Adsorption kinetics of Au(III) ions on a novel chelating resin silica-gel functionalized by an amino organophosphonic acid. (25th September 2012)

• Record Type: Journal Article
• Authors: Yin, Ping; Tian, Yuan; Qu, Rongjun; Zhang, Jiang
• Is Part Of: Progress in reaction kinetics and mechanism. Volume 37:Number 4(2012)
• Page Start: 344
• Page End: 354
• Publication Date: 2012-09-25
• Subjects: Chemical kinetics -- Periodicals; 541.39405
• DOI: 10.3184/146867812X13481351806773
• Languages: English
• ISSNs: 1468-6783

Abstract

The adsorption kinetics of Au(III) on a novel chelating resin namely silica gel functionalized by an amino phosphonic acid (denoted as SiO2 – EDA – APA) were studied. The results showed that SiO2 – EDA – APA could reach its saturation adsorption capacity within 4 h, and its excellent adsorption capacity for Au(III) was 234.61 mg g–1 when the initial solution concentration was 2.0 mmol L–1 at 35°C. The adsorption kinetics of the as-synthesized hybrid adsorbent for Au(III) at different temperatures can be modelled closely by a pseudo second-order rate equation. The thermodynamic parameters of adsorption, ΔG, ΔH and ΔS were 18.89 kJ mol–1, 19.82 kJ mol–1, and 125.74 J K–1 mol–1, respectively. It can be concluded that the adsorption of Au(III) on SiO2 – EDA – APA is a spontaneous, endotherminc process controlled by film diffusion, which results in its higher adsorption capacity at higher temperatures.