Enzymatic treatment of alginate to reduce membrane fouling for water or wastewater purification

摘要

This disclosure examines using alginate lyase to catalytically degrade alginate in order to decrease affinity and fouling potential to membranes of 0.2 and 0.02 μm pore size, respectively within a process line of a filtration system. Enzymatically treated alginate caused less fouling on both ultrafiltration and microfiltration membranes than original alginate. Enzymatically treated alginate is predicted to cause less fouling on both membranes within the pH range of approximately 3.0 to approximately 10.0. Without the presence of calcium cation, alginate lyase reduced the foulant resistance by more than 82% for both membranes. In the presence of 1 mM calcium cation, alginate lyase reduced the foulant resistance by more than 55%. In addition, the foulant structure composed of enzymatically treated alginate was more readily removed by backwashing, suggesting reversible fouling. The advantages of using enzymatic technique to control membrane fouling include high efficiency and no damage to the membrane materials.