Fouling control of a submerged membrane module (YEF) by filtration modes

Effects of kaolin concentration on the fouling of a submerged module (YEF) were investigated at various filtration modes. With 30,000 mg/L kaolin suspensions, a cross-flow filtration with air scrubbing showed the best performance in the operating mode of 60-minute suction and 1-minute stop. A dead-end filtration has operated best in the operating mode of 30-minute suction and 3-minute stop. The cake resistance of kaolin suspension with a dead-end filtration was 2.4 times higher than that of a cross-flow filtration. Lower cake resistance of the cross-flow mode appeared to be due to easier removal of cake layer accumulated on the membrane surface by the turbulence generated by the continuous aeration. Cake formation was a main fouling factor which could be effectively removed by air scrubbing only. No significant irreversible fouling was observed with the kaolin suspensions.