Effectiveness of treatment of secondary effluent from a municipal wastewater treatment plant in a photocatalytic membrane reactor and hybrid UV/H2O2 - ultrafiltration system

A comparison of effectiveness of two advanced oxidation processes, photocatalysis and ultraviolet (UV) irradiation enhanced with H2O2 addition, coupled with ultrafiltration (UF) for treatment of secondary effluent (SE) from a municipal wastewater treatment plant (VVWTP) is presented. The results were compared with photolysis UF system. The concentration of H2O2 in the UV/H2O2 UF mode ranged from 0.03 to 0.3 g/L, the photocatalyst TiO2 P25 loading was changed from 0.5 to 2 g/L. A ceramic membrane with ZrO2 separation layer was used. No significant influence of photocatalyst or H202 concentration on permeate flux was observed, however, both PMR (photocatalytic membrane reactor) and UV/H2O2 UF systems were less prone to fouling than the photolysis UF one. Adsorption was found to be an important stage of total organic carbon (TOC) removal in PMR, while OF contributed mainly to photocatalyst rejection with minor effect on the overall treatment efficiency. The highest TOC removal of organic contaminants after 5 h of operation was found at 1.5 gTiO(2)/L in PMR (61%) and 0.15 gH(2)O(2)/L in UV/H2O2 UF process (65%). The quality of permeate obtained in both systems was comparable, the product of the latter one exhibited lower ecotoxicity towards crustaceans Thamnocephalus platyurus than the PMR permeate.