Removal of basic dye (crystal violet) from water using wollastonite as adsorbent

Abstract

Batch mode of experiments indicate that low concentration, small particle size of adsorbent, high temperature and alkaline pH of the solution are favourable for the removal of crystal violet (Basic violet ‐ 3) from aqueous solutions by adsorption on wollastonite. The adsorption behaviour of adsorbent follows the Langmuir's isotherm. The kinetics of adsorption has been studied in the light of adherence of adsorbate molecules on the outer interface of adsorbent as well as adsorbate transport within the pores of adsorbent. The thermodynamics of the process at different temperatures indicate favourable adsorption at the solid‐solution interface. Acid‐base dissociation of the hydroxylated oxides of adsorbent and ion exchange with dye cations are the suggested reasons for the maximum removal in alkaline medium.