arsenic; river floodplain; redox; speciation; soil pollution; mining; river hydology; groundwater
Simlmler Michael, Suess Elke, Christl Iso, Kotsev Tsvetan, Kretzschmar Ruben (2016), Soil-to-plant transfer of arsenic and phosphorus along a contamination gradient in the mining-impacted Ogosta River floodplain, in Science of the Total Environment
, 572, 742-754.
Antonov D., Hristov V., Benderev A., Kotsev T. (2015), Comparing the parameters from pedotransfer functions and in situ permeability tests in the vadose zone of the Ogosta River floodplain in connection with validation procedures of contaminant migration, in Proceedings of the National Conference with international participation “GEOSCIENCES 2015”
, Sofia, BulgariaBulgarian Geological Society, Sofia, Bulgaria.
Benderev A., Gerginov P., Antonov D., Van Meir N., Kretzschmar R. (2015), Conceptual hydrogeological model of the Ogosta River floodplain (Western Balkan, Bulgaria) and its application for predicting groundwater contamination with arsenic, in SGEM2015 Conference Proceedings
, International Multidisciplinary Scientific GeoConference-SGEM, Bulgaria.
Tcherkezova Emilia (2015), GIS-based delineation and regionalisation of geomorphographic units in the floodplain of Ogosta River between the settlement Gavril Genovo and the “Ogosta” reservoir (NW-Bulgaria), in Problems of Geography
, 1-2, 114-122.
Stoyanova Velimira (2015), Variables for groundwater vulnerability assessment from arsenic contamination in the Ogosta River floodplain between the village of Martinovo and the „Ogosta“ dam lake., in Problems of Geography
, 3-4, 73-86.
Mikutta Christian, Mandaliev Petar N, Kretzschmar Ruben (2013), New clues to the local atomic structure of short-range ordered ferric arsenate from extended X-ray absorption fine structure spectroscopy., in Environmental science & technology
, 47(7), 3122-31.
Mikutta Christian, Mandaliev Petar N, Kretzschmar Ruben (2013), Response to Comment on "New Clues to the Local Atomic Structure of Short-Range Ordered Ferric Arsenate from Extended X-ray Absorption Fine Structure Spectroscopy"., in Environmental science & technology
, 47(22), 13201-2.
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 focuses 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 goals of the project are (i) to investigate the magnitude and spatial distribution of As contamination in floodplain soils and sediments in relation to river system dynamics (topography, hydrology, flood extent and frequency), (ii) to improve the process-oriented understanding of As release from soils to river and groundwater by microbial (e.g., reduction) and physico-chemical (e.g., desorption, dissolution, dispersion of colloids) processes during periods of low and high flow, and (iii) to explore advanced approaches for integrating process-oriented, molecular scale knowledge and river-system scale information to better understand As speciation, As fluxes, and impacts on water quality at the river-system scale.The project is structured in three work packages (WP). In the first WP, a spatial analysis of the river floodplain area (upper reach of Ogosta river) using GIS tools will be conducted to derive a map of morphologic units within the floodplain, which reflect factors that are hypothesized to influence As contamination. This includes, for example, topography (from aerial LiDAR survey), historic hydrologic data (1951-2010), existing soil maps, and other spatial information. Based on the results, a field detailed survey for As contamination by core drilling will be conducted. Soil samples will be analyzed for total contents of As, Fe, Mn, and other elements by X-ray fluorescence (XRF) spectrometry. The data will be used to identify critical areas within the floodplains acting as primary source of As contamination of Ogosta river during various flow regimes.The second WP will explore the mechanisms of As release during high and low flow periods, focusing on the most critical areas. Microbial community structure analyses of soil samples collected along geochemical gradients (e.g., As concentration, moisture regime) will reveal the possible influence of As on microbial activity and communities, and provide information about the most important As-reducing bacteria present in the system. Soil microcosm experiments will provide information on potential As mobilization from selected soils (sampled at different depths) and factors influencing As reduction.In the third WP, river water and groundwater will be sampled and analyzed for dissolved and colloidal As(III) and As(V), and other elements. These data will be combined with spatial information (GIS database) and hydrologic data and flood modeling to estimate As fluxes in Ogosta river during various flow periods.The project is expected to yield novel process-oriented knowledge on the dynamics of As in highly contaminated river floodplains. New ways of integrating molecular-scale and river-system scale information will be explored, which can then also be applied to other river systems in Bulgaria. The project will provide the scientific basis for river management and potential remediation strategies for Ogosta river. Ultimately, it will help protect the local population from adverse health effects arising from the legacy pollution with As and other heavy metals by former mining.