Microcosm Studies
Solute transport through heterogeneous environments is often poorly understood because of inadequate definition of aquifer stresses and boundary conditions. One approach to address these concerns is to transport a large, minimally disturbed, highly heterogeneous aquifer mesocosm to a controlled laboratory setting. This approach will bridge the gap between small-scale laboratory studies and large-scale field studies.
Field Scale Bioremediation Design and Reactive Transport
Ground-water contamination with volatile organic compounds is a significant national and international problem. Waters containing these contaminants are typically pumped from contaminated aquifers and treated by air stripping or sorption onto activated carbon. These methods are costly, do not destroy the contaminants, may require pumping and disposal of large water volumes, and do not effectively remove contaminants sorbed to the aquifer material.Accordingly, there has been a great deal of interest in alternative treatment strategies, such as enhanced in-situ remediation. Our research group in collaboration with the Departments of Civil and Environmental Engineering and the Center for Microbial Ecology designed and installed a cost-effective biocurtain that is currently being used to remove carbon tetrachloride from an aquifer in Schoolcraft, Michigan. Novel aspects of the design are the use of closely-spaced wells to recirculate solutes through a biocurtain, well screens spanning the vertical extent of contamination, and a semi-passive mode of operation, with only six hours of low-level pumping per week.