Computational modelling of mineral-organic binding in soil

Soils contain large amounts of organic matter (also called “soil organic carbon”): there is three times as much carbon stored in soil than in the atmosphere as CO₂. Presence of organic carbon is essential for the stability and fertility of soils. However, intensive agriculture leads to release of the stored carbon through harvested plants and through soil erosion. To maintain the fertility of soils, it is necessary to preserve and replenish organic carbon in soils. As an important first step to achieving this, it is necessary to understand the factors that control the stability of organic carbon in soils, and in particular the nature and strength of binding of organic carbon to soil mineral particles.

This project aims to explain why specific organic functional groups are well-suited to sorption in soil, using theoretical modelling of interactions between organic molecules and soil minerals.

We will model the nature and strength of binding of common organic molecules, such as acids and alcohols, to a range of typical soil minerals, such as quartz and mica. These calculations will reveal the nature and strength of binding in these varied mineral/organic systems, and in particular they will show which minerals and which organic molecules bind most strongly and why. As a result of this study, we will predict the types of organic molecules that are likely to be stable in soil, tailored to the mineral composition of soil.

There is scope for collaboration with experimental researchers at the University of Sheffield, to verify these theoretical predictions on strong molecule-mineral binding using vibrational spectroscopy experiments. These results will have great potential to be applied in agriculture, to help select strongly-binding minerals or organic and biomolecules with suitable chemical composition that can be added to soil in the fields to preserve soil carbon.

Email: n.martsinovich@shefield.ac.uk

Web link to staff page: www.sheffield.ac.uk/chemistry/people/academic/natalia-martsinovich

Subject Area: computational chemistry, theoretical chemistry, physical chemistry, materials chemistry

Requirements: At least a 2:1 honours degree or an MSc with merit/distinction (or equivalent) in Chemistry, Physics or Materials Science. Experience in computational modelling (quantum chemistry or force fields) is essential.