Non-equilibrium thermodynamic simulation of metal uptake in the bacterial electrical double-layer

摘要

A non-equilibrium thermodynamic (Onsager) formalism is presented for modeling transport processes in the bacterial electrical double-layer. This formalism is then applied to model the time-dependent metal uptake within the bacteria electrical double-layer that occurs in response to gradients in concentration and electrostatic potential. The formal development of the equations is presented along with an efficient numerical procedure to solve the system of equations for spherical geometry. Numerical results are given for two values of ionic strength, I = 0.1 and 0.001 M and a bulk trivalent tracer concentration of 1 * 10~(-6) M. Equilibrium distribution of the trivalent tracer cations was shown to be reached very rapidly, in about 2 ms at I = 0.1 M and 0.2 s at I = 0.001 M. Therefore diffusion-conduction was demonstrated to be a highly efficient mechanism of ionic transport on the nanoscale for the conditions at which electrostatic metal uptake is significant.