Determination of Interplate Distance between Two Clays and Initial Bulk Concentrations: An Inverse Problem

Abstract

The space between two clay particles consists of two electric double layers, one adjacent to each clay surface and in-between effective pore space. While solving the Poisson-Boltzman equation, one boundary condition is that, at infinite distance from the clay surface potential is zero. Practically midpoint of the interplate distance is considered to be at infinite distance from the clay surface. Without knowing the interplate distance, the Poisson-Boltzman equation can not be solved for computing the electric double layer. In this paper, a method is suggested for computation of effective pore space as well as electric double layer and consequently the interplate distance. The existing methods of bulk concentration measurement suit the evaluation of electric double layer and effective pore space in saturated soil. However, applying mass balance for individual ion, the bulk concentration and the distribution of ions in unsaturated state are predicted accurately treating it as an inverse problem.