聚乙烯亚胺改性蔗渣纤维素/蒙脱土复合球的制备及对Cd(Ⅱ)的吸附

Preparation of polyethyleneimine modified bagasse cellulose/montmorillonite composite spheres and their adsorption performance on Cd(II)

摘要:

以甘蔗渣纤维素（SBC）和蒙脱土（Mt）为原料，碳酸钙为致孔剂，通过简单凝固浴法制备PEI-SBC/Mt复合小球。采用FTIR、SEM、XRD等对所制备的球形吸附剂结构进行了表征，并系统研究了该吸附剂对模拟废水中的镉离子Cd(Ⅱ)的吸附行为。结果表明，拟二级动力学模型和Langmuir模型能够准确描述吸附过程，在温度为25 ℃、pH=6、Cd(Ⅱ)初始质量浓度为600 mg/L时PEI-SBC/Mt对Cd(Ⅱ)的最大吸附量为234.3mg/L ，表明吸附过程是单分子化学吸附，PEI的加入为吸附剂吸附Cd(Ⅱ)提供了更多的活性位点。此外，吸附剂具有可重复使用性，经过5次循环吸脱附后，其吸附量只由原有的94%降至79.8%。

Abstract:

PEI-SBC/Mt composite spheres were prepared by simple coagulation bath method using bagasse cellulose (SBC) and montmorillonite (Mt) as raw materials and calcium carbonate as porogenic agent. The structures of the prepared spherical adsorbents were characterized by FTIR, SEM and XRD, and the adsorption behaviors of the adsorbents on cadmium ion Cd(II) in simulated wastewater were systematically investigated. The results showed that the proposed secondary kinetic model and Langmuir model could accurately describe the adsorption process, and the maximum adsorption amount of Cd(II) by PEI-SBC/Mt at the temperature of 25 ℃, pH=6 and the initial mass concentration of Cd(II) was 600 mg/L , indicating that the adsorption process was single-molecule chemisorption, and the addition of PEI provided a more efficient way for the adsorbent to adsorb Cd The addition of PEI provided more active sites for the adsorbent to adsorb Cd(II). In addition, the adsorbent was reusable and its adsorption capacity only decreased from the original 94% to 79.8% after five cycles of adsorption and desorption.