原子吸收光谱法研究空心壳聚糖微球吸附Cd^(2+)的性能

AAS Study on Adsorption of Cadium(Ⅱ) Ion by Hollow Microspheres of Chitosan

利用空壳状壳聚糖微球具有比表面大的特点,结合其表面氨基易于配位的特点,对其吸附Cd^(2+)的前后结构进行了表征,并对其吸附Cd^(2+)的初步条件进行了探索。试验发现在室温下,pH=7时,当浓度为1 000 mg·L^(-1)时可达到吸附平衡,此时吸附容量约为420 mg(Cd^(2+))·g^(-1),吸附率约为42%。吸附达到平衡大约需要40 min。吸附温度(15～50℃)及微球的粒度(75～250μm)的变化对吸附无显著影响。

Making use of the distinguishing features of large specific surface and coordination reaction of amino groups at its surface, the adsorption of Cd^2＋ ion by hollow microspheres of chitosan was studied. Especially, the microphenomena of structure of the microspheres of chitosan before and after the adsorption of Cd^2＋ ion was characterized. Optimum conditions, including acidity of the reaction medium, temperature for adsorption,adsorption capacity at equilibrium and interferences of Pb^2＋ and Zn^2＋ ions, were studied. It was found that at the optimum acidity of pH 7, adsorption equilibrium was attained when the concentration of Cd^2＋ ion was 1 000 mg·L^-1 , and the adsorption capacity calculated achieved to a value of 424 mg of Cd^2＋ per one gram of chitosan hollow microspheres, having the adsorption rate of 42. 4%. Forty minutes were required to attain the adsorption equilibrium. Changes in temperature （15-50℃） for adsorption and size （75-250μm） of the microspheres showed no significant effects on the adsorption.