Dredging Operations Technical Support Program. Comparison of the Heavy-Metal Uptake of Cyperus esculentus and of Agronomic Plants Grown on Contaminated Dutch Sediments

Heavy-metal uptake by Cyperus esculentus from three highly contaminated fluvial sediments and from two uncontaminated substrates under reduced (flooded) and oxidized (upland) disposal conditions was studied in the greenhouse. Heavy-metal uptake by lettuce, radish, spring wheat, and red fescue grass from four highly contaminated sediments and one uncontaminated fluvial sediment under oxidized soil conditions was also studied. The sediments were collected from upland disposal sites or from polders where the clay soils originate from sedimentation under natural conditions in the freshwater tidal area. Part of the substrates was used under anaerobic conditions by immersing the soil in the inner container of a double bucket filled with demineralized water and maintaining a 5-cm layer over the soil. Cyperus esculentus from tubers planted in the sediments was grown to a maximum vegetative growth (45 days). Seeds of lettuce, radish, spring wheat, and red fescue grass were planted in the relevant substrates. The crops were harvested at commercial maturity; red fescue grass was cut four times at 15-cm length. All plant species performed well, both on uncontaminated and contaminated substrates.