CONICET | Buscador de Institutos y Recursos Humanos

Arsenic water contamination is a worldwide public health problem, due to its carcinogen power and its neurotoxicity. Nevertheless, its toxicity varies depending on the compound, being As (III) more toxic than As (V). A possible solution to the removal of this water contaminant is phytoremediation. This is why we are interested in studying the capability of As (III) and As (IV) accumulation in Potamogeton pusillus, a native macrophyte plant. Even more, it is of special interest to know the spatial distribution of the different As compounds in the P. pusillus. This plant is one of the most distributed species in Argentina. It can be found in the northeast, northwest and the Litoral, Cuyo and even in Buenos Aires [1]. As to achieve our goal, we measured RIXS/RRS spectra [2] in a conventional 45 ? 45 geometry at the XRF-D09B beamline @LNLS with a focal spot size of a few microns. We then analyzed the spectra to extract the chemical state information [3]. We measured spectra from the plant?s root, stem and leafs as to study where the plant concentrated the absorbed arsenic, and if the arsenic?s chemical environment suffered any changes in the absorption process. For this, many different P. posillus plants were left in 200 ppm As solutions (of As (V), As (III) and a mixture of both) for one week. Preliminary results show that these plants effectively absorb both types of As, but the As suffers chemical environment changes in the absorption process. There is a non-uniform spatial distribution in the plant, having larger amount of As in the roots than in the leafs. This observation is negative for the use of the plant for water phytoremediation since it implies the extraction of the plant as to remove the arsenic. Nevertheless, to the author?s knowledge, it is the first time that an As speciation is performed without grinding the plant, allowing a spatial analysis.