环氧氯丙烷交联壳聚糖/海藻酸钠吸附铜离子的研究

Study on the Adsorption of Copper Ions by Epichlorohydrin-Crosslinked Chitosan/Sodium Alginate Adsorbent

以壳聚糖、海藻酸钠为原料,环氧氯丙烷为交联剂制备了交联壳聚糖/海藻酸钠吸附剂,并采用红外光谱对其结构进行了表征.考察了吸附时间、pH值、吸附剂用量和交联度等因素对吸附容量的影响,研究了该吸附剂的吸附性能,同时对吸附动力学进行了研究.结果表明:pH值为4.0～6.0、吸附时间为120min、在100mL 50mg/L的Cu2+溶液中吸附剂的投加量为0.10g时,平衡吸附容量达46.4 mg/g;该等温吸附在低浓度时的吸附过程较符合Freundlich模型,在高浓度时较符合Langmuir模型;吸附过程动力学符合拟二级动力学方程,线性相关性良好(r2=0.944 4).

In this paper, first, a new kind of crosslinked chitosan/sodium alginate absorbent was prepared, with chitosan and sodium alginate as the raw materials and with epichlorohydrin as the crosslinking agent. Next, the structure of the product was characterized by means of FT-IR. Then, the adsorption capacity affected by the adsorption time, the pH value, the adsorption agent dosage and the crosslinking degree was investigated. Finally, the ad- sorption properties of the prepared absorbent were analyzed and the corresponding adsorption kinetics was discussed. The results indicate that, when 0. 10 g of absorbent is added in 100 mL of 50 mg/L Cu^2＋ solution at pH 4. 0 - 6.0 to perform an adsorption for 120 min, the adsorption capacity reaches 46.4 mg/g, that the isothermal adsorption at low or high concentration respectively accords with the Freundlich or the Langmuir equation, and that the absorption kinetics accords with the pseudo-second-order equation with good linear correlation （r2 = 0. 9444）.