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Effect of support material pore size on the filtration behavior of dynamic membrane bioreactor

Cai, Donglong, Huang, Ju, Liu, Guoqiang, Li, Mingyu, Yu, Yang, Meng, Fangang
Bioresource technology 2018 v.255 pp. 359-363
chemical oxygen demand, cleaning, filters, filtration, membrane bioreactors, porosity, turbidity
The effect of support material pore size on the filtration behaviors during start-up and stabilized stages in the dynamic membrane bioreactors (DMBR) was studied. Before the dynamic membrane (DM) was formed, the turbidity at 50-μm could be more than 250 NTU, while it was less than 40 and 10 NTU at 25- and 10-μm, respectively. After the DM was formed, the stabilized stage lasted for 61 days with low transmembrane pressure <0.6 kPa and the 5-, 10-, and 25-μm filters had similar effluent turbidity (<1 NTU) and chemical oxygen demand. However, their averaged flux was 66.4, 25.1, and 3.5 L·m−2·h−1, respectively, suggesting that the 25-μm filter had significantly lower filtration resistance. Consequently, to avoid unallowable high effluent turbidity during start-up or after membrane cleaning and to achieve high flux with low pressure filtration, a mesh size of ∼25 μm is more suitable for DMBR.