Using sulfur and oxygen isotope to trace the source of sulphate in Baotuquan spring area of Jinan

In recent years, sulphate concentration of karst water in Jinan is increasing. In order to effectively prevent sulphate pollution and guarantee the safety of drinking water, it is very important to identify the source of sulphate pollution. Based on the systematic analysis of hydrogeological conditions in the study area, the authors identified the major sulphate pollution sources in Baotuquan spring area of Jinan by using sulfur and oxygen isotope technology according to the actual sampling data. The contribution rates of sulphate pollution sources were estimated by IsoSource mass conservation model. The results show that the major sulphate pollution sources were atmospheric sedimentation, sewage and soil. Among them, the contribution rate of atmospheric sedimentation source is the largest, with an average value of 53.9%, followed by sewage source, with an average value of 31%, and the contribution rate of soil source is the smallest, with an average value of 15.1%. This study provides a new method for the quantitative study of sulphate sources of groundwater in northern karst areas, and provides a scientific basis for the prevention and control of sulphate pollution in Baotuquan spring area of Jinan.