DESTRUCTION OF HUMIC MATTERS AND AMMONIA IN THE LANDFILL LEACHATE BY SUPERCRITICAL WATER OXIDATION |
Y. K. Kim1†, J. S. Ahn1, and W. Leung2 |
1Department of Environmental Engineering, Hankyong National University, Ansung, Kyonggido, Korea 456-749 2College of Engineering and Idaho State University Biomedical Research Institute, Idaho State University, Pocatello, Idaho, U.S.A. 83209 |
Corresponding Author:
Y. K. Kim ,Tel: +82-31-670-5173, Fax: +82-31-670-5170, Email: ykkim@hknu.ac.kr |
Received: March 9, 2006; Accepted: June 13, 2006. |
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ABSTRACT |
Feasibility of destroying synthetic and actual leachate containing humic acids and ammonia compounds by supercritical water oxidation (SCWO) was evaluated. In this study, destruction efficiencies of humic acids and ammonia respectively were investigated at various reaction temperatures and residence times under pressure a supercritical pressure (280 atm). To lower reaction temperature, chemical oxidants were used. The experiment was carried out in a cylindrical batch reactor made of Hastelloy C-276 that can withstand high temperature and pressure. Concentrations of humic acids and ammonia were measured using a CODcr method and an ammonia selective electrode, respectively. The optimal destructive condition of humic acids in the presence of stoichiometric oxygen (air) was 3 min at 380°C, but the temperature could be lowered to subcritical region (360°C) along with H2O2 as an oxidant. For ammonia, the optimal destructive condition with air was 5 min at 600°C, but it was possible to operate the process for 3 minutes at 550°C or 2 min at 600°C along with H2O2 as an oxidant. At 2 min and 550°C along with H2O2 as an oxidant, humic and ammonia compounds in the actual leachate were easily destructed and the effluent quality met the Korea Standard Leachate Quality.
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Keywords:
Humic acid | Ammonia | Leachate | Subcritical and Supercritical Water Oxidation | Oxidants |
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