Weathering of Some Norwegian Alum Shales, II. Laboratory Simulations to Study the Influence of Aging, Acidification and Liming on Heavy Metal Release
Titel:
Weathering of Some Norwegian Alum Shales, II. Laboratory Simulations to Study the Influence of Aging, Acidification and Liming on Heavy Metal Release
Auteur:
Jeng, Alhaji S.
Verschenen in:
Acta agriculturae Scandinavica. Section B, Soil and plant science
Paginering:
Jaargang 42 (1992) nr. 2 pagina's 76-87
Jaar:
1992-06-01
Inhoud:
Pulverized rock samples of alum shale were agitated in distilled water for up to 100 days, in acid solutions of increasing concentrations for 24 h, and lastly treated with increasing amounts of lime as CaCO3 and equilibrated for 100 days. The effects of the different treatments on the release of Fe, Cu, Zn, Ni, Cd, Pb and Mn were studied. The aging experiment indicated that, with time, large amounts of heavy metals may be released by alum shales. The MUNCH sample, with a high buffer capacity against acid, was found to be slow in heavy metal release. The high correlation coefficients for added H+ versus % of total metal released, however, reflect that under the influence of 'foreign' acids, this sample will also be capable of releasing heavy metals relatively easily. Liming was effective in rendering the heavy metals immobile. 90-100 tons of CaCO3 were found to be enough to immobilise most of the metals released from a shale waste to an acceptable level, assuming a shale waste density of 1-2 kg dm-3.
Tijdschrift beschrijving