Evaluation of the solar photo-Fenton process to treat the petroleum wastewater by response surface methodology (RSM)

The objective of this study was to investigate the performance of employing solar photo-Fenton to treat petroleum wastewater from Sohar oil refinery, evaluate this process by a central composite design with response surface methodology and evaluate the relationship among operating variables such as pH, H2O2 dosage, Fe+2 dosage, and reaction time to identify the optimum operating conditions. Quadratic models proved to be significant with very low probabilities (<0.0001) for the following responses: total organic carbon (TOC) and chemical oxygen demand (COD). The optimum conditions were H2O2 dosage (850 mg L-1), Fe+2 dosage (60 mg L-1), pH (3.68) and reaction time (127 min) in this method. The experimental results of the maximum TOC and COD removal rates corresponded good with the predictions, which were 59.3 and 74.7 %, respectively. This method achieved well degradation efficiencies for TOC and COD and reduced the treatment time comparing with the previous work.