柘城地区浅层地下水中“三氮”污染特征及机理分析

Analysis of“Three Nitrogen”pollution characteristics and mechanism in shallow groundwater of Zhecheng area

通过研究柘城地区浅层地下水中"三氮"污染情况、污染分布特征,分析研究了污染源、污染机理及防治对策。结果表明:该区硝酸盐氮基本不超标、氨氮超标面积较大,亚硝酸盐氮超标呈点状分布;造成该区浅层地下水"三氮"污染的主要原因是农业上含氮化肥、农药的过量使用,其次是工业废水及生活污水的排放。包气带岩性颗粒较粗,厚度较薄以及该区地下水为偏碱性水是研究区氨氮大面积超标的重要原因。

By studying on pollution situation and distribution of＂three nitrogen＂in Zhecheng area,this paper analyzes the pollution sources、Pollution mechanism and control countermeasures.The results show that nitrate nitrogen are in limit almost,ammonia nitrogen exceeding with large area and nitrite nitrogen pollution present dotted distribution;excessive use of agricultural nitrogen fertilizer and pesticide is the main reason of shallow groundwater pollution of ＂three nitrogen＂,the second is industrial wastewater and domestic sewage discharge.Lithology and thickness of vadose zone,weakly-alkaline water are important reason why ammonia nitrogen is widely distributed.