Abstract:

Temperature is one of the most critical operational parameters for biological purification filter. In order to investigate the removal efficiency of ammonia, iron and manganese in the process of water temperature dropping from about 25℃ to 6℃, the biological purification filter was used to treat the simulated groundwater containing ammonia, iron and manganese. The results showed that the concentration of ammonia, total iron and manganese in the effluent was lower than 0.15mg/L, 0.1mg/L and 0.05mg/L, respectively, which were all lower than the national standards. Total iron and manganese in the effluent were not adversely affected by the decrease of water temperature, but ammonia in the effluent gradually increased from about 0.02mg/L to about 0.12mg/L. Further analysis showed that iron was mainly removed in 0—0.4m of the filter layer, and iron removal was not affected by the variation of water temperature. Ammonia and manganese were mainly removed in 0—0.8m of the filter bed, and their concentrations along the filter bed obviously increased with the decrease of water temperature. Biological ammonia and manganese removal were observed to follow a first-order kinetic reaction. When the water temperature was 24.6℃, 15.3℃ and 6.7℃, the kinetic constants k were 0.154min^-1, 0.186min^-1; 0.143min^-1, 0.175min^-1; 0.103min^-1 and 0.163min^-1, respectively, and the half reaction times t_1/2 were 4.51min, 3.72min; 4.83min, 3.96min; 6.72min and 4.24min, respectively. With the decrease of water temperature, the removal efficiency of ammonia and manganese was obviously and adversely affected.

Key words: ammonia, iron, manganese, biological purification filter, temperature, kinetics, groundwater

摘要：

温度是生物净化滤柱运行的一个重要参数，采用生物净化滤柱处理模拟含氨氮、铁、锰地下水，考察水温从约25℃降到约6℃过程中氨氮、铁、锰的去除效果。结果表明，出水氨氮、总铁、锰的浓度分别低于0.15mg/L、0.1mg/L、0.05mg/L，均低于国家标准。出水总铁、锰均未受到水温下降的影响，但是出水氨氮浓度逐渐从约0.02mg/L升高到约0.12mg/L。进一步分析发现，铁主要在滤层的0~0.4m段去除，去除效果没有受到水温变化的影响。氨氮、锰主要在滤层的0~0.8m段去除，其沿程浓度均随水温降低而明显升高。氨氮、锰的生物去除符合一级动力学反应，水温为24.6℃、15.3℃、6.7℃时，两者的动力学常数k分别为0.154min^-1、0.186min^-1，0.143min^-1、0.175min^-1，0.103min^-1、0.163min^-1；半反应时间t_1/2分别为4.51min、3.72min，4.83min、3.96min，6.72min、4.24min。随着试验水温的降低，氨氮、锰的去除效果明显受到影响。

关键词: 氨氮、铁、锰, 生物净化滤柱, 温度, 动力学, 地下水