Direct current electric fields can be used to reduce cake formation in crossflow membrane filtrations. A crossflow microfiltration test apparatus is described, and effects of the operating parameters (filtration pressure, crossflow velocity, electric field gradient, pH and feed concentration) on filter performance were determined when using constant and pulsed potentials. Both constant and pulsed potential fields can reduce fouling in microfiltration. Through a combination of electrokinetic phenomena the deposition rate of foulants at the filtering surface is substantially reduced and sometimes almost eliminated, at the expense of an electric energy input. Effects of electric field gradient and pulsation interval on the permeate flux and total power consumption are presented. Flux and power data for electrically enhanced microfiltrations are compared with data obtained by operating the filter under the same conditions but without added electric fields. A Normalized Power Factor is defined for this purpose.