Sorption of indium (III) onto carbon nanotubes

• A new adsorbent for the rare metal, In(III) was described.
• Multiwalled carbon nanomaterials adsorbed >80% of In(III) in solution.
• Equilibrium adsorption, adsorption kinetic and rate law were analyzed for In(III) adsorption.

Indium has numerous applications in different industrial sectors and is not an abundant element. Therefore appropriate technology to recover this element from various process wastes is needed. This research reports high adsorption capacity of multiwalled carbon nanotubes (MWCNT) for In(III). The effects of pH, kinetics, isotherms and adsorption mechanism of MWCNT on In(III) adsorption were investigated and discussed in detail. The pH increases improves the adsorption capacity for In(III). The Langmuir adsorption model is the best fit with the experimental data. For the kinetic study, the adsorption onto MWCNT could be fitted to pseudo second-order. The adsorption of indium(III) can be described to a mechanism which consists of a film diffusion controlled process. Metal desorption can be achieved with acidic solutions.