淀粉基水凝胶St/CMC-g-PAA对Cu^(2+)的吸附性能研究

Adsorption Properties of Cu^(2+)by Starch Based Hydrogel St/CMC-g-PAA

以玉米淀粉(St)、羧甲基纤维素钠(CMC)为原料,丙烯酸(AA)为接枝单体,通过接枝和交联反应合成了淀粉基水凝胶St/CMC-g-PAA。考察了投药量、pH、Cu^(2+)初始浓度(ρ0)、吸附时间对吸附效果的影响。结果表明,当ρ0=40 mg/L,投药量为300 mg/L,pH=5.2时,Cu^(2+)的去除率可达92.7%。实验数据拟合结果表明,水凝胶对Cu^(2+)的吸附过程符合Langmuir吸附模型和准二级动力学模型,属于单分子层的化学吸附过程。在25℃时,水凝胶对Cu^(2+)的饱和吸附容量qm=142.86 mg/g。水凝胶再生性能较好,经过4次吸附-脱附循环后,Cu^(2+)去除率仍可达到82.1%。

Starch-based hydrogel St/CMC-g-PAA was synthesized by grafting and crosslinking reaction with corn starch(St),sodium carboxymethyl cellulose(CMC)and acrylic acid(AA)as raw materials.The effects of dosage,pH value,initial concentration of Cu^(2+)(ρ0)and adsorption time on the adsorption were investigated.The results showed that whenρ0=40 mg/L,the dosage was 300 mg/L and pH=5.2,the removal rate of Cu^(2+)could reach 92.7%.The fitting results of experimental data showed that the adsorption process of Cu^(2+)by hydrogel was consistent with the Langmuir adsorption model and quasi-second-order kinetic model,and belonged to the chemical adsorption process of a single molecular layer.At 25℃,the saturated adsorption capacity qm=142.86 mg/g.The hydrogel had good regeneration performance.After 4 adsorption-desorption cycles,the removal rate of Cu^(2+)could still reach 82.1%.