HG-197 MEHG ASSESS · Evaluation of Methyl-mercury production and decomposition by using Hg-197 radiotracer produced out of mercury enriched in Hg-196 isotope
FP7 — People (Marie Curie Actions)
- Duration
- 2009-12-16 → 2010-12-15
- EU contribution
- €15,000
- Participants
- 1
- Scheme
- MC-IIFR
Lines connect the coordinator with its partners.
Results in brief
Evaluation of Methyl-mercury production and decomposition by using Hg-197 radiotracer produced out of mercury enriched in Hg-196 isotope
Background The project approved proposed the implementation of mercury (Hg) laboratory experiments to study the transformation of inorganic mercury (Hg2+) to organic species, reproducing natural conditions. The main analytical tool proposed was the use of the short lived Hg isotope 197Hg (T? = 64.14 h) in tracing the transformation processes, being this radiotracer produced in the nuclear research reactors of the Joef Stefan Institute, Ljubljana, Slovenia (TRIGA Mark II reactor 250 kW), and Centro Atómico Bariloche, Argentina (RA-6 MTR reactor, 500 kW), which showed an excellent performance in environmental studies developed in previous works. Before the fellowship start, the chance to performed laboratory experiments in Hg retention in flue gas desulphurisation (FGD) systems in coal power plants using the 197Hg radiotracer came out. The Hg emissions generated in the operation of coal power plants are the main anthropogenic atmospheric source at present, whereas the understanding of the chemical processes undergoing in the Hg retention in the FGD systems are key in the development of efficient retention systems in order to minimise the global Hg gaseous emissions. Therefore, the focus of the work to be developed in the project moved to this topic. Also, experiments in the preservation of Hg in natural waters were performed due to the relevance of this topic in environmental studies and the advantages provided by using the 197Hg radiotracer.
Data: CORDIS, © European Union
Project objective
Mercury (Hg) is in the form of monomethylmercury (MeHg) a biological neurotoxin, harmful to the wildlife and to humans. MeHg species is produced from Hg2+ by natural processes occurring within the water bodies. MeHg can also be degraded by natural processes; therefore, the net MeHg production arise form the combination of both kind of processes. The analytical tools to assess these processes consist in the use of labelled Hg in laboratory experiments to trace Hg transformations. One of the factors affecting Hg transformations is its concentration. MeHg production studies performed up to present in the water column are few and limited, due to the limitation of existing techniques in simulating natural levels or real environmental contamination situations that involve levels of Hg2+ from 0.1 to 50 ng.L-1, while most studies in sediments involve unrealistic Hg2+ additions, since Hg concentrations at natural or low contaminated levels range from 10 to 200 ng.g-1, with a bio-available fraction for MeHg production from 0.1 to 10 %. Recent collaboration between the author and the DES of the Jozef Stefan Institute (JSI), Slovenia, showed the feasibility of these studies using the short-lived radiotracer Hg-197 produced out of Hg enriched isotopically in Hg-196, allowing realistic Hg2+ additions to study MeHg production both in the water column and sediments. This project propose the development of analytical techniques to study de-methylation processes in water and sediments, by using traced MeHg in laboratory experiments. These processes are currently assesed using either C-14 and Hg-203 radiotracers, but the use of Hg-197 radiotracer will allow much lower MeHg additions, and hence realistic simulations of natural de-methylation processes. The project also consider the application of the Hg-197 radiotracer in the evaluation of MeHg production, including reduction of Hg2+ to Hg0, in different real situations in environmental studies on going in the DES of the JSI.
Original text from CORDIS.
Participants
- COMISION NACIONAL DE ENERGIA ATOMICA · BUENOS AIRESCoordinatorArgentina
Links
Data: CORDIS, © European Union