College of Material Science and Art Design, Inner Mongolia Agricultural University, Laboratory of Fibrosis and Energy Utilization of Shrubby Resources in Inner Mongolia Autonomous Region, Hohhot 010018, China.
Water Sci Technol. 2021 Jul;84(1):43-54. doi: 10.2166/wst.2021.205.
Super-absorbent polyaspartic acid/carboxymethyl Salix psammophila powder (PASP/CMS) hydrogel was prepared by aqueous solution polymerization. PASP/CMS hydrogel was characterized by Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The results showed that PASP/CMS hydrogel is prepared by graft copolymerization of the -COOH of polyaspartic acid (PASP) and the -CHOH of CMS. The surface of the hydrogel became dense from loose porosity, and Pb and Cd were adsorbed onto the surface of hydrogel. The crystallinity of CMS was destroyed by the addition of PASP. The initial concentration of Pb and Cd, pH, adsorption time and adsorption temperature on the adsorption effect were studied through experiments. Results showed that hydrogel has a good removal effect on Pb(II) and Cd(II) ions. Pseudo-second-order kinetics and Langmuir isotherm models are represented in the process, which are spontaneous, exothermic and decreased in randomness, and it is a single layer chemical adsorption. At the same time, the effect of desorption experimental parameters (HNO initial concentration, desorption time, and desorption temperature) on the experiment was studied and optimized.
超吸水性聚天冬氨酸/羧甲基沙柳粉（PASP/CMS）水凝胶是通过水溶液聚合制备的。采用傅里叶变换红外光谱（FTIR）、X 射线衍射（XRD）、扫描电子显微镜（SEM）和 X 射线光电子能谱（XPS）对 PASP/CMS 水凝胶进行了表征。结果表明，PASP/CMS 水凝胶是通过聚天冬氨酸（PASP）的-COOH 和 CMS 的-CHOH 接枝共聚制备的。水凝胶的表面由疏松多孔变得致密，Pb 和 Cd 被吸附到水凝胶表面。CMS 的结晶度因添加 PASP 而被破坏。通过实验研究了初始 Pb 和 Cd 浓度、pH 值、吸附时间和吸附温度对吸附效果的影响。结果表明，水凝胶对 Pb（II）和 Cd（II）离子具有良好的去除效果。在该过程中，伪二级动力学和 Langmuir 等温线模型表示为自发、放热和随机度降低，这是单层化学吸附。同时，研究并优化了解吸实验参数（HNO 初始浓度、解吸时间和解吸温度）对实验的影响。
