氨氮污染地下水的动态实验研究

Dynamic Experiment Research on Ammonia Nitrogen as the Major Nitrogen Form Polluting Groundwater

目的研究浑河流域水文地球环境化学特征对地下水中氮表现形式的控制机理,为地下水修复与水源开发建设提供科学的理论指导.方法通过室内动态实验模拟污染河流中的氨氮渗入地下后的迁移转化过程.实验土柱中装填入浑河流域第四纪松散沉积物在110 m深的钻孔地质剖面中有代表性的岩层,通过间歇监测水样中氨氮、硝酸盐氮、亚硝酸盐氮、铁离子、锰离子、氯离子、高锰酸盐指数、pH值等指标随时间的变化,分析三氮转化的机理及周围环境因素对其的影响作用.结果研究结果表明在地下水pH<7,高含量铁、锰离子所营造的还原性环境中氨氮是污染地下水的主要氮素形态.用统计的方法分析各指标变化趋势发现:氨氮与环境中的锰、高锰酸盐指数呈正相关;与硝酸盐氮负相关.结论区域水文地球化学场与饱水岩层的岩性和结构对氮转化的方向有决定作用.

The paper researched on the control mechanism of environmental hydro-geochemical feature of Hunhe River basin for nitrogen forms in groundwater.And this offers scientific theory-guidance to groundwater remediation and water source development.By means of dynamic lab-experiment,we simulate the migrating and transforming course of ammonia nitrogen in polluted river permeating in soil column.The experimental soil column was filled with representative sand of Quaternary period loose sediment which are taken from a 100m deep drilling section near the Hunhe River bank.And through intermittentlg.monitoring the differences between time and the indexes of water sample such as ammonia nitrogen,nitrate,nitrite,iron ions,manganese ions,chloride ion,CODMn as well as PH value,we analyse the transformation mechanism among different sorts of nitrogen and the influence of other environmental factors on nitrogen transformation.The result shows that in reducing environment of PH〈7 and high concentration of iron ions and manganese ions in groundwater,the major nitrogen form polluting groundwater is ammonia nitrogen.Using statistic method to analye the change tendency of each index,ammonia nitrogen appears positive correlation with manganese ions and CODMn,and negative correlation with nitrate.The conclusion is that regional environmental hydro-geochemical field exists,and water saturated rock stratum characters and structure decide the direction for nitrogen transformation.