贫营养条件下膜生物反应器污泥混合液可滤性分析

采用膜生物反应器(MBR)运行16d,未向反应器内活性污泥投加营养物质,对溶解性微生物代谢产物(SMP)、污泥颗粒粒径分布(PSD)、胞外聚合物(EPS)、SMP相对分子量分布(MWDs)进行了定期监测.修正的污染指数(MFI)用来考察与SMP和EPS相关的污泥混合液可滤性.结果表明,MFI值由1.8′104迅速增加到7.3′104s/L2,说明长时间的内源代谢过程对MBR内污泥混合液可滤性有负面的影响.污泥混合液上清液中SMP相对分子量>10kDa的大分子有机物和污泥絮体中1~10μm细小颗粒的增加,将严重恶化污泥混合液的可滤性.

Analysis of the filterability of mixed sludge under low nutrition in MBR

During a 16d period, membrane bioreactor (MBR) was operated without nutrient addition to the mixed liquid. Soluble microbial products (SMP), particle size distributions (PSD) of flocs, extracellular polymeric substances (EPS) and molecular weight (MW) distributions of SMP were periodically monitored. The modified fouling index (MFI) was used to investigate the filterability of mixed sludge closely related with the SMP and EPS. The results showed that the MFI increased rapidly from 1.8×104 to 7.3×104s/L2, which indicated the long time endogenous metabolism process had a negative influence on the filterability of mixed sludge in MBR. It was also found that the increase of SMP with MW >10kDa in supernatant and small particles in the range of 1~10μm in sludge remarkably affected the filterability of mixed sludge under long time low nutrition.