曝气生物滤池处理生活污水亚硝化的实验研究

Research on partial nitritation for domestic sewage by biological aerated filter

为探究低氨氮生活污水亚硝化的可行性,采用高负荷生物滤池-上向流曝气生物滤池（UBAF）两段式反应器考察水流方向对高负荷生物滤池去除COD、氨氮效果及温度、DO对UBAF亚硝化效果的影响.结果表明,在水力负荷为0.58 m3/（m2·h）、COD容积负荷为2.30 kg/（m3·d）、气水比为3.6∶1、常温条件下,上向流进水方式能够获得稳定的低COD、高氨氮的二级出水.在水温30~33℃、DO 2.5~3.0 mg/L、进水pH 7.8~8.1条件下,UBAF出水氨氮平均转化率为84.58%,亚硝氮平均质量浓度达23.01 mg/L.UBAF反应器中各种含氮化合物沿程变化及FISH检测表明,在反应器末段存在一定程度的同步亚硝化厌氧氨氧化作用.该两段式反应器能驯化单独的脱碳、脱氮优势菌群,实现低氨氮生活污水的亚硝化.

To study the feasibility of partial nitritation of domestic sewage with low ammonia nitrogen, actual domestic sewage was treated by high rate bio-filter and up-flow biological aerated filter（UBAF）. The effect of flow direction on the performance of high rate bio-filter removing COD and NH4 ＋ - N and the effect of temperature and DO on the efficiency of UBAF for partial nitritation were researched. Results showed that at the hydraulic loading of 0.58 m3/（ m2 · h）, COD volume loading of 2.30 kg/（ m3 · d）, air-water ratio of 3.6：1 and room temperature, up-flow filtration achieved high COD and low ammonia-nitrogen removals. Ammonia nitrogen removal rate reached 84.58% and nitrite content in the effluent of UBAF achieved 23.01 mg/Lon the conditions of temperature 30-33 ℃, DO 2.5 -3.0 mg/L and pH value 7.8 -8.1. Further study on the change of nitrogenous compounds in different depth combining with FISH demonstrates that a certain degree CANON process could exist at the end of UBAF. The two-stage reactor could domesticate decarbonizing and denitrifying bacterias independently, the partial nitritation of domestic sewage with low ammonia nitrogen can be achieved.