The quantitative assessment of sorption and desorption processes is vital to the complete understanding of contaminant fate and transport in the subsurface. The sorption and desorption of a synthetic organic pesticide, diuron, was studied by optical ultraviolet (UV) absorption spectroscopy in two configurations. The first utilized the "grab sample" method and a conventional laboratory benchtop UV/VIS spectrophotometer, and the second employed a fiber optic spectrophotometer. The "grab sample" method is susceptible to systematic errors related to the removal of the sample from the subsurface system for analysis. Fiber optic spectrophotometry has the potential for noninvasive, nondestructive measurements obtained within the subsurface media. The hypothesis of this work was that fiber optic spectrophotometry can be used to determine the fate and transport of a pesticide in laboratory systems of subsurface media, using a one dimensional column configuration. The results of this research demonstrate that fiber optic spectroscopic methods can be used for one-dimensional subsurface media column sorption/desorption and tracer experiments under the conditions used in this study. In addition, sorption kinetic experiments indicate that equilibrium conditions are not attained after 140 days of equilibration. Data from equilibrium distribution experiments support this conclusion.Master of Science in Environmental Engineerin
