Study On Biological Nitrogen Removal Of Ammonium-rich Leachate By Anaerobic Ammonium Oxidation (ANAMMOX) Process

Landfill leachate contaminated with high concentrations of ammonium and hazardous organic compounds, it is difficult to dispose. If we couldn't deal with this kind of high concentration wastewater well, it can cause secondary pollution to the earth surface water, groundwater and soil. The leachate components are very complex, and which are difficult to biological treat. Because of the high concentration of ammonium, so the conventional biological processes are not well-suited to treat it. Therefore, searching for a good biologic method to treat leachate is the fundamental way to resolve the landfill leachate pollution.The conventional processings of nitrogen removal were introduced, especially, the characteristic and the influencing factors of the shortcut nitrification-denitrification, simultaneous nitrification-denitrification (SND) and anaerobic ammonium oxidation (ANAMMOX) was discussed in this paper.The ANAMMOX process was used to study nitrogen removal of ammonium rich leachate in the anaerobic fluidized bed (AFB) reactor. When the HRT of the AFB reactor was 5.5h, and influent NH3-N and CODCr were 313.6-445.4 mg/L with a average value of 357.8 mg/L and 2675.4-4289.1 mg/L, effluent NH3-N and CODCrof the system were 211.8 mg/L and 1001.6-2617.7mg/L, respectively. And the average removal rates of NH3-N and CODcr were 39.2% and 48%. The results show that the AFB reactor could remove NHa-N of leachate in case, the nitrogen removal should be through the way of ANAMMOX, and the scanning electron microphotographs (SEM) of the biocoated particles shows some bacteria was similar to the Candidates Brocadia anammxidans.The microorganism activity was observed between pH 7.5 and 8.5, with an optimum at pH 7.8 and a temperature at 34±0.5℃.A anaerobic fluidized bed (AFB) / aerobic fluidized bed system was set up to treat leachate. When the total HRT of the system was 10.5h (AFB: 5.5h; the aerobic fluidized bed: 5h ), and influent NH3-N and CODCr were 313.6-445.4 mg/L and 2789.4-4198.3 mg/L, effluent NH3-N and CODCr of the system were 24.5-133 mg/L with a average value of 60.3 mg/L and 45-433.4 mg/L with a average value of 143.9 mg/L, And the average removal rates of NH3-N and CODcr were 83.6% and 94.63%, respectively.This study shows that it is possible to treat leachate by the anaerobic fluidized bed (AFB) / aerobic fluidized bed system, and the system is very efficient for landfill leachate. It gave us a new method to study on leachate treatment.