Asymptotic results for injection of reactive solutes from a three-dimensional well

In this paper we consider some asymptotic aspects related to the proole of a reactive solute, which is injected from a well (radius > 0) into a three-dimensional porous medium. We present a convergence result for # 0 as well as the large time behaviour. Regarding the latter we show that the solute proole evolves in a self-similar way towards a stationary distribution and we give an estimate for the rate of the convergence. This paper extends earlier work of van Duijn & Peletier 5], where the two-dimensional case was treated. Note: Work carried out under the proyect MAS 1.2 \Partial Diierential Equations in Porous Media Research".