Application of the BRC Sequential Extraction Schem

Authors: Risto Pöykiö Mikko Mäkelä Hannu Nurmesniemi Olli Dahl Masahiro Oguchi

Publish Date: 2012/11/07

Volume: 4, Issue: 4, Pages: 821-830

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Abstract

Extractions tests are widely used as tools to estimate the potential release of constituents for example from waste materials over a range of possible waste management activities including recycling reuse and landfill disposal Sequential extraction procedures offer the advantage of simulating to a certain extent the various natural environmental conditions In this study the mobility and bioavailability of heavy metals in woodbased bottom ash and fly ash was evaluated by the threestage BCR sequential extraction procedure in which elements in the bottom ash and fly ash were fractionated between acidsoluble CH3COOH BCR1 reducible NH2OH–HCl BCR2 and oxidisable H2O2 + CH3COONH4 BCR3 fractions For the bottom ash the extractable concentration of Al 88 mg/kg dw and Ba 82 mg/kg dw in the BCR1 fraction were moderate whereas the extractable concentrations of Mn 110 mg/kg dw S 310 mg/kg dw and Zn 200 mg/kg dw were relatively high In the fly ash the highest extractable concentrations in the BCR1 fraction were observed for S 14400 mg/kg dw and Ba 26 mg/kg dw Therefore when these ashes are disposed of in a landfill or utilized for example in earth construction the abovementioned metals are likely to be released from the bottom ash and from the fly ash since the elements associated with the acidsoluble CH3COOH fraction are more mobile and bioavailable than the metals in easily reduced NH2OH–HCl and oxidisable H2O2 + CH3COONH4 fractionsThe authors wish to thank the technical staff of Suomen Ympäristöpalvelu Oy who kindly conducted all the chemical analyses Thanks also to Mr Olli TaikinaAho at the Institute of Electronic Optics University of Oulu for the XRD data and Dr Roy Siddall for correcting the English language

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