In situ chemical oxidation of carbamazepine solutions using persulfate simultaneously activated by heat energy, UV light, Fe²⁺ ions, and H₂O₂

In situ chemical oxidation of a carbamazepine solution was performed using persulfate anions simultaneously activated by heat energy (thermal, ultrasound), UV-C light, Fe²⁺ ions, and hydrogen peroxide. The main objective of this study was to analyze the mineralization reactions that occurred during the studied operating conditions. Solution TOC removal was nearly complete (99%) within 90min, which prevented the accumulation of toxic intermediates. The mineralization process of carbamazepine solutions can be described using pseudo-second-order kinetics. Under acidic conditions, Fe²⁺ can exhibit catalytic effects on H₂O₂ decomposition and persulfate activation. With excess persulfate, an unproductive S₂O₈^2- decomposition reaction (with no generation of SO₄^-) or a rapid reaction between excess sulfate radicals to produce sulfate anions could occur. Sulfate and hydroxyl radicals were involved in the main mineralization pathway. The influences of chloride ions on mineralization were also evaluated. The results demonstrated that this activated persulfate-based oxidation system could be used to control water pollution by emerging contaminants, such as carbamazepine.