Uranium (VI) recovery from aqueous medium using novel floating macroporous alginate-agarose-magnetite cryobeads
Uranium (VI) recovery from aqueous medium using novel floating macroporous alginate-agarose-magnetite cryobeads
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DOI：
10.1016/j.jhazmat.2012.12.002
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发表时间：
2013-02-15
影响因子：
13.6
通讯作者：
D'Souza, Stanislaus Francis
中科院分区：
文献类型：
--
作者：
Tripathi, Anuj;Melo, Jose Savio;D'Souza, Stanislaus Francis
本研究提出了一种用于从水下表面回收六价铀的浮式聚合物磁铁矿冷冻头的新进展。采用低温凝胶法制备了海藻酸盐-琼脂糖-磁铁矿低温微球。低温微球的理化性质表现为高表面积和高连通孔隙率（接近90%）。这些低温微珠的低密度解释了它们在水介质中的漂浮特性。低温微球的流变学分析表明，吸附铀后，其稳定性和刚度增加。在多孔低温微珠中存在的磁铁矿纳米颗粒通过施加外部磁场促进了这些微珠的回收。在pH为4.5 ~ 5.5的范围内，铀的最大吸附量为97 +/- 2%。热力学参数显示为被动吸热吸附。盐酸是一种有效的铀解吸剂。对生物吸附剂中铀进行5次循环解吸，铀回收率为69 +/- 3%。这些结果表明，这些新型漂浮磁铁矿冷冻珠在环境条件下具有稳定性，具有从受污染的水地下回收铀的潜力。(C) 2012 Elsevier B.V.版权所有
This study presents a novel development of a floating polymeric-magnetite cryobead for the recovery of hexavalent uranium from the aqueous sub-surfaces. The alginate-agarose-magnetite cryobeads were synthesized by the process of cryotropic-gelation at subzero-temperature. The physico-chemical properties of cryobeads showed high surface area and high interconnected porosity (similar to 90%). Low density of these cryobeads explains their floating property in the aqueous medium. The rheological analysis of cryobeads showed its stability and increased stiffness after uranium adsorption. The presence of magnetite nanoparticles in the porous cryobeads facilitates the recovery of these beads by applying an external magnetic field. Maximum uranium adsorption (97 +/- 2%) was observed in the pH range of 4.5-5.5. The thermodynamic parameters suggest passive endothermic adsorption behaviour. HCl was found to be an efficient eluent for the uranium desorption. Five repeated cycles for the desorption of uranium from biosorbent showed 69 +/- 3% of uranium recovery. These results suggest stability of these novel floating magnetite-cryobeads under environmetal conditions with potential for the recovery of uranium from contaminated aqueous subsurfaces. (C) 2012 Elsevier B.V. All rights reserved.