Grande Ronde groundwater composition

Table I. Reference Grande Ronde Groundwater Composition at 25°C ...

Sufficient DO data were not obtained from basalt-synthetic Grande Ronde groundwater experiments to allow determination of a definitive rate law. A first order kinetic model with respect to DO concentration was assumed. Rate control by diffusion kinetics and by surface-reaction mechanisms result in solution composition cnanges with different surface area and time dependencies (32,39). Therefore, by varying reactant surface area, determination of the proper functional form of the integrated rate equation for basalt-water redox reactions is possible. 

The simulated groundwater used in these experiments was prepared to represent the compositon of groundwater from Well DC-6, Grande Ronde Formation, which samples water primarily from 200 m below the Umtanum unit on the U S DOE Hanford site near Richland, WA (1) Its composition is shown in Table II The groundwater used in these experiments was continually sparged with N2 gas before it entered the apparatus to reduce the dissolved oxygen level and to limit CO2 pickup ... 

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