Low-grade MgO used to stabilize heavy metals in highly contaminated soils.
Low-grade MgO may be an economically feasible alternative in the stabilization of heavy metals from heavily contaminated soils. The use of MgO is described acting as a buffering agent within the pH 9-11 range, minimizing heavy metals solubility and avoiding the redissolution that occurs when lime is used. The effectiveness of LG-MgO has been studied as stabilizer agent of heavily polluted soils mainly contaminated by the flue-dust of the pyrite roasting. The use of LG-MgO as a reactive medium ensures that significant rates of metal fixation, greater than 80%, are achieved. The heavy metals leachate from the stabilized soil samples show a concentration lower than the limit set to classify the waste as non-special residue. Regardless of the quantity of stabilizer employed (greater than 10%), LG-MgO provides an alkali reservoir that allows guaranteeing long-term stabilization without varying the pH conditions.
García
M A
MA
Department of Chemical Engineering and Metallurgy, University of Barcelona, Martí i Franqués, 108028 Barcelona, Spain.
Chimenos
J M
JM
Fernández
A I
AI
Miralles
L
L
Segarra
M
M
Espiell
F
F
D004787:Environmental Pollution / Q000517:prevention & control*; D006863:Hydrogen-Ion Concentration; D008277:Magnesium Oxide / Q000737:chemistry*; D019216:Metals, Heavy / Q000737:chemistry*; D012015:Reference Standards; D012989:Soil Pollutants / Q000032:analysis*; D012995:Solubility; D013030:Spain; D014961:X-Ray Diffraction
D019216:Metals, Heavy; D012989:Soil Pollutants; D008277:Magnesium Oxide