Ongoing Projects

FATE OF MINERAL ASSOCIATED ORGANIC MATTER

Organic matter (OM) turnover regulates the balance of carbon in the environment, including soil carbon sequestration and CO2 emissions. In soils, OM interacts with soil minerals to form strong mineral-OM associations that influence key biogeochemical processes such as microbial activity and nutrient/contaminant mobility, inclusive of carbon mineralization to CO2. 

We are currently studying the reactivity of iron mineral-OM assemblages, focusing on transformation reactions that influence mineral structure, OM composition and distribution uner changing redox conditions. We use an array of micro-to-nanoscale characterization techniques, along with thermodynamic measurements, to identify the underlying mechanisms that contribute to the resilience of OM-soil mineral assemblages.

HARNESSING NATURAL Phenomena FOR CO2 MITIGATION

CO2 levels are rising and with them the disastrous effects of climate change. To mitigate CO2 emissions we need to develop environmentally friendly strategies that remove CO2 from the atmosphere. We are currently engaged in two projects:

1. Enhanced silicate mineral weathering in agricultural soils has the potential to capture CO2, preserve organic matter, and serve as a liming agent. We study the mechanisms controlling the dynamics of the weathering process, putting emphasis on the effects of soil texture, pH, and organic matter content. 

2. Deep sea burial of organic matter (OM) can store the carbon far away from the atmosphere. OM decay under deep sea conditions, particularly anoxic ones, displays slower degradation rates and distinct degradation mechanisms. Therefore, deep sea burial is a promising practice to reduce CO2 emissions. We study the kinetics and degradation pathways of OM under anoxic marine conditions. 

COMPOSITION-SIZE-REACTIVITY RELATIONSHIPS IN BIOGEOCHEMICAL REACTIONS

Particle dynamics govern biogeochemical cycling by controlling the migration, stability and bioavailability of nutrients, contaminants, organic matter, and microbes in soil and water systems. We monitor the lifecycle of soil particles at the nano- and molecular-scale in order to unravel the intricate relationships between their composition, size, and reactivity. In our studies we focus on the mechanisms and rates of these reactions, with special emphasis on organic matter composition and  redox chemistry.

MICROBE-SOIL MINERAL INTERACTIONS

Microbial activity drives biogeochemical cycling. Therefore, understanding microbe-mineral interactions and how they influence soil biofilm development is paramount. We are interested in the establishment of the bacterial-mineral interface, how the size and composition of the minerals impact biofilm formation, and in turn, how microbial growth influences mineral characteristics.