DIFFUSION EXPERIMENTS AS A NEW APPROACH TO THE EVALUATION OF COPPER TRANSPORT IN HUMICS-CONTAINING SYSTEMS

摘要

Diffusion measurements seem to provide a valuable approach to mapping studies on heavy metal transport in systems containing humic substances. The paper deals with the diffusion of cupric ions in a humic hydrogel. The diffusion coefficients of Cu^sup 2+^ in this medium were determined using in-diffusion from the constant source, diffusion couple and instantaneous planar source. The applicability of the experimental arrangements and mathematical description of metal ion transport are discussed in terms of the influence of complexation of Cu^sup 2+^ with humic acids. All determined diffusion coefficients of Cu^sup 2+^ in humic gel were lower but of the same order of magnitude compared with that obtained in water. [PUBLICATION ABSTRACT]