Removal of Ammonium and its Effect on Electrochemical Oxidation in the Treatment of Landfill Leachate

• Main Authors: Kin-Te Lai, 賴金德
• Other Authors: Juu-En Chang
• Format: Others
• Language: zh-TW
• Published: 1994
• Online Access: http://ndltd.ncl.edu.tw/handle/63960920865652083062

碩士 === 國立成功大學 === 環境工程研究所 === 82 === Landfill leachate always contains high concentration of ammonium, which would depress COD removal in electrochemical oxidation process. Consequently, removal of ammonium as a pre- treatment before electrochemical oxidation was planed to improve the COD removal in electrochemical oxidation treatment of landfill leachate. In this study, three processes including nitrification, sequencing batch reactor(SBR), and air stripping were adopted to investigate the feasibility for the removal of ammonium in landfill leachate. In addition, the effluents from the above-mentioned processes were electrolyzed to investigate the influences of these processes on the treatment performance of electrochemical oxidation. Experimental results showed that nitrification process was feasible for the removal of ammonium from landfill leachate. As influent NH4-N concentration and HRT was controlled at 2800mg/L and 7 days, respectively, ammonium in the landfill leachate was completely nitrified. SBR performed nitrification/denitrification well when 1500mg/L of NH4-N was feeded under a 12-day HRT, and an external carbon source(sodium acetate was used)of ΣNaAc/ΣNOx =9. Air stripping reduced ammonium strength readily, in which about 97% of ammonium in the landfill leachate was removed after aeration for 72 hours at pH 12.8. In electrochemical oxidation was faster than the raw leachate. The enhancing effect of nitrification may be due to the indirect oxidation effect of nitrate radical (NO3．), which is induced from NO3-, promotes the removal of COD in electrochemical oxidation process. In addition, comparing the electrolysis results from various processes, it discovers that both SBR and air stripping did not significantly improve the COD removal of electrochemical oxidation process. In this study, the efficiency of electrochemical oxidation for the removal of COD in various pre- treated leachates was as follow, nitrification>air stripping> SBR>raw leachate.