生物砂滤池去除亚硝酸盐氮的效果及影响因素分析

以邯郸市滏阳河微污染原水为对象，研究了生物砂滤池对NO2-N的去除效果及温度、NH4^＋-N、NO2^--N、CODMn反冲洗等对去除NO2^--N的影响。试验结果表明：生物砂滤池对NO2^--N的平均去除率为89．3％；水温是影响生物砂滤池去除NO2^--N效果的主要因素，低水温时去除NO2^--N的效果较差；在水温相同的条件下，当原水NH4^＋-N浓度较高时生物砂滤池出水NO2^--N浓度也较高；原水NO2^--N浓度越高则对其去除率越高；在水温及NH4^＋-N和NO2^--N浓度相同的条件下，原水CODMn值越大则对NO2^--N的去除率越低，反之则越高。为防止附着在滤料表面生物量的流失，宜采用不加氯水进行反冲洗；为保证对NO2^--N的去除效果，应控制水中溶解氧〉5mg／L。生物砂滤池去除NO2^--N的效果优于普通砂滤池，是一种经济、有效的给水处理技术。

Removal Effect of Nitrite Nitrogen by Biological Sand Filter and Its Influencing Factor

The effects of NO~-_2-N removal in micro-polluted water and its influencing factors such as temperature,NH~+_4-N,NO~-_2-N,COD_(Mn),and backwash etc.were investigated.The result shows that the removal of NO~-_2-N by biological sand filter is apparent and its average removal rate is(89.3%).Temperature is the main influencing factor.The removal effect is ineffective at low temperature.At the same temperature,when NH~+_4-N concentration in raw water is high,the effluent NO~-_2-N concentration is also high.Under the same temperature and same concentration of NH~+_4-N and NO~-_2-N,the higher the COD_(Mn) is,the lower removal efficiency of NO~-_2-N is,and the higher of the opposite.In order to avoid the losing of the biomass on filter,water of no chlorine is used in backwashing.And DO is kept above 5 mg/L to ensure the removal of NO~-_2-N.The removal of NO~-_2-N by biological sand filter is better than ordinary sand filter.Biological sand filter is an economic and effective treatment technique.