Fouling mechanism of 0.2 ?m Al_2O_3 ceramic membrane in microfiltration of Qiju Dihuang Pill aqueous extract / 中草药

ABSTRACT

Objective To discusse the fouling mechanism of 0.2 ?m Al_2O_3 ceramic membrane in the microfiltration of Qiju Dihuang Pill aqueous extract. Methods Qiju Dihuang Pill aqueous extract was microfiltered in this experiment. The distributions of filtration resistance were studied according to the Darcy-Poiseuille principle. The substance of deposit on the membrane surface was analysed by Fourior transform infra-red spectrum and particle diameter analysis. The characteristic of the surface and cross section of the polluted membrane was observed by SEM. Results The filtration resistance was mainly concentrated on the surface of deposit resistance, the membrane itself and the concentration polarization resistance were less important, and the pore blocking resistance was the least important. Moreover, this result was proved by SEM analysis. The molecule of the fouling substance mainly contained peptid, carbonyl, and hydroxy bonds by IR. The particle size distribution of the deposit substance on the polluted membrane surface The particle radius taking a larger percentage in volume concentrated in 18.267 ?m around, while the particle radius taking a larger percentage in quantity concentrated in 0.424 ?m around. Conclusion Study on the fouling mechanism of the membrane in the microfiltration provides a great significant guidance for exploring the effective measure of relieving the reduced membrane flux and the appropriate cleaning procotrol.