反硝化生物滤池深度脱氮机理

研究了反硝化生物滤池对污水中硝酸盐氮的脱氮机制及其影响因素。结果表明,在实验室小试条件下,反硝化生物滤池启动14 d后出水基本达到稳定,NO3--N和TN的去除率分别为80%～88%和76%～80%,COD的去除率达到80%以上。稳定运行期,在室温20～29℃、水力负荷为1.5～2 m3/(m2.h)、COD/TN为3.7～4.5的条件下,反应器对NO3--N和TN的去除率分别为70%～85%和47%～64%,且在运行过程中出现了少量NO2--N的积累。分析反硝化生物滤池沿水流方向有机物浓度及氮形态分布发现,沿水流方向NH4+-N浓度基本保持不变;NO2--N浓度在滤层底部至40 cm高处积累较为明显,其后浓度基本不变。

Denitrification biological filter as tertiary treatment for nitrogen removal

The mechanism of nitrogen removal from wastewater by denitrification biological filter(DNBF) and the related influencing factors were investigated.The results showed that the start–up period of the DNBF was performed when ran after 14 days,and the removal efficiencies of NO-3-N and TN were 80%~88% and 76~80%,respectively,while the removal efficiency of COD was over 80% in the laboratory-scale experiments.In stable running period of the DNBF reactor,the removal efficiency of NO-3-N and TN kept stable with the removal efficiency of 70%~85% and 47%~64%,respectively,when the water temperature was 20~29℃,hydraulic loading was 1.5~2 m3/(m2·h),and COD/TN was 3.7~4.5.Meanwhile,a little NO-2-N accumulated in the effluent of DNBF.The level of NH+4-N was approximately unchanged through the filter,while the level of NO-2-N accumulated from the bottom to 40 cm of the filter layer,and then kept stable.