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Adsorption Of Pb And Cd Onto Metal Oxides And Organic Material In Natural Surface Coatings As Determined By Selective Extractions: New Evidence For The Importance Of Mn And Fe Oxides, Deming Dong, Yarrow M. Nelson, Leonard W. Lion, Michael L. Shuler, Whilliam C. Ghiorse
Adsorption Of Pb And Cd Onto Metal Oxides And Organic Material In Natural Surface Coatings As Determined By Selective Extractions: New Evidence For The Importance Of Mn And Fe Oxides, Deming Dong, Yarrow M. Nelson, Leonard W. Lion, Michael L. Shuler, Whilliam C. Ghiorse
Civil and Environmental Engineering
Surface coatings (biofilms and associated minerals) were collected on glass slides in the toxic surface waters of Cayuga Lake (New York State, U.S.A.) and were used to evaluate the relative contributions of Fe, Mn and Al oxides and organic material to total observed Pb and Cd adsorption by the surface coating materials. Several alternative selective extraction techniques were evaluated with respect to both selectivity and alteration of the residual unextracted material. Pb and Cd adsorption was measured under controlled laboratory conditions (mineral salts solution with defined metal speciation, ionic strength 0.05 M, 25°C and pH 6.0) before and after extractions …
Lead Distribution In A Simulated Aquatic Environment: Effects Of Bacterial Biofilms And Iron Oxide, Yarrow M. Nelson, Waihung Lo, Leonard W. Lion, Michael L. Shuler, William C. Ghiorse
Lead Distribution In A Simulated Aquatic Environment: Effects Of Bacterial Biofilms And Iron Oxide, Yarrow M. Nelson, Waihung Lo, Leonard W. Lion, Michael L. Shuler, William C. Ghiorse
Civil and Environmental Engineering
Biofilms influence the transport and fate of heavy metals in aquatic environments both directly by adsorption and complexation reactions and indirectly via interactions with oxides of iron and manganese. These reactions were investigated by introducing lead into a continuous-flow biofilm reactor that was designed to simulate conditions in a flowing freshwater aquatic environment. The reactor provided controlled conditions, and use of a chemically-defined growth medium allowed calculation of lead speciation with a chemical equilibrium program (MINEQL). Pseudomonas cepacia was employed as a test cell strain because of its ability to grow and form biofilms in the defined medium. This bacterium …