An anoxic/oxic membrane bioreactors (AO-MBR) and three identical anaerobic side-stream reactor coupled with anoxic/oxic membrane bioreactors (ASSR-MBR) were constructed and operated in parallel to investigate the appropriate filling fraction of carriers packed in ASSR, influences on pollutants removal, sludge reduction, membrane fouling and microbial community of ASSR-MBR. Inserting ASSR achieved efficient COD removal and nitrification, and packing carriers in ASSR obtained the highest sludge reduction efficiency of 50.5 % at filling fraction of 25 %. Compared to AO-MBR, inserting ASSR without carriers induced the release of viscous components in extracellular polymeric substances (EPS) and the formation of calcium carbonate-related bacteria on membrane surface, and thus deteriorated membrane fouling. Packing carriers with 25 % filling fraction promoted the hydrolysis of soluble microbial products and EPS, whilst reduced the viscoelasticity of sludge flocs. Higher filling fraction of 50 % increased the shear forces to the biofilm and biomarkers related to membrane fouling, and thus showed little improvement to alleviate membrane fouling. MiSeq sequencing revealed that although it enriched in the bulk sludge of conventional ASSR-MBR and the coupled reactor with filling fraction of 50 %, the floc-forming, hydrolytic and fermentative bacteria were more inclined to attach on the membrane surface and alleviate fouling process.

中文翻译：

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评估厌氧侧流反应器中填充的载体填充率对偶联膜生物反应器的膜污染和微生物群落的影响。

构造并运行厌氧/氧化膜生物反应器（AO-MBR）和三个相同的厌氧侧流反应器与厌氧/氧化膜生物反应器（ASSR-MBR）并进行并行操作，以研究包装在ASSR中的载体的适当填充率，影响去除ASSR-MBR的污染物，减少污泥，膜结垢和微生物群落。插入ASSR可实现有效的COD去除和硝化作用，而ASSR中的填料载体在25％的填充率下可获得最高的污泥减少效率（50.5％）。与AO-MBR相比，插入没有载体的ASSR会导致细胞外聚合物（EPS）中粘性成分的释放以及膜表面上碳酸钙相关细菌的形成，从而加剧膜污染。填充分数为25％的填料载体促进了可溶性微生物产物和EPS的水解，同时降低了污泥絮凝物的粘弹性。50％的较高填充率增加了对与膜结垢有关的生物膜和生物标记物的剪切力，因此显示出几乎没有改善以减轻膜结垢。MiSeq测序显示，尽管絮凝物形成，水解和发酵细菌更富集常规ASSR-MBR和耦合反应器的大量污泥，填充率达到50％，但它们更倾向于附着在膜表面并减轻结垢过程。50％的较高填充率增加了对与膜结垢有关的生物膜和生物标记物的剪切力，因此显示出几乎没有改善以减轻膜结垢。MiSeq测序显示，尽管絮凝物形成，水解和发酵细菌更富集常规ASSR-MBR和耦合反应器的大量污泥，填充率达到50％，但它们更倾向于附着在膜表面并减轻结垢过程。50％的较高填充率增加了对与膜结垢有关的生物膜和生物标记物的剪切力，因此显示出几乎没有改善以减轻膜结垢。MiSeq测序显示，尽管絮凝物形成，水解和发酵细菌更富集常规ASSR-MBR和耦合反应器的大量污泥，填充率达到50％，但它们更倾向于附着在膜表面并减轻结垢过程。