New insights in dynamic modeling of a secondary settler—I. Flux theory and steady-states analysis

A dynamic model of the settling process in the secondary settler of a wastewater treatment plant is given by a nonlinear scalar conservation law for the sludge concentration under the form of a partial differential equation (PDE). Theoretical results on stationary solutions are found to be related with the limiting flux theory, allowing new insights into this latter theory, especially when the settler is overloaded.