Kinetics and Thermodynamic Studies of Oxytetracycline Mineralization Using UV/H 2 O 2

Oxytetracycline (OTC), a widely used antibiotic, was taken as the model contaminant to study the kinetic and thermodynamic parameters of mineralization using a UV/H 2 O 2 system. Mineralization experiments were carried out at different initial OTC concentrations of 0.0156–0.0531 M, initial H 2 O 2 concentrations of 0.043–0.116 M and at a temperature range of 20 − 50°C. The OTC mineralization process was monitored by measuring the total organic carbon as well as H 2 O 2 consumption. The analysis of mineralization data showed two phases of mineralization: phase I: 0 ≤  t  ≤ 30 min and phase II: 30 ≤  t  ≤ 180 min. Based on this, the kinetic and thermodynamic parameters were established. The order of reaction obtained for organic C and H 2 O 2 is 0.624 and 0.599 (phase I) and 0.954 and 0.062 (phase II), respectively. Based on this kinetic model, the OTC degradation rate constants were 0.0069 min −1 (phase I) and 0.0051 min −1 (phase II). The activation energy for phase I and phase II oxidation was 10.236 and 9.913 kJ mol −1 , respectively. The estimated Δ # G and Δ # H values are positive, whereas negative Δ # S values were obtained.