Blow-off & Catalytic Oxidizing Method Treatmenting High Concentrated Ammonia-nitrogen Wastewater

Based on the experiment of dealing with high concentrated ammonia-nitrogen wastewater by blow-off & catalytic oxidizing process, the influences of pH value, temperature and air flow are investigated in this paper. The activity of catalyst ,Cr₂O₃/Al₂O₃ and NiO/Al₂O₃, is mainly studied as catalytic oxidizing method of treatment ammonia from stripping.The result shows that the efficiency of blow-off method improves with the increase of pH value, the rising of temperature, the growth of air flow, and that the best pH value is 11, the suitable temperature is 40℃, and the portion of air to wastewater flow is 360 to 1. The efficiency of blow-off method can be above 95 percent with the experiment facilities.The influences of different loadings of activity component, responding temperatures, ammonia concentration, are systematically studied on ammonia catalytic oxidizing on Cr₂O₃/Al₂O₃ and NiO/Al₂O₃ catalysts. For the NiO/Al₂O₃ catalysts, the research shows that the efficiency of ammonia catalytic oxidizing rises and then reduces with the growth of Cr₂O₃ loading, and that 12%(quality to quality) Cr₂O₃ loading catalyst has the most activity when the experimental temperature was nearby 425℃ . For the NiO/Al₂O₃ catalysts, the result shows that catalytic activity is better as the NiO loading grows, and that 20%(quality to quality) NiO loading catalyst has the most activity when the experimental temperature was about 375℃.One kinetic equation is established basing analysis to the mechanism of ammonia catalytic oxidizing, which will ground a theoretical help in further research.