The Source Apportionment Of Groundwater Nitrate Nitrogen Pollution

The riparian groundwater area is an important water source of water supply in Shenyang. Nitrate nitrogen is one of the main pollutants in the groundwater. To carry out the source of nitrate nitrogen is very importance to protecting of groundwater.Based on the study area land use type and pollution source investigation, and used traditional water chemistry analysis and clustering analysis, the method of combining the study of hydrochemical characteristics of groundwater in the studied area and pollution characteristics were analyzed. Identify the nitrate nitrogen pollution of groundwater preliminarily by nitrogen-oxygen stable isotope techniques, then Combine factor analysis to extract common factors. Reveal the factors affecting the groundwater chemistry of the water, further identify the nitrate pollution sources of the study area. Finally, with the aid of the isotope source analytical model based on bayesian analysis, to analyses the contribution of the nitrate nitrogen pollution sources in the study area, The main conclusions are listed below.(1) The hydrochemical characteristics of groundwater were different between the south and the north of the area. Significant differences chemical types of groundwater in north and south of the study area. The South has main type of HCO3-Ca · Na and the north has main type of Cl · SO4- Mg · NA. The study area was divided into A, B two region because of the differences in water chemistry characteristics. Region A located in the south of the study area near the Hun River with alkaline characteristics and significantly oxidation. Region B is a small river in the northwest region of the study area, showing acidic characteristics, reducing significantly.(2) Nitrogen and oxygen stable isotopic analysis results show that the waste and sewage are the main source of nitrate nitrogen pollution of groundwater in the study area, and Natural factor’s contribution to the research area of groundwater nitrate nitrogen pollution is minimal. The north and south of the study area are different in migration and transformation of nitrate nitrogen. However, Southern region mainly bynitrates denitrification, the northern region mainly nitrate nitrogen by nitrification.(3)Factor analysis results suggest that the study area in the south mainly comes from agricultural ammonium nitrate pollution and high nitrogen isotope value source of manure, the main source of nitrate nitrogen in northern and sewage, waste pollution,etc.(4)The isotope source analytical model based on bayesian analysis shows that the waste and sewage are the main source of nitrate nitrogen pollution of groundwater in the study area, and Natural factor’s contribution to the research area of groundwater nitrate nitrogen pollution is minimal. As a whole, nitrogen of the research area is mainly from manure and sewage pollution, and the contribution rate is 60.5%; The atmospheric deposition pollution and nitrate pollution contribution rate is roughly the same, respectively, 19.5%, 20%...