3D printing calcium alginate adsorbents for highly efficient recovery of U(VI) in acidic conditions

Song Fuxiang; Wang Na; Zhang Qiangqiang; Weibo Jie; Liu Bin

doi:10.1016/j.jhazmat.2022.129774

3D printing calcium alginate adsorbents for highly efficient recovery of U(VI) in acidic conditions

J Hazard Mater. 2022 Oct 15:440:129774. doi: 10.1016/j.jhazmat.2022.129774. Epub 2022 Aug 17.

Authors

Song Fuxiang¹, Wang Na¹, Zhang Qiangqiang², Weibo Jie³, Liu Bin⁴

Affiliations

¹ School/Hospital of Stomatology, Lanzhou University, Lanzhou 730000, PR China; Key Laboratory of Dental Maxillofacial Reconstruction and Biological Intelligence Manufacturing, School of Stomatology, Lanzhou University, Lanzhou 730000, PR China.
² College of Civil Engineering and Mechanics, Lanzhou University, Lanzhou 730000, PR China; Key Laboratory of Mechanics on Disaster and Environment in Western China (Lanzhou University), The Ministry of Education of China, Lanzhou 730000, PR China. Electronic address: zhangqq@lzu.edu.cn.
³ School/Hospital of Stomatology, Lanzhou University, Lanzhou 730000, PR China.
⁴ School/Hospital of Stomatology, Lanzhou University, Lanzhou 730000, PR China; Key Laboratory of Dental Maxillofacial Reconstruction and Biological Intelligence Manufacturing, School of Stomatology, Lanzhou University, Lanzhou 730000, PR China. Electronic address: liubkq@lzu.edu.cn.

PMID: 35988488
DOI: 10.1016/j.jhazmat.2022.129774

Abstract

In this study, a three-dimensional (3D) porous calcium alginate (3D CA) scaffold was successfully constructed using a direct-ink-writing-based 3D printing method combined with an in-situ calcium ion cross-linking procedure. The 3D CA contained orderly aligned microstructures with excellent structural robustness and an abundant number of active binding sites. The adsorption experiments verified that 3D CA had a considerably wide pH value (3-10) serving range, but also delivered a significantly higher adsorption capacity for U(VI) (117.3 mg/g at pH = 2.5) under acidic conditions, compared to other previously reported alginate-based porous adsorbents. The adsorption mechanisms originated from the synergistic effect of electrostatic interactions and ion exchange. The 3D CA eluted the adsorbed U(VI) in a strong acid solution through protonation mechanism, facilitating the continued enrichment and recycling of U(VI). In addition, the 3D CA demonstrated good microstructure stability and absorption capacity stability when it was immersed in hydrochloric acid solutions at different concentrations (3.6 × 10^-3 to 2 mol/L) for 24 h. Therefore, the 3D CA could be used for the removal and recycling of U(VI) from acidic solutions beyond its wide pH working range, due to its stronger acid stability and higher U(VI) adsorption capacity.

Keywords: Acidic aqueous solution; Adsorption capacity; Direct-ink-writing-based 3D printing; Porous calcium alginate.