RETRASO

RETRASO simulates transport processes (advection, dispersion and diffusion) and chemical reactions (acid-base reactions, redox, complexation, adsorption, cation exchange, precipitation and dissolution of minerals). Chemical reactions can be assumed to follow either an equilibrium or a kinetic approach. The numerical solution is carried out using the global implicit or direct substitution approach. That means that all equations are solved simultaneously by applying Newton-Raphson.