陆源排水对近海纳污区微生物群落组成及碳代谢功能的影响

IMPACTS OF LAND-BASED WASTEWATER DISCHARGE ON MICROBIAL COMMUNITY COMPOSITION AND CARBON METABOLISM IN COASTAL EFFLUENT-RECEIVING AREAS

随着现代城市和工商业的快速发展,污水处理厂成为保护水环境的重要设施,然而污水处理厂的尾水排放仍然对受纳水体产生不利影响。沿海地区的污水处理厂长期将尾水排入近海,引起海水水质变差,但是近海环境微生物对污染的响应尚不清晰。选择我国污染形势严峻的杭州湾北岸、南岸各1片纳污区(简称JX和SY)为研究对象,进行环境质量调查,并对沉积物微生物群落进行宏基因组测序,分析不同类型的废水排放对纳污区微生物群落结构和功能的潜在影响。研究结果表明,陆源废水排放对纳污区沉积物的微生物群落产生影响。JX和SY群落的物种组成和多样性存在差异,造成这种差异的关键环境因子为水中COD以及水深;JX和SY群落的碳代谢功能也存在差异,JX群落中与甲烷代谢相关的功能基因丰度更高,而SY群落中与糖异生途径相关的功能基因丰度更高,主要影响因子为水中COD和沉积物中TOC及石油类。上述结果对纳污海域的环境管理具有重要意义,并为完善污水处理厂排放标准提供了科学依据。

With the rapid development of modern cities and industrialization,wastewater treatment plants(WWTPs)have become essential facilities for protecting water environments.However,the tailwater discharged from a WWTP still has adverse effects on the effluent-receiving area(ERA).Long-term discharge of WWTP effluents into coastal areas has led to deteriorating seawater quality,but the response of coastal microbial communities is not yet well understood.This study chose two ERAs,named as JX and SY respectively,on the north and south coast of Hangzhou Bay,China,as the study areas.Environmental quality surveys were conducted,and microbial communities in sediment were analyzed using metagenomic sequencing to assess the potential impacts of wastewater discharge on microbial community structures and functions.The results indicated that land-based discharge had impacts on microbial communities in the sediment of the ERAs.JX and SY exhibited distinct community compositions,with key environmental factors being water chemical oxygen demand(COD)and water depth.Functional differences were also observed between the two ERAs,particularly in carbon metabolism.In JX,differential genes related to methane metabolism were found;while in SY,differential genes related to sugar fermentation pathways were identified.Water COD and sediment total organic carbon(TOC)and petroleum compounds were identified as the major influence factors.These findings are of great importance for the environmental management of ERA and provide scientific reference for improving the discharge standards of WWTP.