Activated carbons from Angolan wood wastes for the adsorption of MCPA pesticide

Abstract

The work now reported presents the activated carbons production from Angolan woods wastes, namely Candeia, Hama, Njiliti, Nuati and Tchitiotioli. The physical activation with carbon dioxide produced materials with apparent surface area between 603 and 801 m2/g, pore volume from 0.26 to 0.36 cm3/g, mean pore width from 0.68 to 0.98 nm, and low external surface areas, less than 47 m2/g for all samples. All samples present a basic nature with point of zero charge in the range 8.58 to 11.90. Selected samples were tested for the adsorption of a problematic pesticide, MCPA (4-chloro-2-methylphenoxyacetic acid) from aqueous solutions. The maximum adsorption was between 85 and 295 mg/g after 24h of equilibrium. With this work a time window of potential applications for these precursors is open, with a not negligible economic impact for the country.