Optimizing Sulfate Radical Based Advanced Oxidation Process for Reducing Effluent Organic Matter of Pulp and Paper Mill Wastewater Using Response Surface Method

The pulp and paper industries are one of the largest water-consuming industries in the world. The high organic load of wastewater makes conventional treatment methods like biological and coagulation, ineffective for making the discharge effluent meet environmental standards. Advanced oxidation processes have been considered a promising solution due to their high oxidation power and low operating cost compared to other methods. These processes based on the type of radical production have different types, which are divided into two main categories of hydroxyl radicals and sulfate radicals, which are selected depending on the conditions and their purpose. In this research, by using the Response Surface Method (RSM) experiment design, sulfate radical efficiency, the initial oxidizing concentration and pH were optimized. To investigate the effect of factors, Chemical Oxygen Demand (COD) removal was measured at the end of each experiment as an index for organic pollutant removal. In the maximum state whit this method, 75% of the initial COD can be removed. In the economic optimal mode, with the initial dimensionless peroxy-disulfate dose = 0.407 and initial pH = 8.37, COD removal% = 53.53% is demonstrated.