Removal of malachite green from aqueous solutions using a modified chitosan composite.

The synthesis of a novel composite adsorbent prepared from coir pith activated carbon (CPAC), chitosan and sodium dodecyl sulphate (SDS, an anionic surfactant) is reported. The characterisation of the composite was done using SEM, XRD, UV-visible and IR spectroscopy studies. The effectiveness of the composite was made for the removal of a toxic cationic dye, malachite green (MG) from waste water based on adsorption studies. The reaction conditions for the adsorption studies were optimized based on initial dye concentration, dose rate, reaction time, pH and temperature. Langmuir and Freundlich isotherm models were adopted to study the mechanism of adsorption. The adsorption process was found to follow pseudo second order kinetics. The results of the present study indicate that the CPAC based composite could be an effective low cost adsorbent for the removal of MG from waste water.