Assessment of Photocatalytic Process Using Composite Photocatalysts for COD Reduction for Al-Dewaniyah Petroleum Refinery Wastewater: RSM Approach

Abstract

A slurry bubble photoreactor with air blowing for circulating and oxidizing using composite photonanocatalyst nanoparticles (TiO2/ZnO) with UV radiation light lamp was used successfully to remove of COD from petroleum refinery wastewater. Effect of the main effective parameters like catalyst dosage, pH and time on the reduction efficiency (RE%) was investigated and optimized using response surface methodology (RSM). Results showed that catalyst dosage has the most significance effect on RE% with a contribution of 13.23%, followed by time with a contribution of 7.68%, and finally pH with 0.6%. The optimum results were TiO2 dosage of 1.25g/l, pH=9, and time of 103 min in which RE% of 80.7% was achieved with requiring a specific energy consumption of 25.5 kWh/m3.