The removal of toxic metals from liquid effluents by ion exchange resins. Part VII: Manganese(VII)/H+/Amberlite 958

The anionic exchange resin Amberlite 958 was used to remove manganese(VII), as permanganate ion, from aqueous solutions of different pH values. Besides the aqueous pH, other variables involved in the exchange process were investigated, including, stirring speed of the system, temperature, ionic strength and resin concentrations. The non-lineal fit of the experimental points, indicated that the equilibrium isotherm is best explained by the Langmuir equation, whereas the anion exchange equilibrium is endothermic and nonspontaneous. The Mn(VII) loading performance of Amberlite 958 resin was compared with that of other anion exchangers and multiwalled carbon nanotubes. The elution of the Mn(VII) loaded onto Amberlite 958 was investigated using hydrazine sulphate solutions, which render manganese to the eluate as the somewhat less hazardous form of Mn(II).