济南市新旧动能转换区浅层地下水硝酸盐污染特征

Shallow Groundwater Nitrate Pollution Features in Jinan City Zone to Replace Old Growth Drivers with New Ones

为查清济南市新旧动能转换先行区浅层地下水NO_(3)^(-)污染问题,对研究区7种污染源类型64件浅层地下水样品水质结果进行统计分析后认为:受人类活动影响,地下水中NO_(3)^(-)含量的高低往往与几种特定的水化学类型存在对应关系。4类主要污染源类型浅层地下水NO_(3)^(-)含量一般顺序为:垃圾渗滤液>禽畜养殖>生活污水>农业种植。垃圾渗滤液下渗导致的NO_(3)^(-)污染对应的主要地下水化学类型为HCO_(3)·Cl^(-)Na·Mg型,粪便渗滤液及尿液下渗主要对应产生HCO_(3)·SO_(4)-Na·Mg型、生活污水入渗对应产生HCO_(3)·Cl^(-)Na·Ca型,农业种植区主要对应HCO_(3)-Na·Ca型。离子相关性分析表明,NO_(3)^(-)含量与Ca^(2+)、Cl^(-)存在相关关系。研究区以农业种植为主,大量氮素化肥和石灰等土壤改良剂的使用是导致浅层地下水NO_(3)^(-)与Ca^(2+)相关的主要因素。NO_(3)^(-)与Cl^(-)在地下水中同属较稳定离子,由长期的人类活动排放、入渗积累或蒸发浓缩富集,是一个地区人类活动密集程度和历史长度的综合反映,提出了NO_(3)^(-)与Cl^(-)质量浓度联合评价地下水污染的基本方法。

To identify shallow groundwater NO_(3)^(-)pollution issue in the Jinan City prior zone to replace old growth drivers with new ones has carried out statistical analysis for water quality tested results of 64 shallow groundwater samples from 7 pollution sources;the study has considered that impacted by human activities,groundwater NO_(3)^(-)content differences have existed correspondence with several specific hydrochemical types.General NO_(3)^(-)content sequence of 4 categories main pollution source type shallow groundwater is:waste percolation filtrate>livestock farming>domestic sewage>agricultural cultivation.Waste percolation filtrate down infiltration caused NO_(3)^(-)pollution corresponding main groundwater hydrochemical type is HCO_(3)·Cl^(-)Na·Mg type,feces percolation filtrate and urine down infiltration mainly corresponding HCO_(3)·SO_(4)-Na·Mg type,domestic sewage infiltration corresponding HCO_(3)·Cl^(-)Na·Ca type,agricultural cultivation mainly corresponding HCO_(3)-Na·Ca type.Ion correlation analysis has shown that NO_(3)^(-)content and Ca^(2+),Cl^(-)is correlated.Study area economy is mainly agricultural cultivation,the use of a massive nitrogen fertilizer and lime etc soil ameliorant is the main factor to cause correlation between NO_(3)^(-)and Ca^(2+)in shallow groundwater.NO_(3)^(-)and Cl^(-)both belong to rather stable ion,from human activities discharge chronically,infiltration build-up or evaporation enrichment,thus an integrated expression of human activities density and length of history in an area.The study has also proposed basic approach to assess groundwater pollution from NO_(3)^(-)and Cl^(-)combined mass concentration.