DEGRADATION EFFICIENCY AND KINETIC STUDY OF METRONIDAZOLE BY CATALYTIC OZONATION PROCESS IN PRESENCE OF MGO NANOPARTICLES

Pharmaceutical products، particularly antibiotics، due to their cumulative and inappropriate effects and creating drug resistances، as inevitably pollutants، have been created a major concern in environmental control. Metronidazole (MTN) is one of these antibiotics. Hence، the aim of this study was investigation of MTN removal efficiency by catalytic ozonation process (COP) in presence of produced magnesium oxide nanocrystals as catalyst. The influences of several operational factors for their effects on removal were evaluated، including solution pH (3-12)، reaction time، MgO dosage (0. 25-4 g/L) and initial MTN concentration (1-40 mg/L). Also degradation kinetic، biodegradability improvement and mineralization rate were studied for the COP. For degradation kinetic the best compatibility was with pseudo-second order (liner type II) model. The optimum pH and MgO dosage for COP were determined to be 10 and 0. 25 g/L، respectively. Under optimum condition the complete removal of 40 mg/L MTN solution was observed after 20 min. The results illustrate that MgO nanocrystals markedly accelerated the MTN degradation in and the COP significantly increased BOD5/COD ratio and caused 94% MTN mineralization.