Trace element mobility in a contaminated soil two years after field-amendment with a greenwaste compost mulch.
Application of greenwaste compost to brownfield land is increasingly common in soil and landscape restoration. Previous studies have demonstrated both beneficial and detrimental effects of this material on trace element mobility. A pot experiment with homogenised soil/compost investigated distribution and mobility of trace elements, two years after application of greenwaste compost mulch to shallow soils overlying a former alkali-works contaminated with Pb, Cu and As (approximately 900, 200 and 500 mg kg(-1), respectively). Compost mulch increased organic carbon and Fe in soil pore water, which in turn increased As and Sb mobilization; this enhanced uptake by lettuce and sunflower. A very small proportion of the total soil trace element pool was in readily-exchangeable form (<0.01% As, <0.001% other trace elements), but the effect of compost on behaviour of metals was variable and ambiguous. It is concluded that greenwaste compost should be applied with caution to multi-element contaminated soils.
Clemente
Rafael
R
Faculty of Sciences, Liverpool John Moores University, Liverpool L3 3AF, UK. rclemente@cebas.csic.es
Hartley
William
W
Riby
Philip
P
Dickinson
Nicholas M
NM
Lepp
Nicholas W
NW
D052918:Environmental Restoration and Remediation / Q000379:methods*; D008670:Metals / Q000032:analysis; D012987:Soil / Q000032:analysis*; D012989:Soil Pollutants / Q000032:analysis*; D014131:Trace Elements / Q000032:analysis*
D008670:Metals; D012987:Soil; D012989:Soil Pollutants; D014131:Trace Elements