Membrane fouling inducing the flux decline for polyethylene capillary membranes was examined by measuring the flux of Al_(2)O_(3) colloidal suspensions through the cross flow microfiltration. The flux decline was due to the membrane fouling such as cake formation on the membrane surface and pore blockings (standard & complete) by particles. Three fouling mechanisms were simultaneously responsible for membrane fouling during microfiltration. The permeate resistance of the suspension with 1.0 μm Al_(2)O_(3) particles was less than that of the 0.6 μm Al_(2)O_(3) particles, and he approach to the steady state was fast. The cake filtration model was dominant at the initial period of filtration, which followed the pore blocking model. At steady state, the fouling mechanism was approximately govemed by the cake fiitration model again. In Comparing the ratio of each fouling component to the total fouling for the 1.0 μm Al_(2)O_(3) suspension, standard blocking was about 8%, complete blocking was 12% and cake filtration was 80%. For the 0.6 μm Al_(2)O_(3) suspension. total fouling was composed of about 4% pore blockings and 96% cake filtration. For the membrane with 0.34 μm pore size, the permeate resistance increased more slowly than that with 0.24 μm pore size, and the fouling mechanism was mainly governed by cake filtration at the initial stage of filtration followed by two pore blocking. The pore blocking effect of large pore membrane to the total fouling was larger than that of small pore membrane. The ratio of pore blocking to total fouling increased with the trans-membrane pressure and decreased with the suspension concentration.

AI_(2)O_(3) 현탁액의 투과유속을 감소시키는 폴리에틸렌 정밀여과 모세관 막의 오염에 대하여 검토하였다. 투과유속의 감소원인은 막 표면 위에서 케익층의 성장과 입자들에 의한 표준 및 완전세공막힘 때문이었으며, 막오염은 이들 세 가지 오염형태가 동시에 발생한다. 입자의 크기가 1.0 ㎛인 AI_(2)O_(3) 콜로이드 용액의 투과저항은 0.6 ㎛인 콜로이드 용액보다 작았고, 정상상태에 도달하는 시간도 빨랐다. 운전초기에는 케익오염이 지배적이었으나 이어 세공막힘오염이 나타났고 정상상태에 도달하면 투과유속은 다시 케익여과 오염에 의해 지배받는다. 총 막오염에 대한 성분오염의 비율은 입자크기가 1.0 ㎛인 AI_(2)O_(3) 현탁액에서 표준세공막힘 8%, 완전세공막힘 12%, 그리고 케익여과 80%였으며, 0.6 ㎛ AI_(2)O_(3) 현탁액에서는 표준 및 완전세공막힘 4% 그리고 케익여과 96%였다. 세공의 크기가 0.34 ㎛인 막의 투과저항은 세공의 크기가 0.24 ㎛인 막보다 작고 서서히 증가하였다. 막오염의 형태는 운전초기에 강한 케익여과에 이은 2번의 세공막힘이 나타났다. 총 오염에 대한 세공막힘의 영향은 세공이 큰 막에서 컸다. 그리고 총 오염에 대한 세공막힘의 비율은 투과압력에 비례하고 농도에 반비례하여 컸다.