冷冻固定化硝化菌去除废水中氨氮的研究

Research on Removal of Ammonia Nitrogen from Wastewater by Frozen Immobilized Nitrifying Bacteria

采用聚乙烯醇(PVA)循环冷冻法制备固定化硝化菌颗粒,经活化后在颗粒填充率为9％的三相流化床中进行氨氮废水处理试验。处理低浓度氨氮有机废水(NH3-N质量浓度为75 mg/L,COD约为400 mg/L,水力停留时间为4 h)时,NH3-N去除率约为90％,COD、TIN的去除率可达82％和60％左右;处理高浓度氨氮废水(NH3-N质量浓度450-500 mg/L,水力停留时间为20 h)时,NH3-N去除率在98％以上,氨氧化产物中NO2-N质量分数在95％以上,为亚硝酸盐反硝化提供了有利条件。用该法制成的硝化菌颗粒寿命在3个月以上。

The immobilized nitrifying bacteria pellets were made by iterative PVA freezing and thawing. The cultivated pellets were used to treat NH3 - N wastewater in a biological fluidized bed reactor (BFBR) in which the volume fraction of the immobilized pellets was 9% . In the treatment of low concentration wastewater with 75 mg/L of influent NH3 - N concentration, 400 mg/L of influent COD and 4 h of reaction time, the removal rate of NH3 - N reached about 90% and those of COD and TIN reached about 86% and 60% respectively. While the influent NH3 - N concentration was increased to 450 - 500 mg/L and the reaction time prolonged to 20 h, the removal rate of NH3 - N was above 98 % and the mass fraction of NO2- - N in the NH3 - N oxidation products was more than 95%, which benefited the denitrification of nitrites. The life of nitrifying bacteria pellets cultivated by the process was more than 3 months.