The removal of toxic metals from liquid effluents by ion exchange resins. Part XIX: Chromium(III)/OH-/Dowex 1x8

The removal of chromium(III) from alkaline solutions by the anion exchange resin Dowex 1x8 was investigated. Several experimental variables were considered in this investigation: hydrodynamic conditions applied on the system, temperature, NaOH concentration in the aqueous feed and resin dosage. Based on the experimental results several models were used to a better understanding of the anion exchange process, thus, it was found that this exchange process was governed by the particle (resin bead) diffusion rate law, and follows the pseudo-second order kinetic model. Also, chromium(III) uptake onto the resin responded well to the Langmuir type-2 isotherm in a spontaneous process. In terms of chromium(III) uptake, the resin presented a better metal-load that multiwalled carbon nanotubes. HCl solutions presented acceptable characteristics to be used as eluents for chromium(III) loaded onto the resin.