Ph.D. Title: Anthropogenic REE and yttrium in mussels and fish from major rivers and lakes in Europe
Quantification of geogenic and anthropogenic levels of rare earth elements and yttrium (REY) in mussels and fish (and duckweed) from major European rivers and selected lakes, and evaluation of the bioavailability of anthropogenic REY in river and lake waters.
Context: Rare earth elements and yttrium (REY) are crucial to a wide range of modern technologies with regard to their chemical, optical, electro-optic, and paramagnetic properties. The increasing demand with respect to global REE production makes them technologically ‘critical elements’. Their widespread use in agriculture (e.g., fertilizers), animal production (e.g., micronutrients), technology (e.g., fluid cracking catalysts), and medicine (e.g., contrast-agents) leads to increased emissions into the environment. As a consequence, REY are now considered to be ‘emerging contaminants’ for which negative effects on environmental health have been suggested. It is, therefore, important to evaluate the current state of European rivers and lakes with regard to geogenic and anthropogenic REY. Under environmental conditions, natural REY tend to bind to surfaces of particles and nanoparticles/colloids, resulting in (ultra)low dissolved concentrations in natural waters. However, very little is known of the particle-reactivity of anthropogenic REY and their (eco)toxicity and potential impact on aquatic organisms.
Objectives and approach: Trace metals have been shown to bioaccumulate in organisms such as plants, mussels, shellfish, fish or mammals and this bioaccumulation of trace metals increases along the food chain. Toxic effects may occur when organisms are exposed to elevated concentrations, which is usually due to their anthropogenic release into the environment. An evaluation of the REY distribution in the tissues, organs, shells and bones of mussels and fish (and in duckweed) in European rivers and selected lakes will show if and how these organisms accumulate geogenic and anthropogenic REY and how these elements transfer along the food chain. As humans typically form the end of the food chain and anthropogenic REE have already been identified in drinking water and beverages, these results will also provide vital information on how the potentially toxic REE behave in organisms and may give new insights into potential effects of long-term exposure to elevated concentrations of (anthropogenic) REY. This project (ESR 5) is closely related to and will investigate organisms from the same rivers and lakes the waters of which are studied with a focus on their geogenic and anthropogenic REY inventory in an accompanying project (ESR 4) at Jacobs University.
Presentation of the research project (cooperative aspect)
This PhD position is within the framework of a European ITN project named PANORAMA: “EuroPean trAining NetwOrk on Rare eArth elements environMental trAnsfer: from rock to human” involving 15 PhD positions.
Under the supervision of Prof. Dr. Michael Bau (and colleagues at the different institutions), the PhD student will perform:
– sampling, on-site sample preparation and measurements at major rivers and selected lakes within the EU (field work, JUB, IST);
– sample preparation and subsequent chemical analyses of mussels (incl. shells), fish and duckweed by ICP-OES and ICP-MS using trace element separation and pre-concentration methods if necessary (JUB, IST);
– definition of baselines for REY in freshwater mussels, fish and duckweed (JUB);
– identification of “hot spots” for anthropogenic REY (micro)contamination of organisms in EU rivers and lakes (JUB, HAW);
– incubation/growth experiments using duckweed and (micro)contaminated river and lake waters (JUB, HAW).
The project involves a strong collaboration with the following institutions, including mandatory 2-months research stays (secondments): Instituto Superior Técnico (IST), Lisbon/Portugal, and University of Applied Science Hamburg (HAW), Hamburg/Germany.
The PhD student will be also involved in scientific/soft-skills meetings and in research activities conducted in other laboratories/companies from Europe and associated countries.
An important component of the training will be the participation to 4 main major training events:
WS1-(December 2020) REE as emerging contaminants: Properties, uses and dissemination –Germany-fundamental REE biogeochemistry and currently known anthropogenic REE inputs into the environment
SS1 (May 2021) – AMD and REE contamination mitigation – Portugal-Management and remediation solutions of AMD in old mining areas and Management of WEEE, recycling areas
WS2 – Colloids and nanoparticles as REE vectors -France- Structural characterization of colloids and nanoparticles by innovative and fine spectroscopic and scattering techniques: X-Ray absorption fluorescence and scattering, light scattering. REE interactions with bearing phases.
SS2 – (Eco)toxicology of REE –Germany- (Eco)toxicological concepts and approaches, Physico-chemical properties of REE for bioavailability, ecotoxicity and environmental risk
In addition to these major milestones of the program, the PhD students will 1) continuously develop their core research skills via their own research project locally and within the network while at secondments and conferences, 2) receive a mandatory amount of hard and soft-skills training specific to their own doctoral school, along with mentoring by joint supervising bodies, 3) use conferences both as dissemination events for ESRs results and network events for progress reports and evaluations, and 4) collaborate into practical activities aimed at network-structuring legacy deliverables.
PANORAMA’s research objective is to elucidate the man-induced environmental dissemination of REE and the associated effects on the environmental health. For that purpose, interdisciplinary approaches are required combining geochemistry, ecotoxicology, hydrology, chemical analysis and coupling field monitoring, original in and ex situ experimental set-up and modelling from the element speciation to the environmental impact
PANORAMA’s key aim is to set-up an optimal scientific and non-scientific training to the understanding and forecasting of the environmental impacts of new emerging pollutants such as REE.