Evaluation of the photocatalyst of TiO2/Fenton/ZnO to treat the petroleum wastewater

The current study aimed to evaluate the performance of employing the solar photocatalyst of TiO2/Fenton/ZnO process to treat petroleum wastewater. The operating factors such as TiO2 dosage, ZnO dosage, Fenton-reagent concentration, and pH were evaluated to identify the optimum operational conditions of the treatment process. The obtained optimum conditions were a TiO2 dosage (0.5 g L−1), ZnO dosage (0.5 g L−1), Fenton ratios 100 (1 g L−1 H2O2/0.01 g L−1 Fe2+), and pH 7. The treatment efficiencies were significantly improved by adding of ZnO/Fenton with the solar photocatalyst of TiO2 process. The removal efficiencies increased from 18% to 88% for TOC and from 24% to 61% for COD at pH 7, therefore no need to adjust pH during this treatment. The treatment time was reduced up to 150% compared with the photocatalyst of TiO2 process. Using renewable solar energy and treating with minimum chemical input make this method to be a unique treatment process for petroleum wastewater.