Almond, pecan, English walnut, black walnut and macadamia nut shells were chosen as hard, lignocellulosic precursors for the production of granular activated carbons (GACs). They were activated with H3PO4 under a variety of conditions. Following activation, a portion of each GACs was oxidized in air at 300 degrees C for 4 h in order to create a carbon surface presumably with more oxygen functional groups for the adsorption of metal cations. Also investigated was a streamlining of the production techniques used. Several of the samples were subjected to a ＇Continuous＇ process in which the carbon was activated and upon cooling to 300 degrees C was oxidized with air. Beyond this activation, methods were developed wherein the activation process took place under air and without a discrete, separate oxidation step. These processes were designed to determine if any of the carbon＇s capabilities would be lost or enhanced in comparison to the more standard activate-cool-wash-oxidize method. The carbons produced from these various activation/oxidation methods consistently, and without regard to precursor composition, sequestered over 90% of available copper from a 3 mM copper chloride test solution and often adsorbed organic contaminants as effectively as some commercial carbons.