Journal of Colloid and Interface Science 307 (2007) 40–49 www.elsevier.com/locate/jcis Sorption of Cu(II) onto vineyard soils: Macroscopic and spectroscopic investigations Stéphanie Boudesocque a , Emmanuel Guillon a,∗ , Michel Aplincourt a , Eric Marceau b , Lorenzo Stievano b a GRECI (Groupe de Recherche en Chimie Inorganique), Université de Reims Champagne-Ardenne, BP 1039, 51687 Reims Cedex 2, France b Laboratoire de Réactivité de Surface, Université Pierre et Marie Curie, UMR CNRS 7609, 4 place Jussieu, 75252 Paris Cedex 05, France Received 7 September 2006; accepted 31 October 2006 Available online 30 November 2006 Abstract The sorption of Cu on five vineyard soils was examined via macroscopic and spectroscopic investigations. The composition of the soils was previously determined using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). X-ray absorption spectroscopy (XAS) was employed to determine the metal environment with regard to the identity and interaction of the nearest atomic neighbors, the bond distances, and the coordination numbers. The five soils present similar sorption properties and there is no XAS evidence that the nature of the soil samples affects the local chemical environment of Cu(II). The kinetics of the Cu sorption reactions is rapid, with the equilibrium loading of Cu on the surface achieving approximately 200 μmol g −1 , i.e., 12.7 mg g −1 . The XAS data indicate that Cu is adsorbed in the form of inner-sphere complexes with first shell Cu–O parameters of four equatorial Cu–O bonds equal to 1.93 Å and two axial Cu–O bonds at 2.43 Å. This is in accordance with a Jahn–Teller distorted octahedron environment around copper. Our results provide evidence of the complexation of Cu(II) onto soil organic matter coated with an inorganic surface (quartz, clay, and goethite).  2006 Elsevier Inc. All rights reserved. Keywords: Copper; Sorption; Soil; DRX; EXAFS; XANES 1. Introduction One of the most important factors influencing the transport and environmental fate of chemicals in soil and sediment is the adsorption–desorption process. Among these chemicals, heavy metals display a special behavior. Their bioavailability, mobil- ity, toxicity, and fate are directly related to the sorption capacity of the soils [1]. The soil pH and the presence of metallic oxides are very important factors controlling the solubility of a metal in these systems [2–5]. Nowadays, research focuses on the mech- anisms by which metal contaminants from (i) dumped or acci- dentally spilled industrial waste and (ii) agricultural treatment either bind to the soil or leach down into underground aquifers that provide drinking water to people. By predicting how met- als react with soils, it is possible to determine their form, or * Corresponding author. Fax: +33 0 3 26 91 32 43. E-mail address: emmanuel.guillon@univ-reims.fr (E. Guillon). speciation, and how tightly they are bound to soils. Such infor- mation is necessary to predict the long-term fate and transport of pollutants in soils and waters and to devise effective remedia- tion strategies. Among the metals that are hazardous to humans, plants, fishes, and wild animals, copper is one of the widely encountered [6,7], especially in wine regions, due to vineyard treatment. Great progress has been made in the understanding of the long-term fate of heavy metals in soils in the past two decades. However, there remain some uncertainties and several impor- tant issues find no answer. Advanced spectroscopic methods are to be used to resolve some of these uncertainties. Environmental chemistry has seen great advances in analytical instrumentation that allow molecular-based spectroscopic studies. Some appli- cations of advanced spectroscopic methods, such as X-ray ab- sorption spectroscopy (XAS), have the potential to derive fun- damental information on the molecular environment of heavy metals in soils [8,9]. To answer many questions about the long- 0021-9797/$ – see front matter  2006 Elsevier Inc. All rights reserved. doi:10.1016/j.jcis.2006.10.080