Levy-Ontman Oshrat, Yanay Chanan, Alfi Yaron, Paz-Tal Ofra, Wolfson Adi
Department of Chemical and Green Engineering, Shamoon College of Engineering, Beer-Sheva 8434231, Israel.
Nuclear Research Center, Negev, Beer-Sheva 8419001, Israel.
Polymers (Basel). 2023 Nov 18;15(22):4457. doi: 10.3390/polym15224457.
Renewable and biodegradable polysaccharides have attracted interest for their wide applicability, among them their use as sorbents for heavy metal ions. Their high sorption capacity is due mainly to the acidic groups that populate the polysaccharide backbone, for example, carboxylic groups in alginate and sulfate ester groups in the iota and lambda carrageenans. In this study, these three polysaccharides were employed, alone or in different mixtures, to recover different heavy metal ions from aqueous solutions. All three polysaccharides were capable of adsorbing Eu, Sm, Er, or UO and their mixtures, findings that were also confirmed using XPS, TGA, and FTIR analyses. In addition, the highest sorption yields of all the metal ions were obtained using alginate, alone or in mixtures. While the alginate with carboxylic and hydroxyl groups adsorbed different ions with the same selectivity, carrageenans with sulfate ester and hydroxyl groups exhibited higher adsorption selectivity for lanthanides than for uranyl, indicating that the activity of the sulfate ester groups toward trivalent and smaller ions was higher.
可再生且可生物降解的多糖因其广泛的适用性而备受关注，其中包括它们作为重金属离子吸附剂的用途。它们的高吸附容量主要归因于多糖主链上存在的酸性基团，例如藻酸盐中的羧基以及ι-卡拉胶和λ-卡拉胶中的硫酸酯基团。在本研究中，单独或使用不同混合物的方式采用了这三种多糖，以从水溶液中回收不同的重金属离子。所有这三种多糖都能够吸附铕、钐、铒或铀酰及其混合物，使用XPS、TGA和FTIR分析也证实了这些发现。此外，单独使用藻酸盐或其混合物时，所有金属离子的吸附产率最高。虽然具有羧基和羟基的藻酸盐以相同的选择性吸附不同离子，但具有硫酸酯基和羟基的卡拉胶对镧系元素的吸附选择性高于对铀酰的吸附选择性，这表明硫酸酯基团对三价和较小离子的活性更高。
