Particle deposition in outside-in hollow fiber filters and its effect on their performance

Effect of transmembrane pressure (TMP), particle deposition and reentrainment coefficients, and specific cake resistance on the performance of a dead-end outside-in hollow fiber (DOIHF) filter and hollow fiber membrane (HFM) adsorber is studied using the adsorption-peptization model. It is shown that the increase in TMP causes a higher decline in the permeate velocity for both a DOIHF filter and HFM adsorber. The rise in the adsorption (particle deposition) coefficient can considerably increase the productivity (produced volume of clarified liquid) of these membrane devices. The increase in the peptization (particle reentrainment) coefficient can noticeably decrease their productivity. The volume of clarified liquid produced by the HFM adsorber is 1.6-2 times higher than that produced by the DOIHF filter for the same operation time and process parameters. The values of the particle deposition coefficient, particle reentrainment coefficient, and specific cake resistance are suggested to be adjusted by changing process parameters such as the ionic strength, TMP, and pH, as well as by choosing the material of hollow fibers that provides favorable (attractive) surface interactions between the membrane and particles.