Factors affecting the performance of a low-pressure submerged membrane photocatalytic reactor

A hybrid system combining a low-pressure submerged membrane module and a photocatalyst suspension was used to purify water containing bisphenol-A (BPA). The influences of pH, aeration rate, titanium dioxide (TiO2) and initial BPA concentration were investigated in batch kinetic tests. In these studies, a combination of pH 4, 0.5 g/L TiO2 and 0.5 L/min aeration rate were determined to be the optimized conditions for application in the continuous submerged membrane photocatalytic reactor (SMPR). The effect of initial BPA concentration in the range of 5–50 ppm fits the Langmuir–Hinshelwood (L–H) kinetics well. With 100 L/(m^2 h) of permeate flux which resulted in 2 h residence time, 97% degradation and higher than 90% mineralization of the 10 ppm BPA were achieved after 90 and 120 min, respectively. The effect of filtration flux and intermittent permeation were also studied in terms of production rate of treated water, efficiency of the SMPR and membrane performance sustainability. A simple CSTR model had limited success predicting the effect of initial concentration of BPA on the performance of the SMPR. The SMPR has the potential to be used for removing low concentrations of organic pollutants in a more cost effective way.