Adsorption of Chromate onto Goethite. An ATR-FTIR Study”.

B. C. BARJA; M. DOS SANTOS AFONSO

San Diego, California, USA

Simposio; ACS Geochemistry Division Symposium "Transformation at the Oxic/Anoxic Interface".; 1994

The interactions and chemical reactions that occur at the solid/water interface play a major role in geochemical and weathering processes. Substances adsorbed on minarla oxides modify the properties and reactivity of their surfaces. The main purpose of this research study is the experimental determination of the structure of the surface complexes in order to understand the nechanism of the natural processes. This paper will present the study of CrO42- adsorption onto goethite using an FTIR technique (ATR-FTIR) at different pH and fixed ionic strength. Standard IR methods are of restricted use due to the the strong absorption of water. The introduction of ATR-FTIR techniques allows us to get direct information of solutes in solution because of short effective path lengths through the aqueous systems.