Highly stable and magnetically separable alginate/Fe3O4 composite for the removal of strontium (Sr) from seawater. (December 2016)

• Record Type: Journal Article
• Authors: Hong, Hye-Jin; Jeong, Hyeon Su; Kim, Byoung-Gyu; Hong, Jeongsik; Park, In-Su; Ryu, Taegong; Chung, Kang-Sup; Kim, Hyuncheol; Ryu, Jungho
• Is Part Of: Chemosphere. Volume 165(2016)
• Page Start: 231
• Page End: 238
• Publication Date: 2016-12
• Subjects: Strontium -- Removal -- Alginate -- Iron oxide -- Seawater; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2016.09.034
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: In this study, a highly stable alginate/Fe3 O4 composite was synthesized, and systematically investigated for the practical application of strontium (Sr) removal in complex media, such as seawater and radioactive wastewater. To overcome the drawbacks of the use of alginate microspheres, high contents of alginic acid and Fe3 O4 were used to provide a more rigid structure with little swelling and facile separation, respectively. The synthesized composite was optimized for particle sizes of <400 μm and 1% content of Fe3 O4 . The alginate/Fe3 O4 composite showed excellent Sr uptake (≈400.0 mg/g) and exhibited outstanding selectivity for Sr among various cations (Na, Mg, Ca and K). However, in diluted Sr condition (50 mg/L), Ca significantly affected Sr adsorption, resulting in a decrease of K d value from 3.7 to 2.4 at the 0.01 M Ca. The alginate/Fe3 O4 composite could be completely regenerated using 0.1 M HCl and CaCl2 . In real seawater spiked with 50 mg/L of Sr, the alginate/Fe3 O4 composite showed 12.5 mg/g of Sr uptake, despite the highly concentrated ions in seawater. The adsorption experiment for radio-active 90 Sr revealed a removal efficiency of 67% in real seawater, demonstrating the reliability of the alginate/Fe3 O4 composite. Graphical abstract: Highlights: Alginate/Fe3 O4 composite was prepared to remove strontium (Sr) from seawater. Alginate/Fe3 O4 exhibited little swelling in seawater, achieving facile separation. Alginate/Fe3 O4 showed excellent selectivity for Sr among coexisting ions in seawater. 90 Sr was effectively removed by alginate/Fe3 O4 composite in real seawater medium.