Recovery of Lithium Ions from Seawater Using a Continuous Flow Adsorption Column Packed with Granulated Chitosan–Lithium Manganese Oxide

We demonstrated an efficient recovery of lithium ions (Li + ) from seawater using a continuous flow column packed with an adsorbent, chitosan–lithium manganese oxide (LMO). The effects of Li + concentration, contact time, and recyclability were investigated. The adsorbent showed good removal efficiency of Li + from seawater. The maximum adsorption capacity was calculated to be 54.65 mg/g. The adsorption process fit well with the Freundlich isotherm with a correlation coefficient of 0.9924. Kinetics studies showed that the adsorption process was consistent with the pseudo-second-order model. The recyclability was tested after extraction of Li + from the adsorbent using sulfuric acid. The adsorption capacity decreased slightly after recycling the adsorbent three times. This may be due to the dissolution of Mn 2+ and deformation of the chitosan structure. A study of the selectivity of Li + in seawater showed that the selectivity increased in the order Li + > Mg 2+ > Na + .