NOVEL TECHNIQUE FOR SUSTAINABLE BROWNFIELD REMEDIATION OF ARSENIC CONTAMINATED SOILS

Contaminated land is increasingly becoming an important issue worldwide. Many metal contaminants are persistent in soil for a large number of years. Immobilisation of metals has proven to be a challenging task and a cost-effective, non-invasive and socially acceptable technology is required for its remediation. The present study involves the in-situ immobilisation of heavy metals using compost enhanced with iron oxide and/or zeolite (up to 20% w/w) the assessment of their effectiveness with respect to metals containment and greening capability. The preliminary results illustrated that the combination of compost/iron oxide yielded better results for reducing the leaching of As (95%), Cu (97%), and Cd (73%) and the compost/zeolite treatment has reduced the leaching of Zn (97%), whereas compost treatment alone reduced leaching of Pb (90%) from the contaminated soils. It was also evident from the nursery trials that higher biomass production was achieved when using compost/zeolite amendments. Overall, this study has demonstrated that zeolite/iron enhanced composts amendments have a significant potential in reducing metals bioavailability and improving plant growth