Fluorine contents and its characteristics of groundwater in fluorosis area in Laizhou Bay, China

Fluorine concentration and other parameters in groundwater were assessed and attempts were made to clarify the relationship between fluorine (Fl) and seawater intrusion in coastal area of Laizhou Bay, China by comparing samples in fluorosis and non-fluorosis areas. The water from fluorosis villages reflects the influence of seawater intrusion and higher levels of conductivity (Ec), total dissolved solids (TDS), hardness (TH), Cl-, Br-, HCO3-, Li+, Na+, Mg2+, and Sr2+. High Fl concentration was positive correlated with Ec, TDS, Cl-, Br-, Li+, Mg2+, Ca2+, Sr2+ and significantly with Na+, Na+/Ca2+, and sodium adsorption ratio. This investigation also observed that seawater intrusion and fluorosis show similar distribution and originating sources. Thus, the special process-seawater intrusion seems to be an important dynamic of Fl enrichment by changing chemical characters and enhancing Fl release ability. Moreover, the water treated by bone coal adsorption still maintains high risk of Ec, Na+, and TDS, even though Fl was within the safe limit. This study indicates that in Laizhou Bay, together with other coastal areas, seawater intrusion is a cause for concern when examining mechanism underlying fluorosis occurrence and developing integrated treatment technology.Fluorine concentration and other parameters in groundwater were assessed and attempts were made to clarify the relationship between fluorine (Fl) and seawater intrusion in coastal area of Laizhou Bay, China by comparing samples in fluorosis and non-fluorosis areas. The water from fluorosis villages reflects the influence of seawater intrusion and higher levels of conductivity (Ec), total dissolved solids (TDS), hardness (TH), Cl-, Br-, HCO3-, Li+, Na+, Mg2+, and Sr2+. High Fl concentration was positive correlated with Ec, TDS, Cl-, Br-, Li+, Mg2+, Ca2+, Sr2+ and significantly with Na+, Na+/Ca2+, and sodium adsorption ratio. This investigation also observed that seawater intrusion and fluorosis show similar distribution and originating sources. Thus, the special process-seawater intrusion seems to be an important dynamic of Fl enrichment by changing chemical characters and enhancing Fl release ability. Moreover, the water treated by bone coal adsorption still maintains high risk of Ec, Na+, and TDS, even though Fl was within the safe limit. This study indicates that in Laizhou Bay, together with other coastal areas, seawater intrusion is a cause for concern when examining mechanism underlying fluorosis occurrence and developing integrated treatment technology