Adsorption of the aurocyanide, complex on granular activated carbons derived from macadamia nut shells – A preliminary study

Abstract

In this study, waste macadamia nut shells were investigated for potential use as a hard organic precursor for the production of a granular activated carbon material. The processing of the macadamia shells commenced with the carbonised of the shells under a nitrogen atmosphere. This was followed by the physical activation of the shells under a carbon dioxide atmosphere, which was carried out at different temperatures to investigate the effect of the activation temperature on pore formation. The pore structure and gold loading capacity of the synthesised activated carbons were investigated. The porous nature and surface structure of the macadamia shell based activated carbon were examined by Scanning Electron Microscopy (SEM) at various stages of manufacture. In addition, gold loading studies were carried out in conjunction with elemental mapping of the activated carbon surface to determine the gold adsorption sites. The studies have revealed that the macadamia shell based carbons, activated at higher temperatures have a gold loading capacity that is comparable to the commercially available coconut based activated carbons.

Review on Dye Removal from Its Aqueous Solution into Alternative Cost Effective and Non-Conventional Adsorbents

“…However due to the high cost associated with its production and regenerat-4 ing, researchers are developing alternative cost effective and nonconventional potential adsorbents in the removal of dye from its aqueous solution. Various adsorbents such as commercial activated carbon [22], mineral [23], Clay [24], agricultural solid wastes [25][26][27] and agricultural solid waste based activated carbon [28][29][30] have been used in the removal of dyes from wastewater.…”

“…Physical activation involves carbonization of a carbonaceous material followed by activation of the resulting charcoal at high temperature in the presence of suitable oxidizing gases where oxidization agents such as steam has shown the best potential for producing activated carbons with high surface area and good pore ratio (Şahin and Saka, 2013). Biomass based activated carbon (AC) through physical activation and its adsorptive behaviour has been reported by various researchers [29,41,42].…”

Adsorption of Gold on Granular Activated Carbons and New Sources of Renewable and Eco-Friendly Activated Carbons

“…Other nut-shell sources include almond, hazelnut, macadamia, pecan, and walnut while fruit stones such as apricot, cherry, peach, and plum have all been studied as precursor for activated carbons [44][45][46][47][48][49][50][51]. The importance of the inherent properties of the raw material cannot be underestimated since these properties have a significant influence on the final chemical and physical properties of the resulting activated carbon [52].…”

“…Typical atmospheres can consist of flue gas (source of carbon dioxide (CO 2 )), steam or atmospheric air or various combinations of these gases [40,50,76]. During activation, disordered carbon located in spaces between the aromatic sheets and more reactive regions of the carbonized structure are exposed to oxygen and undergo endothermic reactions as described by Eqs.…”

Adsorption of Coomassie Brilliant Blue R-250 Dye Onto Novel Activated Carbon Prepared From Nigella Sativa L. Waste: Equilibrium, Kinetics and Thermodynamics Running Title: Adsorption of Brilliant Blue Dye Onto Nigella Sativa L. Waste Activated Carbon

“…The activation process could be either physical or chemical and sometimes both processes are involved in the preparation of activated carbon. The physical activation involves carbonization of a carbonaceous materials followed by activation of the resulting char in the presence of activating agents such as CO 2 or steam 5 . On the other hand, chemical activation is a single step method involving the use of a chemical activating agent such as ZnCl 2 , KOH, H 2 SO 4 , etc.…”