Phytoavailability of Trace Elements from a Landfill Containing Coal Combustion Waste

摘要: The 488-D Ash Basin (488-DAB) is an unlined, earthen landfill on the U.S. Department of Energy’s Savannah River Site, SC that contains approximately one million tons coal combustion wastes (CCWs). Pyrite co-mingled with CCWs has undergone oxidation and formed sulfuric acid, which dissolved metals trace elements in facilitated their mobility. acid leachate contributes to ground-water deterioration area threatens biota on, adjacent to, landfill. A study was undertaken examine vegetation 488-DAB assess potential for phytoavailability these determine if a secondary contamination source exist. Results indicated element concentrations were higher than those native soils area. Mean pH (1.79 ± 0.75) As (64.7 43.0 mg kg−1) range critical plant toxicity. Sequential extractions Mn, Zn, Ni, Cr organically bound exchangeable fractions material likely phytoavailable, while Pb Se tightly crystalline extractable (residual) fractions. fractionation patterns Al, As, Cd Fe very similar most poorly fraction, suggest solubilities are controlled by common precipitate or mineral CCWs. Tissue analysis Mn Zn accumulated species growing 488-DAB, as predicted. However, Ni not at levels above Uptake tissue observed over several species, but all. Given conditions, results periodic monitoring should continue ensure toxicity contaminant problems do arise.