Fenton and Solar Photo-fenton Oxidation of Industrial Wastewater Containing Pesticides

Assessment the efficiency of Fenton process (Fe 2+ /H2O2), versus photo-Fenton reaction (TiO2/Fe 2+ /H2O2/UV) for removal of Chloropyrifos, and COD from pesticide wastewater were investigated. Solar compound parabolic collectors (CPC) pilot scale with borosilicate tubes was used for photo-Fenton process. The effect of reaction time, initial pH and dosage of H2O2, FeSO4, TiO2 were studied for both processes. The results obtained indicated that the optimum pH and reaction time were 3.6, and 120 min respectively. Both Fenton and photo-Fenton reaction were very effective for removal of COD and Chloropyrifos at dosage of 2 gm/L for TiO2, 4 gm/L for FeSO4.7H2O, and 1 gm/L for H2O2. However, photo catalytic oxidation process improved the removal efficiency of Chloropyrifos by a value of 27 % as compared to Fenton process. The effluent quality of COD resulting from Fenton reaction was 3070 mg/L and significantly decreased up to 2190 mg/L after the post-precipitation using lime. Photo-Fenton reaction achieved an effluent quality of 2230 mg/l for COD of which greatly decreased up to 1650 mg/L with lime precipitation. Based on these results, it is recommended to apply photo-catalytic oxidation process for treatment of wastewater rich pesticide.