Use of wollastonite in the removal of Ni(II) from aqueous solutions

Abstract

The ability of wollastonite to adsorb Ni (II) from water has been carried out. A removal of 92% of Ni (II) with 20 g L-1 of adsorbent was observed at 50 mg L-1 adsorbate concentration, 6.5 pH and 30 °C. The process follows a first order rate kinetics with diffusion controlled nature and the data fits the Langmuir adsorption isotherm. Removal of Ni increases from 10 to 92% with the rise of pH from 3.0 to 8.0 and thereafter it remains almost unchanged. This change has been explained on the basis of aqueous-complex formation and the subsequent acid base dissociation at the solid-solution interface. © 1990 Kluwer Academic Publishers.