Mobilization of chromium by organic matter in reduced systems

Objective

Long-term pollution mitigation requires a better understanding of the biogeochemical processes that regulate the behavior and fate of trace metals, such as chromium (Cr), in subsurface environments. The emerging role of organic ligands, including siderophores and organic acids, in the speciation, bioavailability and mobility of trace metals is receiving increasing attention. However, the relative importance of the opposing Cr reduction and mobilization processes in sediments remain poorly constrained, and the Cr-ligand interaction has not been explicitly determined. Whilst stable isotope compositions of Cr are an effective tool for assessing biogeochemical cycling and redox processes, there have been few studies reporting the isotope effect of ligand-induced Cr mobilization. This project combines an interdisciplinary set of field sampling, controlled experiments, isotopic analysis alongside geochemical modelling, aiming to test the hypothesis that (1) solid Cr can be effectively remobilized by organic matter in reduced environment despite Cr reduction, and (2) aqueous Cr can be stabilized in the form of organic complexes with a distinct Cr isotope signature. The extent and mechanism of Cr mobilization by organic ligands under various environmental conditions will be quantified. Stable Cr isotopes in sediment pore water will be accurately determined and validated as a tracer for Cr-ligand complexation. The fate of Cr in relation to Fe and organic ligands in sediments will be predicted. This project will shed new light on the role of organic ligands in the Cr redox cycle, and will reveal the sensitivity of subsurface environments to anthropogenic activities. This project includes both the transfer of knowledge to the host institution and the training of the candidate in advanced techniques. Results from this project will be disseminated to the environmental science and geochemistry research community and to the wider public.

Fields of science

• natural sciences › chemical sciences › organic chemistry › organic acids
• natural sciences › chemical sciences › inorganic chemistry › metals
• natural sciences › earth and related environmental sciences › geochemistry › biogeochemistry
• natural sciences › earth and related environmental sciences › environmental sciences
• natural sciences › chemical sciences › inorganic chemistry › inorganic compounds

Programme(s)

• H2020-EU.1.3.2. - Nurturing excellence by means of cross-border and cross-sector mobility

Topic(s)

• MSCA-IF-2020 - Individual Fellowships

Call for proposal

H2020-MSCA-IF-2020
See other projects for this call

Funding Scheme

MSCA-IF-EF-ST - Standard EF

Coordinator

UNIVERSITAT WIEN

Address

Universitatsring 1
1010 Wien
Austria

Activity type

Higher or Secondary Education Establishments

EU contribution

€ 174 167,04