SOME ASPECTS OF THE HYDRODYNAMIC DISPERSION OF SOLUTES IN POROUS MATERIALS

The paper reviews some quantitative aspects of the hydrodynamic dispersion of solute that occurs under the combined influence of molecular diffusion and convection when a solution flows through a porous material. In particular, the paper (i) describes several methods of analysing the breakthrough curve of one solution as it displaces another from- a column of porous material to yield a coefficient of hydrodynamic dispersion (K); (ii) discusses the form of K as a function of particle size and fluid velocity in granular beds composed of solid particles or of aggregates; (iii) discusses the effect of K on the dispersion observed in a column of porous material, as fluid velocity and particle size vary, as an aid in assessing the efficiency of leaching.