Abstract
Inexpensive porous activated biocarbons were prepared from biomass and agriculture waste following the method of thermal and hydrothermal carbonization and activation with superheated water vapor. The activated biocarbons were characterized by nitrogen adsorption-desorption at 77 K, SEM, XRD, Raman spectrometry, FTIR spectroscopy, determination of particle size, and elemental composition by XRF. The specific surface area was in the range of 240-709 m(2)/g, and the total pore volume was from 0.12 to 0.43 cm(3)/g. The percentage of microporosity in activated biocarbons was 89-92%. These activated biocarbons have been used for CO(2) and heavy metal sorption. Activated biocarbons based on pine cones and birch prepared by thermal carbonization and activation with superheated water vapor had the highest ability to capture CO(2) and amounted to 6.43 and 6.00 mmol/g at 273 K, as well as 4.57 and 4.22 mmol/g at 298 K, respectively. The best activated biocarbon was characterized by unchanged stability after 30 adsorption and desorption cycles. It was proved that the adsorption of CO(2) depends on narrow micropores (<1 nm). Activated biocarbons have also been analyzed as effective adsorbents for removing Cu(2+), Zn(2+), Fe(2+), Ni(2+), Co(2+), and Pb(2+) ions from aqueous solutions. Activated biocarbons are effective adsorbents for the removal of lead and zinc ions from aqueous solutions.