Enzymatic cleaning of ultrafiltration membranes fouled in wool-scouring effluent

Polysulphone membranes used for the ultrafiltration of raw biological streams, like abattoir and wool-scouring effluents, are subjected to severe fouling. In a previous study the authors developed a static membrane fouling system to investigate the nature of foulants from abattoir effluent and the effects of fouling on membrane performance and character. Enzymes specific for the degradation of proteins and lipids were subsequently successfully used in cleaning mixtures to remove foulants from membranes fouled in abattoir effluent. Membranes fouled by wool-scouring effluent were also found to be severely contaminated by protein and lipid material. In this study, the same approach, followed for the enzymatic removal of proteins and lipids from abattoir-effluent-fouled membranes, was applied to membranes that were statically fouled in wool-scouring effluent. The effectiveness of a number of enzyme-based cleaning agents was determined by comparing their ability to remove adsorbed protein and lipid material from the fouled membrane, as well as their ability to restore the water-contact angle and the pure-water flux to the same levels of unfouled membranes. This study showed that the enzymatic approach to biological foulant removal could be successfully applied to polysulphone ultrafiltration membranes used in the wool-scouring industry.