Powdered activated carbons from Pinus caribaea sawdust

Activated carbons with different porous structures have been prepared from Pinus caribaea sawdust through the Use Of CO2 and steam as activating agents. The evolution of the Brunauer-Emmett-Teller (BET) surface area upon activation becomes fairly similar in both cases, and values above 1000 m(2)/g can be reached at high burn-off levels. Activation with steam produces a more developed porous structure, with a substantially higher contribution of mesoporosity, than does activation with CO2. Increasing the activation temperature leads in both cases to a wide pore-size distribution. The presence of a well-developed mesoporosity makes the resulting products good candidates for adsorbents for water and wastewater treatment. For these purposes, the characteristics of these activated carbons are comparable to those used as commercial adsorbents in those fields, showing in the case of the steam-activated carbons, a somewhat higher mesopore volume than many of the commercial products while maintaining similar surface area values to them. The relative simplicity of the process makes the production of steam-activated carbons a feasible and economically valuable alternative for sawmill wastes.