Dr. Reyes Sierra-Alvarez is a professor at the Department of Chemical and Environmental Engineering, University of Arizona (UA). Prior to joining the UA in 2001, Dr. Sierra was an Associate Professor of Environmental Engineering at the Wageningen University in The Netherlands (1993 – 2000) and an assistant professor at the UNESCO Water Research Institute in Delft, The Netherlands (1991 – 1993). Dr. Sierra holds a PhD degree in Environmental Engineering from the Wageningen University (1990) and an MS degree in Chemical Engineering from the University of Valladolid in Spain (1985). Prof. Sierra’s current research work focuses on the microbial transformation of metals and hazardous organic pollutants, biological wastewater treatment, and environmental implications of nanotechnology. Her work has led to the publication of over 130 peer-reviewed scientific papers.