CHANGES IN LEACHING AND CHEMICAL Print
Written by Desiree Nordmark   
Wednesday, 13 October 2010 14:39

CHANGES IN LEACHING AND CHEMICAL FRACTIONATION OF ARSENIC, CHROMIUM AND COPPER IN SOIL AFTER

THERMAL TREATMENT. Authors:  D. NORDMARK*, R. RÖNKKÖ**, J. KUMPIENE*, L. ANDREAS* AND

A. LAGERKVIST*. Presented at  Sardinia 2009, Twelfth International Waste Management and Landfill Symposium.


SUMMARY: Thermal treatment is used for remediation of soils contaminated with both organic

and inorganic contaminants. The target is destruction of organic contaminants while the residue

containing the inorganic contaminants has to be further treated. The effects of thermal treatment

on As, Cr and Cu in contaminated soil are evaluated in laboratory and field tests, using leaching

test, As speciation and sequential extraction test. In laboratory tests on four particle size

fractions, the leaching of As and Cr increased by factors of 18-40 and 2-23, respectively, while

the mobility of Cu decreased 12-14 fold after thermal treatment. The concentration of As(V) in

the finest soil fraction increased 19 fold, while As(III) remained constant. Arsenic, Cr and Cu

associated to the reducible soil fraction decreased, possibly due to enhanced crystallisation of Fe

oxides and reduction of available adsorption sites. In the field test, the concentration of As, Cr

and Cu was 1-4 times higher in the filter fraction compared to the treated soil.

 

Last Updated on Wednesday, 13 October 2010 14:40