一体化A^(2)/O-MBR系统中抗性基因分布及去除效果研究

Study on the distribution and removal effect of resistance genes in integrated system of A^(2)/O-MBR

选取北京市某农村一体化A^(2)/O-MBR污水处理系统,系统研究了系统中抗生素抗性基因(Antibiotic Resistance Genes,ARGs)及病原菌在全流程各个处理单元中的分布特征,基于宏基因组学的高通量测序技术对农村生活污水进水、MBR池中污泥和出水样品中ARGs及病原菌的丰度变化及去除效果进行了系统分析.结果表明:ARGs广泛存在于污水处理系统中,共检测出包括tetracycline类、aminoglycoside类和sulfonamide类在内的19类ARGs,进水中ARGs的相对丰度远远高于其在出水中的浓度,通过污水处理系统后ARGs相对丰度下降了72.25%,而大多数的ARGs在污水处理系统并不能得到完全去除.微生物群落结构变化显示,32种潜在病原体相对丰度下降明显,但大多数病原菌也无法得到完全去除.出水中残留的ARGs和病原菌仍会对受纳水体造成一定的潜在污染风险.

The increase of antibiotic resistance genes among microorganisms has become the main transmission source for sewage treatment plants.The purpose of this study was to explore the removal effect of Antibiotic Resistance Genes(ARGs)and pathogenic bacteria in rural domestic sewage treatment process and evaluate the water quality safety.This study selected a integration A^(2)/O-MBR wastewater treatment system in the village of Beijing,systematic study was implemented in integrated system of A^(2)/O-MBR wastewater treatment system to get the distribution law of ARGs and pathogenic bacteria in the each processing unit.Based on macro genomics,the high-throughput sequencing technology was used to analysis the the ability of removing ARGs and pathogenic bacteria in genus through integrated system of A^(2)/O-MBR.Results showed that the ARGs widely existed in sewage treatment system,19kinds of ARGs including tetracycline class,aminoglycoside class and sulfonamide class were detected,the relative abundance of the ARGs in influent was much higher than its concentration in the effluent,relative abundance of the ARGs fell by 72.25%,but most of the ARGs in sewage treatment system was not fully removed.The changes of microbial community structure showed that the relative abundance of 32potential pathogens decreased significantly,and most pathogenic bacteria could not be completely removed.The residual ARGs and pathogenic bacteria in the water will lead to the potential pollution risk of receiving water body.