Recovery of molybdenum using adsorption/desorption by nickel–aluminum or nickel–aluminum–zirconium complex hydroxides from aqueous media

Abstract

The potential of nickel–aluminum (NA series) and nickel–aluminum–zirconium (NAZ series) complex hydroxides in the recovery of molybdenum (Mo) ions was assessed in this study. Batch adsorption experiments, elemental distributions, binding energy analyses, and desorption experiments were performed. The amount of adsorbed Mo increased with increasing aluminum content (NA41 < NA31 < NA21 < NA11 < NA12). Additionally, the incorporation of zirconium in NA did not significantly affect the Mo ion adsorption capacity. The optimal conditions for Mo adsorption were determined. A pH of 5.0 was the most suitable for Mo ion adsorption. The adsorption equilibrium was reached approximately 3 h after the start of adsorption. The adsorbed amount did not change at adsorption temperatures from 7 to 45 °C. To elucidate the adsorption mechanism, ion exchange capacity, elemental distribution, and binding energy analyses were conducted. The results showed that ion exchange with sulfate ions in the adsorbent interlayer and surface characteristics had a significant impact on the adsorption capacity. Finally, a sodium sulfate solution was used as a desorption agent for the recovery of Mo ions from the aqueous phase. These findings offer important insights into the adsorption and desorption of Mo ions from aqueous environments using the NA or NAZ series adsorbents. The recovery of rare metals from aqueous environments can be greatly aided by the treatment recommended in this study.