HRT对硫自养反硝化脱氮性能及微生物群落结构的影响

Effects of HRT on Denitrification Performance and Microbial Community Structure in Sulfur Autotrophic Denitrification

为探究水力停留时间(HRT)对单质硫源驱动下硫自养反硝化系统的影响,构建了硫自养反硝化UASB反应器,研究不同HRT下单质硫自养反硝化系统脱氮性能,并从微生物群落结构的角度分析系统种间协同竞争作用。结果表明:①不同HRT,单质硫自养反硝化系统脱氮性能存在差异,HRT下降到16 h后NO_(3)^(-)-N去除率从75%降低到20%;②HRT=48 h,出水SO_(4)^(2-)浓度低于理论值,发生硫酸盐还原反应;③Thiobacillus为反应器中的优势菌属,相对丰度达到26.3%,随HRT降低,反应器中脱氮微生物丰度降低,部分菌属丰度降低到0%;④硫酸盐还原菌在HRT=48 h大量富集,反应器内部存在硫循环过程。本实验为硫自养反硝化脱氮提供技术支持,对硝酸盐污染控制具有重要的指导价值。

To investigate the effect of hydraulic retention time(HRT)on the sulfur autotrophic denitrification system driven by an elemental sulfur source,a sulfur autotrophic denitrification UASB reactor was construct.Study of nitrogen removal performance of an elemental sulfur autotrophic denitrification system under different HRT and analyzed the synergistic competition among system species from the perspective of microbial community structure.The results showed that:①There were differences in the denitrification performance of the monolithic sulfur autotrophic denitrification system with different HRT,and the NO3--N removal rate decreased from 75%to 20%after the HRT decreased to 16 h.②When HRT=48 h,the SO42-concentration of effluent is lower than the theoretical value,and sulfate reduction reaction occurs.③Thiobacillus was the dominant bacterium in the reactor,with a relative abundance of 26.3%.With the decrease of HRT,the abundance of denitrification microorganisms in the reactor decreased,and the abundance of some bacteria decreased to 0%.④Sulfate-reducing bacteria were enriched in large quantities at HRT=48 h,and there was a sulfur cycle in the reactor.This paper provides technical support for sulfur autotrophic denitrification and nitrogen removal,which has important guiding value for nitrate pollution control.