Multicomponent equilibrium chemistry in groundwater quality models

Abstract

A technique is described for modeling the groundwater transport of a multicomponent solution of metals and ligands. By this method both soluble complexation and competitive sorption among chemical species may be accommodated. A finite element solution is presented for an arbitrary number of components. It is shown that although this technique leads to strongly nonlinear equations, accurate solutions may still be achieved. It is also shown that the interaction mechanisms modeled can have significant impact on the transport potential of solution components.

UTILITY OF MECHANISTIC MODELS FOR DIRECTING ADVANCED SEPARATIONS RESEARCH & DEVELOPMENT ACTIVITIES: Electrochemically Modulated Separation Example

“…As a result, the SIA is usually the approach of choice for more complex two-and three-dimensional models. That said, numerous examples exist in the literature in which both DSA [Valocchi 1981;Jennings 1982;Miller 1983] and SIA [Kirkner 1984;Walsh 1984;Cederberg 1985] have been utilized effectively within reactive transport models.…”

Research and development related to the Nevada Nuclear Waste Storage Investigations: Progress report, October 1--December 31, 1984

“…Once a Kj has been determined by laboratory field methods, it is used to define the retardation factor that in turn describes the velocity of the reactive solute relative to the average linear groundwater velocity (Freeze and Cherry 1979). Because this approach is conceptually and computationally simple, the use of distribution coefficients has been liberally applied to explain observed contaminant transport in soils and aquifers (Grove and Wood 1979;Krishnaswame et al 1982;Schwartz et al 1982;Jackson and Inch 1983 The technique of separating the algebraic equation set for the equilibrium chemistry from the differential equation set for the mass transport has been used with some success (Grove and Wood 1979;Jennings et al 1982). Grove and Wood (1979) reformulation of the finite element matrices within each time step is not required.…”

Numerical Simulation of Cesium and Strontium Migration Through Sodium Bentonite Altered by Cation Exchange with Groundwater Components

“…The advantages and disadvantages of using the one-step and two-step approaches to simulate reactive chemical transport have been discussed by Jennings et 4l. [9].…”