The impacts of various operating conditions on submerged membrane photocatalytic reactors (SMPR) for organic pollutant separation and degradation: a review

The rapid expansion and development of membrane based wastewater treatment in recent decades have led to the emerging technology of submerged membrane photocatalytic reactors (SMPR), which exhibit not only a lower degree of fouling but are also capable of separating and degrading organic pollutants simultaneously during the treatment process. This review intends to provide an update on the influence of several key operational parameters, i.e. photocatalyst loading (both suspended and immobilized), feed pH and concentration, wavelength and intensity of UV light, membrane module packing density and air bubble flow rate on the efficiencies of SMPR in treating degradable organic pollutants. The structure and properties of the photocatalytic membrane as well as membrane performance stability under UV irradiation are also discussed. Understanding the effect of each operational parameter is of paramount importance towards achieving optimum SMPR performance and addressing the challenges encountered in the development of SMPR. Strategies and approaches are also recommended in this review to overcome the persistent problems and facilitate the research and development of SMPR.