Chemical Characteristics And Genesis Of Mineral Water In Southern Jiangxi Mountainous Areas

Drinking natural mineral water is a precious liquid mineral resource.Understanding its hydrochemical characteristics and formation mechanism provides a basis for rational development of mineral water in order to produce greater economic and social value.Taking Ningdu County,a typical mountainous area in southern Jiangxi Province as an example,this paper analyses the formation mechanism and hydrochemical characteristics of mineral water from the aspects of stratigraphic lithology,geological structure and hydrogeochemical conditions,which is of great social significance and economic value for developing the green industry of mineral water and realizing the exploitation and utilization of mineral water in mountainous areas of southern Jiangxi Province.The paper draws the following understandings:(1)NNE-trending and NE-trending structures are the main structures controlling mineral water in the region.They erode the hilly terrain of the structure and cut the terrain deeply.They provide a good place for the storage and migration of mineral water,and are conducive to the circulation of mineral water.The development of rock fracture near the tectonic belt is conducive to the infiltration of atmospheric precipitation,and runoff downward along the fracture is gushing out of the surface at the low position,which belongs to the canon.Fracture shallow circulation leaching mineral water of type I is widely distributed in mountainous areas with short runoff path,low temperature and small discharge,and abundant mineral water resources.(2)Most of the mineral water exposed in this area is weak alkaline water.Ca2+and Na+are the main cations,HCO3-is the main anion,and HCO3-Ca·Na water is the main groundwater type.According to the characteristics of water quality,it belongs to low mineralization and high metasilicic acid cold mineral spring.From the quality of water quality,it belongs to class I and class ? water,and the water quality is excellent.The main characteristic item of mineral water in this area is metasilicic acid,which belongs to metasilicic acid mineral water.It meets the requirements of various indicators in Drinking Natural Mineral Water Standard.The content of metasilicic acid in 36 groups(80%)samples is above 30 mg·L-1,and the monitoring indicators of mineral water are basically stable.(3)The formation of hydrochemistry of mineral water is related to the weathering and dissolution of silicates,which corresponds to the typical granite geological background in Ningdu County,through Gibbs diagram,ion ratio coefficient and correlation analysis.The granite in the mountainous area of southern Jiangxi has a high background of SiO2,which is the material basis for forming mineral water.The reverse simulation of hydrogeochemistry is carried out by PHREEQC software.The water-rock interaction and cation exchange of mineral water are determined by combining the saturation index and mineral transfer amount of each mineral.It is concluded that the dissolution of illite,biotite and albite and strong cation exchange are the main manifestations.