Environ. Sci. Technol. 2005, 39, 2080-2086
Root-Induced Cycling of Lead in Salt Marsh Sediments B J Ø R N S U N D B Y , * ,†,‡ M I G U E L C A E T A N O , § CARLOS VALE,§ CHARLES GOBEIL,| GEORGE W. LUTHER, III,⊥ AND DONALD B. NUZZIO¶ Institut des Sciences de la Mer de Rimouski, Universite´ du Que´bec a` Rimouski, Rimouski, Que´bec G5L 3A1, Canada, Earth & Planetary Sciences, McGill University, Montreal, Que´bec H3A 2A7, Canada, Department of Biogeochemistry and Environmental Impact, Instituto Nacional de Investigac¸ a˜o Agra´ria e das Pescas, 1449-006 Lisbon, Portugal, Terre et Environnement, Institut National de la Recherche Scientifique, Centre Eau, CP 7500, Sainte-Foy, Que´bec G1V 4C7, Canada, College of Marine Studies, University of Delaware, Lewes, Delaware 19958, and Analytical Instruments Systems, P. O. Box 458, Flemington, New Jersey 08822
A gold-mercury amalgam microelectrode was used in situ to measure Pb(II) by anodic stripping voltammetry and O2, Fe(II), Mn(II), and HS- by square-wave voltammetry in sediment pore water in a Haliomione portulacoides stand in a Tagus estuary salt marsh. The measurements were made in spring, summer, and fall, and were supplemented with analysis of Pb in solid phases and stable isotope analysis of Pb. In spring, the pore water was anoxic, Fe(II) reached concentrations as high as 1700 µmol/L, and Pb(II) was undetectable (
