Study On Fluorine-Hydro-geochemical Characteristics Of Shallow Groundwater In The North Of Xingguo County,Jiangxi Province

Fluorine not only affects groundwater quality,but is also closely related to human drinking water safety.The distribution and behavioral characteristics of fluoride in groundwater are critical for areas where groundwater is the main source of drinking water.The research on the hydro-hydrogeochemical characteristics of groundwater in the northern part of Xingguo County is of great practical significance for the evaluation of groundwater resources and the identification and evaluation of groundwater environmental problems in the poverty alleviation project in southern Fujian.This thesis is based on the project of“Happy and Average Village:1:50,000 Hydrogeological Survey”?DD20179262?.Through field investigations,440 groundwater F^-contents were tested and the test data was collated.The Shukalev classification was used to determine the type of groundwater hydrochemistry.The spatial distribution characteristics of fluorine in groundwater of different aquifers were studied by mathematical statistics and fluorine contour method.The influencing factors of fluoride enrichment in groundwater were systematically analyzed.On this basis,the PHREEQC software was used to simulate the dissolution and precipitation conditions of fluorite in groundwater.According to the research,the fluorine in groundwater is mainly derived from the dissolution of fluorine-containing minerals.It mainly exists in the F^-form in groundwater,and the concentration of fluorine is positively correlated with the content of biotite,apatite and fluorine in the rock.It is also positively correlated with the pH,TDS,HCO₃^-and Ca²⁺of groundwater.The fluorine content in groundwater in the granite area is generally higher than that in loose rock and clastic rock.The fluorine content in groundwater in the study area is generally low,which is the result of the interaction between the larger precipitation in this area and the stronger water.The abnormal fluorine content is mainly related to fluorite mining.The favorable condition for fluorine enrichment in groundwater in the northern part of Xingguo County is that there is a certain content of fluorine-containing minerals in the rock.The disadvantages are better hydrodynamic conditions and groundwater environment with weak acidity,low HCO₃^-,low Ca²⁺and low TDS.In summary,although the humid climate mountain area has a certain content of fluorine-containing minerals in the rock,the better hydrodynamic conditions and the groundwater environment with weak acidity,low HCO₃^-,low Ca²⁺and low TDS make the content of fluorine in groundwater.Still low,groundwater dynamic conditions are an important factor in controlling the fluorine content in groundwater.