High Adsorption Capacity Carbons from Biomass and Synthetic Polymers for the Removal of Organic Compounds from Water

Activated carbons from cellulose, sawdust, and their mixtures with polystyrene and polypropylene have been produced by a two-step pyrolysis process followed by steam activation at 850 °C. Selected activated carbons were used to determine the adsorptive properties towards phenol, Congo red and vitamin B12. The equilibrium time and equilibrium sorption capacity were determined. All obtained carbons have basic surface characteristics. The cellulose-based activated carbons are predominantly microporous, whereas the sawdust-based activated carbons have well developed both micro and mesoporous structure. Activated carbon from cellulose has high adsorption capacity toward phenol, whereas carbon from sawdust is found to be very efficient adsorbent for the removal of Congo red and vitamin B12. The adsorption of phenol and Congo red was enhanced by electrostatic forces that appeared between the adsorbed molecules and activated carbon surface.