前置+后置反硝化滤池强化脱氮效果研究

Study on Nitrogen Removal Effect of Pre and Post Denitrification Filter

通过中试实验研究了三级组合生物滤池强化脱氮效果,考察了第二级好氧滤柱回流比对工艺前置反硝化的影响,第三级滤池外加碳氮比对后置反硝化强化脱氮效果的影响。结果表明,在进水流量为0.5 m^3/h,水温为18℃左右,第二级好氧滤柱气水比为3:1时,在回流比为100%时,前置反硝化脱氮能达最佳效果,TN去除率为54.07%,出水TN浓度平均值为19.94 mg/L,不同回流比下,COD、NH_4^+-N均有较高去除率。为进行强化脱氮,在第三级缺氧滤柱前投加碳源,碳氮比为7:1时,第三级对TN去除率为40.7%,出水TN平均值为11.84 mg/L。三级组合生物滤池结合前置和后置反硝化工艺对TN有很好的去除效果,稳定运行后,系统对TN平均去除率达到72.96%。

The effect of nitrogen removal by three stage combined biofilter was studied in pilot scale, test the influence of the reflux ratio of second stage aerobic filter column on pre-denitrification, and test the influence of the C/N ratio of third stage filter on post-denitrification. The result show that when the influent flow was 0.5 m3/h,the water temperature was about 18 ℃, the average value of TN concentration was 19.94 mg/L. Under different reflux ratio, COD and ammonia nitrogen had high removal rate. In order to enhance the removal of nitrogen, the test added carbon source before the third stage anoxic filter column. When C/N ratio was 7, the TN removal rate of third stage was 40.7%,the average effluent value of TN was 11.84 mg/L. Three stage combined biological filter combined pre and post denitrification process, had a good removal effect on TN, the average removal rate of TN was achieved 72.96%.