1. Efficient and selective lanthanide recovery from highly acidic solutions by using a porous pillar[5]arene-based diglycolamide impregnated resin.
- Author
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Cai, Yimin, Wang, Mengxin, Zeng, Yaxin, Hu, Bowen, Wang, Ying, Yuan, Lihua, and Feng, Wen
- Subjects
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RARE earth metals , *LIQUID waste , *ADSORPTION capacity , *ARSENIC removal (Water purification) , *ADSORPTION isotherms , *ENVIRONMENTAL protection , *SUSTAINABLE development - Abstract
The recovery of lanthanides from high level liquid waste (HLLW) is of great significance for both environmental protection and sustainable development of resources. Traditional methods for this purpose are often plagued by poor selectivity, low capacity, and limited acid tolerance. Here we report a new material prepared by impregnating P[5]A-DGA onto porous Amberlite XAD-7 resin for efficient and selective lanthanide adsorption from highly acidic solutions. The as-prepared composite material (PDA resin) shows outstanding sorption efficiency for lanthanides in a wide range of acidities (0.01–3 M HNO 3) and exhibits good selectivity towards lanthanides over different kinds of competing metal ions in simulated nuclear wastewater. Adsorption equilibrium can be achieved within 60 min and the pseudo-second-order model shows better correlation with the kinetic data, indicating that chemical adsorption is the rate determining step. Adsorption isotherm data can be well fitted by Langmuir model, giving a Eu(III) sorption capacity of 33.3 mg/g at 1 M HNO 3 , which is superior to other materials employed for the similar purpose. Importantly, the adsorption capacity can be regenerated by using a mixture of 1 M guanidine carbonate and 0.05 M EDTA-2Na solution as the eluent, and the lanthanide adsorption efficiency from simulated nuclear wastewater remains at the initial level after three desorption-adsorption cycles. Finally, the possible configurations of the ligand-Ln(III) complexes were optimized by DFT calculations, which suggest that each Ln(III) tends to bind to three DGA arms via a nine coordination mode. This research advances the development of pillar[5]arenes for lanthanide recovery by demonstrating a simple and generally applicable method to convert P[5]A-DGA extractant into an efficient adsorbent. [Display omitted] • The first pillar[5]arene-based ligand impregnated resin (PDA) was prepared. • The maximum adsorption capacity for Eu was as high as 33.3 mg/g at 1 M HNO 3. • It can operate in a wide range of acidity (0.01–3 M HNO 3) with good performance. • Simulated nuclear wastewater experiments indicate good selectivity for lanthanides. • PDA resin can be reused for three cycles without decrease in sorption efficiency. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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