Project

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

Applicant Kretzschmar Ruben
Number 142978
Funding scheme Bulgarian-Swiss Research Programme (BSRP)
Research institution Institut für Biogeochemie und Schadstoffdynamik ETH Zürich
Institution of higher education ETH Zurich - ETHZ
Main discipline Pedology
Start/End 01.11.2012 - 30.04.2016
Approved amount 324'442.00
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All Disciplines (5)

Discipline
Pedology
Geomorphology
Geochemistry
Other disciplines of Environmental Sciences
Hydrology, Limnology, Glaciology

Keywords (8)

arsenic; river floodplain; redox; speciation; soil pollution; mining; river hydology; groundwater

Lay Summary (English)

Lead
Lay summary

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, (ii) to improve the process-oriented understanding of As release from soils to river and groundwater by microbial and physico-chemical 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 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.

Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants

Employees

Publications

Publication
Soil-to-plant transfer of arsenic and phosphorus along a contamination gradient in the mining-impacted Ogosta River floodplain
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.
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
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.
Conceptual hydrogeological model of the Ogosta River floodplain (Western Balkan, Bulgaria) and its application for predicting groundwater contamination with arsenic
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.
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)
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.
Variables for groundwater vulnerability assessment from arsenic contamination in the Ogosta River floodplain between the village of Martinovo and the „Ogosta“ dam lake.
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.
New clues to the local atomic structure of short-range ordered ferric arsenate from extended X-ray absorption fine structure spectroscopy.
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.
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".
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.

Collaboration

Group / person Country
Types of collaboration
Prof. Andreas Kappler, Geomicrobiology, University of Tübingen Germany (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Research Infrastructure
Genetic Diversity Center (GDC), ETH Zurich Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Research Infrastructure
National Institute of Geophysics, Geodesy and Geography - BAS Bulgaria (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Research Infrastructure

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
Goldschmidt Conference Talk given at a conference Speciation and mobility of trace elements in wetland soils 25.08.2013 Florence, Italy Kretzschmar Ruben;


Knowledge transfer events



Self-organised

Title Date Place
Field demonstration for pupils from a local school 06.06.2013 Project field sites, Ogosta valley, Bulgaria
Field excursions for the local population (April 10-12, June 3-6, August 6, 2013) 19.04.2013 Research sites, Ogosta River Valley, Bulgaria
Chiprovtsi townhall meeting 09.04.2013 Chiprovtsi townhall , Bulgaria

Associated projects

Number Title Start Funding scheme
155890 Redox-induced speciation changes and reductive mobilization of arsenic, manganese, and iron in highly-contaminated river floodplains 01.01.2015 Project funding (Div. I-III)
138003 Redox-induced speciation changes and reductive mobilization of arsenic and iron in highly-contaminated river floodplains 01.01.2012 Project funding (Div. I-III)

Abstract

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.
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