Abstract: An innovative technology for nutrient removal from high nitrogen soybean wastewater was developed by controlling dissolved oxygen(DO) concentration in sequencing batch reactor (SBR). The experimental results showed that when DO concentration was maintained at 0.5 mg•L^-1 during aeration， nitrosation rate (NO^-₂-N/NO^-_x-N) was always more than 93% during nitrification, and ammonia removal via simultaneous nitrification-denitrification was up to 87.6% when aeration was ended. So nitrification-denitrification via nitrite and simultaneous nitrification-denitrification (SND) were achieved in a single reactor by controlling DO concentration at 0.5 mg•L^-1. Based on theoretical analysis and calculations of the new technology, the specific growth rate of ammonium oxidizers was about 2.22—2.43 times than nitrite oxidizers at DO=0.5 mg•L^-1, and the anoxic area for denitrification was easily built in activated sludge in the DO condition.In conclusion,stable nitrogen removal from wastewater by simultaneous nitrification-denitrification via nitrite at normal temperature could be achieved so long as DO was controlled at 0.5 mg•L^-1.

摘要： 采用序批式活性污泥法，通过控制溶解氧浓度开发出处理高氮豆制品废水的新工艺.实验结果显示，当曝气阶段反应器内溶解氧浓度保持在0.5 mg•L^-1左右时，曝气过程中NO^-₂-N/NO^-_x-N的比率始终维持在93%以上，并且曝气结束时，有大约87.6%的氨氮是通过同步硝化反硝化途径去除的.因此，控制反应器内溶解氧浓度在0.5 mg•L^-1左右时，在一个反应器内同时实现了亚硝酸型硝化反硝化和同步硝化反硝化.经过理论计算和机理分析，在此溶解氧下，亚硝酸菌的比增殖速率近似为硝酸菌的2.22～2.43倍，并且低溶解氧容易在活性污泥颗粒内形成进行反硝化作用的缺氧区.因此，在常温下，只要采用溶解氧传感器控制SBR反应器内溶解氧浓度在0.5 mg•L^-1左右，就可以实现稳定的亚硝酸型同步硝化反硝化生物脱氮工艺.