Characteristics of bio-fouling in a submerged MBR Original Research Article

The production and behavior of soluble microbial products (SMP) were investigated by employing a submerged MBR (membrane bio-reactor) process. The two types of bioreactors at different loading rates were conducted to understand the mechanism of bio-fouling and the behavior of SMP in a MBR process. Resultantly, the permeate flux of Run I (low loading rate) was maintained for 35days, while Run II (high loading rate) was maintained for 23 days. The filtration resistance values were similar because they were determined by the accumulated SMP concentration in the bioreactor. The production rate of SMP for Run II was measured as 0.0071 L/day, higher than for Run I (0.0056 L/day). After cleaning the membrane, the permeate flux showed on unstable and gradually decreased high SMP concentration in a short period. It is considered that the rate of accumulation of SMP relates to the biodegradability of utilization-associated products at different loading rate. From this research, we could determine that the volumetric loading rate affected to produce SMP, and SMP effected to not only membrane bio-fouling but also microbial activity.