Distribution And Correlation Of Fluoride Between Unconfined Water And Soil Of Inner Mongolia Tuoketuo County

Excessive fluoride in groundwater has become an important factor affecting our drinking water safety of arid and semi-arid areas of north. Among them, the excess fluoride of Inner Mongolia Tuoketuo County groundwater has seriously restricted the safety of drinking water and the development local economy. By combining hydrogeology, groundwater dynamics and hydrogeochemistry, the distribution and occurrence Regularity of unconfined water fluoride and soil fluoride in the study area are analyzed, and to further explore the mechanism of interaction and influence of both, mainly on the the following conclusions:1.The hydrochemical type of unconfined water are mainly NaCl type. Mixed CaHCO3, mixed CaMgCl type, CaCl type and NaHC03 type water are relatively small. This distribution of hydrochemical type in the study area is mainly due to the Shallow buried depth of the groundwater table, the ground strongly evaporating. Resulting in low solubility Ca2+, Mg2+ is easy to form precipitation, and NaCl type water due to high solubility, and thus become the main hydrochemical type of unconfined water in the study area.2.The Correlation analysis of the fluorine content of groundwater and groundwater other chemical components show:for unconfined aquifer, cation Ca2+ and F-most relevant, was a significant negative correlation, Proved that Ca2+ is the biggest influence on fluorine content in unconfined aquifer.3.The minimum value of unconfined water fluorine in study area is 0.15 mg/L, a maximum of 7.19 mg/L, with an average of 2.3mg/L. Overall, Overall, unconfined water fluorine content of lacustrine platform in the study area is higher than the fluvial plain. In most of the fluorine content of unconfined water in the study area is beyond the groundwater quality standard (GB/T14848-1993) Ⅲ water quality of upper limit of 1.0 mg/L, show that unconfined water quality has generated fluorine pollution, and has not as a drinking water source.4.Spatial distribution characteristics of groundwater and soil in fluorine concentration with high similarity, have shown a trend east to the west; the highest values are concentrated in central of Alluvial lake plains and Lacustrine platform.The lowest value appears in coast of the Daheihe river and the Yellow River and in large area west of Daheihe river.The study area in the eastern part of Man han mountain is the main recharge of groundwater and the geological period has experienced at least four times of basalt eruption that a large number of rich fluorine mineral in the long geological evolution, weathering and water rock interaction was brought into the inner band lacustrine sedimentary platform, which become an important source of fluoride in soil and groundwater.In addition, in the plains of the fluvial and lacustrine terraces in valleys between zones, low-lying, poor hydrodynamic conditions, combined with shallow groundwater depth, strongly influenced by evaporation, and further promote the groundwater fluoride enrichment.