Abstract: The main objective of this study was to investigate the effect of diatomite filter aid on fouling and performance of membrane bioreactor (MBR) after high salt shock. The results show that diatomite additive is an effective approach for the performance improvement of both membrane fouling and pollutants removal when MBR was suffering high salt shock. Compared with the control reactor, the performance of MBR is enhanced by addition of 60 mg·L^-1 diatomite addition, the removal of COD, NH₄⁺-N and TP increases by 4.9%, 3.2% and 74.5%, respectively. It was observed that after high salt shock the membrane fouling rate is significantly higher, about four-fold, for the contrast than for the MBR with diatomite addition. The flocculating and adsorption capacities of diatomite make soluble products of microbial metabolism (SMP) significant decrease. So, the rate of membrane fouling was significantly mitigated. Furthermore, the addition of diatomite makes mean flocs sizes (d_p) and its related hydrophobic (RH) increase, which would be beneficial to the mitigation of membrane fouling.

Key words: membrane bioreactor, high salt shock, soluble microbial product, extracellular polymeric substances, membrane fouling

摘要： 以膜生物反应器（membrane bioreactor，MBR）受高盐度废水冲击前后的活性污泥为研究对象，考察了助滤剂（硅藻土）投加对于MBR污染物去除及膜污染减缓的影响。实验结果表明投加硅藻土对高盐废水冲击后的MBR性能恢复效果显著。与对照反应器相比，投加60 mg·L^-1硅藻土可提高系统对传统污染物的去除效率，COD、NH₄⁺-N及TP去除效率分别提高了4.9%、3.2%及74.5%；高盐度废水冲击显著增加了对照反应器的膜污染速率，其膜污染速率是投加硅藻土MBR的4倍。硅藻土具有的吸附性能及絮凝能力显著降低了MBR本体溶液中的溶解性微生物代谢产物含量，减小了膜污染速率。进一步研究发现，投加硅藻土增加了平均絮体粒径（mean particles sizes， d_p）及相对疏水性（related hydrophobic， RH），有利于减缓膜污染。

关键词: 膜生物反应器, 高盐度冲击, 溶解性微生物产物, 胞外聚合物, 膜污染