离子交换树脂脱除地下水中的硝酸盐

Nitrate Removal from Groundwater by Ion Exchange Resin Processes

地下水是我国华北地区最重要的饮用水水源之一,特别是华北农村生活饮用水几乎全部来自地下水。然而,华北又是我国地下水硝酸盐污染比较严重的地区。研究开发适合华北农村分散式供水特点的地下水脱硝酸盐技术,对于保障农村的饮水安全具有十分重要的意义,为此把简单、高效且投资和运行费用相对较低的离子交换法用于脱除地下水中的硝酸盐。考察了普通强碱性阴离子交换树脂Purolite A 300E和硝酸盐选择性强碱性阴离子交换树脂Purolite A 520E脱除地下水中硝酸盐的效果,比较了地下水中SO42-和Cl-等阴离子对两类不同树脂交换性能的影响。结果表明,Purolite A 300E和Purolite A 520E树脂均能有效地去除地下水中的硝酸盐,两者的NO3--N饱和交换容量分别为49.02和48.54 mg/g。但是,当地下水中含有较高浓度的SO42-或Cl-时,Purolite A 520E脱除硝酸盐的效果明显优于Purolite A 300E。

Groundwater is one of the most important drinking water source in North China,especially in some rural areas of North China,groundwater may be the only drinking water source.But unfortunately the groundwater has badly been contaminated by nitrate in North China.To research and develop an appropriate nitrate removal process which can fit in with the needs of the rural area water supply has great significance for guaranteeing drinking water safety of peasants.Thus,the ion exchange process with characteristics of simple,efficiency as well as relatively low investment and operating cost was applied to remove nitrate from groundwater.The performances of nitrate removal from groundwater by a strongly basic anion exchange resin（Purolite A 300E） and a nitrate selective macroporous strong basic anion resin（Purolite A 520E） were evaluated,and the effect of sulfate and chloride in groundwater on these two resins＇ efficiency was compared.The results show that the nitrate in groundwater can be effectively removed by both Purolite A 300E and Purolite A 520E resins,and the saturation capacity of the two types of ion exchange resins on NO3——N are 49.02 and 48.54 mg/g,respectively.However,when concentration of the sulfate or chloride in the groundwater is high,the efficiency of Purolite A 520E resin may be better than that of Purolite A 300E.