Welcome to the Environmental Geochemistry Group 

We are studying geochemical processes that control trace element cycling and mobility in natural and engineered environmental systems from the molecular to the global scale. We are conducting experimental and computational investigations in the laboratory, or we are sampling rocks, plants, aerosols, rainwater, soils, and waters and analyze them for isotope composition or elemental concentrations and speciation.

Our principal motivation is to address fundamental and applied problems in the context of environmental science and engineering. There are three distinct types of problems we study.

First, we study natural geochemical processes which we need to understand to develop engineering or policy solutions. For example, we study the formation of metal-organic ligand complexes to understand how plants acquire micronutrients such as zinc, iron etc. and take them up. This process we need to understand to develop new fertilizers together with synthetic chemists or to predict the amount of micronutrient available to plants with plant growers.

Second, we try to understand how environmental changes affect these geochemical processes. Of particular interest to us is the impact of climate change and human activities on trace element cycles. We study how and try to assess if these changes important. For example, do increased industrial activities affect the bioavailabity of trace metals and as such lead to increased fertilization of oceans or bioavailabity of toxic metals in agricultural systems? Or what happened with lead in the environment since the phasing out of leaded gasoline. Are there new sources? Did concentrations go back as expected and did the introduced policies work?

Finally, we try to contribute to engineering solutions. For example, we study the chemistry of actinides in very saline and alkaline solutions to predict their mobility in the near field of nuclear waste repositories. This is of fundamental importance to selecting the right waste site. Or we study the adsorption and photo catalysis of multimineral systems to test the possible application of multifunctional sorbents for effective and sustainable water treatment.

Our work is underpinned by development of experimental tools, computational codes, and analytical techniques to study and predict these geochemical processes, to measure elemental isotope ratios, concentrations, and speciation in the environment and to develop proxies to study trace elements cycles and geochemical processes

Important contributions from our group to date include

• Development of peat archives to study atmospheric trace element deposition and carbon accumulation
• Determining onset of global atmospheric lead pollution and of its natural isotopic composition
• Establish new geochemical proxies (isotopes, element ratios) to identify sources including mineral dust and anthropogenic sources in Asia and South America
• Demonstrating how weak and strong ligands interact in soil solutions
• Measuring pH gradients around single cells
• Establishing isotope fractionation models for micronutrient metals in the plant soil environment and base metals in ore forming fluids
• Establishing the isotope ratio technique to trace non-combustion contributions of Zn and Cu in atmospheric particles
• Development of mass spectrometric techniques to measure high precision isotope ratios of metals in the environment
• Conducting among the first high precision measurements of trace metals in environmental matrixes and demonstration of significant isotope variability for Cu, Zn and Fe in the environment
• Development of resins that selectively remove arsenic (ImpAs)
• Establishment of accurate surface complexation model for arsenic on multimineral sorbents and of a revised pseudo second order model
• Establishment of DFT calculations to determine stability of U-siderophore complexes and of stability series

Please look at the publication list for the relevant papers and details of the research areas are discussed in detail in the research section of this web page.

While we publish our work in the leading peer reviewed scientific literature, we are also very much involved in translational activities including outreach, commercialization and consulting and policy and we are developing state of the art teaching curriculums.

‘Excellence is never an accident. It is always the result of high intention, sincere effort, and intelligent execution. It represents the wise choice of many alternatives – choice, not chance, determines your destiny’ (Aristotle)