High-efficiency lithium recovery from desalination brine via MnAl layered double hydroxide

The increasing global population necessitates the exploration and adoption of environmentally friendly extraction methods and alternative sources to meet the growing demand for lithium (Li). Adsorption offers high selectivity for Li and has emerged as a promising and cost-effective alternative. However, current methods utilizing manganese- and titanium-based adsorbents present environmental risks and exhibit instability under acidic conditions. Layered double hydroxides (LDHs) show significant potential for Li extraction from various sources, including brine. This study aimed to synthesize a novel manganese‑aluminum double-layered hydroxide (MnAl LDH) combined with keratin for Li extraction from brine. The Keratin/Mn-Al LDH demonstrated efficient Li adsorption with a capacity of 49.7 mg/g and a desorption rate of 92 %. Both the Langmuir and Temkin isotherms effectively represented the equilibrium data, indicating monolayer adsorption with chemisorption characteristics. Moreover, the Pseudo-Second-Order (PSO) kinetic model accurately depicted the adsorption rate, suggesting that chemical interactions predominantly govern the process. Furthermore, the maximum adsorption capacity, as determined by the Langmuir model, was 384.62 mg/g. These results suggest a promising direction for exploring the potential of LDH in Li extraction.