Influence of a salt marsh plant (Halimione portulacoides) on the concentrations and potential mobility of metals in sediments

摘要: Influence of Halimione portulacoides, commonly found in temperate salt marshes, on sediment metal contents, speciation and potential mobility case re-suspension was evaluated. Both colonized non-colonized sediments were studied for total Cd, Cu, Pb Zn contents fraction exchangeable to water collected situ. Sediment elutriates, prepared with from each site, used simulate a phenomenon. As the characteristics degree contamination may influence system behaviour, marshes two Portuguese estuaries, Cavado (NW coast) Sado (SW coast), studied. higher than ERL (quality guideline, effect range-low) observed, indicating risks living organisms. Strong Cu-complexing organic ligands, also determined both rhizosediment at concentrations similar, or even higher, those Cu. Such ligands condition metals column probably bioavailability. From significant amounts Cu transferred aqueous phase, 2-8 times present water. In contrast, elutriates removed water, levels being 2-6 lower initial ones. Cd not measurable most cases. Results clearly indicate that solubility rhizosphere plants markedly surrounding sediment. The obtained results indicated H. portulacoides presence (and other marsh plants) cause marked increase dissolved phase (pore if is re-suspended). be abundant subtropical estuaries costal lagoons, this phenomenon should disregard future studies towards sustainable management such environments.