The polyvinyl formal (PVFM) biocarrier addition in a membrane bioreactor (MBR) was evaluated at high and low carbon/nitrogen (C/N) ratio of 20.0 and 6.7. Results indicated that static biocarrier addition could enrich nitrification and denitrification bacteria, dominating by Tauera, Amaricoccus and Nitrosospira at the genus level and slightly improved the total nitrogen removal even at a low C/N ratio. The bulk sludge characteristics (such as bigger particle size, lower SMP, lower SMP P/C) were also significantly changed in the hybrid MBR (HMBR), leading to a more sustainable membrane operation. The biocarrier addition also reduced the relative abundance of Sphingobacterials_unclassified, Ohtaekwangia and Rhodocyclaceae_unclassified at the genus level, indicating less membrane fouling in the HMBR. Consequently, HMBR with static PVFM addition could partially overcome the drawback of low C/N ratio for total nitrogen removal and membrane fouling control, providing a more resilient MBR to the undesirable environment such as low C/N ratio.

中文翻译：

---

静态生物载体对不同COD：N比的浸没式膜生物反应器中微生物群落，脱氮和膜污染的影响。

在高和低碳/氮（C / N）比率分别为20.0和6.7的情况下，评估了在膜生物反应器（MBR）中添加的聚乙烯醇缩甲醛（PVFM）生物载体。结果表明，添加静态生物载体可以丰富硝化和反硝化细菌，以金牛座，链球菌和亚硝基螺菌属占主导地位，即使在低C / N比下，总氮去除率也略有提高。混合MBR（HMBR）的整体污泥特性（例如较大的粒径，较低的SMP，较低的SMP P / C）也发生了显着变化，从而使膜的运行更具可持续性。生物载体的添加还降低了属下未归类的Sphingobacterials，未发生的大黄旺和杜鹃科的相对丰度，表明HMBR中的膜污染较少。所以，