INTRINSIC BACKGROUND FLUORESCENCE ANALYSIS AS AN EASY TOOL TO DELINEATE ORGANIC CONTAMINANT PLUMES

Most organic substances show intrinsic fluorescent properties, which can be measured using a spectro-fluorometer. As a logical extension we investigated the applicability of using the intrinsic background fluorescence of organic contaminants to study their spatial extension on selected sites in the northeastern United States.

The background fluorescence signal of contaminated groundwater has distinctive fluorescent peaks, some of which are sufficiently characteristic to be used as a ‘natural’ tracer. These considerations suggested that we test the hypothesis if intrinsic background fluorescence at organic-rich sites can be used to locate ‘hot-spots’ and delineate contaminant plumes.

We compared intrinsic fluorescence data with organic chemistry and the hydrogeology of several sites. Distinct wavelengths (between 400 nm and 600 nm) of an emission synchroscan have been chosen and its relative fluorescence intensity plotted to the corresponding wells. Contours separate zones of the same relative fluorescence intensity.

We found that increasing fluorescence intensities match with increasing concentrations of a contaminant plume. Deciphering data from background fluorescence studies gives valuable qualitative information regarding possible anthropogenic impacts and extent and provides a valuable tool when selecting a remediation strategy.