Assessment of Cu stabilisation in a contaminated soil from a wood preservative treatment site using the PlantTox test

摘要

Copper was main metal contaminant (2600μg·g 1) limiting plant growth in the topsoil of a barren area at a wood treatment site. Stabilisation of Cu is a relevant soil remediation option, especially in the purpose to further use phytostabilisation and to restore plant community with a high biodiversity. Therefore, soil amendments were either singly or in combination mixed into this high Cu contaminated soil. Their effectiveness at reducing root exposure to Cu and promoting plant growth was assessed using the PlantTox test with Phaseolus vulgaris. Amendments with organic matter (OM) or increasing pH were the most efficient for Cu stabilisation whereas amendments with phosphates or decreasing pH were not effective. Most efficient treatments immobilised Cu up to 99% and restored plant growth. Less efficient treatments increased Cu in soil solution (4. 5 times), peroxidase activity in bean roots due to oxidative stress, and chlorophyll densities in leaves due to their small development. For Cu stabilisation in such contaminated soil, Ca oxide, Thomas basic slags, and OM singly or in combination with zerovatent iron grit were recommended to be tested in field experiment.