Author/Authors :
Safari1، Gholam Hossein نويسنده 1Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran , , Nasseri، Simin نويسنده 1Department of Environmental Health Engineering, School of Public Health and Institute for Environmental Research, Tehran University of Medical Sciences, Tehran, Iran , , Mahvi، Amir Hossein نويسنده Department of Environmental Health Engineering, School of Health; National Institute of Health Research; Center for Solid Waste Research, Institute fo , , Yaghmaeian، Kamyar نويسنده Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran , , Nabizadeh، Ramin نويسنده Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran , , Alimohammadi، Mahmood نويسنده Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran ,
Abstract :
Background: In this study, a central composite design (CCD) was used for modeling and optimizing the operation parameters such as pH, initial tetracycline and persulfate concentration and reaction time on the tetracycline degradation using sono-activated persulfate process. The effect of temperature, degradation kinetics and mineralization, were also investigated. Results: The results from CCD indicated that a quadratic model was appropriate to fit the experimental data (p < 0.0001) and maximum degradation of 95.01 % was predicted at pH=10, persulfate concentration=4 mM, initial tetracycline concentration=30.05 mg/L, and reaction time=119.99 min. Analysis of response surface plots revealed a significant positive effect of pH, persulfate concentration and reaction time, a negative effect of tetracycline concentration. The degradation process followed the pseudo-first-order kinetic. The activation energy value of 32.01 kJ/mol was obtained for US/S2O8 2- process. Under the optimum condition, the removal efficiency of COD and TOC reached to 72.8 % and 59.7 %, respectively. The changes of UV–Vis spectra during the process was investigated. The possible degradation pathway of tetracycline based on loses of N-methyl, hydroxyl, and amino groups was proposed. Conclusions: This study indicated that sono-activated persulfate process was found to be a promising method for the degradation of tetracycline.
