Document Type : Original Article

Authors

• Mohammad Amin Karami ¹
• Mohammad Mehdi Amin ²
• Heshmatollah Nourmoradi ³
• Mohsen Sadani ¹
• Fahime Teimouri ¹
• Bijan Bina ²

¹ Department of Environmental Health Engineering, School of Health; Student Research Committee, Isfahan University of Medical Sciences, Isfahan, Iran

² Student Research Committee; Environment Research Center, Research Institute for Primordial Prevention of Non-communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran

³ Department of Environmental Health Engineering, Ilam University of Medical Sciences, Ilam, Iran

Abstract

Aim: The aim of this study was to investigate the degradation of an azo dye, reactive red 198 (RR198), by ozone, H₂O₂/O₃, and persulfate from aqueous solutions. Materials and Methods: The application of several advanced oxidation processes including single ozonation, O₃/H₂O₂, and persulfate for degradation of RR198 at concentration of 200 mg/L was investigated. The effect of various parameters including pH, H2O2, persulfate doses, and temperature was studied on the degradation of RR198 from aqueous solutions. In addition, the effects of these processes on biodegradability of RR198 were evaluated. Results: The results showed that the degradation rate was increased by increasing H₂O₂ concentration. The optimum H₂O₂ concentration was obtained in the range of 0.03 mol/L at dye concentration of 200 mg/L. Alkaline pH, higher temperature, and persulfate dose (12 mM) were favored in dye and COD removal. Moreover, compared with ozone and peroxone, the persulfate oxidation could achieve a higher color and COD removal at the same reaction time. Persulfate has greater potential to improve the biodegradability of RR198 solution than ozone and ozone/H₂O₂ process. Biochemical oxygen demand/COD ratio of the dye solution treated by persulfate, ozone/H₂O₂, and ozone at reaction time 40 min was 0.73, 0.63, and 0.59, respectively. Conclusion: These findings show that oxidation by persulfate is a promising alternative for the treatment of RR198 containing solution as a recalcitrant pollutant.

Keywords

• Degradation
• dye
• hydrogen peroxide
• ozone
• persulfate