生物气循环模式对AnDMBR污水处理效能的影响

Effect of Biogas Circulating Mode on Wastewater Treatment Performance of Anaerobic Dynamic Membrane Bioreactor

基于小试厌氧动态膜生物反应器(AnDMBR),研究了不同尼龙网孔径(200目和500目)及生物气循环模式(连续冲刷、无冲刷及间歇冲刷)对AnDMBR污水处理效能的影响。结果表明,当膜基材孔径为200目时,AnDMBR的运行周期延长。间歇2 h、气体循环1 min为优化的气体循环模式,此时气态甲烷产量较高,溶解性甲烷产量最低,并且膜污染速率最低。AnDMBR对COD的去除率超过80%,对浊度的去除率约为90%。扫描电镜能谱分析(SEM-EDX)表明生物气循环强度影响泥饼层的致密性和厚度。持续的生物气循环会导致污泥颗粒破碎和泥饼层脱落,使污泥平均粒径减小。反应器的细菌群落主要有变形菌门(Proteobacteria)、绿弯菌门(Chloroflexi)、厚壁菌门(Firmicutes)和拟杆菌门(Bacteroidetes),古菌群落主要有Methanoregula、甲烷丝菌属(Methanothrix)和甲烷杆菌属(Methanobacterium)。

The effects of nylon mesh size(200 meshes and 500 meshes)and biogas circulating mode(continuous sparging,no sparging and intermittent sparging)on the wastewater treatment performance of a lab-scale AnDMBR were investigated.The operating cycle of AnDMBR was extended when the membrane supporting material aperture was 200 meshes.The optimal biogas circulating mode was sparged every 2 hours for 1 min.Under this operating mode,the gaseous methane production was higher,and the dissolved methane production and the membrane fouling rate were the lowest.The removal rate of COD by AnDMBR was more than 80%,and that of turbidity was approximately 90%.SEM-EDX analysis showed that the biogas sparging intensity affected the density and thickness of the cake layer.The continuous biogas circulation led to the breakage of sludge particles,the stripping of sludge cake layer and the decrease in the average particle size of sludge.The bacterial phyla in the bioreactor mainly included Proteobacteria,Chloroflexi,Firmicutes and Bacteroidetes,while the archaea genera mainly consisted of Methanoregula,Methanothrix and Methanobacterium.