PNNL

Abstract

The reported investigation represents a first step toward development of a sensor methodology for in-situ determination of ionic species retained on ion exchange column. Raman spectroscopy was demonstrated as a detection method for determining perchlorate loading on a non-selective ion exchange resin, Purolite A850 acrylic gel. This method has been established using laboratory water (DIW) samples and actual California ground water (CAGW) samples with the complexities of competing ions, dissolved organics, and other potential interfering agents. The detection limit for this method of monitoring perchlorate on resin was measured to be 0.014 meq g-1 for both DIW and CAGW systems. The anion selectivity of the A850 resin was determined via batch contact experiments using CAGW. Linear correlation between resin loading with perchlorate and the intensity of the Raman perchlorate signal was observed and quantitatively described. The obtained relationship was applied for the determination of the perchlorate retained on the A850 resin in the column elution experiments.