Use of alternating electrical fields as anti-fouling strategy in ultrafiltration of biological suspensions – Introduction of a new experimental procedure for crossflow filtration

Abstract Results of a parameter study concerning the electro-ultrafiltration with alternating electric fields of aqueous solutions of bovine serum albumin are presented. The alternating electric field diminishes membrane fouling and hence yields a higher specific filtrate flux. The effect of the electric field depends on frequency (0.5–50 Hz), field strength (0–80 V cm−1), conductivity (1–10 mS cm−1), protein concentration (0.1–5 w%), and membrane material (values in brackets are the range of each parameter examined in this work). Low frequency and high field strength yield the best result for electro-ultrafiltration with alternating fields. The effectiveness of the electric field increases with rising conductivity up to the point where a limiting electrolytic current is reached. Increasing protein concentration diminishes the effect of the electric field. A new procedure to perform crossflow filtration experiments, the so-called step-change experiment, is proposed. The results of the new procedure are compared to results of conventional experiments. The step-change experiments yielded reproducible results in good agreement with conventional experiments.