Major geochemical controls on fluoride enrichment in groundwater: A case study at Datong Basin, northern China

Abstract

Hydrogeochemical investigations were carried out in the Datong (大同) Basin, northern China to understand the sources and mechanisms of fluoride enrichment in the groundwater. The results indicate that fluoride concentrations reached up to 7.2 mg/L, and the hydrochemical type changed from Ca-HCO₃, Ca-Mg-HCO₃ water in the recharge areas to Na-HCO₃, Na-Mg-HCO₃ in the flow-through area and ultimately to Na-Cl-HCO₃, Na-SO₄-Cl and Na-Cl in the discharge areas. The total fluorine contents in the soils ranged between 277.6 and 1 292.5 mg/kg, which can provide large amounts of fluorine from fluorine-bearing minerals, such as fluorite, biotite and amphibole. The concentration of water-soluble fluorine ranged from 3.9 to 49.9 mg/kg (mostly less than 1% of the total fluorine) in the soils and rocks that, may have released sufficient fluorine into the groundwater. The results of PHREEQC simulations indicate that most of the analyzed samples are under-saturated with respect to fluorite (CaF₂) from the recharge area to the discharge area. The fluctuation of F concentration in the 11 months indicates that the seasonal variation and the agricultural activity also affect the fluoride content in the groundwater. Fluoride enrichment in groundwater is predominantly controlled by fluorite solubility, residence time, evapotranspiration intensity and seasonal variation in this arid and semi-arid area.

Keywords

hydrogeochemical / Datong Basin / fluoride / groundwater

References

Abu Rukah Y, Alsokhny K. Geochemical Assessment of Groundwater Contamination with Special Emphasis on Fluoride Concentration, North Jordan. Chemie Der Erde-Geochemistry, 2004, 64(2): 171-181.

Battaleb-Looie S, Moore F, Jafari H, . Hydrogeochemical Evolution of Groundwaters with Excess Fluoride Concentrations from Dashtestan, South of Iran. Environmental Earth Sciences, 2012, 67(4): 1173-1182.

Delrazo L M, Corona J C, Garciavargas G, . Fluoride Levels in Well-Water from a Chronic Arsenicism Area of Northern Mexico. Environmental Pollution, 1993, 80(1): 91-94.

Deng Y M, Nordstrom D K, McCleskey B R. Fluoride Geochemistry of Thermal Waters in Yellowstone National Park: I. Aqueous Fluoride Speciation. Geochimica et Cosmochimica Acta, 2011, 75(16): 4476-4489.

Fung K F, Zhang Z Q, Wong J W C, . Fluoride Contents in Tea and Soil from Tea Plantations and the Release of Fluoride into Tea Liquor during Infusion. Environmental Pollution, 1999, 104(2): 197-205.

Furi W, Razack M, Abiye T A, . Fluoride Enrichment Mechanism and Geospatial Distribution in the Volcanic Aquifers of the Middle Awash Basin, Northern Main Ethiopian Rift. Journal of African Earth Sciences, 2011, 60(5): 315-327.

Guo H M, Wang Y X. Hydrogeochemical Processes in Shallow Quaternary Aquifers from the Northern Part of the Datong Basin, China. Applied Geochemistry, 2004, 19(1): 19-27.

Guo H M, Wang Y X. Geochemical Characteristics of Shallow Groundwater in Datong Basin, Northwestern China. Journal of Geochemical Exploration, 2005, 87(3): 109-120.

Guo Q H, Wang Y X, Ma T, . Geochemical Processes Controlling the Elevated Fluoride Concentrations in Groundwaters of the Taiyuan Basin, Northern China. Journal of Geochemical Exploration, 2007, 93(1): 1-12.

Jacks G, Bhattacharya P, Chaudhary V, . Controls on the Genesis of Some High-Fluoride Groundwaters in India. Applied Geochemistry, 2005, 20(2): 221-228.

Kim K, Jeong G Y. Factors Influencing Natural Occurrence of Fluoride-Rich Groundwaters: A Case Study in the Southeastern Part of the Korean Peninsula. Chemosphere, 2005, 58(10): 1399-1408.

Li J X, Wang Y X, Xie X J. Hierarchical Cluster Analysis of Arsenic and Fluoride Enrichments in Groundwater from the Datong Basin, Northern China. Journal of Geochemical Exploration, 2012, 118: 77-89.

McInnes P M, Richardson B D, Cleatonjones P E. Comparison of Dental Fluorosis and Caries in Primary Teeth of Preschool-Children Living in Reid High and Low Fluoride Villages. Community Dentistry and Oral Epidemiology, 1982, 10(4): 182-186.

Reddy D V, Nagabhushanam P, Sukhija B S, . Fluoride Dynamics in the Granitic Aquifer of the Wailapally Watershed, Nalgonda District, India. Chemical Geology, 2010, 269(3–4): 278-289.

Salve P R, Maurya A, Kumbhare P S, . Assessment of Groundwater Quality with Respect to Fluoride. Bulletin of Environmental Contamination and Toxicology, 2008, 81(3): 289-293.

Saxena V, Ahmed S. Dissolution of Fluoride in Groundwater: A Water-Rock Interaction Study. Environmental Geology, 2001, 40(9): 1084-1087.

Tang Y L, Guan X H, Su T Z, . Fluoride Adsorption onto Activated Alumina: Modeling the Effects of pH and Some Competing Ions. Colloids and Surfaces A—Physicochemical and Engineering Aspects, 2009, 337(1–3): 33-38.

Turner B D, Binning P, Stipp S L S. Fluoride Removal by Calcite: Evidence for Fluorite Precipitation and Surface Adsorption. Environmental Science and Technology, 2005, 39(24): 9561-9568.

Wang L F, Huang J Z. Outline of Control Practice of Endemic Fluorosis in China. Social Science and Medicine, 1995, 41(8): 1191-1195.

Wang Y X, Shvartsev S L, Su C. Genesis of Arsenic/Fluoride-Enriched Soda Water: A Case Study at Datong, Northern China. Applied Geochemistry, 2009, 24(4): 641-649.

Xie X J, Wang Y X, Su C, . Arsenic Mobilization in Shallow Aquifers of Datong Basin: Hydrochemical and Mineralogical Evidences. Journal of Geochemical Exploration, 2008, 98(3): 107-115.

Xie Z M, Wu W H, Xu J M. Translocation and Transformation of Fluorides in the Environment and Their Biological Effects. Chinese Journal of Environmental Engineering, 1999, 7(2): 41-54.

Zhu C S, Bai G L, Liu X L, . Screening High-Fluoride and High-Arsenic Drinking Waters and Surveying Endemic Fluorosis and Arsenism in Shanxi Province in Western China. Water Research, 2006, 40(16): 3015-3022.