盐度对悬浮填料式SBR工艺处理性能及微生物群落的影响

Effects of salinity on treatment performance and microbial community of suspended carrier SBR

为探究不同盐度对悬浮填料式SBR工艺处理性能以及悬浮填料上附着微生物群落结构的影响,在进水盐度为0、5、10、15 g/L的4个梯度下,对SBR1(对照组,不添加填料)和SBR2(添加30%有效容积的悬浮填料式SBR工艺)2组工艺的COD和NH_(4)^(+)-N去除性能进行研究,并采用16S rRNA高通量测序技术分析了悬浮填料中微生物的群落特征。实验结果表明:当盐度从0增加至15 g/L时,SBR1系统COD和NH_(4)^(+)-N平均去除率分别从92.6%、92.5%降至64.7%、68.2%,SBR2则是从96.0%、94.2%降至67.8%、73.8%,2个系统COD、NH_(4)^(+)-N的平均去除率均受到盐度影响而下降,且相比于COD,系统对NH_(4)^(+)-N的降解效果更好,此外,SBR2系统对COD、NH_(4)^(+)-N的去除效果始终强于SBR1系统;悬浮填料上附着微生物中主要优势门为变形菌门和拟杆菌门,其相对丰度维持在77%以上;Epsilonbac-teraeota的丰富度随着盐度的升高呈明显的上升趋势;随着盐度的增加,悬浮填料上微生物的群落多样性逐渐减少,但在中间盐度(5 g/L)时微生物的丰富度会增加。研究从微生物群落特征的角度,探讨了盐度渐增对微生物群落结构和多样性的影响,可为高盐胁迫下悬浮填料式SBR系统中COD和NH_(4)^(+)-N的去除机制研究提供参考。

In order to explore the effect of salinity on the performance of suspended packing SBR process and the mi-crobial community structure attached to suspended packing,the removal performance of COD and NH_(4)^(+)-N in SBR1(control group without filler)and SBR2(suspended filler SBR process with 30%effective volume)processes was studied under four gradients influent salinity of 0,5,10,15 g/L.The characteristics of microbial community were analyzed by 16S rRNA high-throughput sequencing technology.Experiments results showed that,salinity reduced the removal performance of COD and NH_(4)^(+)-N in SBR system.When salinity increased from 0 to 15 g/L,the removal rates of COD and NH_(4)^(+)-N in SBR1 system decreased from 92.6%and 92.5%to 64.7%and 68.2%,respectively,and that of SBR2 decreased from 96.0%and 94.2%to 67.8%and 73.8%.The average removal rates of COD and NH_(4)^(+)-N in the two systems were inhibited by salinity,and compared with COD,NH_(4)^(+)-N had better degradation effect,and the removal effect of SBR2 system was always better than that of SBR1 system.Proteobacteria and Bacteroidetes were the dominant phyla,and their relative abundance was more than 77%.The abundance of Epsilonbacteraeota showed an obvious upward trend with the increase of salinity,and it was suitable for the growth and reproduction of salt-tolerant bacteria in high salinity environment.The community diversity of microorganisms on the suspended filler decreased with increasing salinity,but their richness increased in microorganisms at intermediate salinity(5 g/L).From the perspective of microbial community characteristics,this study discussed the effects of increasing salinity on microbial community structure and diversity,which could provide reference for the study of COD and NH_(4)^(+)-N removal mechanism in suspended carrier SBR system under high salt stress.