Analytical solution and simplified analysis of coupled parent-daughter steady-state transport with multirate mass transfer

Abstract

In this technical note, a steady-state analytical solution of concentrations of a parent solute reacting to a daughter solute, both of which are undergoing transport and multirate mass transfer, is presented. Although the governing equations are complicated, the resulting solution can be expressed in simple terms. A function of the ratio of concentrations, In (daughter/parent + P), can be used as a metric of mass transfer and reaction if the reactions are mostly confined to the immobile domain, where P is the ratio of production of daughter to decay of parent. This metric is applied with the resazurin-resorufin (Raz-Rru) tracer system in a stream to obtain an integrated measure of respiration that occurs on or in a stream bed. The slope of the graph of In (Rru/Raz + P) versus advective travel time is a function of the strength of surface—bed interaction and respiration. This graph can be used for rapid comparison of different experiments and streams.

Citation

Haggerty, R. 2013. Analytical solution and simplified analysis of coupled parent-daughter steady-state transport with multirate mass transfer. Water Resources Research. 49: 635-639.