Cu^(2+)印迹交联壳聚糖微球制备及其对水中Cu^(2+)的吸附研究

Study on Preparation of Metal-Ion Imprinting Cross-Linked Chitosan and Its Adsorption of Cu^(2+) in Aqueous

研究利用离子印迹技术,以壳聚糖为基材、环氧氯丙烷为交联剂制得Cu^(2+)印迹交联壳聚糖树脂微球,并用于水中Cu^(2+)的吸附。结果表明,正交实验确定优化的制备条件:壳聚糖质量分数4%、Cu^(2+)印迹量500 mg/L、交联剂1m L。单因素实验确定的吸附条件:p H为5.0、温度25℃时,此时吸附容量可达到95.0 mg/g,显示良好的Cu^(2+)吸附能力。对Cu^(2+)的吸附过程符合准2级吸附动力学模型和Langmuir吸附等温模型,以表面反应过程控制的化学吸附为主,为放热、自发过程;当Zn^(2+)、Cd^(2+)、Pb^(2+)分别与Cu^(2+)共存时,印迹微球对Cu^(2+)的选择吸附系数最大,达到28.7以上,离子选择性极高;经过5次循环实验后,对Cu^(2+)的吸附率仍达到96.8%,材料的重复利用性和稳定性好。

Cu2＋ imprinted cross-linked chitosan resin microspheres were prepared by using metal-ion imprinting method, in which chitosan was as absorbent and epichlorohydrin was served as crosslinking agent, and the as-obtained adsorbent was used for Cu^2＋ adsorption. The results showed that, The optimum preparation conditions and adsorption conditions were determined by orthogonal experiment and single factor experiment, respectively. The optimum preparation condition was as follow, chitosan mass fraction was 4%, Cu^2＋ imprinted mass concentration was 500 mg/L and crosslinking agent was 1 mL. Under the best performing conditions of 25 ℃ and pH 5.0, the adsorption capacity of Cu^2＋ could reach 95.0 mg/g, indicating a strong adsorption ability. Cu^2＋ adsorption process accorded with the pseudo-second-order adsorption kinetics model and the Langmuir adsorption isotherm model, which was mainly controlled by the chemical adsorption on the microsphere surface and was an exothermic and spontaneous process. When Cu^2＋ coexisted with Zn^2＋, Cd^2＋, Pb^2＋, the selective adsorption coefficient for Cu2＋ was the maximum, which reached 28.7, indicating a high selectivity of thks adsorbent towards Cu2＋ After 5 times repeated treatment, the prepared Cu2＋ imprinted crosslinked chitosan resin microspheres still had a high adsorption efficiency of 96.8%, it had an excellent recyclability and a strong stability.