Arsenic contamination of Ogosta river: Linking biogeochemical processes in floodplain soils with river system dynamics (ASCOR)

Funding:  Swiss National Science Foundation (1.1.2012 – 31.12.2015), Bulgarian-Swiss Research Program (1.11.2012 - 31.10.2016)
Project Team:  Katrin Ehlert, Michael Simmler, Petar Mandaliev, Elke Suess, Christian Mikutta, Iso Christl, Kurt Barmettler, Ruben Kretzschmar
Collaborators:  Tsvetan Kotsev (Bulgarian Academy of Sciences, Sofia)

The sustainable management of land, which has been heavily contaminated by industrial or mining activities, poses an important challenge to many industrialized countries, including Bulgaria. This project focused on arsenic (As) contamination in NW Bulgaria, where the floodplains of the Ogosta river received large amounts of As-rich mining wastes near Chiprovtsi between 1964 and 1979. The research project had three main goals: (i)  Investigation of the magnitude and spatial distribution of As contamination in the floodplains of Ogosta river (Bulgaria) using an integrated approach based on topography, hydrology, and geochemistry, (ii) improvement of our process-understanding of As speciation and mobility in highly-contaminated, mining affected river floodplains during alternating periods of high/low flow and flooding/drainage, and (iii) exploration of novel approaches for integrating process-oriented, molecular-scale knowledge and river-system scale information to better understand As dynamics, As fluxes, and impacts on water quality at the river-system scale. The project has been completed, but we are still working on the analysis of some data and the development of improved soil contamination maps.

Key Publications:
Simmler, M., Bommer, J., Frischknecht, S., Christl, I., Kotsev, T., and Kretzschmar, R. (2017): Reductive solubilization of arsenic in a mining-impacted river floodplain: Influence of soil properties and temperature. Environ. Pol. 231(1): 722-731. external pageLinkcall_made
Simmler, M., Suess, E., Christl, I., Kotsev, T., Kretzschmar, R. (2016): Soil-to-plant transfer of arsenic and phosphorus along a contamination gradient in the mining-impacted Ogosta river floodplain. Sci. Total Environ. 572: 742-754. external pageLinkcall_made
Ehlert, K., Mikutta, C., and Kretzschmar, R. (2016): Effects of manganese oxide on arsenic reduction and leaching from contaminated floodplain soil. Environ. Sci. Technol. 50: 9251-9261. external pageLinkcall_made
Mikutta, C., Mandaliev, P.N., Mahler, N., Kotsev, T., and Kretzschmar, R. (2014): Bioaccessibility of arsenic in mining-impacted circumneutral river floodplain soils. Environ. Sci. Technol. 48, 13468−13477. external pageLinkcall_made
Mandaliev, P.N., Mikutta, C., Barmettler, K., Kotsev, T., and Kretzschmar, R. (2014): Arsenic species formed from arsenopyrite weathering along a contamination gradient in circumneutral river floodplain soils. Environ. Sci. Technol. 48: 208-217. external pageLinkcall_made