Activated carbons for wastewater treatment could be effectively
prepared from both jacaranda fruit and plum kernels by the two
simple methodologies considered in this study. In general, results
showed that activated carbons obtained from plum kernels offered
the best adsorption properties for the removal of these priority
water pollutants. Removal of Pb2+ ions by the activated carbons
prepared seemed to be controlled by the textural properties of the
adsorbents. Hence, adsorbents with higher total pore and micropore
volumes performed better. The adsorption of AB25 and MB
dyes, however, was strongly conditioned by the surface chemistry
of the adsorbents. For these particular pollutants, the presence of
the calcium salts on the surface of the activated carbons prepared
by impregnation using a calcium solution extracted from egg shell
wastes prior carbonization seemed to play a primary role. Retention
capacities obtained were comparable to those reported for
activated carbons prepared by following conventional activation
routes. Accordingly, the activation process using a calcium solution
extracted from egg shell wastes could be considered as an alternative
and low-cost approach to improve the adsorption properties
of activated carbons for wastewater treatment. Finally, modeling
of the adsorption data pointed out the ability of the Sips model to
fit adequately the experimental results obtained, in comparison to
Langmuir and Freundlich models.