A powdery lithium ion sieve (HMO) derived from biogenic birnessite was homogeneously integrated in sodium alginate (AL) beads. The composite beads were then characterized and their Li+ adsorption properties were investigated. Scanning electron microscopy–energy dispersive spectroscopy analysis showed that the HMO particles were homogeneously dispersed in the AL beads even after drying. The adsorption isotherm of Li+ adsorption to HMO encapsulated in AL beads (HMO–AL) was well fitted by the linear Langmuir model, and the beads showed a maximum adsorption capacity of 3.61 mmol/g based on HMO, which is comparable with the value of the original powdery HMO. Kinetic studies revealed that adsorption of Li+ follows a pseudo-second-order model with rate constant k2 = 2.8–11.9 × 10− 3 g/(mmol min) for the initial Li+ concentration range 2.56–4.23 mM. Diffusion of Li+ from aqueous solution to the HMO particle through the Ca–AL network is the rate-limiting step for Li+ adsorption to HMO–AL beads. The HMO-AL beads enhanced the handling efficiency for Li+ adsorption and reused without significant reduction of Li+ adsorption efficacy.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)