Environmental Physical Chemistry

The group of environmental Physical Chemistry brings together Chemists, Physicists, Engineers and Mathematicians interested in the study of the distribution, transformations, physiological effects and the global cycling of elements in the environment, waters, soils and foods, Our research tries to elucidate the availability of trace elements (such as Pb, Cd, Cu, Ni, In, As, etc.) and other elements (such as Zn, Mg, Ca, K, P, N, etc.), by combining the basic physicochemical processes (such as diffusion, reaction, adsorption, complexation, dissociation, precipitation, etc.). We develop theoretical frameworks to understand the experimental measurements and the global functioning of the processes that control availability of metals and nanoparticles by developing concepts, physicochemical models, numerical simulations and new experimental techniques to be applied in situ for the dynamic speciation of metals and nanoparticles in environmental and food matrices. Current research lines are:

1.Thermodynamic modelling of the speciation of metals with Dissolved Organic Matter (such as Humic and Fulvic Acids). We describe the specific binding between organic matter and metal ions with stepwise binding constants or with the Conditional Affinity Spectrum (concept introduced by our group).

2.Dynamic aspects of metal and nanoparticles behaviour.This includes the quantitative description of the relationship between reaction and diffusion, using tools such as the lability degree (introduced by the group). Other studied dynamic systems are dissolution, aggregation and settling of nanoparticles and the modelling of bioavailability and biouptake.

3.Emerging analytical techniques for metal speciation. We designed and and keep developing the technique AGNES (Absence of Gradients and Nernstian Equilibrium Stripping) for a direct measurement of free metal ion concentrations. We are also working with DMT (Donnan Membrane Technique) and DGT (Diffusion Gradients in Thin Films), as complementary techniques to provide information on the target system.

Jordi Sans-Duñó
Lucía López
Ricardo Pedroza
Carol de Faria
Joao Macedo
Ana Hernández
Kevin Rosales