Speciation of Cu, Zn and Cr in Excavated Fine Fraction of Waste at Two Landfills

Abstract

Mining landfills and open dumpsites is associated with (40-70% by mass) fine fraction of particle sizes less than 20 or 10 mm. Soil and trace elements of considerable concentrations typically dominate the composition of this fraction. In the present paper, a modified three steps sequential extraction procedure was used to fractionate Cu, Zn and Cr in the fine fraction of waste sampled from Högbytorp (Sweden) and Torma (Estonia) landfills. The results showed that the major concentrations of Cu (98.8 and 98.6 wt%) and Cr (98.5% and 98.4 wt %) in fines from Högbytorp and Torma landfills, respectively. These data were found associated to the residual fraction. Noticeable concentrations of Cu and Cr were also found associated within the water -soluble fraction, which could be regarded as a potential risk. The Zn displayed different behavior by distributing in all the sequential extraction fractions in the fine fractions from the two landfills. Specifying the metals content using this method is essential to explore the valorization as well as the potential environmental risks by these fines fractions.

Keywords

• metals speciation
• metals fractionation
• sequential extraction
• metals mobility
• fine fraction