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本文通过柠檬酸、磷酸、氨水改性贝壳砂制备1种新型的除氟材料(CPAS),并通过静态和动态试验研究它对氟的去除效果。结果表明,制备CPAS材料最佳条件为质量分数5%的柠檬酸以1:5的固液比浸泡24 h,水洗、烘干,600℃焙烧1 h,0.6 mol.L-1的磷酸以1:30的固液比浸泡3 h,氨水调pH为8,室温下老化3 h;在静态试验中,CPAS材料在pH 3～10范围内除氟率均高于97%,10 h可达到吸附平衡,吸附符合Lagergren一级吸附动力学模型;共存阴离子Cl-、SO42-对材料除氟干扰很小;材料的除氟吸附等温线符合Langmuir方程,35℃下对氟的最大饱和吸附容量达16.54 mg.g-1;通过动态柱吸附试验可得CPAS材料去除氟的能力为7.53 mg.g-1。
In this paper, a new kind of fluoride removal material (CPAS) was prepared from citric acid, phosphoric acid and ammonia modified shell sand, and its removal of fluorine was studied by static and dynamic tests. The results showed that the optimum conditions for the preparation of CPAS material were citric acid with a mass fraction of 5%, soaking in solid-liquid ratio of 1: 5 for 24 h, washing with water, drying and calcining at 600 ℃ for 1 h. The phosphoric acid with 0.6 mol·L- : 30 solid-liquid ratio soaking for 3 h, ammonia water adjusted to pH 8, room temperature aging 3 h; in the static test, CPAS material in the range of pH 3 ~ 10 fluoride removal rate were higher than 97%, 10 h adsorption Equilibrium adsorption is in accordance with the Lagergren first-order adsorption kinetics model. Coexistent anions Cl- and SO42- have little interference on fluoride removal. The fluoride adsorption isotherms of the materials conform to the Langmuir equation. The maximum adsorption capacity of fluoride at 35 ℃ is 16.54 mg.g-1. The CPAS material’s ability to remove fluorine was 7.53 mg.g-1 by dynamic column adsorption test.