Chromatographic analysis of heterogeneous sorption systems

Abstract

This thesis deals with the chromatographic behavior of sorbates involved in three types of heterogeneous sorption systems: (1) a system with simultaneous ion exchange and electrolyte adsorption; (2) a system with various types of sorption sites; and (3) a multiphase system. The local equilibria between the phases are assumed, and the theory of shock waves and the concept of coherence are used to predict the dynamic behavior of these systems. For the type-1 system, a simplified model with a Langmuir type sorption isotherm is proposed. Through case studies and experiments, it is shown that electrolyte adsorption may play an important role in the migration of solutes through geologic media. For the type-2 system, a new concept of sorption affinity is proposed for predicting the chromatographic propetry of a general competitive sorption. In addition, some concrete expressions of affinity order are derived and examined to show the usefulness of the concept. For the type-3 system, a set of equations governing the multiphase transport of sorbates are formulated and applied to the colliod-facilitated governing the multiphase transport of radionuclides. Through numerical calculation, several conditions under which such transport is important are presented and examined.