Purpose A former wood exploitation revealing high Cu
and As concentration of the soils served as a case study for
assisted phytoextraction.
Method P-spiked Linz–Donawitz (LD) slag was used as a
soil additive to improve physico-chemical soil properties
and in situ stabilize Cu and other trace metals in a sandy
Cu-contaminated soil (630 mg kg−1 soil). The LD slag was
incorporated into the contaminated soil to consist four treatments: 0% (T1), 1% (T2), 2% (T3), and 4% (T4). A
similar uncontaminated soil was used as a control (CTRL).
After a 1-month reaction period, potted soils were used for
a 2-week growth experiment with dwarf beans.
Results Soil pH increased with the incorporation rate of LD
slag. Similarly the soil electrical conductivity (EC, in
millisiemens per centimetre) is ameliorated. Bean plants
grown on the untreated soil (T1) showed a high phytotoxicity.
All incorporation rates of LD slag increased the root and shoot
dry weight yields compared to the T1. The foliar Ca
concentration of beans was enhanced for all LD slagamended
soil, while the foliar Mg, K, and P concentrations
were not increased. Foliar Cu, Zn, and Cr concentrations of
beans decreased with the LD slag incorporation rate.
Conclusions P-spiked LD slag incorporation into polluted
soil allow the bean growth and foliar Ca concentration, but
also to reduce foliar Cu concentration below its upper
critical value avoiding an excessive soil EC and Zn
deficiency. This dual effect can be of interest for soil
remediation at larger scale.