Periodic Reporting for period 1 - CoLiBRI (Cobalt and Lithium speciation, toxicity, and Bacterial community Regulations at the sediment-water-Interface)
Période du rapport: 2023-09-01 au 2025-08-31
Lithium and cobalt are still essential elements for battery technologies and thus important for renewable energy systems. In the EU's transition toward a climate-neutral economy these elements continue to be relevant. Due to mining activities, incomplete recycling and inappropriate waste disposal, these elements can be released into the environment, including aquatic systems.
Aquatic sediments can act as sinks and sources for metal contaminants. Biogeochemical parameters can impact their speciation and thus the bioavailability and toxicity. Climate related ecological changes can alter their chemical behaviour and lead to their remobilisation. The goal of the project was to integrate biogeochemistry, toxicology and microbiology to assess the environmental risk of lithium and cobalt in aquatic systems holistically in three research objectives:
1. Investigating the impact of pH on the distribution of lithium and cobalt at the sediment-water interface
2. Determining the toxicity of lithium and cobalt to zebrafish at different stages
3. Determining microbial community changes in the sediment as reaction to lithium and cobalt contamination
Aquatic sediments can act as sinks and sources for metal contaminants. Biogeochemical parameters can impact their speciation and thus the bioavailability and toxicity. Climate related ecological changes can alter their chemical behaviour and lead to their remobilisation. The goal of the project was to integrate biogeochemistry, toxicology and microbiology to assess the environmental risk of lithium and cobalt in aquatic systems holistically in three research objectives:
1. Investigating the impact of pH on the distribution of lithium and cobalt at the sediment-water interface
2. Determining the toxicity of lithium and cobalt to zebrafish at different stages
3. Determining microbial community changes in the sediment as reaction to lithium and cobalt contamination
The work performed in this project was assessed in three work packages. The main achievements of Work package 1 were the development of a microcosm experimental system and the investigation of Lithium and Cobalt distribution. Both elements showed different behaviour. Cobalt was found to a higher extent in sediment, while Lithium was more prominent in the aqueous phase and decreased over time.
Work package 2 assessed the embryotoxicity of the two substances using exposure to water and sediment. A long-term exposure of adult zebrafish was performed during the microcosm experiment, revealing differences in toxicity depending on the pH.
The achievement of work package 3 was the extraction of microbial 16S DNA from sediment samples extracted from the microcosm study at different time points to observe lithium and cobalt related microbial community changes. HiFi sequencing was successfully performed in collaboration with the German Federal Institute of Hydrology.
Work package 2 assessed the embryotoxicity of the two substances using exposure to water and sediment. A long-term exposure of adult zebrafish was performed during the microcosm experiment, revealing differences in toxicity depending on the pH.
The achievement of work package 3 was the extraction of microbial 16S DNA from sediment samples extracted from the microcosm study at different time points to observe lithium and cobalt related microbial community changes. HiFi sequencing was successfully performed in collaboration with the German Federal Institute of Hydrology.
The project’s novel microcosm setup combined chemical, toxicological, and microbial analyses for long-term exposure studies, which was successfully used to study lithium and cobalt under climate relevant conditions. Using pH as a proxy for environmental changes, the project revealed patterns in metal distribution and behaviour over time. Lithium showed a higher mobility while cobalt remained largely sediment-bound.
Toxicity tests with different developmental stages of zebrafish revealed sub-lethal effects such as gene expression changes, particularly under lower pH. Combining this data with microbial profiling of contaminated sediment the project sheds light on different aspects of ecosystem level impacts.
With these findings, the project provides new tools and data to improve current risk assessment approaches. It highlights the need for more comprehensive testing strategies especially under dynamic conditions. Moreover, the data supports the establishment of a lithium threshold for aquatic systems.
The experimental setup developed is already implemented in a follow-up project investigating climate change effects on contaminated sediments, as it offers a framework for a comprehensive study of contaminated sediments.
Toxicity tests with different developmental stages of zebrafish revealed sub-lethal effects such as gene expression changes, particularly under lower pH. Combining this data with microbial profiling of contaminated sediment the project sheds light on different aspects of ecosystem level impacts.
With these findings, the project provides new tools and data to improve current risk assessment approaches. It highlights the need for more comprehensive testing strategies especially under dynamic conditions. Moreover, the data supports the establishment of a lithium threshold for aquatic systems.
The experimental setup developed is already implemented in a follow-up project investigating climate change effects on contaminated sediments, as it offers a framework for a comprehensive study of contaminated sediments.