Evaluation of the environmental impact of MSWI bottom ash reused in road construction : a ten-year field experimentation
Résumé
Environmental impact assessment of waste recycling scenario critically needs for reliable field data. This paper aims at discussing the results - in terms leachate chemistry and mineralogical evolution of a field experimentation undertaken during 10 y with MSWI bottom ash used in road construction. Data interpretation is supported by batch test performed on drilled core samples and geochemical modelling. Conductivity, pH and concentrations of the leachate in major elements (Ca, Cl, Na) as well as in metallic elements (Al, Cu, Pb, Zn) quickly drop in 1.5 y to reach, on the long term, relatively permanent values within the same orders of magnitude than a reference road built with calcareous aggregates. Carbonation processes within the MSWI bottom ash may be far to be completed and still in progress after 10 y