytical methods for them are mostly based on colorimetric methods, which have high method detection limits (MDLs) and rely on chemical reactions that are likely sensitive to coexisting chemicals. To overcome these issues, we herein proposed a facile and reaction-free method to detect CYA and FC together in just one run by ion chromatography (IC) equipped with both conductivity and ultraviolet absorbance detectors. The method features obvious advantages over colorimetric methods in being lower MDLs (3.6 μg/L for CYA and 9.0 μg/L for FC), environmental-friendly (i.e., no organic solvent involved), and more resistant to alkaline solution. With this method, trace levels of CYA (i.e., 34–44 μg/L), which were nondetectable by conventional method, were found in two river water samples, implying that the local environment was already polluted by CCAs during the pandemic period. Overall, this study demonstrates a robust tool that may assist better understanding and monitoring the fate and transport of trace CCA derivatives in water.
研究领域:
环境科学
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分析化学
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公共卫生
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHIMICA ACTA
·
2016
·Vol. 183
·期 7
·2221-2227
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IF 4.831
Lin Yanping,Yao Bixia,Huang Tingting,Zhang Shichao,Cao Xiaotong,Weng Wen
The authors report that nitrogen-doped carbon dots (N-CDs) represent a viable fluorescent probe for the determination of dissolved free chlorine. The N-CDs can be fairly easily prepared by a solvothermal method using citric acid, tartaric acid and ethanediamine as the precursors, display excitation/emission maxima of 360/460 nm, and have a quantum yield of 42.2 %. Free chlorine and ClO − quench fluorescence, and this was exploited to design a method for fluorometric determination of chlorine and hypochlorite. The probe has a short response time (< 1 min), excellent selectivity, high sensitivity, and a linear response range that extends from 0.1 to 27 μM. The limit of detection is as low as 29.7 nM. The method was applied to the determination of chlorine dissolved in tap water.
Fluorescent nitrogen-doped carbon dots (N-CQDs) displaying excitation/emission maxima of 360/460 nm were fabricated by a one-pot solvothermal method. The photoluminescence (PL) of the N-CQDs is quenched by free chlorine and ClO − , and this was exploited to design a method for fluorometric determination of chlorine and hypochlorite.
研究领域:
分析化学
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环境科学
✓ 已验证
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2025
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IF 7.2
Xinwei Xu,Hui Sun,Jueyao Li,Yongming Tang
The reactive species of electrochlorination (E-Cl) in the ultrahigh salinity water (1 %-15 % NaCl) were investigated using pyridine (Pyr) as the model pollutant. No • OH signal can be detected for the E-Cl process in the ultrahigh salinity water. The free radicals are dominantly composed of the reactive chlorine species (RCS) such as Cl • , Cl 2 •− and ClO • . Moreover, the steady concentrations of Cl 2 •− and ClO • , and thus their contributions to the Pyr removal, are higher than that of Cl • . In 15 % NaCl solution, at the current density lower than 3 mA cm −2 , the RCS cannot be generated. Compared with the RCS species, the contribution of free chlorine (FC) to the Pyr removal is slightly higher due to the abundant FC generated during the E-Cl process. However, the reactivity of RCS to Pyr is much higher than that of FC. The second-order reaction rate constants of Cl • , Cl 2 •− , ClO • and FC with Pyr are 4.1 × 10 9 M −1 s −1 , 8.0 × 10 6 M −1 s −1 , 2.2 × 10 5 M −1 s −1 and 1.9 × 10 −3 M −1 s −1 , respectively. Among the background substances, SO 4 2- ions shows the significantly inhibitory effect on the Pyr degradation. Furthermore, the degradation pathway of Pyr was also proposed in the study.
研究领域:
环境化学
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电化学
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水处理
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污染物降解
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DOI
高影响因子
ACS Omega
·
2023
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IF 4.1
Xinwei Jiang,Julin Yuan,Zhijie Zheng,Yufang Tao,Xiaogang Wu
This study evaluated the effects of ultraviolet (UV) photolysis combined with electrochemical oxidation on sulfonamides (SAs) as well as its treated effluent on the bacterial community in surface water. In terms of degradation rate, the best anode material for electrochemical oxidation was Ti/RuO2–IrO2, which had the highest degradation kinetic constant compared to Ti/Ta2O5–IrO2 and Ti/Pt. Experiments showed the highest degradation rate of SAs at 8.3 pH. Similarly, increasing the current leads to stronger degradation due to the promotion of free chlorine production, and its energy consumption rate decreases slightly from 73 to 67 W h/mmol. Compared with tap water, the kinetic constants decreased by 20–62% for SAs in three different surface water samples, which was related to the decrease in free chlorine. When extending the reaction time to 24 h, the concentrations of chemical oxygen demand and total organic carbon decreased by approximately 30–40%, indicating that the SAs and their products could be mineralized. The diversity analysis showed that the effluents influenced the richness and diversity of the bacterial community, particularly in the 4 h sample. Additionally, there were 86 operational taxonomic units common to all samples, excluding the 4 h sample; significant differences were derived from changes in the Actinobacteriota and Bacteroidota phyla. The toxicity of the products might explain these changes, and these products could be mineralized, as observed in the 24 h sample. Therefore, the extension of treatment time would greatly reduce the ecological harm of treated effluent and ensure that the UV/electrochemical process is a feasible treatment option. Overall, this study provides valuable insight into the optimization and feasibility of UV/electrochemical processes as a sustainable treatment option for sulfonamide-contaminated water sources, emphasizing the importance of considering ecological impacts and the need for extended treatment times that address environmental concerns and ensuring improved water quality.
研究领域:
环境科学
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水处理
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微生物学
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Wei Luo,Lin Deng,Jun Hu,Bohui Xu,Chaoqun Tan
Dimetridazole (DMZ) is widely used as a veterinary antibiotic, but it is recalcitrant in the water environment. The residual of DMZ has raised widespread concern because of its harmful effects on human health and environmental safety. This work aimed to investigate the degradation of DMZ and the corresponding formation of halonitromethanes (HNMs) during the ultraviolet (UV)/chlorine process. The UV/chlorine process presented an excellent performance in DMZ degradation. The observed degradation rate constant of DMZ by UV/chlorine was 1.4 × 10 −1 min −1 . The hydroxyl radicals (·OH) and chlorine radicals (·Cl) were the predominant reactive species for DMZ degradation, and corresponding contributions were 79.8% and 13.7%, respectively. With the increase of free chlorine dosage, the degradation efficiency of DMZ firstly increased and then slightly decreased, while the formation of HNMs increased after 40 min UV/chlorine treatment. The higher degradation efficiency of DMZ was observed at acid circumstances, while higher HNMs formation was found at alkaline conditions due to base-catalyzed hydrolysis and less degradation of HNMs. The presences of Cl – , Br – , HCO 3 – and humic acid (HA) inhabited the degradation of DMZ. Furthermore, the possible degradation pathways of DMZ were proposed based on five intermediate products identified by UPLC/MS. Overall, the UV/chlorine was an efficient method for DMZ removal, but the formation of HNMs from DMZ should be evaluated before using UV/chlorine.
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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分析化学
✓ 已验证
产品关联
DOI
高影响因子
WATER RESEARCH
·
2022
·
IF 13.4
Shengqi Zhang,Qian Yin,Shangwei Zhang,Kyriakos Manoli,Lei Zhang,Xin Yu,Mingbao Feng
Chlorination of a typical anticancer drug with annually ascending use and global prevalence (methotrexate, MTX) in water has been studied. In addition to the analysis of kinetics in different water/wastewater matrices, high-resolution product identification and in-depth secondary risk evaluation, which were eagerly urged in the literature, were performed. It was found that the oxidation of MTX by free available chlorine (FAC) followed first-order kinetics with respect to FAC and first-order kinetics with respect to MTX. The pH-dependent rate constants ( k app ) ranged from 170.00 M −1 s −1 (pH 5.0) to 2.68 M −1 s −1 (pH 9.0). The moiety-specific kinetic analysis suggested that 6 model substructures of MTX exhibited similar reactivity to the parent compound at pH 7.0. The presence of Br − greatly promoted MTX chlorination at pH 5.0–9.0, which may be ascribed to the formation of bromine with higher reactivity than FAC. Comparatively, coexisting I − or humic acid inhibited the degradation of MTX by FAC. Notably, chlorination effectively abated MTX in different real water matrices. The liquid chromatography-high resolution mass spectrometry analysis of multiple matrix-mediated chlorinated samples indicated the generation of nine transformation products (TPs) of MTX, among which seven were identified during FAC oxidation for the first time. In addition to the reported electrophilic chlorination of MTX (the major and dominant reaction pathway), the initial attacks on the amide and tertiary amine moieties with C-N bond cleavage constitute novel reaction mechanisms. No genotoxicity was observed for MTX or chlorinated solutions thereof, whereas some TPs were estimated to show multi-endpoint aquatic toxicity and higher biodegradation recalcitrance than MTX. The chlorinated mixtures of MTX with or without Br − showed a significant ability to increase the conjugative transfer frequency of plasmid-carried antibiotic resistance genes within bacteria. Overall, this work thoroughly examines the reaction kinetics together with the matrix effects, transformation mechanisms, and secondary environmental risks of MTX chlorination.
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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微生物学
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药学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2020
·
IF 5.774
Feilong Dong,Qiufeng Lin,Cong Li,Liping Wang,Andreina García
The disinfection of algal-impacted surface waters results in high concentrations of disinfection byproducts (DBPs). Here, the formation of DBPs when water containing Pseudanabaena limnetica ( P. limnetica ) was disinfected combining chlorination and ultraviolet irradiation (UV) was investigated. Because of UV/chlorination to inhibit algal growth and reduce DBP formation effectively, the effects of UV doses, free chlorine doses, reaction time and pH on the formation of DBPs during UV/chlorination were studied. The results showed that higher UV dose, longer oxidation time, neutral and acidic pH were beneficial in controlling DBPs. Moreover, UV/chlorination could enhance the formation of brominated DBPs, and reduce the formation of chlorinated DBPs in algal solutions containing bromide. In addition, the DBP formation from intracellular and extracellular organic matter (IOM and EOM, respectively) derived from algae was compared. Finally, the economic efficiency of our system using the electrical energy per order (EE/O) was evaluated, which was calculated to be 18.68 kWh/m 3 during the reaction. This information indicated that UV/chlorination was a feasible treatment method for algal-rich water.
研究领域:
环境科学
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水处理
·
消毒工艺
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）