Department of Environmental Engineering, National Chung Hsing University, 250 Kuo Kuang Rd., Taichung 402, Taiwan, ROC.
Bioresour Technol. 2011 May;102(9):5375-80. doi: 10.1016/j.biortech.2010.11.093. Epub 2010 Nov 26.
Soluble extracellular polymeric substances (EPSs) cause membrane fouling in membrane bioreactors (MBRs), correlated with MBR sludge characteristics. Effects of F/M ratios on the evolution of soluble EPSs, fouling propensity of supernatants, and sludge metabolic activity were measured in this study in a two-period sequencing batch reactor (SBR). The experimental results show that fouling propensity was directly correlated with soluble-EPS concentration and composition. Sludge that had entirely lost active cells by long-term starvation released 64.4 ± 0.9 mg/L of humic acids, which caused a rapid increase in membrane resistance (40.67 ± 2.24 × 10(11) m(-1)) during fouling tests. During short-term starvation, induced by incubation at a normal to low F/M ratio of 0.05 d(-1), sludge can use previously secreted utilization-associated products (UAPs) to maintain endogenous respiration. Therefore, the strategies of accumulating sludge and prolonging sludge retention time in MBRs may create long-term starvation and promote membrane fouling.
可溶细胞外聚合物(EPS)导致膜生物反应器(MBR)中的膜污染,这与 MBR 污泥特性有关。本研究在两段式序批式反应器(SBR)中,测定了 F/M 比对可溶 EPS 演变、上清液污染倾向和污泥代谢活性的影响。实验结果表明,污染倾向与可溶-EPS 浓度和组成直接相关。长期饥饿使活性细胞完全丧失的污泥会释放出 64.4 ± 0.9 mg/L 的腐殖酸,这会导致在污染测试过程中膜阻力(40.67 ± 2.24×10(11) m(-1))迅速增加。在正常至低 F/M 比(0.05 d(-1))下进行短期饥饿诱导时,污泥可以利用先前分泌的利用相关产物(UAPs)来维持内呼吸。因此,在 MBR 中积累污泥和延长污泥停留时间的策略可能会导致长期饥饿并促进膜污染。