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Min Yang - One of the best experts on this subject based on the ideXlab platform.
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distribution of antibiotic resistance in the effluents of ten Municipal Wastewater Treatment plants in china and the effect of Treatment processes
Chemosphere, 2017Co-Authors: Weiwei Ben, Yu Zhang, Min Yang, Jing Wang, Rukun Cao, Zhimin QiangAbstract:Municipal Wastewater Treatment plant (WWTP) effluents represent an important contamination source of antibiotic resistance, threatening the ecological safety of receiving environments. In this study, the release of antibiotic resistance to sulfonamides and tetracyclines in the effluents of ten WWTPs in China was investigated. Results indicate that the concentrations of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) ranged from 1.1 × 101 to 8.9 × 103 CFU mL-1 and 3.6 × 101 (tetW) to 5.4 × 106 (tetX) copies mL-1, respectively. There were insignificant correlations of the concentrations of ARB and ARGs with those of corresponding antibiotics. Strong correlations were observed between the total concentrations of tetracycline resistance genes and sulfonamide resistance genes, and both of which were significantly correlated with intI1 concentrations. Statistical analysis of the effluent ARG concentrations in different WWTPs revealed an important role of disinfection in eliminating antibiotic resistance. The release rates of ARB and ARGs through the effluents of ten WWTPs ranged from 5.9 × 1012 to 4.8 × 1015 CFU d-1 and 6.4 × 1012 (tetW) to 1.7 × 1018 (sul1) copies d-1, respectively. This study helps the effective assessment and scientific management of ecological risks induced by antibiotic resistance discharged from WWTPs.
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dynamics of the microfauna community in a full scale Municipal Wastewater Treatment plant experiencing sludge bulking
European Journal of Protistology, 2013Co-Authors: Bo Hu, Yu Zhang, Rong Qi, Wei An, Muqi Xu, Jian Gu, Min YangAbstract:We investigated the dynamics of the microfauna community in activated sludge, with special reference to sludge bulking, in two parallel Municipal Wastewater Treatment systems in Beijing, China over a period of 14 months. Annual cyclic changes in microfauna community structures occurred in both systems. RELATE analysis based on Spearman's Rank correlation indicated that microfauna community structures were highly correlated with the sludge volume index (SW) (p<0.001), which indicates sludge settleability. Nutrient conditions of raw sewage (p<0.01) and hydraulic retention time (HRT) (p<0.05) were also related to microfauna community structures. Abundances of the species Epistylis plicatilis and Vorticella striata increased significantly with an increase in SW (p<0.001) and decrease in water temperature (p<0.001), suggesting that sludge bulking may have created favorable conditions for the two species, even under unfavorable temperature conditions. Sludge de-flocculation primarily due to the excessive growth of Microthrix parvicella-like filaments could be an important driving force for the microfauna community changes. The release of flocculated non-filamentous bacteria may represent a suitable food source for these species. The two species may be considered as potential bioindicators for sludge bulking. (C) 2013 Elsevier GmbH. All rights reserved.
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dynamics of the microfauna community in a full scale Municipal Wastewater Treatment plant experiencing sludge bulking
European Journal of Protistology, 2013Co-Authors: Yu Zhang, Xue Bai, Haipeng Bao, Yang Wen, Min YangAbstract:We investigated the dynamics of the microfauna community in activated sludge, with special reference to sludge bulking, in two parallel Municipal Wastewater Treatment systems in Beijing, China over a period of 14 months. Annual cyclic changes in microfauna community structures occurred in both systems. RELATE analysis based on Spearman's Rank correlation indicated that microfauna community structures were highly correlated with the sludge volume index (SVI) (p<0.001), which indicates sludge settleability. Nutrient conditions of raw sewage (p<0.01) and hydraulic retention time (HRT) (p<0.05) were also related to microfauna community structures. Abundances of the species Epistylis plicatilis and Vorticella striata increased significantly with an increase in SVI (p<0.001) and decrease in water temperature (p<0.001), suggesting that sludge bulking may have created favorable conditions for the two species, even under unfavorable temperature conditions. Sludge de-flocculation primarily due to the excessive growth of Microthrix parvicella-like filaments could be an important driving force for the microfauna community changes. The release of flocculated non-filamentous bacteria may represent a suitable food source for these species. The two species may be considered as potential bioindicators for sludge bulking.
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systematic analysis of microfauna indicator values for Treatment performance in a full scale Municipal Wastewater Treatment plant
Journal of Environmental Sciences-china, 2013Co-Authors: Bo Hu, Rong Qi, Min YangAbstract:The indicator values of microfauna functional groups and species for Treatment performance were systematically evaluated based on the continuous monitoring of the entire microfauna communities including both protozoa and metazoa over a period of 14 months, in two parallel full-scale Municipal Wastewater Treatment systems in a plant in Beijing, China. A total of 57 species of ciliates, 14 species (units) of amoebae, 14 species (units) of flagellates and 4 classes of small metazoa were identified, with Arcella hemisphaerica, Vorticella striata, Vorticella convallaria, Epistylis plicatilis and small flagellates (e.g. Bodo spp.) as the dominant protozoa, and rotifers as the dominant metazoa. The abundance of the sessile ciliates was correlated with the removals of BOD5 (Pearson's r = 0.410, p < 0.05) and CODCr (r = 0.397, p < 0.05) while the testate amoebae was significantly positively related to nitrification (r = 0.523, p < 0.01). At the same time, some other associations were also identified: the abundances of the large flagellates (r = 0.447, p < 0.01), the metazoa (r = 0.718, p < 0.01) and species Aspidisca sulcata (r = 0.337, p < 0.05) were positively related to nitrification; the abundance of Aspidisca costata was correlated to the TN (total nitrogen) removal (r = −0.374, p < 0.05); the abundances of the sessile species Carchesium polypinum (r = 0.458, p < 0.01) and E. plicatilis (r = 0.377, p < 0.05) were correlated with the removal of suspended solids.
Yu Zhang - One of the best experts on this subject based on the ideXlab platform.
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Detection, Occurrence, and Fate of Fluorotelomer Alcohols in Municipal Wastewater Treatment Plants
2017Co-Authors: Chen Hongrui, Peng Hui, Yang Min, Hu Jianying, Yu ZhangAbstract:Fluorotelomer alcohols (FTOHs) are the most well-known precursors of perfluoroalkyl carboxylic acids (PFCAs), but limited information is available on their occurrence and fate in Municipal Wastewater Treatment plants (WWTPs). The occurrence of FTOHs was investigated in influent, secondary effluent, and sludge of 12 Municipal WWTPs in nine cities of China. FTOHs were detected in all WWTPs, and 8:2 FTOH was the predominant congener, with concentrations of 2.10-11.0 ng/L, 3.05-12.4 ng/L, and 0.36-1.91 ng/g dry weight in the influent, secondary effluent, and sludge, respectively. Relatively high proportions of long-chain FTOHs (C10-16) were mainly detected in sludge samples. The mass balance of FTOHs and PFCAs in one of the WWTPs with an anaerobic-anoxic-oxic process was further explored. The decrease of mass loads was observed for 4:2 FTOH (mass change percentage: 21 +/- 3.3%), 8:2 FTOH (22 +/- 1.5%), and 10:2 FTOH (29 +/- 7.3%) through aerobic Treatment, while the increase of mass loads was observed for 12 PFCAs from 18 +/- 16% (perfluorononanoic acid) to 165 +/- 15% (perfluorobutyric acid)), suggesting the potential biotransformation of FTOHs to PFCAs in the aerobic unit. This work provides the first report on the occurrence of FTOHs in sludge samples of Municipal WWTPs and their mass balance and highlights a new emission route to environment via WWTPs
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distribution of antibiotic resistance in the effluents of ten Municipal Wastewater Treatment plants in china and the effect of Treatment processes
Chemosphere, 2017Co-Authors: Weiwei Ben, Yu Zhang, Min Yang, Jing Wang, Rukun Cao, Zhimin QiangAbstract:Municipal Wastewater Treatment plant (WWTP) effluents represent an important contamination source of antibiotic resistance, threatening the ecological safety of receiving environments. In this study, the release of antibiotic resistance to sulfonamides and tetracyclines in the effluents of ten WWTPs in China was investigated. Results indicate that the concentrations of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) ranged from 1.1 × 101 to 8.9 × 103 CFU mL-1 and 3.6 × 101 (tetW) to 5.4 × 106 (tetX) copies mL-1, respectively. There were insignificant correlations of the concentrations of ARB and ARGs with those of corresponding antibiotics. Strong correlations were observed between the total concentrations of tetracycline resistance genes and sulfonamide resistance genes, and both of which were significantly correlated with intI1 concentrations. Statistical analysis of the effluent ARG concentrations in different WWTPs revealed an important role of disinfection in eliminating antibiotic resistance. The release rates of ARB and ARGs through the effluents of ten WWTPs ranged from 5.9 × 1012 to 4.8 × 1015 CFU d-1 and 6.4 × 1012 (tetW) to 1.7 × 1018 (sul1) copies d-1, respectively. This study helps the effective assessment and scientific management of ecological risks induced by antibiotic resistance discharged from WWTPs.
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dynamics of the microfauna community in a full scale Municipal Wastewater Treatment plant experiencing sludge bulking
European Journal of Protistology, 2013Co-Authors: Bo Hu, Yu Zhang, Rong Qi, Wei An, Muqi Xu, Jian Gu, Min YangAbstract:We investigated the dynamics of the microfauna community in activated sludge, with special reference to sludge bulking, in two parallel Municipal Wastewater Treatment systems in Beijing, China over a period of 14 months. Annual cyclic changes in microfauna community structures occurred in both systems. RELATE analysis based on Spearman's Rank correlation indicated that microfauna community structures were highly correlated with the sludge volume index (SW) (p<0.001), which indicates sludge settleability. Nutrient conditions of raw sewage (p<0.01) and hydraulic retention time (HRT) (p<0.05) were also related to microfauna community structures. Abundances of the species Epistylis plicatilis and Vorticella striata increased significantly with an increase in SW (p<0.001) and decrease in water temperature (p<0.001), suggesting that sludge bulking may have created favorable conditions for the two species, even under unfavorable temperature conditions. Sludge de-flocculation primarily due to the excessive growth of Microthrix parvicella-like filaments could be an important driving force for the microfauna community changes. The release of flocculated non-filamentous bacteria may represent a suitable food source for these species. The two species may be considered as potential bioindicators for sludge bulking. (C) 2013 Elsevier GmbH. All rights reserved.
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dynamics of the microfauna community in a full scale Municipal Wastewater Treatment plant experiencing sludge bulking
European Journal of Protistology, 2013Co-Authors: Yu Zhang, Xue Bai, Haipeng Bao, Yang Wen, Min YangAbstract:We investigated the dynamics of the microfauna community in activated sludge, with special reference to sludge bulking, in two parallel Municipal Wastewater Treatment systems in Beijing, China over a period of 14 months. Annual cyclic changes in microfauna community structures occurred in both systems. RELATE analysis based on Spearman's Rank correlation indicated that microfauna community structures were highly correlated with the sludge volume index (SVI) (p<0.001), which indicates sludge settleability. Nutrient conditions of raw sewage (p<0.01) and hydraulic retention time (HRT) (p<0.05) were also related to microfauna community structures. Abundances of the species Epistylis plicatilis and Vorticella striata increased significantly with an increase in SVI (p<0.001) and decrease in water temperature (p<0.001), suggesting that sludge bulking may have created favorable conditions for the two species, even under unfavorable temperature conditions. Sludge de-flocculation primarily due to the excessive growth of Microthrix parvicella-like filaments could be an important driving force for the microfauna community changes. The release of flocculated non-filamentous bacteria may represent a suitable food source for these species. The two species may be considered as potential bioindicators for sludge bulking.
Hong Chen - One of the best experts on this subject based on the ideXlab platform.
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effects and mechanisms of ultraviolet chlorination and ozone disinfection on antibiotic resistance genes in secondary effluents of Municipal Wastewater Treatment plants
Chemical Engineering Journal, 2017Co-Authors: Ji Zheng, Like Xu, Chao Su, Jianwen Zhou, Yanyun Qian, Hong ChenAbstract:Abstract 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.
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antibiotic resistant genes and antibiotic resistant bacteria in the effluent of urban residential areas hospitals and a Municipal Wastewater Treatment plant system
Environmental Science and Pollution Research, 2015Co-Authors: Jianan Li, Weixiao Cheng, Like Xu, P J Strong, Hong ChenAbstract:In this study, we determined the abundance of 8 antibiotics (3 tetracyclines, 4 sulfonamides, and 1 trimethoprim), 12 antibiotic-resistant genes (10 tet, 2 sul), 4 antibiotic-resistant bacteria (tetracycline, sulfamethoxazole, and combined resistance), and class 1 integron integrase gene (intI1) in the effluent of residential areas, hospitals, and Municipal Wastewater Treatment plant (WWTP) systems. The concentrations of total/individual targets (antibiotics, genes, and bacteria) varied remarkably among different samples, but the hospital samples generally had a lower abundance than the residential area samples. The WWTP demonstrated removal efficiencies of 50.8 % tetracyclines, 66.8 % sulfonamides, 0.5 logs to 2.5 logs tet genes, and less than 1 log of sul and intI1 genes, as well as 0.5 log to 1 log removal for target bacteria. Except for the total tetracycline concentration and the proportion of tetracycline-resistant bacteria (R2 = 0.330, P 0.05). In contrast, various relationships were identified between antibiotics and antibiotic resistance genes (P < 0.05). Tet (A) and tet (B) displayed noticeable relationships with both tetracycline and combined antibiotic-resistant bacteria (P < 0.01).
Fang Tang - One of the best experts on this subject based on the ideXlab platform.
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Monitoring and evaluation of antibiotic-resistant bacteria at a Municipal Wastewater Treatment plant in China
Environment International, 2012Co-Authors: Jing-jing Huang, Sun-qin Lu, Yun Lu, Hong-ying Hu, Fang Tang, Yi Li, Bin WeiAbstract:The prevalence of antibiotic-resistant bacteria in Municipal Wastewater Treatment plants (WWTPs) is becoming a concern of public health. In order to acquire information on the emission of antibiotic-resistant bacteria from WWTP effluents into natural waters, both average antibiotic tolerance and concentrations of antibiotic-resistant bacteria in the effluent of a WWTP in Beijing, China were investigated. A new index of IC(50)/MIC ratio (the antibiotic concentration required to inhibit 50% of total heterotrophic bacteria compared to the highest minimum inhibitory concentration value of a group of pathogens according to a specific antibiotic, as defined by CLSI) was used to reflect the average antibiotic tolerance of total heterotrophic bacteria in the secondary effluent. The results showed that the IC(50)/MIC ratios of heterotrophic bacteria in the secondary effluent to penicillin, ampicillin, cephalothin, chloramphenicol and rifampicin were >2, >1, >1, and 1.08, respectively, which reflected a significantly high general level of heterotrophic bacteria found in the secondary effluent resistant to these five antibiotics. The concentrations of penicillin-, ampicillin-, cephalothin-, and chloramphenicol-resistant bacteria were as high as 1.5×10(4)-1.9×10(5), 1.2×10(4)-1.5×10(5), 8.9×10(3)-1.9×10(5) and 2.6×10(4)-2.0×10(5) CFU/mL, and the average percentages in relation to total heterotrophic bacteria were 63%, 47%, 55%, and 69%, respectively. The concentrations of tetracycline- and rifampicin-resistant bacteria were 840-6.1×10(3) and 310-6.1×10(4) CFU/mL with average percentages of 2.6% and 11%, respectively. Furthermore, our study found that five- and six-antibiotic-resistant bacteria were widely distributed in four types of enterobacteria from the secondary effluent. The presence of multiple-antibiotic-resistant bacteria from effluents of WWTPs into natural waters could pose a serious problem as a secondary pollutant of drinking water.
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Inactivation and reactivation of antibiotic-resistant bacteria by chlorination in secondary effluents of a Municipal Wastewater Treatment plant.
Water research, 2011Co-Authors: Jing-jing Huang, Fang TangAbstract:Reports state that chlorination of drinking water and Wastewater affects the proportions of antibiotic-resistant bacteria by potentially assisting in microbial selection. Studies on the effect of chlorination on like species of antibiotic-resistant bacteria, however, have shown to be conflicting; furthermore, few studies have inspected the regrowth or reactivation of antibiotic-resistant bacteria after chlorination in Wastewater. To understand the risks of chlorination resulting from potentially selecting for antibiotic-resistant bacteria, inactivation and reactivation rates of both total heterotrophic bacteria and antibiotic-resistant bacteria (including penicillin-, ampicillin-, tetracycline-, chloramphenicol-, and rifampicin-resistant bacteria) were examined after chlorinating secondary effluent samples from a Municipal Wastewater Treatment plant in this study. Our experimental results indicated similar inactivation rates of both total heterotrophic bacteria and antibiotic-resistant bacteria. Microbial community composition, however, was affected by chlorination: treating samples with 10 mg Cl(2)/L for 10 min resulted in chloramphenicol-resistant bacteria accounting for nearly 100% of the microbial population in contrast to 78% before chlorination. This trend shows that chlorination contributes to selection of some antibiotic-resistant strains. Reactivation of antibiotic-resistant bacteria occurred at 2.0 mg Cl(2)/L for 10 min; specifically, chloramphenicol-, ampicillin-, and penicillin-resistant bacteria were the three prevalent groups present, and the reactivation of chloramphenicol-resistant bacteria exceeded 50%. Regrowth and reactivation of antibiotic-resistant bacteria in secondary effluents after chlorination with a long retention time could threaten public health security during Wastewater reuse.
Jing-jing Huang - One of the best experts on this subject based on the ideXlab platform.
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Monitoring and evaluation of antibiotic-resistant bacteria at a Municipal Wastewater Treatment plant in China
Environment International, 2012Co-Authors: Jing-jing Huang, Sun-qin Lu, Yun Lu, Hong-ying Hu, Fang Tang, Yi Li, Bin WeiAbstract:The prevalence of antibiotic-resistant bacteria in Municipal Wastewater Treatment plants (WWTPs) is becoming a concern of public health. In order to acquire information on the emission of antibiotic-resistant bacteria from WWTP effluents into natural waters, both average antibiotic tolerance and concentrations of antibiotic-resistant bacteria in the effluent of a WWTP in Beijing, China were investigated. A new index of IC(50)/MIC ratio (the antibiotic concentration required to inhibit 50% of total heterotrophic bacteria compared to the highest minimum inhibitory concentration value of a group of pathogens according to a specific antibiotic, as defined by CLSI) was used to reflect the average antibiotic tolerance of total heterotrophic bacteria in the secondary effluent. The results showed that the IC(50)/MIC ratios of heterotrophic bacteria in the secondary effluent to penicillin, ampicillin, cephalothin, chloramphenicol and rifampicin were >2, >1, >1, and 1.08, respectively, which reflected a significantly high general level of heterotrophic bacteria found in the secondary effluent resistant to these five antibiotics. The concentrations of penicillin-, ampicillin-, cephalothin-, and chloramphenicol-resistant bacteria were as high as 1.5×10(4)-1.9×10(5), 1.2×10(4)-1.5×10(5), 8.9×10(3)-1.9×10(5) and 2.6×10(4)-2.0×10(5) CFU/mL, and the average percentages in relation to total heterotrophic bacteria were 63%, 47%, 55%, and 69%, respectively. The concentrations of tetracycline- and rifampicin-resistant bacteria were 840-6.1×10(3) and 310-6.1×10(4) CFU/mL with average percentages of 2.6% and 11%, respectively. Furthermore, our study found that five- and six-antibiotic-resistant bacteria were widely distributed in four types of enterobacteria from the secondary effluent. The presence of multiple-antibiotic-resistant bacteria from effluents of WWTPs into natural waters could pose a serious problem as a secondary pollutant of drinking water.
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Inactivation and reactivation of antibiotic-resistant bacteria by chlorination in secondary effluents of a Municipal Wastewater Treatment plant.
Water research, 2011Co-Authors: Jing-jing Huang, Fang TangAbstract:Reports state that chlorination of drinking water and Wastewater affects the proportions of antibiotic-resistant bacteria by potentially assisting in microbial selection. Studies on the effect of chlorination on like species of antibiotic-resistant bacteria, however, have shown to be conflicting; furthermore, few studies have inspected the regrowth or reactivation of antibiotic-resistant bacteria after chlorination in Wastewater. To understand the risks of chlorination resulting from potentially selecting for antibiotic-resistant bacteria, inactivation and reactivation rates of both total heterotrophic bacteria and antibiotic-resistant bacteria (including penicillin-, ampicillin-, tetracycline-, chloramphenicol-, and rifampicin-resistant bacteria) were examined after chlorinating secondary effluent samples from a Municipal Wastewater Treatment plant in this study. Our experimental results indicated similar inactivation rates of both total heterotrophic bacteria and antibiotic-resistant bacteria. Microbial community composition, however, was affected by chlorination: treating samples with 10 mg Cl(2)/L for 10 min resulted in chloramphenicol-resistant bacteria accounting for nearly 100% of the microbial population in contrast to 78% before chlorination. This trend shows that chlorination contributes to selection of some antibiotic-resistant strains. Reactivation of antibiotic-resistant bacteria occurred at 2.0 mg Cl(2)/L for 10 min; specifically, chloramphenicol-, ampicillin-, and penicillin-resistant bacteria were the three prevalent groups present, and the reactivation of chloramphenicol-resistant bacteria exceeded 50%. Regrowth and reactivation of antibiotic-resistant bacteria in secondary effluents after chlorination with a long retention time could threaten public health security during Wastewater reuse.
