Analysis of Particle Fouling in Constant‐Pressure Submerged Membrane Filtration

Abstract

Particle fouling in constant pressure submerged membrane filtration is analyzed. A particulate sample, with a wide size distribution ranging from submicron to micron, is filtered using a flat-sheet membrane module. The effects of filtration pressure and aeration conditions on the particle deposition probability, cake properties and filtration flux are discussed. Particle deposition is analyzed theoretically using a force balance model. The particle size distribution in a filter cake is smaller than that in the original suspension and gradually decreases during a filtration. An increase in filtration pressure leads to a higher filtration flux in the early period of filtration; however, after 3000 s the flux gradually approaches a pseudo-steady value. The filtration flux is significantly enhanced by sparging air bubbles. An increase in air volumetric flow rate or a decrease in bubble size leads to a smaller particle size distribution in the cake. The particle deposition probability, cake mass and average specific filtration resistance calculated by using the proposed models agree fairly well with available experimental data.