Self-sealing/healing isolation and immobilization caused by chemical discontinuities in porous media

Abstract

In this thesis the mechanism of formation of self-sealing/healing isolation and immobilization in layered materials is investigated, with particular emphasis on the impact of such self-forming layer on the transport and mobility of chemical constituents. As principal example the layered acidic jarosite/alkaline coal fly ash system is considered. The approach to this program starts with investigating the formation potential of self-sealing layer in the layered jarosite/fly ash system. Next, characteristics of the sealing layer and its impact on transport and mobility of chemical constituents are examined experimentally, followed by a mathematical description of sealing layer development. Finally, chemically reactivity of self-sealing layer in the jarosite/fly ash is explored. For application purposes self-sealing isolation and immobilization, rather than neutralization, is recommended. Placing a layer of acidic jarosite adjacent to a layer of alkaline coal fly ash offers the optimal solution to the waste acidic jarosite environmental problem.