载镧改性沸石对高氟水除氟效果的研究

Study on Defluoridation of Water Using Lanthanum-Modified Permutite

目的研究载镧改性沸石对高氟水除氟的效果。方法用0.5mol/L的NaOH溶液浸泡活化沸石2h,以固液比1:5加入150g/L氯化镧溶液,以氨水调节pH值为11～12,浸渍振荡24h,干燥后于400～500℃焙烧3～4h。采用载镧改性沸石对10mg/L含氟水样进行静态除氟实验(适宜条件为:载镧改性沸石用量为3g/L时,pH值为4～5,140r/min振荡速度下于室温吸附200min)和动态除氟实验(适宜条件为:载镧改性沸石用量为1.33g/L,pH值为4～5,室温下以4～5ml/min的流速通过吸附柱)。并拟合Langmuir吸附等温线。结果静态除氟的除氟率在90%以上,吸附容量为3.24mg/g;动态除氟的吸附容量为7.67mg/g。拟合Langmuir吸附等温线所得方程为y=0.1334x+0.0181,相关系数达到0.9974,饱和吸附量(q∞)为7.50mg/g,吸附平衡常数(KL)为7.37L/mg。结论载镧改性沸石对高氟水除氟容量大,除氟效率高。

Objective To study the defluoridation of water using lanthanum-modified pemutite. Methods A lanthanum- modified permutite adsorbent was prepared by impregnating with 0.5 mol/L NaOH for 2 h, adding 150 g/L lanthanum chloride with solid-liquid ratio 1：5, pH value adjusted 11-12 with ammonia water, oscillating for 24 h, drying and roasting in 400-500 ℃ for 3- 4 h. The water containing F^- of 10 mg/L was treated with lanthanum-modified permutite in static test （the optimal conditions： the dosage of adsorbent was 3.0 g/L, pH value was 4-5, contact time was 200 min by oscillating at room temperature at 140 r/min） and column test （the optimal conditions were： the dosage of adsorbent was 1.33 g/L, pH value was 4-5,simulated water flowed through column with 4-5 ml/min at room temperature）. And equilibrium adsorption data fitted to langmuir adsorption isotherm. Results The removal rate of fluoride was more than 90% and adsorption capacity was 3.24 mg/g in static test. Defluoridation capacity was 7.67 mg/g in column test. The equilibrium adsorption data fitted well to＇langmuir adsorption isotherm and showing y=0.133 4x＋ 0.018 1, R^2=0.997 4, maximum fluoride adsorption capacity of 7.50 mg/g and equilibrium constant of 7.37 L/mg. Conclusion The lanthanum-modified permutite adsorbent shows high adsorption capacity and efficiency in fluoride removal.