Biogeochemical Transformations

The interplay of geology, chemistry, and biology among Earth systems is fundamentally important for understanding the role of critical minerals in the U.S. energy system and for keeping Earth’s air and water clean and plants healthy. Our biogeochemical transformations expertise crosses scientific boundaries to investigate how nutrients, minerals, contaminants, and other chemical compounds move and change in the environment. With new information on how these exchanges occur, we can develop and improve predictive models to anticipate and manage their effects on Earth system processes and the U.S. energy system’s vulnerabilities to major disturbances such as wildfire in its surrounding environment. 

The science 

We use the latest platforms and approaches to gain new insights into the physiochemical effects of elemental cycling in the environment and their interactions with microbial metabolic pathways. From molecules to cellular and community-scale processes, we seek to improve the scientific understanding of microbial metabolism and mineral and nutrient cycling in subsurface environments. 

How we do the science 

The Environmental Molecular Sciences Laboratory (EMSL) has biogeochemical expertise that combines multiple scientific disciplines and data visualization approaches with multiscale modeling platforms. 

• We have a suite of assaying methods related to environmental microbiology investigations. 
• X-ray diffraction and X-ray photoelectron spectroscopy techniques are used to detect critical minerals and soil mineralogy. 
• Transmission electron microscopy and scanning electron microscopy are employed to investigate fungal-driven mineral weathering as well as the allocation of carbon and other plant nutrients in arid, semiarid, subhumid, and humid environments. 
• Mass spectrometry and nuclear magnetic resonance are used to attain high-resolution chemical information about natural organic matter, including its interactions with minerals, as well as the minerals themselves. Our mass spectrometry imaging capabilities are capable of encompassing a range of spatial scales to provide molecular and/or elemental mapping with high resolution and isotope sensitivity. 
• Analytical techniques, including inductively coupled plasma mass spectrometry and ion chromatography, are used to determine soil and sediment pore water chemistry. 
• Mössbauer spectroscopy provides information on chemical speciation (e.g., ⁵⁷Fe compounds) and gives insight into redox chemistry. 
• X-ray photoelectron spectroscopy can provide elemental analysis and chemical-state information from the very top of sample surfaces for elements critical to geochemical cycling (carbon, nitrogen, and oxygen). N-depth compositional information is also available via Ar⁺ ion beam depth profiling. 

Research in action 

Nutrient, mineral, and organic matter cycling 

Nutrient, mineral, and organic matter cycles distribute essential elements and provide energy to organisms. These processes are the foundation of the health and function of ecosystems and the bioavailability of critical minerals. By studying the physiochemical effects of nutrient, mineral, and organic matter cycling, we are growing American scientific leadership to understand and mitigate how environmental changes and disturbances such as wildfires affect energy security. 

Microbial impacts on biogeochemistry 

Microorganisms mediate biogeochemical processes by consuming, transforming, and producing compounds such as nutrients, waste products, or pollutants. At EMSL, researchers study microorganisms to advance our basic scientific understanding of nutrient cycling and the decomposition of organic matter. This insight is vital for bioremediation, waste management, ecosystem health, and understanding and combating anthropogenic impacts on our environment. 

Pore water dynamics 

Pore water, the liquid between soil and sediment particles, transports vital nutrients like nitrogen, sodium, iron, phosphorus, and potassium. It is crucial for plant and microbial health. By researching pore water, scientists can aid in protecting and managing groundwater resources and geothermal energy production.