E3S Web of Conferences
Volume 1, 2013Proceedings of the 16th International Conference on Heavy Metals in the Environment
|Number of page(s)||4|
|Section||Heavy Metals in Contaminated Sites II: Mining and Smelting|
|Published online||23 April 2013|
Leaching of Trace Metals from Soil under Alternating Oxic-anoxic Conditions: a Column Study
1 “Politehnica” University of Bucharest, 011061, Bucharest, Romania
2 Geological Institute of Romania, 012271, Bucharest, Romania
3 Di.Va.P.R.A – Chimica Agraria, University of Turin, 10095, Grugliasco, Turin, Italy
One of the most important and abundant transition metals in the Earth’s crust is iron, which plays a key role in environmental biogeochemistry. A large number of trace metals and other contaminants are associated to Fe(III) minerals; under anoxic conditions, Fe(III) can be reduced and, consequently, potentially dangerous compounds can be released. In this work we present column experiments of metal mobilization from soils sampled from a mining area in Northeastern Romania. A preliminary study was carried out to determine the extractability of metals in CaCl2 0.01 M solution and the influence of adding 1 g L−1 lactose as a carbon source. The results showed that the heavy metals were rapidly brought into solution in the medium supplemented with lactose. Then, the release of metals was studied using columns packed with soil percolated with the CaCl2 solution. It was observed that, while Zn and Pb are released in the solution congruently with the reduction of Fe and Mn, copper is mobilized immediately and can be found in the leachate. This suggests that, under alternating oxic-anoxic conditions, the soil can become a source of contamination.
Key words: Column study / heavy metals / leachate / redox transformations
© Owned by the authors, published by EDP Sciences, 2013
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 2.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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