天津市地下水硝酸盐污染现状与年际变化规律研究

Study on Nitrate Pollution in Groundwater and Interannual Change Regulation in Tianjin

摘要: 硝酸盐含量是衡量地下水水质的重要指标，直接关系到人类的健康。为了摸清天津市地下水硝酸盐污染现状，2005~2008年连续8年对天津市地下水进行了取样调查及硝酸盐含量监测，对地下水硝酸盐污染现状及年际变化规律进行了分析研究。结果表明，天津市地下水含量总体较低，平均值为6.82 mg/L，其中约14.98%的地下水样超过WHO饮用水标准，约10.84%的地下水样超过我国地下水质量标准。地下水硝酸盐含量年际之间变化较大，总体表现为先降低后增加后又趋于平缓的趋势，由2005年的11.88 mg/L降至2007年的3.59 mg/L，而后逐渐升高至2012年的7.52 mg/L。不同监测时期地下水10 mg/L、20 mg/L超标率与相应时期地下水平均含量均呈极显著正相关。地下水平均含量每升高1 mg/L，10 mg/L、20 mg/L超标率分别提高1.90和1.67个百分点。

Abstract: Nitrate content is an important index to evaluate the quality of groundwater which affects human health di-rectly. As to evaluate the nitrate contamination of groundwater in Tianjin, an eight-year, large-scale investigation and water-sampling analysis on nitrate concentration in Tianjin groundwater was performed from 2005 to 2008. At the same time, the nitrate pollution status and interannual change regulation were studied. The results showed that the average concentration of in groundwater was 6.82 mg/L, and about 14.98% samples exceeded the criterion of WHO drinking water quality, 10.84% samples exceeded the criterion of national drinking water quality. The interannual change of annual average concentration of has showed a trend which decreased firstly and then increased. The annual average concentration of has decreased from 11.88 mg/L in 2005 to 3.59 mg/L in 2007, and then increased to 7.52 mg/L in 2012 gradually. The over standard rate of 10 mg/L, 20 mg/L of different monitoring period and average concentration of of corresponding period were significantly positive correlated. The average concentration of was increased by 1 mg/L, the over standard rate of 10 mg/L, 20 mg/L were increased by 1.9% and 1.67% respectively.