Removal of malachite green from aqueous solutions using wheat bran: optimisation, equilibrium and kinetic studies

Abstract

In this study, the use of wheat bran as possible adsorbent has been successfully demonstrated in the removal of malachite green (MG) from aqueous solution. The effect of different parameters such as temperature, adsorbent dose, contact time, adsorbent size and agitation speed were investigated. The optimum conditions obtained from response surface methodology are: temperature – 39°C, adsorbent dose – 2.7 g/l, contact time – 202 min, adsorbent size – 0.09 mm (170 mesh) and agitation speed – 210 rpm. The effect of pH and initial substrate concentration were studied. The pseudo-first order and pseudo-second order kinetics were tested. The sorption equilibrium, expressed by the Langmuir and Freundlich equations, indicated that the process was in compliance with Freundlich isotherm.