D751树脂对水溶液中氟的静态吸附性能研究

Static adsorption of fluoride in aqueous solution by the D751 resin

基于水溶液中的氟、铝配位作用,提出了一种离子交换除氟的新思路。向含氟溶液中精准投加铝盐,将氟转型为氟铝配合物,再利用鳌合树脂即可实现对氟铝配合物的选择性吸附。基于该思路,通过静态吸附实验考察了D751树脂对氟化钠溶液的吸附性能。结果表明,Al3+的添加量对氟的吸附起决定性作用,控制溶液初始Al/F摩尔比为0.4-0.8时,溶液中的氟主要以AlF2+的形态被树脂吸附,吸附效率较高。树脂吸附速率较快,在30分钟即可基本完成。树脂吸附选择性很强,Na+、K+、Ca^2+、Mg^2+、Cl-、SO42-等竞争离子对吸附影响不大。树脂吸附容量较大,当溶液剩余氟浓度为203.9 mg·L^-1时,干树脂吸附量达到50.8 mg·g^-1。

A novel ion exchange method for removal of fluoride was proposed based on coordination of aluminum and fluoride in aqueous solution.Aluminum salts were accurately added into the fluoride containing solution for the conversion of fluoride to aluminum fluoride complexes.Then the aluminum fluoride complexes were adsorbed selectively by the chelating resin.The adsorption abilities of the D751 resin were investigated by the static adsorption experiment according to the new method.The results showed that the addition of aluminum was crucial for adsorption of fluorine.In the condition of initial solution with Al/F molar ratio from 0.4 to 0.8,fluorine was adsorbed in the form of AlF2+with high efficiency by the resin.The adsorption was basically completed in 30 min with rapid speed.The resin was high in adsorption selectivity,while the competitive ions such as Na+、K+、Ca^2+、Mg^2+、Cl-、SO42-had little influence on fluorine adsorption.The resin was high in adsorption capacity.The capacity was 50.8 mg·g^-1 when the residual fluoride concentration was 203.9 mg·L^-1.