Removal of Cd(II) from wastewater by adsorption on “waste” Fe(III)/Cr(III) hydroxide

Effect of initial metal ion concentration, agitation time, temperature and pH on Cd(II) adsorption by “waste” Fe(III)/Cr(III) hydroxide was investigated in batch mode studies. The equilibrium data could be described well by the Langmuir and Freundlich isotherm equations. The Lagergren rate constants of adsorption are reported. The intraparticle diffusion of Cd(II) through pores in the adsorbent was shown to be the main rate limiting step. Desorption of Cd(II) was 70% at pH 3.80. The studies showed that the “waste” Fe(III)/Cr(III) hydroxide can be used as an efficient adsorbent material for Cd(II) removal from wastewater.