Recovery of Lithium from Wastewater Using Development of Li Ion-Imprinted Polymers

Abstract

Recycling lithium from waste lithium batteries is a growing problem, and new technologies are needed to recover the lithium. Currently, there is a lack of highly selective adsorption/ion exchange materials that can be used to recover lithium. We have developed a magnetic lithium ion-imprinted polymer (Fe 3 O 4 @SiO 2 @IIP) by using novel crown ether. The Fe 3 O 4 @SiO 2 @IIP has been synthesized by a surface imprinting technique using our newly synthesized 2-(allyloxy) methyl-12-crown-4 as a functional monomer. The Fe 3 O 4 @SiO 2 @IIP was analyzed by Fourier infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The optimum pH for adsorption is 6. Fe 3 O 4 @SiO 2 @IIP shows fast adsorption kinetics for lithium ions (10 min to reach complete equilibrium), and the adsorption process obeys an external mass transfer model. Homogeneous binding sites are proved by the Langmuir isotherm, and the maximum adsorption capacity is 0.586 mmol/g. Fe 3 O 4 @SiO 2 @IIP has excellent selectivity for Li(I) because the selectivity separation factors of Li(I) with respect to Na(I), K(I), Cu(II), and Zn(II) are 50.88, 42.38, 22.5, and 22.2, respectively. The adsorption capacity of sorbent remained above 92% after five cycles. Fixed-bed column adsorption experiments indicate that the effective treatment volume was 140 bed volumes (BV) in the first run with a breakthrough of 10% of the inlet concentration for an inlet concentration of 0.5 mmol/L, and 110 BV was treated for the second run under identical conditions. We demonstrated that 89.8% of the lithium was recovered during bed regeneration using 0.5 mol/L HCl solution. Fe 3 O 4 @SiO 2 @IIP also exhibited excellent removal efficiency for Li(I) in real wastewater, validating its great potential in advanced wastewater treatment. Accordingly, we have developed a new method for wastewater treatment that meets Li emission standards, and recovery of Li creates economic interest.

Dual‐template crown ether‐functionalized hierarchical porous silica: Preparation and application for adsorption of energy metal lithium

“…The adsorption capacity of 2M12C4‐HPS for Li + is found to be larger than that of Mn 2 O 3 reported by Wang et al . However, it is smaller than that of Fe 3 O 4 @SiO 2 @MIP and agar gelated sphere reported by Luo et al . and Han et al .…”

“…2M12C4‐HPS was compared with other adsorbents for the adsorption of Li + and the results are presented in Table . The adsorption capacity of 2M12C4‐HPS for Li + is found to be larger than that of Mn 2 O 3 reported by Wang et al .…”

Simultaneous adsorption of Li(I) and Rb(I) by dual crown ethers modified magnetic ion imprinting polymers

“…Magnetic polymeric nanoparticles is easily separated from a liquid system by using a magnetic field. Moreover, specific functional groups (such as ‐COOH, ‐OH, ‐NH 2 , crown ethers) grafted on the surface of magnetic polymeric nanoparticles can exert good capability to bind with target metal ions with high selectivity . In particular, crown ethers, which are composed of cyclic ethyleneglycol ((OCH 2 CH 2 ) n ), have selective binding ability with alkali metal ions, heavy metal ions and rare earth metal ions which possess similar size with the ring of them, due to their unique chemical structure.…”

“…In particular, crown ethers, which are composed of cyclic ethyleneglycol ((OCH 2 CH 2 ) n ), have selective binding ability with alkali metal ions, heavy metal ions and rare earth metal ions which possess similar size with the ring of them, due to their unique chemical structure. So, numerous applications are brought to crown ethers, such as ion‐selectivity sensors, phase transfer catalyst, and ion adsorption …”

“…In particular, crown ethers (CEs) can chelate the target metal ions stably, due to the size of the crown ring fitting with the diameter of the target metal ions. Lou et al successfully synthesized magnetic ion imprinted polymers, using CEs as the functional monomer . In this work, we prepared dual‐functional magnetic ion imprinting polymers (Fe 3 O 4 @SiO 2 @IIPs) for simultaneous adsorption of Li(I) and Rb(I) from simulative salt lakes, using 12‐crown‐4 (12C4) and 18‐crown‐6 (18C6) as functional monomer.…”