壳聚糖/羟基磷灰石微球对水中Cr^(6+)的吸附研究

Adsorption of Cr^(6+) from Aqueous Solution by Chitosan/Hydroxyapatite Microspheres

以壳聚糖和羟基磷灰石为原料,采用反相乳化法制备了壳聚糖/羟基磷灰石微球作为吸附剂,并对其结构进行表征。考察了pH、Cr^(6+)初始浓度以及吸附时间对该微球吸附性能的影响。结果表明:壳聚糖/羟基磷灰石微球为圆球形,分散度好,平均粒径为30μm,具有较好的吸附性能。温度30℃,体系p H4.0,吸附时间240 min的条件下,25 mg微球对10 mg/L Cr^(6+)的吸附率高于73%.Lagergren一级吸附速率方程能更好的描述微球对Cr^(6+)的吸附行为。30℃下,微球对Cr^(6+)的吸附平衡符合Langmuir等温吸附方程。

Chitosan/hydroxyapatite microspheres were prepared by inverse emulsion method,and the microspheres were characterized by SEM. The effects of initial concentration of Cr^6＋,pH and adsorption time on the adsorption process were investigated. The results showed that chitosan/hydroxyapatite microspheres were spherical,dispersed well,and the average particle size is 30 μm. The removal efficiency of Cr^6＋（ 10 mg/L） by the microspheres（ 25 mg） was greater than 73% when the temperature was 30℃,pH was 4.0 and adsorption time was 240 min. Lagergren first-order kinetic equation could describe the adsorption behavior better than kinetic models of second-order adsorption. It was found that the adsorption of Cr^6＋ on microspheres was correlated well with Langmuir isotherm equation at 30 ℃.