净化低温含铁高锰地下水锰极限浓度的探求

Maximum Manganese Concentration in Biofilter for Treatment of Low-temperature Groundwater Containing Iron and High Concentration of Manganese

采用生物除铁除锰滤池处理低温含铁高锰地下水,考察了不同滤速下锰的极限浓度。以滤柱模拟水厂滤池,在水温为5~6℃、溶解氧为8.3~8.5 mg/L、进水总铁为0.5~3.0 mg/L的条件下,当滤速分别为6、7、8 m/h时,锰的极限浓度分别为(8.0~8.5)、(7.0~7.5)、(6.0~6.5)mg/L;进水总铁为12~20 mg/L时锰的极限浓度为(5.0~5.5)、(4.3~4.7)、(3.5~3.8)mg/L。沿程分析发现:随着进水锰浓度的升高,锰的去除带逐渐向下延伸;沿滤层向下一定深度,相同厚度滤料的除锰量逐渐减少;锰浓度升高过程中对除铁无影响。在滤层厚度和温度一定的条件下,锰的极限浓度受进水总铁浓度和滤速的影响,进水总铁浓度和滤速较低时其极限浓度较高。

A pilot-scale biofilter was constructed to investigate the maximum manganese concentra- tion in the treatment of low-temperature groundwater containing iron and high concentration of manga- nese. The experimental conditions were as follows： temperature was 5 to 6 ℃, and the dissolved oxygen in influent was 8.3 to 8.5 mg/L. When the filtration rate was 6, 7 and 8 m/h, respectively, the maxi- mum concentration of manganese with the total iron concentration of 0.5 to 3.0 mg/L was 8.0 to 8.5 mg/ L, 7.0 to 7.5 mg/L and 6.0 to 6.5 rag/L, respectively, and the maximum concentration of manganese with the total iron concentration of 12 to 20 mg/L was 5.0 to 5.5 mg/L, 4.3 to 4.7 mg/L and 3.5 to 3.8 mg/L, respectively. The manganese removal band was gradually extended downward and there was no influence of manganese concentration increasing in influent on iron removal; along the filter depth, manganese removal quantity was reduced in the same depth of the filter. The maximum concentration of manganese was limited by the concentration of total iron in influent and the filtration rate under the condi- tion of the given filter layer thickness and temperature. When the concentration of total iron in influentand the filtration rate were low, the maximum concentration of manganese could be high.