Utilization of enzymatic detergents to clean inorganic membranes fouled by whey proteins

In this work inorganic membranes used for whey protein fractionation were cleaned with enzymatic detergents. The inorganic membrane Carbosep® M1 (Orelis S.A., France), of 150 kg/mol molecular weight cut-off and ZrO2 filtering layer, was used and the commercial detergent P3-Ultrasil® 62 (Henkel Ibérica S.A., Spain) was selected for the cleaning. Hydraulic and chemical methods were considered to characterize the membrane cleanliness. Cleaning efficiency was observed to be a function of the operating conditions: recycling versus non-recycling of permeate, cleaning solution pH, enzymatic agent concentration and cleaning time. The optimum conditions to perform the cleaning were related to the optimum conditions to hydrolyze whey proteins in a batch reactor. Very high cleaning efficiencies (∼100%) were reached in short operating times (20 min). However, residual matter was detected on the membrane surface after the cleaning.