Hydrogeochemistry of fluoride in shallow groundwater of the abandoned Yellow River delta, China

Abstract Fluorosis is the most widespread and serious endemic disease in abandoned Yellow River flooding delta of East China. One important causes fluorosis drinking high-fluorine groundwater. In this study, 313 groundwater samples were collected central part to address chemistry high-fluoride groundwater, 33 core from one borehole 150 m depth analyse vertical distribution characteristics total fluorine water-soluble fluorine. The concentration ranges 0.2 6.7 mg/L, 72.8% have above China maximum permissible limit 1.0 mg/L for water. These can be divided into nine hydrochemical subtypes, over 77% belong bicarbonate types. High-fluorine (over 3.0 mg/L) generally alkaline water with high HCO3− low Ca2+. decreases gradually increase formation depth, that sediment negatively correlated Ca2+ Cl−, but positively HCO3−. According calculation by PHREEQC package, MgF+ CaF+ are dominant species controlling study area.