PARENT SESSION
PS19 - Bioavailability
Sunday, 17 November 2002
8:00 AM to 6:30 PM
Exhibit Hall
(P184) Metal Extractability and Bioavailability to Plants of Copper-Rich Industrial Wastes/Products.
Ginocchio, Rosanna*,1, Silva, Yasna2, Sepúlveda, Nancy2, Bustamante, Elena2, Torres, Juan Carlos2, Rodríguez, Patricio2, 1 Departamento de Ecología, Pontificia Universidad Católica de Chile, Santiago, Chile2 Centro de Investigaciones Mineras y Metalúrgicas, Santiago, Chile
ABSTRACT- Metal toxicity to plants has been frequently evaluated in the lab using pure salts as metal sources. However, metals incorporated into soils by industrial activities have diverse chemical forms that may result in different metal extractability and bioavailability to plants. Chemical characterization of copper-rich industrial wastes/products is thus necessary for a better understanding of the impact of these materials on plants when incorporated into soils. In this project we characterized copper-rich materials from copper mines (tailing sand, smelter dust, smelter slag, copper ore, copper concentrate) and a primary water treatment plant (sewage sludge), using standard physicochemical analysis (e.g. particle size, pH, CEC, SOC, total metal contents, extracted copper fractions (water, 10 mM CaCl2, 0.01 M HCl, TCLP), optical mineralogical, and X-ray diffraction analysis. Total copper content and pH varied widely in these materials. The amount of copper extracted increased with total copper irrespective of the extractant, but a high extraction and a low extraction group were detected with water and 10 mM CaCl2 extractions. Ore, concentrate, slags, and some tailing sands have relatively low level of Cu extractability for a rather high copper concentration. For a subsample of materials, there was a negative correlation between total extracted copper and mean particle size. Data of the optical mineralogical analysis of the wastes and products are presented. Results from optical mineralogical and XRD analysis are well related to standard chemical characterization of the materials, in terms of copper extractability and solubility. In conclusion, we characterized a set of rather diverse copper-rich wastes and products, which have an interesting range of potential for copper release and thus potential differences in phytotoxic effects. Grants CIMM-ICA and Fondecyt 1000750.
Key words: Mine wastes, Chemical characterization, Metal solubility