填料对接触氧化滤柱去除地下水中铁锰的研究

研究了以河砂和锰砂为填料时，接触氧化滤柱对铁锰的去除效果以及反冲洗对去除效果的影响. 结果表明，在滤速为8.3m/h、进水pH值为6.8、溶解氧为1.7mg/L的条件下，河砂填料和锰砂填料滤柱对铁的去除效果分别需要9d和2d即可稳定，出水铁浓度均在0.3mg/L以下；河砂填料和锰砂填料滤柱对锰的去除效果分别需要48d和16d方可稳定，出水锰浓度均在0.1mg/L以下. 反冲洗之后，河砂滤柱对铁和锰的去除能力需要40min和80min才能完全恢复；锰砂滤柱对铁、锰的去除能力需要20min和40min才能完全恢复. 扫描电境对滤膜形态分析表明，成熟的除铁锰滤膜表面呈絮状，反冲洗之后滤料表面仍然附着有絮状滤膜，该絮状滤膜是反冲洗后除铁锰效果能够快速恢复的基础. 实际工程中可以采取价格便宜的河砂取代锰砂，由此可以节省填料投资的90%.

Fe and Mn removal from groundwater by a contact oxidation process with different fillings

Fe and Mn removal from groundwater by a contact oxidation process and the effects of backwash were studied. It takes 9 days to have stable Fe removal with a filter chamber filled with sand and 2 days for the filter chamber of manganese mineral filtration. Forty-eight days are needed to have stable Mn reinoval with a filter chamber filled with sand, and 2 days for a filter chamber of manganese mineral filtration. Forty minutes and eighty minutes are needed for the filter chamber filled with sand to recover the ability of Fe and Mn removal after backwash. Twenty minutes and forty minutes are needed for the filter chamber of manganese mineral filling to recover the ability of Fe and Mn removal after backwash. SEM photographs show that floculations adhere to the surface of the filter membrane, that is the basis for quick recover of Fe and Mn after backwashing. Manganese mineral can be replaced by the cheaper sand as filling. In doing so, the investment can be greatly decreased.