Removal of Chromium (VI) from wastewater using chemically activated Syzygium jambolanum nut carbon by batch studies

The chemically activated carbon prepared from Syzygium jambolanum nut, an agricultural waste, after activation with ammonium persulphate in the presence of sulphuric acid and then subjected to thermal activation by dolomite process, was successfully used to remove chromium (VI) from wastewater in batch studies by adsorption process. Effects of pH, carbon dose and equilibration time were determined. Desorption of Cr (VI) was done with 1 M NaOH and 10% H2O2 mixture followed by 2 M HCl. Adsorption followed Freundlich, Langmuir and Temkin isotherms but was conformed to Freundlich adsorption isotherm predominantly. Kinetic studies indicated that the removal process followed pseudo second order predominantly rather than pseudo first order and reversible first order reaction. Removal of Cr (VI) followed the film diffusion process. Negative ΔG0 values indicated the feasibility and the spontaneous nature of the adsorption process. The performance of Chemically Activated High Temperature Syzygium jambolanum nut Carbon (CHSJC) was compared with a Commercial Activated Carbon (CAC).