501. Catalytic wet oxidation of 2,4-dichlorophenol solutions: activity of the manganese-cerium composite catalyst and biodegradability of the effluent stream.
- Author
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Lee BN, Lou JC, and Yen PC
- Subjects
- Algorithms, Biodegradation, Environmental drug effects, Carbon metabolism, Catalysis drug effects, Cerium pharmacology, Chlorine pharmacology, Equipment Design, Manganese pharmacology, Models, Biological, Oxidation-Reduction, Water Purification methods, Chlorophenols metabolism, Oxygen pharmacology, Waste Disposal, Fluid methods
- Abstract
Aqueous solutions containing 100 to 1000 mg/L of 2,4-dichlorophenol (2,4-DCP) were oxidized in an upflowing fixed-bed reactor in this study of manganese-cerium composite catalysts, which were prepared by the coprecipitation of both manganese nitrate and ceric nitrate at various molar concentrations. Results showed that 2,4-DCP conversion by wet oxidation in the presence of the manganese-cerium composite catalysts was a function of the molar ratio of the manganese-cerium catalyst. The kinetic behavior of 2,4-DCP oxidation with catalysis could be explained by using a zero-order rate expression. Total organic carbon (TOC) removal by wet oxidation in the absence of any catalyst was nil, while approximately 68% TOC reduction was achieved during wet oxidation over a manganese-cerium (7:3 mol/mol) catalyst at 160 degrees C and an oxygen partial pressure of 1.0 MPa. Moreover, the 5-day biochemical oxygen demand/chemical oxygen demand ratios of all the effluent streams were determined to be greater than 0.45 as the wet catalytic processes were carried out at a liquid hourly space velocity less than 24 h (-1), indicating that they could be made more amenable to further biological treatment.
- Published
- 2002
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