Stability, speciation and spectral properties of Uranyl - Pyrazine Mono and Di carboxylate complexes

The redistribution of uranium and uranium progeny to both surface water and groundwater occurs primarily from the natural erosion of rock and soil; some redistribution also comes from the mining, milling, and, to a lesser extent, conversion portions of the nuclear fuel cycle. In the process of mining uranium, when the depth of the mine is below the water table (either an open-pit or underground mine), the resulting water is pumped from the mine and often discharged directly to the ground or into surface water. Pyrazines are widely distributed in nature, occur naturally and are also anthropogenic. In the present studies, the protonation constants of pyrazine-2-carboxylate and pyrazine-2,3-dicarboxylaic acid were determined by potentiometric titrations whereas the stability constants of these acids with uranyl ion were determined by potentiometry and absorption spectrophotometry