The pH-dependent long-term stability of an amorphous manganese oxide in smelter-polluted soils: Implication for chemical stabilization of metals and metalloids

• Published in: Journal of hazardous materials Vol. 286; pp. 386 - 394
• Main Authors: Ettler, Vojtěch, Tomášová, Zdeňka, Komárek, Michael, Mihaljevič, Martin, Šebek, Ondřej, Michálková, Zuzana
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 09.04.2015
• Subjects: Amorphous manganese oxide; Arsenic - chemistry; Chemical stabilization; Environmental Restoration and Remediation; Hydrogen-Ion Concentration; Industrial Waste; Manganese Compounds - chemistry; Metal(loid)s; Metallurgy; Metals, Heavy - chemistry; Oxides - chemistry; pH-static experiment; Polluted soil; Soil Pollutants - chemistry; Waste Management; Chemical stabilization; pH-static experiment; Polluted soil; Metal(loid)s; Amorphous manganese oxide
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2015.01.018

[Display omitted] •The stability of amorphous manganese oxide (AMO) is pH-dependent.•“Labile” Pb, As and Sb decreased after treatment of a polluted soil with AMO.•Efficient chemical stabilization of Pb, As, Sb and Cu, no effect on Cd and Zn.•Most efficient contaminant retention under acidic conditions.•Increase in chemical stabilization with time (6 months>2 months of incubation). An amorphous manganese oxide (AMO) and a Pb smelter-polluted agricultural soil amended with the AMO and incubated for 2 and 6 months were subjected to a pH-static leaching procedure (pH 3–8) to verify the chemical stabilization effect on metals and metalloids. The AMO stability in pure water was pH-dependent with the highest Mn release at pH 3 (47% dissolved) and the lowest at pH 8 (0.14% dissolved). Secondary rhodochrosite (MnCO3) was formed at the AMO surfaces at pH>5. The AMO dissolved significantly less after 6 months of incubation. Sequential extraction analysis indicated that “labile” fraction of As, Pb and Sb in soil significantly decreased after AMO amendment. The pH-static experiments indicated that no effect on leaching was observed for Cd and Zn after AMO treatments, whereas the leaching of As, Cu, Pb and Sb decreased down to 20%, 35%, 7% and 11% of the control, respectively. The remediation efficiency was more pronounced under acidic conditions and the time of incubation generally led to increased retention of the targeted contaminants. The AMO was found to be a promising agent for the chemical stabilization of polluted soils.