以改性河砂为除锰滤料,对模拟地下水进行过滤处理,研究了水力停留时间、pH值、溶解氧含量、Mn2+质量浓度等对除锰效率的影响。结果表明,水力停留时间为24min、溶解氧为7mg/L、中性及弱碱性、原水Mn2+质量浓度不大于2mg/L等条件下,改性河砂过滤可使出水Mn2+质量浓度持续稳定在0.1mg/L以下,符合国家饮用水标准。通过对改性河砂表面滤膜的电镜扫描和X射线能谱分析,初步确定了改性河砂表面滤膜对除锰发挥了重要作用,主要机理为吸附和自催化作用。
关键词:
改性河砂; 过滤; 除锰; 吸附; 自催化
In order to ameliorate the inferior efficiency of manganese removal and the lengthy period of maturation concerned in the common filter medium, the filter media for manganese removal were prepared by modifying the original river sand The effects of hydraulic retention time, pH value, DO, and Mn2+ concentration on manganese removal efficiency were studied by the filtration test of simulation groundwater. The mechanism of manganese removal was also preliminarily discussed in the test. The results show that the Mn2+ concentration of effluent is constantly lower than 0.1mg/L, which conforms with the state standards for drinking water; under the optimum conditions, the water residence time is about 24min, the content of dissolved oxygen is about 7mg/L, the pH value of the inflow is neutral or alkaline, and the concentration of manganese is no more than 2mg/L. The membrane of modified river sand surface plays a crucial role. The mechanism of manganese removal that is adsorption and self-catalysis processes is preliminary confirmed based on scanning electron microscopy and X-ray spectrum analysis for the filtration membrane of modified river sand surface.