  An accurate modeling of reactive flows in fractured porous media is a key
ingredient to obtain reliable numerical simulations of several industrial and
environmental applications. For some values of the physical parameters we can
observe the formation of a narrow region or layer around the fractures where
chemical reactions are focused. Here the transported solute may precipitate and
form a salt, or vice-versa. This phenomenon has been observed and reported in
real outcrops. By changing its physical properties this layer might
substantially alter the global flow response of the system and thus the actual
transport of solute: the problem is thus non-linear and fully coupled. The aim
of this work is to propose a new mathematical model for reactive flow in
fractured porous media, by approximating both the fracture and these
surrounding layers via a reduced model. In particular, our main goal is to
describe the layer thickness evolution with a new mathematical model, and
compare it to a fully resolved equidimensional model for validation. As
concerns numerical approximation we extend an operator splitting scheme in time
to solve sequentially, at each time step, each physical process thus avoiding
the need for a non-linear monolithic solver, which might be challenging due to
the non-smoothness of the reaction rate. We consider bi- and tridimensional
numerical test cases to asses the accuracy and benefit of the proposed model in
realistic scenarios.
