交联氨基淀粉吸附水中镉离子的影响因素研究

A Study on Influencing Factors in Cd^(2+) Removal with Crosslinked Amino Starch

以双醛淀粉和乙二胺为原料制备了一种新型重金属吸附剂——交联氨基淀粉(CASt),采用单因素吸附实验系统考察了pH值、离子强度、吸附剂用量、反应时间和吸附初始浓度等因素对交联氨基淀粉吸附性能的影响。结果表明:在pH为6、温度为25℃、吸附剂投入量为0.6 g、反应时间为90 min、吸附初始浓度为100 mg/L时,交联氨基淀粉对模拟废水中Cd^(2+)的去除率达到92.46%。吸附过程可以用准二级动力学模型和Langmuir等温吸附模型进行模拟。由交联氨基淀粉吸附Cd^(2+)后的红外光谱(FTIR)图谱可以看出,交联氨基淀粉与Cd2+是通过配位作用结合的,氨基淀粉对Cd^(2+)的吸附属于化学吸附。

Crosslinked amino starch(CASt),a novel adsorbent for heavy metals,was prepared with reaction of dialdehyde starch with ethylenediamine.The factors which affected the adsorption of Cd 2+by CASt such as pH,ionic strength,adsorbent dosage,reaction time and initial concentration were also investigated by single-factor batch experiments.At 25℃,pH 6.0,CASt dosage 0.6 g,adsorption time 90 min and initial heavy metal concentration of 100 mg/L,the removal efficiency of CASt for Cd^2+in simulated wastewater was 92.46%.The adsorption process could be simulated with pseudo-second-order kinetics and Langmiur adsorption isotherm model.The FTIR spectrums of CASt adsorbents after adsorbing Cd^2+showed that,CASt combined with Cd^2+by coordination.The authors regard the adsorption of Cd^2+by CASt as chemical adsorption.