Photo-thermal activation of persulfate for the efficient degradation of synthetic and real industrial wastewaters: System optimization and cost estimation

Abstract The photo-thermal activation of persulfate (PS) was carried out to degrade various pollutants such as reactive blue-222 (RB-222) dye, sulfamethazine, and atrazine. Optimizing the operating parameters showed that using 0. 90 g/L of PS at pH 7, temperature of 90 °C, initial dye concentration of 21. 60 mg/L, and reaction time of 120 min could attain a removal efficiency of 99. 30%. The degradation mechanism was explored indicating that hydroxyl and sulfate radicals were the prevailing reactive species. The degradation percentages of 10 mg/L of sulfamethazine and atrazine were 83. 30% and 70. 60%, respectively, whereas the mineralization ratio was 63. 50% in the case of real textile wastewater under the optimal conditions at a reaction time of 120 min. The treatment cost per 1 m 3 of real wastewater was appraised to be 1. 13 /m 3 which assured the inexpensiveness of the proposed treatment system. This study presents an effective and low-cost treatment system that can be implemented on an industrial scale.