正渗透膜生物反应器运行过程中溶质反渗对微生物群落的影响

以氯化钠为驱动溶质，采用正渗透膜生物反应器(forward osmosis membrane bioreactor, FOMBR)处理生活污水，考察其在运行过程中溶质反渗对系统内微生物群落造成的影响。稳定运行状态下的第7、14、20天的混合液污泥样品分别称为A1、A2、A3，并对微生物群落物种丰度、群落结构、聚类等进行了分析。结果表明：正渗透膜生物反应器运行20 d内水通量从9.5 L/(m²·h)下降到8.17 L/(m²·h)，反向盐通量从29.52 g/(m²·h)增加到35.06 g/(m²·h)。整个运行过程中溶质反渗对微生物群落结构的变化有着一定的影响，3个样品共产生1496个OTUs，各样品间共享的OTUs不尽相同；溶质反渗对3种样品的微生物群落多样性、菌群丰度等影响较小。PCA分析中A2和A3两个样品距离更近，组成更相似，热图聚类分析再次验证A2与A3相似性更高；3个样品斜率较小且非常接近，并且A1和A3两个样品所含物种的丰富程度和均匀程度几乎一样；3个样品的活性污泥群落结构在门、纲、目分类水平上均具有较高的多样性，各分类水平上的菌群丰度存在一定的差异。

Influence of reverse solute osmosis on microbial community during the operation of forward osmosis membrane bioreactor

Using sodium chloride as the driving solute, the forward osmosis membrane bioreactor (FOMBR) was used to treat domestic sewage, and the effect of reverse solute osmosis on the microbial community in the system was investigated. The abundance, community structure and clustering of microbial community were also analyzed. The results revealed that during the 20 d operation of FOMBR, the water flux decreased from 9.5 L/(m²·h) to 8.17 L/(m²·h), and the reverse salt flux increased from 29.52 g/(m²·h) to 35.06 g/(m²·h). Three samples (A1, A2 and A3) of mixed liquid sludge were collected on day 7, day 14 and day 20, respectively. The reverse solute osmosis had certain influence on the change of microbial community structure during the whole operation period. A total of 1496 OTUs were produced from the three samples of A1, A2 and A3. Shared OTUs were different for these three samples. The results also revealed that the reverse solute osmosis had less influence on the microbial community diversity and the abundance of bacteria in these samples. Samples A2 and A3 were closer together in the principal component analysis, which indicated that these two samples were more similar in composition. Heatmap clustering analysis also confirmed that A2 and A3 were more similar. The slopes of these three samples were small and very close, and the abundance of bacteria and uniformity of A1 and A3 samples were nearly the same. The structure of activated sludge communities in these three samples revealed high diversity at the level of phylum, class and order, and the abundance of bacteria in each classification level was different to some extent.