Arsenic uptake and specification in forage plants of contaminated sites on the example of the mining-affected floodplains of Ogosta river, Bulgaria

• Applicant: Dr. Elke Süß
• Subject Area: Hydrogeology, Hydrology, Limnology, Urban Water Management, Water Chemistry, Integrated Water Resources Management
• Term: from 2012 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 221913004

Arsenic (As) is an ubiquitous, toxic contaminant, with known impact and high contamination levels in mining affected areas. Overall, As mobility and bioavailability is critically influenced by its speciation in the contaminated solids and soil waters, since different As species differ in their availability for plant uptake, translocation, detoxification and accumulation in biotic tissues. The transfer into plants, especially crops and forage plants enables As to enter the human and animal food chain, pursuing its toxic fate. However, many highly contaminated sites are still used for agriculture which particularly requires detailed investigations on the uptake and transfer of arsenic into forage plants on-site. Within the proposed postdoctoral research project field studies at a mining affected site (Ogosta River area, Bulgaria) and laboratory experiments will be combined to better characterize and understand the species depending As uptake on contaminated sites on selected non-hyperaccumulating forage plants. The possible occurrence and pathway of thioarsenic species, far reaching unstudied regarding their behaviour in the soil-plant system, is of interest for the studies to expand the current geochemical knowledge for these species. In a complex approach, species information found in the growing media (Ogosta soils, pore waters, hydroponic cultures) will be combined and related with the As speciation (inorganic As, As-phytochelatine complexes and plant thiol compounds) in the plant parts to examine the species dependent As uptake and translocation pathways. To address these issues a novel analytical approach will be used by combining plant As species and (As-)phytochelatin complexes by reversphase HPLC-ICP-MS/ESI-MS with spatial elemental distribution information by synchrotron-based µXRF/µXAS techniques with speciation and bioavailability information from the growing media (IC-ICP-MS/HPLC-ICP-MS and XAS).

• DFG Programme: Research Fellowships
• International Connection: Switzerland, United Kingdom
• Hosts: Professor Dr. Jörg Feldmann; Professor Dr. Ruben Kretzschmar, Ph.D.