Preparation and characterization of active carbon spheres prepared by chemical activation

Active carbon spheres were prepared by chemical activation using acid-pretreated resin beads, composed of sulfonated polystyrene divinylbenzene. Carbonization and activation were carried out simultaneously at various temperature ranges from 200 to 900 °C for 4 h, under gentle fluidization conditions facilitated with N2 flow. Effect of temperature on carbon burn-off of precursor and surface area of active carbon spheres was also studied. Prepared active carbon spheres were characterized using scanning electron microscope, surface area analyzer, thermo gravimetric analyzer, tensile tester, and CHNS instrument. Active carbon spheres exhibited high surface area 976 m2/g and pore volume 0.68 ml/g. They were also evaluated for total surface acidity of 1133 meq/100 g and surface basicity of 275.3 meq/100 g. Active carbon spheres showed their applicability for the removal of CN− (50%) and for various heavy metal ions such as Pb(II), Mn(II), Hg(II), Cu(II), Cd(II), Zn(II), and Ni(II) (50–90%) from their contaminated solution.