Impact of river overflowing on trace element contamination of volcanic soils in south Italy: part I. Trace element speciation in relation to soil properties.

摘要: Volcanic soils affected by different numbers of polluted river flooding events were investigated. Chromium and Cu the major soil contaminants. Nickel, Fe, Zn Mn total content never exceeded Italian mandatory limits. The distribution Cr contents among studied indicated that only contamination was related to overflowing events. In soils, sequential chemical extractions revealed a preferential association with organic forms. A progressive insolubilization ageing observed. Significant amounts extracted NH(4)-oxalate, suggesting metals short-range-order aluminosilicates organo-mineral complexes. Possible methodological drawbacks in use EU-BCR speciation protocol on volcanic are discussed. Micromorphology SEM/WDS analyses enriched silt clay coatings surface subsurface horizons, transfer metal-rich sediments along pore network water movement.