曝气生物滤池好氧反硝化脱氮的研究

采用某钢铁厂含氮废水,利用生物滤池工艺,研究了曝气生物滤池的挂膜、溶解氧、碳氮比对好氧反硝化脱氮的影响.结果表明,利用富含好氧反硝化菌的富集菌液进行挂膜,16 d基本完成挂膜,脱氮率90%.当溶解氧较低时(DO为1.5～4.2mg/L),随着溶解氧的增大,反硝化效率提高,其中以DO为3.5 mg/L时的效果最好,脱氮率为95.4%.随着曝气量继续增加,脱氮率有所下降,当DO为8.0 mg/L时,脱氮率仍有44.8%.可推断系统中有好氧反硝化菌,存在以O2作为电子受体的好氧反硝化现象.随着碳氮比(COD/N)增大,反硝化效果提高.当COD/N为6～7时,基本能够满足反硝化所需碳源.此时脱氮率大于96%,亚硝态氮在整个反应过程中几乎没有积累,COD去除率在85%左右.

Study on Aerobic Denitrification in BAF

The compound inoculation was investigated, and the influences of COD/N ratio and dissolved oxygen on aerobic denitrification in biological aerated filter(BAF) were tested while treating nitrate wastewater from an iron factory. The results show that the efficiency of denitrification was improved, when the concentration of dissolved oxygen was increased from 1.5 mg/L to 4.2 mg/L.When dissolved oxygen value was 3.5 mg/L, the efficiency was the best, it was 95.4%; but the result was opposite when it were increased. When dissolved oxygen value was 8.0 mg/L; the efficiency was still 44.8%.it can be inferred that there were aerobic denitrifer, and oxygen was the electron accepter during aerobic denitrification. The efficiency of aerobic denitrification was improved. When COD /N were 6-7, it can meet the requirement for carbon source during aerobic denitrification, the removal rate of nitrate nitrogen and COD were up to 96%, 85% respectively. Almost no nitrite nitrogen accumulated.