Redox front propagation and banding modalities
Oxygenated waters flowing through a reduced sandstone cause propagating redox fronts. Mathematical reaction-transport models of these fronts studied here show a number of nonlinear phenomena including one-parameter families of constant-velocity fronts, decelerating fronts and two types of front instabilities leading to pattern formation. These redox front phenomena are examples of nonlinear wave propagation and self- organization. Redox fronts in nature are economically important because they can trap accumulations of metallic ores. Furthermore, they are but one example of a wider class of water-rock interaction systems rich in nonlinear reaction-transport phenomena. Analytical results are presented on conservation law and free boundary methods to study the velocity and profiles of the waves. A new model of the Ostwald supersaturation- nucleation-depletion cycle is presented that incorporates features of Liesegang banding not predicted by other formulations: these include finite band widths and continuous undulatory as well as discrete banding.
one-parameter families of constant-velocity fronts
supersaturation-nucleation-depletion cycle
scientific article; zbMATH DE number 3943432