RESUMO
Chemical activated carbons (PET-H2SO4 and PET-KOH) were prepared from post-consumer polyethylene terephthalate (PET) wastes using pyrolysis under moderate reaction temperatures by changing pyrolysis time and chemical activating agents. The produced carbons were characterized and tested in adsorption reactions of manganese, chromium, and cobalt ions in aqueous solutions. Results showed a high percentage removal of these inorganic ions from water: 98 % for Mn2+, 87 % for Cr3+, and 88 % for Co2+. Freundlich isotherms gave a better fit to the experimental data obtained with good correlation coefficient values in the range of 0.99-1 compared to other isotherms. The pseudo-second order kinetic model best described the chemical adsorption process as an exchange of electrons between the carbon and inorganic ions in solutions. The diffusion models showed that the process is controlled by a multi-kinetic stage adsorption process. In summary, this work demonstrates that the production of activated carbon from PET waste bottles is a potential alternative to commercial activated carbon and can be considered a sustainable waste management technology for removing these non-biodegradable plastic wastes from the environment.
