MBR中胞外聚合物对混合液过滤性能的影响

Effect of Extracellular Polymeric Substances on Filtration Characteristics of Mixtures in MBR

胞外聚合物(EPS)的含量和组成对混合液的特性和膜污染有着重要影响。采用SPSS统计分析法研究了紧密粘附胞外聚合物(TB)和松散附着胞外聚合物(LB)数量及其中蛋白质与多糖所占的比例对混合液特性及膜污染的影响。研究表明,随着EPS含量的增加,TB中蛋白质与多糖含量的比值减小,细菌存在状态由不稳定型(R型)向稳定型(S型)转变,SVI值增大;LB中蛋白质与多糖含量比值的增大,降低了混合液的Zeta电位,增加了混合液粘度和相对疏水性。上清液中悬浮固体颗粒的浓度、混合液的Zeta电位及相对疏水性是造成膜污染的主要因子,与膜污染阻力的皮尔逊系数分别为0.853、-0.818、0.832。

The content and composition of extracellular polymeric substances （EPS） have an im- portant influence on mixture characteristics and membrane fouling. The roles of TB-EPS and LB-EPS quantity and ratios of protein to polysaccharide, along with the effect of mixture characters on membrane fouling, were studied by SPSS statistical analysis. The results showed that the ratio of protein to polysac- charide in TB-EPS reduced with increasing EPS content. Consequently, bacteria transformed from unsta- ble state （R） to stable state （S）, and the sludge volume index （SVI） value increased. As the ratio of protein to polysaccharide in LB-EPS increased with increasing EPS content, the Zeta potential decreased, the mixture viscosity and relative hydrophobicity （RH） increased. The suspended solid concentration in the supematant, Zeta potential and RH of the mixture affected membrane fouling the most. The corre- sponding Pearson＇ s correlation coefficients were 0. 853, -0. 818 and 0. 832.