Lab of Environmental Biotechnology, School of Environmental and Civil Engineering, Jiangnan University, Lihu Road 1800, Wuxi City, Jiangsu 214122, China.
Environ Technol. 2010 Oct;31(11):1289-94. doi: 10.1080/09593331003713669.
In this study, the correlations between sludge characteristics, amount of extracellular polymeric substances (EPS) and membrane fouling were investigated and analysed, using continuous sludge discharges from a membrane bioreactor (MBR). The results showed that continuous sludge discharges improved sludge settleability, but not always weakened membrane fouling. The changes in the EPS amount, caused by continuous sludge discharge from MBRs, could resolve this situation well. Soluble EPS concentration could be regulated, to some extent, by sludge discharges. But it was embarrassed to artificially adjust bound EPS amount because the MBRs included living microorganisms and their metabolites. After sludge had been discharged four times, the sludge volume index (SVI) was in the range of 50-60 mL x gSS(-1) with a VSS:SS ratio of about 0.8. Sludge settleability mainly depended on the bound EPS content. The bound EPS content and its components presented a closer relationship to sludge hydrophobicity than to the membrane flux. Soluble EPS dominated both the EPS content on the membrane surface and membrane fouling.
在这项研究中，通过连续从膜生物反应器（MBR）中排出剩余污泥，考察并分析了污泥特性、胞外聚合物（EPS）量与膜污染之间的相关性。结果表明，连续排泥虽然提高了污泥沉降性能，但并不总是减轻膜污染。由 MBR 连续排泥引起的 EPS 量的变化可以很好地解决这个问题。可溶 EPS 浓度在一定程度上可以通过排泥来调节。但由于 MBR 中含有活的微生物及其代谢物，人工调节束缚 EPS 量比较困难。经过四次排泥后，污泥体积指数（SVI）在 50-60mLxgSS(-1)范围内，VSS:SS 比约为 0.8。污泥沉降性能主要取决于束缚 EPS 含量。束缚 EPS 含量及其各组分与污泥疏水性的关系比与膜通量的关系更为密切。可溶 EPS 既主导着膜表面的 EPS 含量，也主导着膜污染。
