The Role of Ion Exchange and Sorptive-Reduction for Interaction of Active Carbons with Noble Metals

Abstract

The sorption behavior of ions on active carbons (ACs) was compared for three elements of the copper group, Cu, Ag and Au, between a basic AC and an acidic AC, and between a deaerated and aeratedd conditions. The difference among the sorption conditions was explained by assuming that the sorption proceeds partly by an ion exchange and partly by the reductive sorption. It was also discussed in terms of electrochemical impedance spectroscopy and quantum chemical analysis.

Waste Conversion into Activated Carbon for Heavy Metal Removal from Waste Water

“…Based on the obtained kinetics results, on previous work on adsorption equilibrium of Cu (II) and Cr (III) on synthetic and natural activated carbons [21,24], and on data reported in the literature [25][26][27][28][29][30][31], we propose a mechanism for the adsorption of 3-d transition metals in real aqueous solutions. In previous work on Cu (II) adsorption over activated carbon in the absence of oxygen surface groups we observed the formation of a metallic film on the carbon surface (similar to the galvanic covering process) [24].…”

“…In previous work on Cu (II) adsorption over activated carbon in the absence of oxygen surface groups we observed the formation of a metallic film on the carbon surface (similar to the galvanic covering process) [24]. However, copper adsorption on carbons enriched with oxygen surface groups originated a decolorized solution with no metallic film formation [24].…”