Selection of membranes for deadend micro- and ultrafiltration outside-in hollow fiber filters

A mathematical model taking into account the adsorption of particles around a membrane pore mouth at the stage of standard blocking is developed. The model is used to study the effect of the average membrane pore size, the cutoff coefficient, and the ratio of the length of the pore inlet region to be blocked to the whole pore length on the product flow rate of a deadend outside-in hollow fiber filter. It is shown that the use of membranes with an average pore size higher than the cutoff diameter for the particles to be removed from the suspension will be profitable only for the first 15-20 min of operation. In this case, the membrane should have an average pore size as large as possible, but not exceeding a limit value at which the membrane selectivity can drop; the cutoff coefficient as low as possible; and a pore inlet region to be blocked as long as possible.