## Research Project

The objective of the PhD project is to develop a numerical method, based on Lattice Boltzman/Cellular Automata concepts, to compute the metal flux at microorganism or bioanalogical sensors, by considering: i) the very large number of ligands, L, present in aquatic media, with their broad range of diffusion coefficients, DL, ii) the corresponding very large number of possible complexes, ML, with the metal ion M and the corresponding stability constants, KML, diffusion coefficients, DML, and association and dissociation rate constants, ka and kd, which may vary over many orders of magnitude, iii) any metal to ligand concentration ratio, iv) the possibility of computing transcient fluxes and v) the complex geometry of diffusion in porous media, like soils and sediments.

The corresponding processes are schematically reproduced in the figure below, for a solution with a single complex ML which is reduced into M° at a voltammetric electrode after dissociation. Figure 1 also shows the reaction layer thickness μ and the diffusion layer thickness δ, which are key parameters to develop a general and accurate numerical method later applicable to a large mixture of complexes and ligands.