Optimization of Fenton process for removing TOC and color from swine wastewater using response surface method (RSM)

The Fenton oxidation process was applied to biologically treated swine wastewater (BSWW) for the removal of TOC and color constituents after coagulation with FeCl₃. Optimizing of operational variables such as FeSO₄ and H₂O₂ doses was achieved by the response surface method (RSM). Statistical analysis led to the conclusion that FeSO₄ is the more important than H₂O₂ in the removal of TOC. However, H₂O₂ plays a more significant role than FeSO₄ in color removal. The optimal conditions for effective removal of TOC and color from swine wastewater were derived by using process optimization. The experimental results show that overall removal of TOC and color is 76.7% and 98%, respectively, when optimal conditions of 800 mg/L (FeSO₄) and 5207 mg/L (H₂O₂) at 120 min were used. Furthermore, the optimization model produces a desirability value of 0.980 that verifies the optimal conditions. Finally, it is observed that removal of undesirable compounds follows a pseudo-first order and pseudo-second order kinetics model with high R² values of 0.99 for both TOC and color removal, respectively. Statistical analysis and process optimization show that the employed model may determine conditions conducive to the effective removal of TOC and color from swine wastewater.