Comment pubs.acs.org/est
A Tribute to René P. Schwarzenbach
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mechanisms of pollutant transformation. Thanks to sophisticated analytical methods such as high-resolution and isotope ratio mass spectrometry as well as theoretical analysis with computational chemistry, reaction products, and reactive intermediates are no longer only a matter of speculation. Instead, intricate details have been uncovered about how pollutants react to both benign as well as highly problematic products, whereas advances have been made to monitor these transformations more reliably. Understanding the behavior of organic molecules in the environment goes hand in hand with knowledge of microbecontaminant interactions as well as the biogeochemical settings, especially across a gradient of redox conditions that make them possible. Accordingly, a major theme in this issue is biological transformation processes, from the cellular scale to the level of microbial community and beyond. This tribute would not be complete without thorough consideration of the implications of chemical pollution and the effects of contaminant transport and transformation. Single contaminant studies illustrate factors determining the fate of antibiotic resistance genes while comprehensive studies include 200+ compounds to assess the origin of toxic effects or the exposure to micropollutants at the catchment scale. Such studies provide stakeholders with solid evidence for taking measures against environmental contamination. The American Chemical Society named René as one of the “Legends in Environmental Chemistry” in 2008, and for his former students, postdocs, and collaborators, that is exactly what he is. As professor emeritus, René has continued to advocate environmental sustainability in his role as Associate Vice President for Sustainability at ETH Zürich and has begun to work on the third edition of The Book with his mates Phil Gschwend and Dieter Imboden (but please do not let this out, as it is a secret). In the following “Perspective” article, Dieter Imboden reflects on the 40 years of collaboration and friendship with René, but neglects to say that René’s always been the better cook. Janet Hering and Rik Eggen look back on René’s time at Eawag, where he left his footprint from 1977 to 2005. René was one of the driving forces in developing the Environmental Science Curriculum at ETH Zürich, which now is the highest ranked environmental science degree in Europe. He would rather go visit a high school class than attend a meeting, and the success of The Book is partially rooted in the fact that it was tested on ETH students during many lessons before it was published. Bernhard Wehrli and Peter Frischknecht reflect on René’s passion for teaching and his role at ETH. Finally, we offer our thanks to René Schwarzenbach for being a true inspiration and mentor. Three of us were under René’s direct supervision and have contributed as pieces to the puzzle in the creative “World According to René.” While there were
t has been a great pleasure and privilege for us to serve as Guest Editors for this tribute issue recognizing and honoring the career of René Schwarzenbach, a singular figure in environmental chemistry. No student of environmental organic chemistry or regular reader of Environmental Science & Technology needs to be convinced of René’s deep influence on our understanding of the behavior of organic molecules in the environment. Arguably, more than any other person, René has identified and clarified the core concepts of modern environmental organic chemistry. A principle vehicle for this has been his groundbreaking and essential textbook, Environmental Organic Chemistry, coauthored by Phil Gschwend and Dieter Imboden, which celebrates its 20th anniversary this year. The Book, as it has been known to generations of students, has served not only as an entry point for countless people interested in the topic of environmental organic chemistry, but also as an irreplaceable reference and guidebook for practitioners and professionals. Even before The Book, René Schwarzenbach had established himself as one of the brightest lights and leading intellectual figures in the field through his pioneering research. The diversity of his group’s contributions, spanning from molecularscale studies of contaminant sorption and reactivity to field studies to ecotoxicology, seemed to touch every corner of the environmental organic chemistry. In 174 publications, of which 115 (or 66%!) were published in Environmental Science & Technology, René and his research group demonstrated what thorough, meaningful, and didactically rich research articles look like. Given the breadth of René’s contributions, it should therefore be no surprise that the research articles in this tribute issue reflect that diversity. René’s four highest cited articles emphasize the breadth of his interests ranging from transport1 to sorption2 to redox processes3 and including a bigger picture view addressing the challenges of micropollutants in aquatic systems.4 The rich collection of papers features virtually every (sub)discipline of environmental organic chemistry, ranging from contaminant sorption to ecotoxicology to biogeochemistry. The 36 research articles collected in this issue illustrate how a fundamental understanding of intermolecular interactions and chemical reactions has led to a substantial development in the field that enables us to address current problems of chemical pollution. The topics of the articles in this issue make clear that while traditional, legacy pollutants continue to be of concern, environmental organic chemists are now focused on a wider range of compounds including prion proteins, nanomaterials, antibiotics, and chemicals in consumer products. Likewise, advances in the characterization of the environmental interfaces and their properties have promoted a more complete understanding of contaminant reactions dynamics, for example, at ice and iron mineral surfaces. As showcased in a large number of papers in this issue, there has been an expansion and deepening of our understanding of © 2013 American Chemical Society
Special Issue: Rene Schwarzenbach Tribute Published: July 2, 2013 6725
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moments of frustration when the red ink spilled far too eagerly, we feel fortunate to have had such an incredible teacher who gave us all the freedom and yet was there when things got tough. And occasionally we catch ourselves repeating exactly what he told us to our own students (remember “back of the envelope calculations”, everyone out there?) and walking casually into their offices chewing on the afternoon apple. We hope that you enjoy reading the contributions as much as we enjoyed editing this tribute issue.
Kristopher McNeill*,† Thomas B. Hofstetter‡ Kai-Uwe Goss§ Beate Escher∥ †
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Institute of Biogeochemistry and Pollutant Dynamics (IBP), ETH Zürich, Switzerland ‡ Swiss Federal Institute of Aquatic Research (Eawag), Switzerland § Helmholtz Centre for Environmental Research (UFZ), Leipzig, Germany ∥ National Research Centre for Environmental Toxicology (Entox), The University of Queensland, Australia
Thomas B. Hofstetter is a Senior Scientist at the department of Environmental Chemistry at EAWAG and lecturer in Environmental Chemistry at the Swiss Federal Institute of Technology ETH Zürich. Dr. Hofstetter obtained his PhD in 1999 under the guidance of René Schwarzenbach. After working three years on the life cycle assessment of chemicals in the Institute of Chemical and Bioengineering of ETH Zürich and in collaboration with the chemical industry, he returned to the world of organic water contaminants that led him as guest investigator to the Woods Hole Oceanographic Institution (WHOI) in Woods Hole (2005) and back to René Schwarzenbach's group at ETH Zürich, where he also obtained his Habilitation in 2008. He joined EAWAG in 2010, where he studies the mechanisms and isotope effects of pollutant transformation, stable-isotope based methods to track such reactions in aquatic and soil environments, as well as the redox properties of Fe minerals.
AUTHOR INFORMATION
Corresponding Author
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[email protected] Notes
Views expressed in this editorial are those of the authors and not necessarily the views of the ACS. The authors declare no competing financial interest. Biographies
Kai-Uwe Goss received his Diploma in environmental sciences 1989 and his PhD in 1993 both from the University of Bayreuth in Germany. He then worked as a postdoctoral researcher at the University of Minnesota for two years. From 1996 to 2006 Dr. Goss did another postdoc and his Habilitation in the group of René Schwarzenbach at EAWAG and ETH Zürich in Switzerland. Since 2007, he has been department head at the Helmholtz Centre for Environmental Research UFZ in Leipzig, Germany and Professor for Environmental Chemistry at the University of Halle in Germany. His research interests are in the partitioning and transport of organic chemicals in the environment including experimental as well as modeling approaches. In recent years, partitioning in biota and the partitioning of ionic organic chemicals have become the focus of research in his group.
Kristopher McNeill received his B.A. in Chemistry from Reed College in 1992 and his Ph.D. in Chemistry from the University of California at Berkeley in 1997, co-advised by Professors Robert G. Bergman and Richard A. Andersen. Dr. McNeill then worked as a postdoctoral researcher with Prof. Philip Gschwend in the Department of Civil and Environmental Engineering at the Massachusetts Institute of Technology from 1997 to 1999. Dr. McNeill joined the faculty at the University of Minnesota in January 2000. In 2009, he and his research group moved to ETH Zürich, where he succeeded René Schwarzenbach as the Professor of Environmental Chemistry. His research group studies environmentally relevant chemical transformations, focusing on the catalytic and photocatalytic degradation of pollutants, the photochemical production of reactive intermediates in aquatic systems, as well as the environmental fate of proteins and synthetic polymers. 6726
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Beate Escher is Deputy Director of the National Research Centre for Environmental Toxicology (Entox) in Brisbane, Australia, and professor at the University of Queensland. In addition, she is lecturer at the Swiss Federal Institute of Technology ETH Zürich, Switzerland and holds adjunct appointments at EAWAG, Switzerland, and Griffith University, Australia. She did her doctorate, postdoc, and Habilitation under the guidance of René Schwarzenbach from 1991 to 2001. Her research interests focus on mode-of-action based environmental risk assessment, including methods for initial hazard screening and risk assessment of pharmaceuticals and pesticides, environmental transformation products and mixtures. More practically oriented aspects of her work include passive sampling and effect-based methods for water quality assessment.
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REFERENCES
(1) Schwarzenbach, R. P.; Westall, J. Transport of non-polar organic compounds from surface-water to groundwater-laboratory sorption studies. Environ. Sci. Technol. 1981, 15, 1360−1367. (2) Schellenberg, K.; Leuenberger, C.; Schwarzenbach, R. P. Sorption of chlorinated phenols by natural sediments and aquifer materials. Environ. Sci. Technol. 1984, 18, 652−657. (3) Klausen, J.; Trober, S. P.; Haderlein, S. B.; Schwarzenbach, R. P. Reduction of substituted nitrobenzenes by Fe(II) in aqueous mineral suspensions. Environ. Sci. Technol. 1995, 29, 2396−2404. (4) Schwarzenbach, R. P.; Escher, B. I.; Fenner, K.; Hofstetter, T. B.; Johnson, C. A.; von Gunten, U.; Wehrli, B. The challenge of micropollutants in aquatic systems. Science 2006, 313, 1072−1077.
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