An Electrochemical Study of the Interactions Between Trace Metals and Humic Substances in Freshwaters by Anodic Stripping Voltammetry with a Thin Mercury Film Rotating Disk Electrode

✍ Scribed by Catherine A. Murimboh; Jianfu Deng; John Murimboh; Jeffrey W. Guthrie; Chuni L. Chakrabarti; David R. S. Lean

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 442 KB
• Volume: 17
• Category: Article
• ISSN: 1040-0397
• DOI: 10.1002/elan.200403329

✦ Synopsis

Abstract

An improved theoretical approach to Anodic Stripping Voltammetry with a Thin Mercury Film Rotating Disk Electrode for elucidating the nature of the interactions of Pb(II), Cd(II) and Zn(II) with humic substances in model solutions of Laurentian fulvic acid, and of Pb(II), Cd(II), Zn(II) and Cu(II) in freshwaters, is presented. Conditional stability constants of Pb(II), Cd(II) and Zn(II) complexes decreased with the ionic potential (z^2^/r) and increased with softness of the metal ion, indicating strong affinity of soft, polarizable donor ligands on humic substances for softer metal ions, resulting in an appreciable covalent character in electrostatic bonding between the metals and humic substances.