中文摘要：

摘要针对广州市地下水硝态氮污染状况及其影响因素开展研究。结果表明，广州市地下水硝态氮质量浓度为（8．53±7．57）mg／L，对照世界卫生组织（WHO）规定的饮用水硝态氮限值（10mg／L），所采集的地下水样品超标率达到34．97％。地下水硝态氮的主要来源有生活污水、工业废水、农业化肥和酸雨。地下水硝态氮浓度受到土地利用类型的影响。其中，城区地下水硝态氮污染最严重（超标率为48．22％），其次为水稻田（超标率为40．00％）与菜园（超标率为36．25％），林地地下水硝态氮污染最轻（超标率为6．25％）。在垂向分布上，地下水硝态氮浓度与地下水埋深呈负相关关系。埋深介于2～5m时，硝态氮浓度较高且有超标的潜在危险；埋深介于5～23m时，地下水硝态氮污染程度减轻；当埋深大于23m时，硝态氮质量浓度基本稳定在2mg／L左右，与珠江三角洲地下水硝态氮背景值接近。

英文摘要：

Abstract： Nitrate nitrogen pollution in groundwater of Guangzhou and its impact factors were investigated and analyzed. The results showed that nitrate nitrogen mass concentrations of the groundwater samples collected were （8.53±7.57） mg/L and 34.97% of the samples exceeded the World Health Organization （WHO） limit for nitrate ni- trogen in drinking water （10 mg/L）. Nitrate nitrogen in groundwater mainly originated from the inappropriate emis- sions of domestic and industrial sewage,agricultural fertilizers and the severe acid precipitation of Guangzhou. Nitrate nitrogen concentrations in groundwater were significantly impacted by the land use types. Nitrate nitrogen pollution was the most serious in urban groundwater （48.22% exceeded 10 mg/L）, followed by paddy field groundwater （40.00±exceeded 10 mg/L） and vegetable field groundwater （36.25%exceeded 10 mg/L）. Nitrate nitrogen concen- trations in woodland groundwater were the lowest （6.25% exceeded 10 rag/L）. Nitrate nitrogen concentrations in groundwater were negatively related to groundwater depths. When the groundwater depth was between 2 m and 5 m, a potential risk existed that nitrate nitrogen concentrations in groundwater might exceed the WHO limit; nitrate ni- trogen concentrations decreased when the groundwater depth was between 5 m and 23 mg/L finally,when groundwater depth exeeeded 23 m, the nitrate nitrogen mass concentrations were basically stable at 2 rag/L, which was close to the background value of nitrate nitrogen concentrations in groundwater of the Pearl River Delta.