Kinetic study of inorganic carbon (IC) removal and COD removal from refinery wastewater by solar Photo-Fenton.

This study evaluated the effectiveness of solar Photo-Fenton’s technique (H2O2/Fe2+/Solar) to treat the refinery wastewater. The experimental data were analyzed using the first and second-order kinetic models. The results clearly indicated that the pseudo-second-order models gave better prediction than the pseudo-first-order models for IC and COD removals, as indicated by the higher regression coefficients (R2). The degradation rate by this treatment could be expressed as a pseudo-second-order reaction with respect to IC and COD removals. The best operating conditions, as elucidated by kapp values, were pH (2), Fe+2 (0.08 g/L), H2O2 (1 g/L), H2O2/Fe2+ ratio (12.5), and reaction time (300 minutes). The solar Photo-Fenton reaction was very fast and reached a maximum IC and COD removals to 62% and 84%, respectively. This study demonstrated that solar Photo-Fenton oxidation process could be used effectively as a post-treatment to enhance the treatment efficiency of petroleum wastewater.