Chemistry Department, Faculty of Science, Damanhur University, Damanhur, 22511, Egypt.
Analysis and Evaluation Department, Egyptian Petroleum Research Institute, 1 Ahmed El-Zomor St, Nasr City, 11727, Cairo, Egypt.
Environ Sci Pollut Res Int. 2023 Oct;30(49):108067-108084. doi: 10.1007/s11356-023-29662-8. Epub 2023 Sep 25.
With the growing need for high-purity rare-earth elements (REEs), the separation of these REEs has received much attention recently. The objective of this research is to produce chitosan from shrimp waste, then modify it with different functionality, and investigate the adsorption properties of chitosan adsorbents towards La(III) ions. First, from shrimp waste, chitosan (ch) with a significant degree of deacetylation, purity, and solubility was produced. The purified chitosan was cross-linked with epichlorohydrin (ep), and then, it was modified with 3,6,9,12-tetraazatetradecane-1,14-diamine (HA) to produce polyaminated chitosan (HA@ep@Ch). The polycarboxylated/imine chitosan (CM@HA@ep@Ch) was obtained by treating polyaminated chitosan with chloroacetic acid in isopropyl alcohol. The chitosan adsorbents were characterized and applied for lanthanum recovery from synthetic and monazite leach liquor samples. The factors controlling the recovery process were studied and discussed. The performance of the adsorbents was achieved through equilibrium, dynamic, and isothermal studies. HA@ep@Ch and CM@HA@ep@Ch showed good performance for lanthanum recovery with a maximum capacity of 114.52 and 141.76 mg/g at 330 K, respectively. The isotherm parameters refer to the monolayer of lanthanum adsorbed into the adsorbents through chelation and ion exchange mechanisms. A 0.5-M HCl solution was found effective to elute 95.8% of the adsorbed lanthanum on HA@ep@Ch, and 93.4% of the adsorbed lanthanum on CM@HA@ep@Ch. The adsorbents showed greater selectivity in extracting La, Ce, Pr, Nd, and Sm (62-75%) from REE leach liquid compared to extracting other REEs (20-41%).
随着对高纯度稀土元素 (REE) 的需求不断增长，这些 REE 的分离最近受到了广泛关注。本研究的目的是从虾废料中生产壳聚糖，然后用不同的官能团对其进行修饰，并研究壳聚糖吸附剂对 La(III) 离子的吸附性能。首先，从虾废料中制备出具有高脱乙酰度、高纯度和高溶解性的壳聚糖 (ch)。将纯化的壳聚糖与表氯醇 (ep) 交联，然后用 3,6,9,12-四氮杂十四烷-1,14-二胺 (HA) 对其进行修饰，得到多胺化壳聚糖 (HA@ep@Ch)。通过在异丙醇中用氯乙酸处理多胺化壳聚糖，得到多羧基/亚胺化壳聚糖 (CM@HA@ep@Ch)。通过平衡、动态和等温研究来评估壳聚糖吸附剂从合成和独居石浸出液中回收镧的性能。研究并讨论了控制回收过程的因素。吸附剂的性能通过吸附等温线、吸附动力学和吸附热力学研究进行评估。HA@ep@Ch 和 CM@HA@ep@Ch 对镧的回收表现出良好的性能，在 330 K 时的最大容量分别为 114.52 和 141.76 mg/g。等温线参数表明镧通过螯合和离子交换机制单层吸附到吸附剂上。发现 0.5-M HCl 溶液可有效洗脱 95.8%吸附在 HA@ep@Ch 上的镧，洗脱 93.4%吸附在 CM@HA@ep@Ch 上的镧。与提取其他 REE（20-41%）相比，吸附剂从 REE 浸出液中提取 La、Ce、Pr、Nd 和 Sm（62-75%）时表现出更高的选择性。
