ORIGINAL ARTICLE Hydrochemical characterization of drinking groundwater with special reference to fluoride in an arid area of China and the control of aquifer leakage on its concentrations Jianhua Wu • Peiyue Li • Hui Qian Received: 28 July 2014 / Accepted: 2 January 2015 Ó Springer-Verlag Berlin Heidelberg 2015 Abstract The objective of the study is to determine the distribution and origin of fluoride in two confined aquifers within the depth of 80–240 m (mid-deep confined aquifers) in Shizuishan City, an arid area in Northwest China. Based on geological and hydrogeological conditions, the distri- bution patterns of fluoride in the two confined aquifers were studied. Correlation analysis was used to reveal the mechanisms and reactions influencing the groundwater chemistry. The control of aquifer leakage induced by intense groundwater abstraction on fluoride concentrations was also discussed. The results show that the concentration of F - in some locations of the study area is beyond the limit of the Standards for Drinking Water Quality of China. Correlation analysis shows that the major reactions occurring in the confined aquifers are dissolution of gyp- sum, fluorite and halite, and precipitation of calcite and dolomite. Groundwater leakage from shallow aquifers is also responsible for the elevation of fluoride in mid-deep confined aquifers. The research is a scientific basis for the rational development and utilization of groundwater in this area, and it may be referenced by international scholars for similar research in other parts of the world. Keywords Fluoride occurrence  Groundwater  Confined aquifers  Hydrochemical controls Introduction Fluorine is the most electronegative and reactive of all elements, and usually present as fluoride (F - ) in drinking water (Totsche et al. 2000). It occurs as F - naturally in soils and natural waters, due to chemical weathering of some F-containing minerals. Fluoride in small amounts is an essential component for normal mineralization of bones and formation of dental enamel. However, excessive intake of F - can cause dental and skeletal fluorosis (Mahraman- lioglu et al. 2002). Drinking water with an F - concentra- tion within 0.5–1 mg/L is considered suitable with respect to human health. Due to the importance of fluorine to human health, scholars and scientists around the world have conducted a lot of research concerning fluorine in groundwater (for example, Zeng 1996; Zhao and Shen 1999; Vikas et al. 2009; Gupta et al. 2005; Lu et al. 2001; Asghari and Fijani 2008; Xu et al. 2009; Sivasankar and Gomathi 2009; Li and Qian 2010; Li P-Y et al. 2010; Li X et al. 2011). Recently, Wen et al. (2013) reviewed the occur- rence of F - in China’s groundwater, which revealed that, in many areas of China residents are facing serious fluoride pollution and associated health risk. Li et al. (2014a) performed an investigation of elevated fluoride in Weihe River. They concluded that the elevation of fluoride was controlled by hydrogeological conditions, but human activities and mixing of different recharge waters were also important reasons. Kumar et al. (2014) conducted an investigation on the factors influencing the high fluoride concentration in groundwater of Vellore District, South India. They found that the major source of F - in groundwater in Vellore District can be attrib- uted to the weathering and the dissolution of fluorites, amphiboles and micas present in the geological J. Wu  P. Li (&)  H. Qian School of Environmental Science and Engineering, Chang’an University, No. 126 Yanta Road, Xi’an 710054, Shaanxi, China e-mail: lipy2@163.com J. Wu  P. Li  H. Qian Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of the Ministry of Education, Chang’an University, No. 126 Yanta Road, Xi’an 710054, Shaanxi, China 123 Environ Earth Sci DOI 10.1007/s12665-015-4018-2