CHEMICAL ENGINEERING JOURNAL
·
2017
·
IF 6.216
Ji Zheng,Chao Su,Jianwen Zhou,Like Xu,Yanyun Qian,Hong Chen
Antibiotic resistance genes (ARGs) in environment have gradually engendered extensive concern recently due to the harm caused to environment and human beings. Wastewater treatment plants are considered as important nodes of ARGs controlling and it is of utmost importance to figure out effects and mechanisms of each process, especially disinfections. In this study, three disinfection processes (ultraviolet, chlorination, and ozone) were used to reduce levels of ARGs in secondary effluents from a municipal wastewater treatment plant. Results indicated that the abundance of ARGs decreased exponentially as the dosage increased during the ultraviolet disinfection treatment ( R 2 = 0.68–0.92). In the 0–5 mg/L available chlorine concentrations, with a contact time of 30 min, the abundance of ARGs decreased linearly as the chlorine concentrations increased ( R 2 = 0.77–0.99). In a 2 mg/L concentration of ozone (O 3 ), the abundance of ARGs had higher removal efficiency, but the removal efficiency was not significantly enhanced by increasing the concentration of ozone. However, an experiment using the DNase I treatment showed that UV and ozone disinfection resulted in apoptosis, and the bacterial DNA was released into the environment; ARGs were mostly found as free DNA in the treated wastewater. These results provide insights into behavior of ARGs during disinfection processes in wastewater treatment plants.
研究领域:
环境科学
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微生物学
·
水处理工程
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产品关联
DOI
高影响因子
Journal of Environmental Sciences
·
2023
·
IF 6.9
Sinong Huang,Hongwei Liu,Kunming Wei,Liang Zhang,Xiaoyan Ma,Qingsong Li,Xueyan Li,Andrea M. Dietrich
As a strong oxidizing agent, ozone is used in some water treatment facilities for disinfection, taste and odor control, and removal of organic micropollutants. Phenylalanine (Phe) was used as the target amino acid to comprehensively investigate variability of disinfection byproducts (DBPs) formation during chlorine disinfection and residual chlorine conditions subsequent to ozonation. The results showed that subsequent to ozonation the typical regulated and unregulated DBPs formation potential (DBPsFP), including trichloromethane (TCM), dichloroacetonitrile (DCAN), chloral hydrate (CH), dichloroacetic acid (DCAA), trichloroacetic acid (TCAA), and trichloroacetamide (TCAcAm) increased substantially, by 2.4, 3.3, 5.6, 1.2, 2.5, and 6.0 times, respectively, compared with only chlorination. Ozonation also significantly increased the DBPs yield under a 2 day simulated residual chlorine that mimicked the water distribution system; DBPs formations followed pseudo first order kinetics. The formation rates of DBPs in the first 6 h was higher for TCM (0.214 h −1 ), DCAN (0.244 h −1 ), CH (0.105 h −1 ), TCAcAm (0.234 h −1 ), DCAA (0.375 h −1 ) and TCAA (0.190 h −1 ) than thereafter. The peak DBPsFP of TCM, DCAN, CH, TCAcAm, DCAA, and TCAA were obtained when that ozonation time was set at 5–15 min. Ozonation times > 30 min increased the mineralization of Phe and decreased the formation of DBPs upon chlorination. Increasing bromine ion (Br − ) concentration increased production of bromine- DBPs and decreased by 59.3–92.2% chlorine-DBPs formation. Higher ozone dosages and slight alkaline favored to reduce DBP formation and cytotoxicity. The ozonation conditions should optimize for all application purposes including DBPs reduction.
研究领域:
环境科学
·
水处理工程
✓ 已验证
产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2018
·
IF 4.61
Guo-Qiang Li,Zheng-Yang Huo,Qian-Yuan Wu,Yun Lu,Hong-Ying Hu
An ultraviolet (UV)-based advanced oxidation process (AOP) for disinfecting water is introduced in this paper. This study aimed to evaluate the potential of UV light-emitting diodes (UV-LEDs)/chlorine AOP (UV/Cl 2 ) for Bacillus subtilis spore inactivation. Chlorine was combined with 265 and 280 nm LEDs (UV 265 /Cl 2 , UV 280 /Cl 2 ) and investigated. The addition of 4.0 mg/L of free chlorine at pH 7.0 in the presence of 125 mJ/cm 2 of UV irradiation resulted in an additional 1.8-log reduction in UV 265 /Cl 2 and 1.5-log reduction in UV 280 /Cl 2 . There was no observed enhancement in spore inactivation with the addition of a radical scavenger, t-BuOH, which indicated the role of • OH in the synergistic effect. To quantitatively evaluate the synergism, the primary treatment with UV/Cl 2 was followed by further UV or Cl 2 treatment. After UV/Cl 2 pretreatment at different pH levels, the 265 and 280 nm LEDs treatment enhanced an approximate 0.4–0.5-log reduction compared to UV only, and Cl 2 treatment enhanced an approximate 0.7–1.1-log reduction compared to Cl 2 only. In addition, at pH 7.0, in UV 265 /Cl 2 -Cl 2 and UV 280 /Cl 2 -Cl 2 , the inactivation rate constant k increased by approximately 2 and 1.5 times, respectively. The CT for the lag phases ( CT lag ) reduced to approximately 67 and 58%, respectively. Similar results were obtained at pH 7.5 and 8.0, and in the secondary effluent. The synergistic effect on spore inactivation suggested that the pathogen inactivation efficiency of sequential UV and chlorine disinfection processes, which are commonly applied, can be significantly enhanced by adding chlorine prior to UV treatment .
研究领域:
微生物学
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环境科学
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水处理技术
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产品关联
DOI
PubMed
高影响因子
MOLECULES
·
2024
·Vol. 29
·期 2
·396
·
IF 4.2
Zhenkun Sun,Zhenyi Chen,Marie Celine Chung Lan Mow,Xiaowen Liao,Xiaoxuan Wei,Guangcai Ma,Xueyu Wang,Haiying Yu
The unrestricted utilization of antibiotics poses a critical challenge to global public health and safety. Levofloxacin (LEV) and sulfaphenazole (SPN), widely employed broad-spectrum antimicrobials, are frequently detected at the terminal stage of water treatment, raising concerns regarding their potential conversion into detrimental disinfection byproducts (DBPs). However, current knowledge is deficient in identifying the potential DBPs and elucidating the precise transformation pathways and influencing factors during the chloramine disinfection process of these two antibiotics. This study conducts a comprehensive analysis of reaction pathways, encompassing piperazine ring opening/oxidation, Cl-substitution, OH-substitution, desulfurization, and S−N bond cleavage, during chloramine disinfection. Twelve new DBPs were identified in this study, exhibiting stability and persistence even after 24 h of disinfection. Additionally, an examination of DBP generation under varying disinfectant concentrations and pH values revealed peak levels at a molar ratio of 25 for LEV and SPN to chloramine, with LEV contributing 11.5% and SPN 23.8% to the relative abundance of DBPs. Remarkably, this research underscores a substantial increase in DBP formation within the molar ratio range of 1:1 to 1:10 compared to 1:10 to 1:25. Furthermore, a pronounced elevation in DBP generation was observed in the pH range of 7 to 8. These findings present critical insights into the impact of the disinfection process on these antibiotics, emphasizing the innovation and significance of this research in assessing associated health risks.
研究领域:
环境科学
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公共卫生
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2022
·
IF 11.357
Di Zhang,Tom Bond,Yang Pan,Mingli Li,Jiayi Luo,Rong Xiao,Wenhai Chu
Identifying disinfection byproducts (DBPs) with high health risk is an unresolved challenge. In this study, six members of a new class of aromatic nitrogenous DBPs─2-chloroaniline, 2-bromoaniline, 2,4-dichloroaniline, 2-chloro-4-bromoaniline, 4-chloro-3-nitroaniline, and 2-chloro-4-nitroaniline─are reported as DBPs in drinking water for the first time. Haloanilines completely degraded within 1 h in the presence of chlorine (1 mg/L), while about 20% remained in the presence of chloramine (1 mg/L) after 120 h. Haloanilines showed high stability in the absence of disinfectants, with <30% degradation at pH 5–9 over 120 h. Eight haloanilines were determined in chloraminated finished water and tap water at total concentrations of up to 443 ng/L. The most abundant was 2-bromoaniline, with a median concentration of 104 ng/L. The cytotoxicity of eight haloanilines and regulated trichloromethane and dichloroacetic acid (DCAA) was evaluated using Hep G2 cell assay. The EC50 values of eight haloanilines were 1–2 orders of magnitude lower than those of the regulated DBPs. The lowest toxic concentration of 2-chloro-4-nitroaniline was 1 μM, 500 times lower than that of DCAA. The formation and control of haloanilines in drinking water warrant further investigation.
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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公共卫生
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Frontiers of Environmental Science & Engineering
·
2024
·Vol. 18
·期 9
·1-14
·
IF 6.1
Liao Xiaobin,Liu Xinyue,He Yueyun,Tang Xueping,Xia Ruanjunjie,Huang Yongjun,Li Wenhua,Zou Jing,Zhou Zhenming,Zhuang Mazhan
During the COVID-19 pandemic, most sewage treatment plants increased disinfectant dosages to inactivate pathogenic viruses and microorganisms more effectively. However, this approach also led to the production of more disinfection by-products (DBPs). To ensure both disinfection efficiency and a reduction in DBP formation, new disinfection protocols are required. In this study, the disinfection efficiency, DBP amounts, and toxicity changes resulting from ozone (O 3 ), ultraviolet (UV), chlorine (Cl 2 ), and their combined processes were examined. The results demonstrated that the O 3 /UV/Cl 2 combination achieved the highest disinfection efficiency. Chlorination produced the most DBPs, whereas UV treatment reduced the formation of trihalomethane (THM), halogenated ketones (HKs), haloacetic acids (HAA), dichloroacetonitrile (DCAN) and N-nitrosodimethylamine (NDMA) by 45.9%, 52.6%, 82.0%, 67.95%, and 47%, respectively. O 3 also significantly reduced their production by 99.1%, 91.1%, 99.5%, 100%, and 35%. Intracellular organic matter (IOM) was identified as the primary DBP precursors, producing 2.94 times more DBPs than extracellular organic matter (EOM). The increased DBP formation during chlorination was attributed to IOM leakage and cell membrane damage, which was verified using scanning electron microscopy (SEM). The toxicities of DBPs were evaluated for six disinfection methods, revealing inconsistent results. The overall toxicities were assessed using zebrafish embryo experiments. Both evaluations indicated that chlorination alone was the least favorable method. In addition, the toxicities followed a sequence: Cl 2 ≈ O 3 /Cl 2 > O 3 > O 3 /UV/Cl 2 > UV > UV/Cl 2 . These findings can serve as a reference for sewage treatment plants in selecting appropriate disinfection methods to manage the COVID-19 epidemic from comprehensive perspective.
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
DOI
高影响因子
Journal of Cleaner Production
·
2021
·
IF 9.297
Maocai Shen,Zhuotong Zeng,Long Li,Biao Song,Chengyun Zhou,Guangming Zeng,Yaxin Zhang,Rong Xiao
As an important contributor of environmental microplastics , wastewater treatment plants have attracted extensive attention. The negative effect of suspended particulate matter on disinfection effect has also been established. The main aims of this study were to understand the potential effects of granular polyethylene microplastic and fibrous polyamide microplastics on ultraviolet and chlorine disinfection in water/wastewater treatment. In the laboratory, microplastics were exposed to different disinfection methods, which represented the disinfection dose and disinfection conditions of real water and wastewater treatment. Escherichia coli (8099) were selected as the experimental object. Microplastic suspended solids were closely related to water turbidity and UV transmittance at 254 nm. The occurrence of microplastics significantly reduced the efficiency of ultraviolet and chlorine disinfection in water/wastewater treatment, and the efficiency decreased with the increase of microplastics concentration or the decrease of disinfectant dosage. When the concentration of microplastics reached a certain level (>50 mg L −1 ), even if the exposure dose continued to increase, the disinfection efficiency could not be improved. Microplastics can reduce the concentration of disinfectants around them by reacting with disinfectants, thus protecting the microorganisms enriched on the surface of microplastics. Although the harsh conditions tested here are rarely met in a typical water treatment process, it represented a worse result. These results were intended to be used by water treatment plants to predict the effects of microplastics in the secondary effluent on UV and chlorine disinfection processes .
研究领域:
环境科学
·
微生物学
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产品关联
DOI
高影响因子
Nano Energy
·
2021
·
IF 17.881
Yang Zhao,Ze-Xian Low,Yifan Pan,Zhaoxiang Zhong,Guandao Gao
Diverse water microbes in water sources pose serious challenges to conventional disinfection techniques, leading to high oxidant and energy cost and large formation of disinfection by-products. Herein, a piezoelectret aluminium oxide (PEAO) was engineered for water disinfection . The piezo-catalytic disinfection system with ultrasonication induced strong electric field intensity of 8.1 × 10 7 V/m on PEAO surface, resulting in microbial cell membrane in-situ electroporation followed by penetration of generated reactive oxygen species (ROS, hydroxyl radical, singlet oxygen and hydrogen peroxide). The proposed piezo-catalytic disinfection strategy exhibited universal water disinfection performances among different microbes, ~1000-fold more efficient than an equivalent amount of preformed hydrogen peroxide, thus significantly improved the oxidant utilization and disinfection efficiency and potentially decreasing the formation of disinfection by-products. This work clearly demonstrates the application and mechanism of in-situ versatile water disinfection process via piezo-catalytic of PEAO and further applications in other water treatment fields are expected.
研究领域:
环境科学
·
水处理
·
材料科学
·
生物技术
✓ 已验证
DOI
高影响因子
MOLECULES
·
2024
·Vol. 29
·期 8
·1879
·
IF 4.2
Zhenyi Chen,Bangyu Chen,Hui Shen,Xunlin Li,Chen Zhou,Guangcai Ma,Xiaoxuan Wei,Xueyu Wang,Haiying Yu
In the face of ongoing water pollution challenges, the intricate interplay between dissolved organic matter and disinfectants like chlorine gives rise to potentially harmful disinfection byproducts (DBPs) during water treatment. The exploration of DBP formation originating from amino acids (AA) is a critical focus of global research. Aromatic DBPs, in particular, have garnered considerable attention due to their markedly higher toxicity compared to their aliphatic counterparts. This work seeks to advance the understanding of DBP formation by investigating chlorination disinfection and kinetics using tyrosine (Tyr), phenylalanine (Phe), and tryptophan (Trp) as precursors. Via rigorous experiments, a total of 15 distinct DBPs with accurate molecular structures were successfully identified. The chlorination of all three AAs yielded highly toxic chlorophenylacetonitriles (CPANs), and the disinfectant dosage and pH value of the reaction system potentially influence chlorination kinetics. Notably, Phe exhibited the highest degradation rate compared to Tyr and Trp, at both the CAA:CHOClratio of within 1:2 and a wide pH range (6.0 to 9.0). Additionally, a neutral pH environment triggered the maximal reaction rates of the three AAs, while an acidic condition may reduce their reactivity. Overall, this study aims to augment the DBP database and foster a deeper comprehension of the DBP formation and relevant kinetics underlying the chlorination of aromatic AAs.
研究领域:
环境科学
·
水处理工程
·
毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
WATER RESEARCH
·
2019
·
IF 7.913
Feilong Dong,Jianing Chen,Cong Li,Xingmao Ma,Jingjing Jiang,Qiufeng Lin,Chenhong Lin,Hongyan Diao
Disinfection is a key step in drinking water treatment process to prevent water-borne infections. However, reactions between chlorine, one of the most common disinfectants, and natural organic matter (NOM) often lead to the formation of hazardous disinfection byproducts (DBPs). However, the cytotoxicity of some DBPs is still poorly understood. Such knowledge is critical for proper selection of disinfection processes. We investigated the effects of DBPs on mouse acute liver injury. The exacerbation of liver damage increased with the DBPs concentrations, likely due to the increased hepatic macrophages. Haloacetonitriles (HANs) and haloketones (HKs) are more toxic to Human Hepatocellular (Hep3B) cells than trihalomethanes (THMs). Cytotoxicity of DBPs were governed by the halogen type (brominated DBPs > chlorinated DBPs) and the numbers of halogen atoms per molecule. Then, we used the pilot-scale WDS to study the best conditions for reducing the formation of DBPs. The result showed that the formation of DBPs followed the order: stainless-steel (SS) > ductile iron (DI) > polyethylene (PE) pipe. Higher flowrate promoted the formation of DBPs in all three pipes. The results suggest that the formation of DBPs in chlorine disinfection can be reduced by using PE pipes and low flow rate in water distribution systems (WDS).
研究领域:
毒理学
·
环境科学
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公共卫生
✓ 已验证
产品关联
DOI
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
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nanotechnology Reviews
·
2023
·Vol. 12
·期 1
·
IF 7.4
Yingzheng Yin,Jie Ding,Yue Cao,Shaozhi Li,Qingbo Ma,Jinyang Li,Xiaoling Xu,David Hui,Zuowan Zhou
It is quite necessary to develop a safe and efficient technique for disinfection of drinking water to avoid waterborne pathogens of infectious diseases. Herein, ZnO nanoarray electrodes with different sizes were investigated for low-voltage and high-efficiency electroporation disinfection. The results indicated that the ZnO nano-pyramid with small tip width and proper length exhibited over 99.9% disinfection efficiency against Escherichia coli under 1 V and a flow rate of 10 mL/min (contact time of 1.2 s). The suitable size of the nanoarray for electroporation disinfection was optimized by establishing the correlation between four kinds of ZnO nanoarrays and their efficiency of electroporation disinfection, which can guide the preparation of next-generation electroporation-disinfecting electrodes.
研究领域:
微生物学
·
环境科学
·
纳米材料科学
✓ 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）