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BioMed Research International
Volume 2013 (2013), Article ID 591634, 10 pages
http://dx.doi.org/10.1155/2013/591634
Research Article

Arsenate Retention by Epipsammic Biofilms Developed on Streambed Sediments: Influence of Phosphate

1Department of Soil Science and Agricultural Chemistry, Facultad de Farmacia, Campus Vida, 15782 Santiago de Compostela, Spain
2Defense University Center, Escuela Naval Militar, Plaza de España 2, 36920 Marín, Spain

Received 27 June 2013; Accepted 7 August 2013

Academic Editor: Ana Moldes

Copyright © 2013 D. M. Prieto et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Natural geological conditions together with the impact of human activities could produce environmental problems due to high As concentrations. The aim of this study was to assess the role of epipsammic biofilm-sediment systems onto As (V) sorption and to evaluate the effect of the presence of equimolar P concentrations on As retention. A natural biofilm was grown on sediment samples in the laboratory, using river water as nutrient supplier. Sorption experiments with initial As concentrations 0, 5, 25, 50, 100, 250, and 500 μg L−1 were performed. The average percentage of As sorbed was and % for the sediment and biofilm-sediment systems, respectively. Phosphate decreased by 25% the As sorption capactity in the sediment devoid of biofilm, whereas no significant effect was observed in the systems with biofilm. Freundlich, Sips, and Toth models were the best to describe experimental data. The maximum As sorption capacity of the sediment and biofilm-sediment systems was, respectively, 6.6 and 6.8 μg g−1 and 4.5 and 7.8 μg g−1 in the presence of P. In conclusion, epipsammic biofilms play an important role in the environmental quality of river systems, increasing As retention by the system, especially in environments where both As and P occur simultaneously.