Fouling performance in the filtration of water containing humic acid and/or kaolin with microporous membrane

Acceleration tests were done using the small-scale microporous membrane (MF ) module to predict the increase in transmembrane pressure at the constant flow rate dead-end filtration in a pilot plant for treating the river water or dam water. The kaolin suspension, solution of humic acid and the mixtur e of kaolin and humic acid were used as feed water in the acceleration test s. The conventional equations of medium blocking filtration were applied to predict the pressure increase for both pilot plant tests and small-scale o nes. The experimental results are summarized as follows: (1) The pilot plant tests: The time course of transmembrane pressure was ex pressed by the complete blocking filtration equation or the standard one wh en the unstable time at the beginning of operation was excluded. (2) The acceleration tests using small-scale membrane module: (a) No increase in transmembrane pressure was observed when the kaolin susp ension and the bentonite one were used as feed water, (b) The increasing rate of transmembrane pressure was lowered by the additi on of coagulant into the humic acid solution, (c) The humic acid had a great influence on the increasing rate of transmem brane pressure in the filtration of water containing kaolin or no kaolin an d (d) Similar curves of filtration time vs, transmembrane pressure were obtai ned in the acceleration tests as were obtained in pilot plant tests.