过滤/曝气两用型膜-生物反应器试验研究

Experimental study on a dual functional filtration/aeration membrane bioreactor

对以聚乙烯微孔管为膜组件的过滤 /曝气两用型膜 生物反应器进行了研究。通过清水过滤试验发现 ,PE 1和PE 4 (孔径分别为 70～ 12 0 μm和 5～ 10 μm) 2种微孔管均具有较高的清水通量 ,单位水头下高达 2 5 0L/m2 ·h。PE 4微孔管对活性污泥混合液的过滤性能略优于PE 1,初始膜通量的选择对二者的过滤性能影响很大 ,但污泥浓度的影响则不甚显著。对膜组件进行过滤 /曝气交替运行 ,可有效地清除膜组件表面的泥饼层 ,较好地保持膜过滤性能的稳定。分别改变过滤 /曝气运行周期和初始膜通量 ,考察了膜过滤性能的变化 ,发现交替运行周期在 0 5～ 3h ,初始膜通量在 6 0～ 14 0L/m2 ·h时 ,系统在连续运行过程中每一运行周期内的平均膜通量先经历了初始的下降阶段 ,然后基本稳定在 5 0～ 80L/m2 ·h的水平 ,但低的初始膜通量可以使平均膜通量表现得更为稳定。过滤 /曝气两用型膜 生物反应器用于处理生活污水 ,可获得与传统膜 生物反应器相似的出水水质 ,并且对冲击负荷具有较好的承受能力。大小

A dual functional filtration/aeration membrane bioreactor(MBR) coupled with polyethylene microporous tubes(MPTs) was studied PE 1 and PE 4, two types of MPTs with pore size of 70～120 μm and 5～10 μm respectively, both had a similar specific membrane flux as high as 250 L/m 2·h when tap water was filtered although their pore sizes are different Permeability of MPTs was largely affected by membrane flux but less affected by activated sludge concentration The alternate operation of filtration and aeration could effectively remove cake layer on the membrane surface and keep up the stability of the membrane filtration characteristics The influences of the alternate operation time T and the initial membrane flux J 0 on the membrane filtration characteristics were further investigated When T varied from 0 5 h to 3 h and J 0 from 60 L/m 2·h to 140 L/m 2·h, the average flux J a in one cycle declined firstly and then leveled off in the range of 50 L/m 2·h to 80 L/m 2·h, but the better stability of J a was found when J 0 was smaller Domestic wastewater was treated by filtration/aeration MBR and the effluent with quality as good as the conventional MBR was achieved even under shock loading There was no much difference between PE 1 and PE 4 in the performance of COD and NH + 4 N removal