Dr. André M. Scheidegger, postdoctoral associate in soil chemistry at the University of Delaware College of Agriculture and Natural Resources, has been awarded the F.W. Clarke Award by The Geochemical Society. The award is given each year to an early-career scientist for a single outstanding contribution to geochemistry. Scheidegger received his award at the Ninth Annual V.M. Goldschmidt Conference at Harvard University in Cambridge, Mass., in August 1999. He is the first soil scientist to receive the Clarke Medal. "The F.W. Clarke Award is a very prestigious award in the field of geochemistry," says Dr. Donald Sparks, Distinguished Professor of Soil Chemistry and chair of the department of plant and soil sciences. "André received this award for his cutting-edge postdoctoral research performed here at UD." World-class geochemist Dr. Michael Hochella, Jr., from the Virginia Polytechnic Institute and State University, elegantly summarized the originality and significance of Scheidegger's research in support of his nomination for the Clarke Medal. "Dr. Scheidegger has changed forever the way we think about water-rock sorption/desorption reactions," says Hochella. "His most recent paper, and others before it, will result in a complete re-evaluation of these processes. He has proven, using direct time-resolved spectroscopic probes, that much of the past foundations of this field determined macroscopically, must now be called into question and seriously re-evaluated." Scheidegger, a native of Switzerland, came to Delaware in the fall of 1993, and worked with the UD team through the spring of 1997. Prior to coming to UD, he had earned his diploma in chemistry from the Swiss Federal Institute of Technology (ETH) in Zurich in 1989, and his Ph.D. in soil chemistry also from ETH in 1993. Soil chemistry is the study of how trace elements, nutrients and organic chemicals react with the soil. Using advanced light sources developed over the past decade, scientists can determine, at the molecular level, how contaminants are bound to soil surfaces. Such information is critical in predicting the form, mobility, and bioavailability of contaminants in soil and water environments and in making sound decisions about remediation. According to Scheidegger, the research for which he won the F.W. Clarke award revealed a new pathway by which metals are immobilized in soils. "Metals can react with aluminum in soil minerals to form a new phase that efficiently traps the metals in a stable molecular form," he says. "This research was possible because I was using a multitude of advanced spectroscopic and microscopic techniques available to our research group at UD and at the Brookhaven National Laboratory. My findings have initiated a significant number of further studies, both at UD and elsewhere." Scheidegger is currently working as a research scientist in the Waste Management | 
