Photocatalytic treatment of spontaneous petrochemical effluents by TiO2 CTAB synthetic nanoparticles.

Removal of pollutants from petrochemical effluents is vital in terms of effluent control and achieving environmental standards. Because of the nature of particular effluents in petrochemical industry, direct biological treatment is not recommended. Therefore, novel techniques such as advanced oxidation processes through photocatalytic processes have been proposed for this purpose. In this study, synthetic photocatalyst TiO2-CTAB (cetyletrimethylammonium bromide) was used for treatment of a real spent-neutral effluent from a neutralization section of the olefin unit of a petrochemical plant. In order to study the chemical oxygen demand (COD) of the process, a double-walled photoreactor was utilized pursuing the Box-Behnken experiment design method. The results show that increasing the concentration of photocatalyst at neutral pH, up to an optimal value of 0.61 g/L in unrestricted conditions and 2 g/L in restricted conditions enhances COD removal by 91.3% and 90.7%, respectively. Furthermore, the effects of oxidation parameters, aeration rate, pH and the amount of catalyst loaded on COD removal efficiency were investigated. It is interpreted from the results that when the oxidant is at its lowest level, removal efficiency is reduced with increasing pH. [ABSTRACT FROM AUTHOR]