能源环境保护2025，Vol.39Issue(6)：107-115,9.DOI:10.20078/j.eep.20250602
不同停留时间下污水处理单元中抗性基因分布
Distribution of Antibiotic Resistance Genes in Wastewater Treatment Units Under Different Hydraulic Retention Times
摘要
Abstract
Antibiotic resistance genes(ARGs)pose a serious threat to public health.Wastewater treatment plants(WWTPs)are hotspots for ARGs,and their operational conditions significantly influence the removal of ARGs from wastewater.However,research on the effects of hydraulic retention time(HRT)in different wastewater treatment units on ARGs remains limited.In this study,two pilot-scale AAO(Anaerobic-Anoxic-Oxic)systems with advanced treatment and disinfection processes were designed with different HRTs to investigate the concentrations and distributions of ARGs at various treatment stages.The correlations among ARGs,water quality parameters,and microbial communities were also analyzed.The results showed that in the long-HRT group,the ARG concentrations in the secondary sedimentation tank effluent were lower than those in the short-HRT group.Regarding the concentrations of ARGs in the activated sludge,the retention of ARGs by sludge was found to be similar in both groups.This suggests that the sludge in the long-HRT group had a longer contact time with the ARGs,potentially promoting their biological degradation.The concentrations of ARGs in the sand filtration effluent of both groups showed no significant decrease compared to those in the secondary sedimentation tank effluent.After disinfection,the concentrations of blaTEM,sul1,tetX,ermB,intIl,and 16S rDNA in the long-HRT group decreased to 4.26×103,2.31×105,7.15×103,7.29×103,4.64×104,and 3.61 ×105 copies/mL,respectively,all of which were lower than those in the short-HRT group.Overall,the removal rates of blaTEM,sul1,tetX,ermB,intIl,and 16S rDNA in the long-HRT group reached 2.55,2.60,3.23,2.99,2.77,and 2.97 log,respectively,indicating that the long-HRT group exhibited higher removal efficiencies of ARGs than the short-HRT group.However,it is worth noting that the ARGs/16S rDNA ratio after disinfection in the long-HRT group was significantly higher than that in the filtration effluent.This indicates that although prolonged disinfection reduces ARG concentration in the effluent,it also significantly increases the ARGs/16S rDNA ratio.This phenomenon may be attributed to horizontal gene transfer of ARGs,as excessive disinfectant dosage damages bacterial cells,increasing the frequency of ARG transfer to non-resistant bacteria.Such changes may impact the microbial community in the receiving water body.In addition,both the biological and disinfection stages reduced the abundance of pathogenic genera such as Aeromonas,Desulfovibrio,and Pseudomonas.However,in both the long-and short-HRT groups,the relative abundance of these genera was higher in the disinfection effluent than in the filtration effluent.Redundancy analysis revealed that genera such as Nitrospira,Dechloromonas,and Ferruginibacter were highly correlated with ARGs,and both 16S rDNA and suspended solids(SS)were highly correlated with ARGs.This study provides theoretical support for better controlling the risks associated with the release of ARGs from WWTPs.关键词
抗生素抗性基因/污水处理厂/水力停留时间/生物处理/消毒Key words
Antibiotic resistance genes/Wastewater treatment plant/Hydraulic retention time/Biological treatment/Disinfection分类
资源环境引用本文复制引用
马艳,韩小蒙,宋姗姗,冯修平..不同停留时间下污水处理单元中抗性基因分布[J].能源环境保护,2025,39(6):107-115,9.基金项目
上海市自然科学基金面上资助项目(23ZR1421200) （23ZR1421200）
上海城投水务(集团)有限公司科研资助项目(KY.WB.23.001) （集团）
