Autori: G. Aouad, J.-L. Crovisier, D. Damidot, P. Stille, E. Hutchens, J. Mutterer, J.-M. Meyer, V.A. Geoffroy

Editorial: Science of the Total Environment, in press, 2006.

Rezumat:

Municipal solid waste incinerator (MSWI) bottom ash can be used in road construction and is therefore likely to be a source of oligoelements for bacteria, the growth of which may impact the rate of leaching of potentially toxic elements. As a consequence, our objective was to highlight the mutual interactions between MSWI bottom ash and Pseudomonas aeruginosa, a common bacteria found in the environment. Experiments were carried out for 19 weeks at 25°C using a modified soxhlet’s device and a culture medium, in a closed, unstirred system with weekly renewal of the aqueous phase. The solid products of the experiments were studied using a laser confocal microscope, which showed that biofilms formed on mineral surfaces, thereby protecting them from leaching. The concentrations of strontium and calcium measured in solution indicate that the rate of cation leaching was slower in the biotic medium (approximately 40%) compared to the sterile medium during the first renewal cycles. However in the longer term, both rates decreased to reach similar end values. The results show that the total mass loss after 19 weeks is at least 17 % greater in abiotic mode, than in the biotic one.

Cuvinte cheie: bottom ash, bacteria, alteration, bioalteration, biofilm, Pseudomonas aeruginosa