At fairly high concentrations, the effective As diffusion coefficient was known to increase linearly as a function of concentration. Here, the markedly enhanced diffusion of As was studied by using asymptotic methods. The results of a previous paper were extended by characterizing an additional (low-concentration) region, by considering the effect of the initial data, and by considering the case of constant surface concentration.

J.R.King: IMI Journal of Applied Mathematics, 1987, 38[2], 87-95