Remediation of metal contaminated soil with mineral-amended composts.
This study examined the use of two composts derived from green waste and sewage sludge, amended with minerals (clinoptilolite or bentonite), for the remediation of metal-contaminated brownfield sites to transform them into greenspace. Soils contaminated with high or low levels of metals were mixed with the mineral-enhanced composts at different ratios and assessed by leaching tests, biomass production and metal accumulation of ryegrass (Lolium perenne L.). The results showed that the green waste compost reduced the leaching of Cd and Zn up to 48% whereas the composted sewage sludge doubled the leachate concentration of Zn. However, the same soil amended with composted sewage sludge showed an efficient reduction in plant concentrations of Cd, Cu, Pb or Zn by up to 80%. The results suggest that metal immobilisation and bioavailability are governed by the formation of complexes between the metals and organic matter. The amendment with minerals had only limited effects.
van Herwijnen
René
R
University of Surrey, School of Engineering, Guildford, Surrey GU2 7XH, UK.
Hutchings
Tony R
TR
Al-Tabbaa
Abir
A
Moffat
Andy J
AJ
Johns
Mike L
ML
Ouki
Sabeha K
SK
D000327:Adsorption; D018533:Biomass; D002104:Cadmium / Q000032:analysis / Q000633:toxicity; D003300:Copper / Q000032:analysis / Q000633:toxicity; D052918:Environmental Restoration and Remediation / Q000379:methods*; D006812:Humic Substances; D007220:Industrial Waste; D007854:Lead / Q000032:analysis / Q000633:toxicity; D008129:Lolium / Q000254:growth & development / Q000378:metabolism; D019216:Metals, Heavy / Q000633:toxicity*; D008903:Minerals; D018517:Plant Roots / Q000737:chemistry; D012722:Sewage; D012989:Soil Pollutants; D015032:Zinc / Q000032:analysis / Q000633:toxicity
D006812:Humic Substances; D007220:Industrial Waste; D019216:Metals, Heavy; D008903:Minerals; D012722:Sewage; D012989:Soil Pollutants; D002104:Cadmium; D007854:Lead; D003300:Copper; D015032:Zinc