The aim of this work is the study of p-nitrophenol (PNP) removal, as a nitroaromatic com-pound, using a hybridized photo-thermally activated potassium persulfate (KPS) in a fullyrecycled batch reactor. Response surface method was used for modeling the process. Reac-tion temperature, KPS initial dosage and initial pH of the solution were selected as variables,besides PNP degradation efficiency was selected as the response. ANOVA analysis revealsthat a second order polynomial model with F-value of 41.7, p-value of 0.0001 and regressioncoefficient of 0.95 is able to predict the response. Based on the model, the process optimumconditions were introduced as initial pH of 4.5, [KPS]0= 1452 mg/L and T = 66◦C. Also exper-iments showed that using thermolysis and photolysis of the persulfate simultaneously, therole of thermolysis is not considerable. A pseudo first order kinetic model was established todescribe the degradation reaction. Operational cost, as a vital industrial criterion, was esti-mated so that the condition of initial pH of 4.5, [KPS]0= 1452 mg/L and T = 25◦C showed thehighest cost effective case. Under the preferred mild condition, the process will reach to 84%and 89% of degradation and mineralization efficiencies, after 60 and 120 min, respectively
