旋转膜组件对污染物去除效能及膜污染控制的影响

Effect of Rotating Membrane Module on Pollutant Removal Efficiency and Membrane Fouling Control

文章采用两组平行装置处理模拟生活污水,对比研究其膜组件状态对污染物去除效能及膜污染控制的影响.结果表明:由于膜组件的旋转作用,适当增加了水流的紊动强度,使活性污泥、有机物与溶解氧之间的充分混合,促进氧气和营养物质的传递,加快微生物的生长繁殖速度.反应器A(旋转)中脱氮除磷及有机物去除效能均高于反应器B(静置),反应器A对NH3-N、TP、COD去除率分别比反应器B提高了5.84%、3.96%、3.97%.活性污泥样品的DGGE图谱分析表明A、B反应器中微生物种属的优势地位不同,可能是导致污染物去除效能差异的主要原因.反应器A、B的污泥平均粒径分别为92.92μm和68.18μm,反应器A中的剪切力作用使污泥粒径增加,易于形成致密的颗粒污泥,在运行期间污泥容积指数SVI一直低于反应器B.旋转膜组件在离心力的作用下,膜表面的滤饼层松散絮体易于脱落,膜通量降低和膜阻力增加速度均低于反应器B.

In this paper, two sets of parallel devices were used to treat simulated domestic sewage, and the effects of membrane module status on pollutant removal efficiency and membrane fouling control were compared. The results showed that: due to the rotating action of membrane components, the turbulent intensity of water flow was properly increased, which fully mixed activated sludge, organic matter and dissolved oxygen, promoted the transfer of oxygen and nutrients, and sped up the growth and reproduction of microorganisms. The removal efficiency of nitrogen, phosphorus and organic matter in reactor A was higher than that in reactor B. The removal rates of NH3-N, TP and COD in reactor A were 5.84%, 3.96% and 3.97% higher than that in reactor B, respectively. DGGE analysis of activated sludge samples showed that the dominant position of microbial species in reactor A and reactor B was different, which might be the main reason for the different pollutant removal efficiency. The average particle size of the sludge in reactor A and B were 92.92 μm and 68.18 μm, respectively. The shear force in reactor A increased the particle size of sludge and was easy to form dense granular sludge. The sludge volume index(SVI) in reactor A was always lower than that in reactor B during operation. Under the action of centrifugal force, the loose filament-cake layer on the surface of the rotating membrane module was easy to fall off.The membrane flux decrease and membrane resistance increase rate were lower than those in reactor B.