Singular shocks in a chromatography model

We consider a system of two equations that can be used to describe nonlinear chromatography and produce a coherent explanation and description of the unbounded solutions (singular shocks) that appear in Mazzotti's model [21] and [22]. We use the methods of Geometric Singular Perturbation Theory, to show existence of a viscous solution to Dafermos–DiPerna regularization.