Investigation of carbazole degradation by the sono-Fenton process.
The present report aimed to describe the roles of ultrasonic power and reaction time in the Fenton reagent-based degradation of carbazole in wastewater, and to analyze the effects of the Fe2SO4 and H2O2 concentrations and the initial pH on the reaction kinetics. Application of 40 or 80 W of ultrasound at a frequency of 40 KHz substantially improved the effectiveness of carbazole degradation, whereas application of 20 W of ultrasound had little effect. The optimal concentration of the Fe2SO4·7H2O catalyst was lower for extended operating times. Increased degradation was observed with increasing H2O2 concentrations below 1.8 mg L(-1), whereas decreased degradation was observed at concentrations above this value. The best performance was obtained at a neutral or slightly alkaline pH range (pH 7-9) rather than at the commonly used acidic pH range (pH 2-4). Under optimal conditions, the extent of carbazole degradation was 98% after 180 min. The degradation process followed second-order kinetics.
Department of Environmental Engineering, Peking University, Beijing, China. jiguodong@pku.edu.cn
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D002227:Carbazoles / Q000737:chemistry* / Q000302:isolation & purification; D005296:Ferrous Compounds / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry*; D007700:Kinetics; D013010:Sonication / Q000379:methods; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000302:isolation & purification; D018508:Water Purification / Q000379:methods*
D002227:Carbazoles; D005296:Ferrous Compounds; D006861:Hydrogen Peroxide; D007501:Iron; D062065:Wastewater; D014874:Water Pollutants, Chemical; C045076:Fenton's reagent; C041514:carbazole; C020748:ferrous sulfate