某污水处理系统生化池碱度与NH_(3)-N关系研究

Study on the Relationship Between Basicity and NH_(3)-N in a Wastewater Treatment System

针对深圳市坪山区某河道整治工程采用的一体化水处理设备在运行过程中发现生化池pH和碱度影响出水NH_(3)-N含量的问题,通过添加CaCO_(3)控制碱度,探究设备运行的优化碱度并对生化池碱度和NH_(3)-N的相互关系。结果表明,碱度在202~237 mg/L时,NH_(3)-N去除效果最好,此时CaCO_(3)的添加量为3.0~4.5 kg/h。CaCO_(3)的添加量为3.8 kg/h碱度条件下运行,NH_(3)-N去除效果显著且稳定。进出水碱度差和进出水NH_(3)-N的质量浓度差呈现线性关系,即每降解1 g的NH_(3)-N会消耗6.58 g碱度。CaCO_(3)补充碱度影响NH_(3)-N去除效果的机理是CaCO_(3)作为碳酸盐在维持系统酸碱平衡的同时,为微生物提供无机碳源,能显著提高NH_(3)-N的去除效率。

The pH and alkalinity of the biochemical pool affect the concentration of NH_(3)-N in the effluent of the integrated water treatment equipment in a river regulation project in Pingshan district,Shenzhen.The optimal alkalinity parameter of the equipment operation was explored,and the correlation between the alkalinity of the biochemical pool and NH_(3)-N was studied by adding CaCO_(3) to control the alkalinity.The results showed that the highest ammonia nitrogen removal rate under the alkalinity between 202~237 mg/L and the amount of CaCO_(3) is 3.0~4.5 kg/h.The results of continuous operation showed that the ammonia nitrogen removal effect is significant and stable under this alkalinity condition with the addition of CaCO_(3) at 3.8 kg/h.There is a linear relationship between the alkalinity difference and the ammonia nitrogen difference of inlet and outlet water,and the 6.58 g alkalinity will be consumed for the per gram NH_(3)-N degraded.This effect mechanism was CaCO_(3) as a carbonate provides an inorganic carbon source for microorganisms while maintaining the acid-base balance of the system,which can significantly improve the removal efficiency of NH_(3)-N.