Equilibrium and kinetic studies for removal of malachite green from aqueous solution by a low cost activated carbon

A low cost activated carbon was synthesized from coconut coir and was applied for the removal of malachite green (MG) from its aqueous solutions. Characterization of the adsorbent was carried out and BET surface area of the adsorbent was found to be 205.27 m2/g. The process of removal of MG was better governed by second order kinetics with a rate constant of 0.21 g mg−1 min−1 at 323 K. The coefficient of mass transfer was found to be 3.70 × 10−5 cm s−1. The value of ΔG° was found to be negative indicating feasibility and spontaneity of the adsorption process.