Comparison of a Homemade Bacuri Shell Activated Carbon With Carbon Nanotubes for Food Dye Removal

The shell of bacuri together with inorganic components [red mud+lime+KOH+KAl(SO4)2+Al(OH)3] at different ratios of 1.0 (BC-1.0), 1.5 (BC-1.5), and 2.0 (BC-2.0) were pyrolized at 1073K. To complete the chemical activation process, the inorganic components were leached from the carbonaceous matrix through acidification with 6M HCl under reflux to obtain ABC-1.0, ABC-1.5 and ABC-2.0. ABC-1.5 showed the highest adsorption capacity among these adsorbents. Fourier transform IR spectroscopy, scanning electron microscopy, N2 adsorption/desorption curves and X-ray diffraction were used to characterize BC-1.5 (precursor) and ABC-1.5 (activated carbon). The analyses indicate that the majority of the inorganic compounds were leached from the carbonaceous matrix, resulting in an activated carbon with a high surface area and pore volume, suitable for dye adsorption. The sorption capacity of ABC-1.5 was compared with multi-walled carbon nanotubes (MWCNT) for removal of Brilliant Blue food dye (BB-FCF) from aqueous solutions. The general order kinetic model described well the adsorption process. The maximum amounts of BB-FCF removed at 323K were 647.9 and 231.5mgg-1 for ABC-1.5 and MWCNT, respectively. In addition, ABC-1.5 and MWCNT were applied for the treatment of two simulated effluents.