Investigation on Nitrate Concentration in Groundwater in Seven Provinces (City) Surrounding the Bo-Hai Sea

Abstract

Nitrate-nitrogen (NO-N) is an important index to estimate drinking water quality which affects human health directly. Nitrate-N in groundwater water is a very serious problem in many parts of China. So the status of NO-N content in groundwater was investigated to evaluate drinking water quality in 7 provinces of north China such as Beijing, Hebei, Henan, Shandong, Liaoning, Tianjin, and Shanxi. The results showed that the content of NO-N in groundwater was a little higher with the average level 11.9 mg·L-1, and about 34.1% exceeded the criterion of WHO. The content of NO-N in groundwater was greatly affected by different types of land use and groundwater depth. The vegetable land had much more NO-N than orchard, cropland and breeding animals, the average concentration was 21.4 mg·L-1, 14.3 mg·L-1, 10.4 mg·L-1 and 7.3 mg·L-1, respectively. NO-N decreased with groundwater depth, and reached 21.7 mg·L-1, 15.9 mg·L-1, 8.8 mg·L-1, 5.8 mg·L-1 and 3.8 mg·L-1 within 10 m, 10~20 m, 20~50 m, 50~100 m and exceed 100 m, respectively. In addition, the content of NO-N varied much among different provinces because of the different fertilization.