化学絮凝预处理对A/O-MBR处理养猪沼液的影响

Influence of chemical flocculation pretreatment by A/O-MBR on piggery biogas slurry

为探讨化学絮凝预处理对后续A/O-MBR工艺处理效果的影响,试验分别采用A/O-MBR工艺和化学絮凝—A/O-MBR工艺处理养猪沼液。试验结果表明:通过化学絮凝预处理,A/O-MBR工艺的出水平均COD从292mg/L下降为191 mg/L;MLVSS/MLSS从0.43升高至0.76,污泥活性明显提升。A/O-MBR工艺膜污染较重,反冲洗效果较差,反应器中溶解性微生物产物(SMP)和胞外聚合物(EPS)的含量均高于化学絮凝—A/O-MBR工艺。浓差极化阻力和滤饼层阻力是两工艺膜过滤阻力增加的主要因素。

In order to investigate the influence of chemical flocculation pretreatment on the subsequent MO-MBR process and chemical flocculation--A/O-MBR process, two processes have been used for treating piggery biogas slurry at the same time. The results show that ：the average effluent COD concentration of A/O-MBR decreases from 292 mg/L to 191 mg/L after chemical flocculation pretreatment, and MLSS/MLVSS value increases from 0.43 to 0.76. The activity of sludge can be improved greatly. A/O-MBR process has more severe membrane fouling and poor backwash efficacy,more soluble microbial products （SMP） and higher extracellular polymeric substances （EPS） content than that of chemical flocculation--A/O-MBR process are detected in the reactor. Concentration polarization resistance and cake resistance are the main factors of membrane filtration resistance .in these two processes.