Low-grade MgO used to stabilize heavy metals in highly contaminated soils

• Published in: Chemosphere (Oxford) 2004-08, Vol.56 (5), p.481-491
• Main Authors: Garcı́a, M.A, Chimenos, J.M, Fernández, A.I, Miralles, L, Segarra, M, Espiell, F
• Format: Article
• Language: English
• Subjects: Applied sciences; Contaminated soils; Decontamination. Miscellaneous; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Environmental Pollution - prevention & control; Exact sciences and technology; Heavy metals; Hydrogen-Ion Concentration; Landfill; Magnesium oxide; Magnesium Oxide - chemistry; Metals, Heavy - chemistry; polluted soils; Pollution; pollution control; Pollution, environment geology; Reference Standards; remediation; Soil and sediments pollution; Soil Pollutants - analysis; soil pollution; Solubility; Spain; Stabilization; X-Ray Diffraction
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2004.04.005

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.