Paper mill wastewater treatment by Fe2+and heat-activated persulfate oxidation: Process modeling and optimization

Abstract

This study investigated Chemical Oxygen Demand (COD) and turbidity removal from paper mill industry wastewater via Fe2+/heat-activated persulfate oxidation. A mathematical model was developed, and the process variables (pH, reaction time, PS/COD, Fe(2+)concentration for Fe2+-activated PS, and temperature for heat-activated PS) were optimized using the Response Surface Methodology and Central Composite Design methods. Under the optimum conditions, respectively, 70.9 and 99.4% COD and turbidity removal efficiencies were obtained for Fe2+-activated PS oxidation, while 56.1 and 98.9% COD and turbidity removal efficiencies were determined for heat-activated PS oxidation. The results indicated that both processes are efficient for paper mill industry wastewater treatment, and central composite design is an appropriate method for designing and optimizing process parameters.