饮用水含氟量超过1毫克/升会引起氟斑牙等慢性氟中毒症。在农村防治地方性饮水氟中毒,最好是“改水”,即改用含氟量合乎卫生标准的水。但有些地方由于地质条件的原因,找不到含氟量低的地下水,则应考虑“降氟”,就是选择当地含氟量较低、水质较好、水量充足的水源进行降氟处理。降氟(或者叫除氟)的方法很多,有电渗析、离子交换、活性氧化铝吸附和硫酸铝混凝沉淀法等。电渗析和离子交换法,可以把水中Ca~(2+)、Mg~(2+)、Na~+、Cl~-、So_4~(2-)、HCO_3~-、等离子都除去,得到高纯度的水;但对降氟处理来说,并无必要把其它可以 Drinking water fluoride content of more than 1 mg / L will cause dental fluorosis and other chronic fluorosis. Prevention and control of endemic fluorosis in rural areas, the best is to “change water”, that is, the use of fluorine content in line with health standards of water. However, in some places, groundwater with low fluorine content can not be found because of geological conditions. Therefore, “reducing fluoride” should be considered, that is, to select the local fluoride source with lower fluorine content, better water quality and adequate water quantity for fluoride treatment. Fluoride (or fluoride removal) of many ways, there are electrodialysis, ion exchange, activated alumina adsorption and aluminum sulfate coagulation and precipitation methods. Electrodialysis and ion exchange method can remove Ca2 +, Mg2 +, Na +, Cl ~ -, So4 ~ (2 -), HCO3 ~ - and plasma in water to obtain high purity Of the water; but for the fluoride treatment, there is no need to put others can