海藻酸钠-氢氧化镧改性Y型分子筛颗粒除氟研究

为解决除氟吸附剂分离困难、有效成分流失等问题,以海藻酸钠（SA）与氢氧化镧改性Y型分子筛（LHMS）为原料,采用滴球法制备了SA@LHMS颗粒吸附剂,并采用模拟废水对其进行了除氟研究。通过正交实验确定了吸附剂最佳制备条件,并通过间歇吸附实验测试了吸附剂投加量、pH、共存离子等因素对吸附的影响,探究了吸附速率、吸附等温线等吸附性能。结果表明,SA@LHMS吸附速率曲线符合拟二级反应速率方程;吸附等温线符合Ⅱ型等温线,为多分子层吸附;初始pH（3~12）对吸附效果没有显著影响;高浓度共存阴离子（50 mg/L）对吸附过程有一定抑制;1 mol/L和2 mol/L氢氧化钠溶液对SA@LHMS再生效果较好,经3次再生仍然保留较高的吸附能力。SA@LHMS颗粒表面和截面形态以及吸附前后颗粒的表面形态差异明显;吸附前后颗粒表面能谱（EDS）分析以及红外光谱（FT-IR）分析结果显示,吸附过程中溶液中的氟离子（F^-）与颗粒表面及内部的羟基（—OH）发生配体交换。

Study on fluoride removal by modified Y zeolite particles with sodium alginate-lanthanum hydroxide

In order to solve the problem of the separation of defluorinated adsorbents and the loss of effective components,SA@LHMS adsorbents were prepared with sodium alginate（SA） and lanthanum hydroxide modified Y zeolite （LHMS） as raw materials.The optimum preparation conditions of adsorbent were determined by orthogonal experiment.The effect of factors,such as dosage of adsorbent,pH and co-existing ions etc.,was tested by batch adsorption experiment,and the adsorption performance of adsorption rate and adsorption isotherm was researched.The results showed that the adsorption rate curve of the SA@LHMS conformed to the second-order reaction rate equation.Adsorption isotherm conformed to the type Ⅱ isotherm,multilayer physical adsorption.The initial pH （3~12） had no significant effect on the adsorption effect.High concentration of co-existing anions （50 mg/L） inhibited the adsorption process.The regeneration effect of 1 mol/L and 2 mol/L NaOH solution on SA@LHMS was better,and SA@LHMS still retained a high adsorption capacity after three regeneration.The surface and cross section morphology of SA @LHMS as well as the surface morphology before and after adsorption were significantly different.EDS component analysis and FT-IR spectrum analysis before and after adsorption showed that ligand exchange occur-curred between F^- and —OH on the surface and inside of particles during adsorption.