Nonclassical transport in fractal media with a diffusion barrier

We investigate the impurity transport in a randomly heterogeneous fractal medium with a diffusion barrier. The barrier is due to low permeable medium surrounding the source. The transport regimes and asymptotic (large-distance) concentration distributions are found. The presence of the diffusion barrier results in the retardation of the transport regimes at short times. As regards the asymptotic concentration distribution, the barrier influence persists for long times as well.