Performance of submerged oscillatory membrane photoreactor for water treatment

Abstract

Enhancement of a slurry hybrid membrane photoreactor (MPR) is investigated using an oscillatory microfiltration membrane and ZnO photocatalyst. The investigation involved the photocatalytic decolourization of methylene blue (MB) dye as a model pollutant compound. The effect of the operating parameters on the dye decolourization and its relation to the membrane-catalyst retention characteristics is studied. The results showed that application of oscillatory motion resulted in minimizing catalyst particles deposition on the membrane which increased its concentration in suspension and led to higher decolourization rates. Such effect was further augmented by the increase in membrane permeate flux due to the lower hydraulic resistance caused by catalyst deposition on the membrane surface. Furthermore, use of ZnO as photocatalyst has the potential of providing several advantages in terms of high UV absorbance as well as alleviating the need for using oxygen scavenging for charge separation. The latter when combined with the relatively low transmembrane pressure drop requirements by microfiltration (MF) membranes, can result in reducing the overall process energy demand. Such effects suggest that the proposed configuration may be considered as an effective approach for augmenting the productivity of membrane photoreactor for water and wastewater treatment applications.