J. Phys. IV France
Volume 107, May 2003
Page(s) 377 - 380

J. Phys. IV France
107 (2003) 377
DOI: 10.1051/jp4:20030320

Arsenic oxidation capabilities of a chemoautotrophic bacterial population: Use for the treatment of an arsenic contaminated wastewater

M.-C. Dictor1, F. Battaglia-Brunet1, F. Garrido1 and P. Baranger1

1  BRGM, Services EPI, avenue Claude Guillemin, BP. 6609, 45060 Orléans cedex 2, France


An autotrophic bacterial population, named CAsOl, able to oxidise arsenic has been isolated from a former gold mine (Saint-Yrieix, France). This bacterial population was composed of two microorganisms: a bacterial strain close to Ralstonia picketii and the second one related to Thiomonas genus (identification by 16S rDNA sequencing). This microbial consortium was able to oxidise arsenic with CO 2 as the carbon source, arsenite as electron donor and oxygen as electron accepter. A significant oxidising activity was observed in a pH range comprised between 3 to 8 (pH optimum 5-7). A laboratory experiment for the biological treatment of a synthetic effluent containing 100 mg.L -1 of arsenic has been carried out. A mineral support, pouzzolana, has been colonised by the population CAsOl and the column was fed continuously with a synthetic medium in order to determine the maximal arsenic oxidation rate and the optimal residence time. In our experimental conditions, the maximum arsenic oxidation rate was 3,9 g As(Ill). L -1 with a residence time of 1 hour after 55 days of continuous running. The performance of our bacterial population for arsenite oxidation in arsenic contaminated wastewater are especially important in the case of a treatment of arsenious wastewater as it presents advantages compared to physico-chemical treatments (consumption and cost of chemicals, potential toxic by-products generation...).

© EDP Sciences 2003