Former Graduate Students & Post-doctoral Fellows

Daniel J. Jacob (Ph.D. 1985)

Bruce C. Faust (Ph.D. 1985)

Detlef W. Bahnemann (PD 1985 - 1987)

Eric B. Betterton (PD 1985-1988)

Martha Conklin (Ph.D. 1986)

Robert Arnold (Ph.D. 1987)

Marta E. Escobar (PD 1987-1988)

Manabu Igawa (PD 1986-1987)

Andrew P. Hong (Ph.D. 1988)

Terese M. Olson (Ph.D. 1988)

J. William Munger (Ph.D. 1989)

Thomas DiChristina (Ph.D. 1989)

Juan Carlos Diaz Ricci (PD 1988-1990)

Jeffrey. L. Collett (Ph.D. 1989)

Elizabeth Carraway (PD 1987-1989)

German Mills (PD 1988-1989)

Dieter Gunz (PD 1987-1989)

Anatassia Kotronarou (Ph.D. 1991)

Maria Encarnación Vázquez Suárez-Iha (PD 1993-1994)

Yigel Erel (Ph.D. 1991; PD 1991-1993)

Simo Pehkonen (Ph.D. 1994)

Scot T. Martin (Ph.D. 1996)

Inez Hua (Ph.D. 1996)

Wongyong Choi (Ph.D. 1996)

Ron L. Siefert (Ph.D. 1996)

Janet Kesselman (Ph.D. 1996)

Linda K. Weavers (Ph.D. 1997)

Joon-wun Kang (PD 1997-1998)

Anne M. Johansen (Ph.D. 1999)

Hui-Ming Hung (Ph.D. 2000)

John Moss (PD 1997-2000)

Steven Szczepankiewicz (Ph.D. 2001)

Yael Dubowski (Ph.D. 2001)

Greg Roberts (Ph.D. 2001)

Weng-Ki Ching (Ph.D. 2001)

Hugo Destaillats (PD 1998-2001)

Daniel J. Jacob (Ph.D. 1985)

Gordon M. MacKay Professor of Atmospheric Chemistry

Division of Engineering and Applied Science

Harvard University

1982	2002
1981	2003

http://www-as.harvard.edu/people/faculty/djj/index.html

http://www.deas.harvard.edu/faculty/profile/Daniel_Jacob

http://www-as.harvard.edu/people/faculty/djj/

Ph.D. California Institute of Technology, 1985

Ph.D. Thesis: The Origins of Inorganic Acidity in Fogs

D. J. Jacob, J. M. Waldman, J. W. Munger, and M. R. Hoffmann "Chemical Composition of Fogwater Collected along the California Coast" Environ. Sci. Technol., 19, 730-735 (1985)

The goal of our research is to understand the chemical composition of the atmosphere and its perturbation by human activity.  We work on global 3-dimensional modeling of atmospheric chemistry and climate change, aircraft measurement campaigns, satellite data retrievals, and analyses of atmospheric observations.

Associate Professor - Resigned

Department of Civil and Environmental Engineering

University of California – Los Angeles

1982

Ph.D. California Institute of Technology, 1985

Detlef W. Bahnemann (PD 1985 – 1987)

Head, Photocatalysis and Nanotechnology

Institute for Technical Chemistry

University of Hannover

Hannover, Germany

2003

www.tci.uni-hannover.de

Bahnemann@iftc.uni-hannover.de

http://www.tci.uni-hannover.de/photochemie.html

D. W. Bahnemann, C. Kormann, and M. R. Hoffmann, "Preparation and Characterization of Quantum Size Zinc Oxide: Fluoresence and Non Linear Optical Effects," J. Phys. Chem. 91, 3789-3798 (1987)

Semiconductor Photocatalysis for Environmental Applications & Remediation

Eric B. Betterton (PD 1985-1988)

Professor of Atmospheric Chemistry

Department of Atmospheric Sciences and Institute of Atmospheric Physics
University of Arizona

1998	2002

Betterton E. A. and Hoffmann M. R., "Oxidation of Aqueous SO₂ by Peroxymonosulfate. Journal of Physical Chemistry 92, 5962-5965 (1988).

Atmospheric and environmental chemistry (including frozen solution chemistry, water isotpic chemistry, aerosols, cloud condensation nuclei, microphysical and chemical properties of winter precipitation, urban air quality, ground water remediation, and chemistry of azides derived from automobile air bags).

Martha Conklin (Ph.D. 1986)

Professor, University of Arizona

Department of Hydrology and Water Resources

http://www.hwr.arizona.edu/~martha/research.html

Ph.D. California Institute of Technology, 1986

Ph.D. Thesis Title: Thermodynamics, Kinetics, and Mechanisms of the Reactions of S(IV) with Fe(III) and Cu(II).

Conklin M. H. and Hoffmann M. R., "Metal-Ion Sulfur(IV) Chemistry .3. Thermodynamics and Kinetics of Transient Iron(III) Sulfur(IV) Complexes. Environmental Science & Technology 22, 899-907 (1988).

Current Research Interests:

She has published extensively in diverse fields of research including sorption of organic contaminants, transport of volatile organic contaminants in unsaturated media, trace metal transport, polar snow and ice, and metal complexation. In May 2003, Martha Conklin and her husband, Roger Bales, (http://faculty.ucmerced.edu/rbales/index.html) moved to the University of California, Merced as founding faculty. After many enjoyable and productive years at the University of Arizona, they decided to take up the challenges of building a new research university in the San Joaquin Valley. They now live in Catheys Valley, in the Sierra Nevada foothills.

Robert Arnold (Ph.D. 1987)

Professor of Chemical Engineering

Department of Chemical Engineering

University of Arizona

http://www.che.arizona.edu/Directory/Faculty/Arnold.htm

Ph.D. Thesis Title: Dissimilative Fe(III) Reduction by Pseudomonas sp. 200

Key Paper from Caltech Days:

Arnold R. G., Olson T. M., and Hoffmann M. R., "Kinetics and Mechanism of Dissimilative Fe(III) Reduction by Pseudomonas Sp. 200 – Alteromonas putrifaciens," Biotechnology and Bioengineering 28, 1657-1671 (1986).

Current Research Interests:

Dr. Arnold’s professional interests include applied microbiology (bioremediation and microbially catalyzed processes of environmental interest) and abiotic catalysis of hazardous waste transformations. He has participated in research aimed at the treatment of hazardous organic pollutants such as chlorinated solvents, wastewater polishing during infiltration through biologically active soils, microbial transport through porous media, and prevention of sewer crown corrosion. Examples of his work in abiotic catalysis include the electrolytic and photoinitiated decomposition of trichloroethylene.

Marta E. Escobar (PD 1987-1988)

Faculty of Science

Departamento de Fisica

National University of La Plata

La Plata, Argentina

Manabu Igawa (PD 1986-1987)

Professor of Applied Chemistry

Kanagawa University

Yokohama, Japan

igawam01@kanagawa-u.ac.jp

http://www.apchem.kanagawa-u.ac.jp/e_HP/e_laboratory/e_igawa_lab.html

Key Paper from Caltech Days:

M. Igawa, Y. Fukushi, T. Hayashita and M. R. Hoffmann, "Selective Transport of Aldehydes Across an Anion-Exchange Membrane via the Formation of Bisulfite Adducts," Ind. Eng. Chem. Res., 29, 857-861 (1990)

Current Research Interests:

The research topics of the Igawa group are acid deposition and membrane separation chemistry. To conduct acid deposition research they collect and analyze not only acid rain, but also highly acidic fog in the mountains and acid dew which affects paint in urban areas, in order to clarify the acidification mechanisms. We also assess environmental effects by exposing vegetation and materials to acid solutions. In research into membrane separation, we are developing artificial films which function similarly to living membranes and which can be used as an efficient separation method.

Andrew P. Hong (Ph.D. 1988)

Associate Professor

Department of Civil Engineering

University of Utah

http://www.civil.utah.edu/faculty/hong/index.htm

Ph.D. California Institute of Technology, 1988

Ph.D. Thesis Title: Catalytic Oxidation of Sulfur Dioxide by Heterogeneous Cobalt Phthalocyanine

Hong A. P., Bahnemann D. W., and Hoffmann M. R., "Co(II)tetrasulfophthalocyanine on TiO₂: 2. Kinetics and Mechanisms of the Photocatalytic Oxidation of Aqueous Sulfur-Dioxide," Journal of Physical Chemistry 91, 6245-6251.

Current Research Interests:

Chemical Oxidation-Contaminant Degradation Kinetics and Pathways, Chemical-Biological Treatment Processes, Groundwater, Soil, Sediment Remediation, Technologies , Hazardous Wastes Management, Water Quality

Terese M. Olson (Ph.D. 1988)

Associate Professor of Environmental Engineering

Department of Civil and Environmental Engineering &

Environmental and Water Resources Engineering

University of Michigan

http://www.engin.umich.edu/dept/cee/program/ewre/faculty/

1988	2003

Ph.D. Thesis Title: Kinetics, Mechanisms, and Thermodynamics of SO2-Aldehyde Addition Compounds.

Olson T. M. and Hoffmann M. R., "Hydroxyalkylsulfonate Formation - Its Role as a S(IV) Reservoir in Atmospheric Water Droplets," Atmospheric Environment 23, 985-997 (1989).

Environmental chemistry, the study of pollutant fate and transformation mechanisms, and oxidation processes for water treatment.

J. William Munger (Ph.D. 1989)

Senior Research Fellow

Division of Engineering & Applied Sciences
Harvard University

http://www-as.harvard.edu/people/staff/jwm/

1989	2002

jwm@io.harvard.edu

Ph.D. California Institute of Technology, 1989

Ph.D. Thesis Title: Carboxylic Acids and Carbonyl Compounds in Clouds, Fogs, and Aerosol

Munger J. W., Tiller C., and Hoffmann M. R., "Identification of Hydroxymethanesulfonate in Fog Water," Science 231, 247-249 (1989).

Current Research Interests:

At Harvard Forest, Dr. Munger and co-workers conduct long-term eddy-covariance measurements of atmosphere-biosphere exchange. Our system of continuous monitoring provides quantitative information, defining the sources and sinks for important atmospheric gases. By constructing long, continuous time series we can understand sources of variance and determine the factors that regulate concentrations and deposition fluxes of greenhouse gases and pollutants.

More general interests: Temperate forest trace gases and fluxes; boreal forest trace gases and fluxes; tropical forest trace gases and fluxes; and airborne measurements of regional fluxes of CO and CO₂

School of Biology

Georgia Institute of Technology

Atlanta, GA

thomas.dichristina@biology.gatech.edu

1998	2003

Ph.D. California Institute of Technology, 1989

Ph.D. Thesis Title: Dissimilative Iron (III) Reduction by Alteromonas putrifaciens sp. 200.

Arnold R. G., DiChristina T. J., and Hoffmann M. R., "Reductive Dissolution of Fe(III) Oxides by Pseudomonas Sp 200," Biotechnology & Bioengineering 32, 1081-1096 (1988).

Prof. DiChristina’s research group focuses on the molecular biology and biogeochemistry of anaerobic bacteria that inhabit marine and freshwater environments. They are interested in anaerobic bacteria that utilize transition metals (iron, manganese, uranium, selenium) as alternate terminal electron acceptors for anaerobic respiration.

Juan Carlos Diaz Ricci (PD 1988-1990)

Professor

Instituto Superior de Investigaciones Biológicas (INSIBIO)

Facultad de Bioquímicas, Química y Farmacia

Universidad Nacional de Tucumán

Tucumán, Argentina

J. C. D. Ricci, B. J. Woodford, J. L. Kirshvinck and M. R. Hoffmann, "Alteration of the Magnetic-Properties of Aquaspirillum-Magnetotacticum by a Pulse Magnetization Technique," Appl. Environ. Microbiol., 57, 3248-3254 (1991).

Jeffrey. L. Collett (Ph.D. 1989)

Professor of Atmospheric Chemistry

Department of Atmospheric Sciences

Colorado State University

http://lamar.colostate.edu/~collett

Phone: (970) 491-8697

Fax: (970) 491-8449

collett@lamar.colostate.edu

Ph.D. California Institute of Technology, 1988

Ph.D. Thesis Title: Characterization of Cloudwater and Precipitation Chemistry and Deposition at Elevated Sites in Central and Southern California.

Collett J. L., Daube B. C., Gunz D., and Hoffmann M. R., "Intensive Studies of Sierra-Nevada Cloudwater Chemistry and Its Relationship to Precursor Aerosol and Gas Concentrations," Atmospheric Environment, 24, 1741-1757 (1990).

Professor Collett's current research is directed toward understanding atmospheric processing of various chemical species and their impacts on pollutant deposition, visibility degradation, and human health. Ongoing work includes studies of the roles fogs and clouds play as processors of atmospheric particles and trace gases and the influence of aerosol particles on visibility degradation in National Parks. The research, primarily of an experimental nature, includes both basic, process-oriented studies as well as more applied work directed toward understanding regional air quality issues.

Elizabeth Carraway (PD, 1987-1989)  

Assistant Professor of Environmental Chemistry

Dept. of Environmental Toxicology

1992	2003

 ecarraw@clemson.edu  

http://people.clemson.edu/~ecarraw

Carraway E. R., Hoffman A. J., and Hoffmann M. R., "Photocatalytic Oxidation of Organic-Acids on Quantum-Sized Semiconductor Colloids," Environmental Science & Technology 28, 786-793 (1994).

Dr. Elizabeth R. Carraway’s investigation of iron chemistry is aimed toward developing better ways to clean contaminated groundwater and surface water. The importance of iron in the environment ranges from treating contaminated groundwater with "iron walls" to releasing nutrients in oceans, lakes and rivers by sunlight. Carraway uses the rusting of the Titanic to illustrate iron chemistry to her students.

German Mills (PD, 1988 - 1989)
Associate Professor
Department of Chemistry

Auburn University

1989	2003

http://www.auburn.edu/academic/science_math/chemistry/docs/faculty_staff/mills.htm

millsge@mail.auburn.edu

http://www.auburn.edu/~millsge/index.html

Mills G. and Hoffmann M. R., "Photocatalytic Degradation of Pentachlorophenol on TiO₂ Particles - Identification of Intermediates and Mechanism of Reaction," Environmental Science & Technology 27, 1681-1689 (1993).

Physical Chemistry: nanomaterials, smart systems, semiconductors, photocatalysis

Dieter Gunz (PD 1987-1989)

Professor - Fachhochschule Liechtenstein

Mitglied der Hochschulleitung

1988	2003

Gunz D. W. and Hoffmann M. R., Atmospheric Chemistry of Peroxides, Atmospheric Environment, 24, 1601-1633 (1990).

Anatassia Kotronarou (Ph.D. 1991)

Research Scientist, National Observatory of Athens

1992	2003

http://www.noa.gr/indexen.html

natasha@env.meteo.noa.gr

Ph.D. California Institute of Technology, 1991

Ph.D. Thesis Title: Ultrasonic Irradiation of Chemical Compounds in Aqueous Solution

Kotronarou A., Mills G., and Hoffmann M. R., "Ultrasonic Irradiation of p-Nitrophenol in Aqueous Solution," Journal of Physical Chemistry 95, 3630-3638 (1991).

The Institute of Environmental Research and Sustainable Development (IERSD) is one of the four institutes that constitute the National Observatory of Athens (NOA), the oldest research center in Greece (the first meteorological observations began in 1842). The head office of the IERSD is on the hill of the Nymphs, opposite the Acropolis and near the center of Athens. (latitude 37° 58' N, longtitude 23° 43' E, and 107m above MSL).

Hartmut Herrmann (PD 1992-1993)

Professor of Atmospheric Chemistry

University of Leipzig &

Leipzig

http://www.uni-leipzig.de/

1992	1999	2003

http://www.uni-leipzig.de/~meteo/LEHRE/VLANK/vakachw.html http://www.tropos.de/INFO/personal/herrmann.html http://www.tropos.de/eng/STAFF/index.html

herrmann@tropos.de

Herrmann H., Martin S. T., and Hoffmann M. R., "Time-Resolved Radio-Frequency Conductivity (TRRFC) Studies of Charge-Carrier Dynamics in Aqueous Semiconductor Suspensions," Journal of Physical Chemistry 99, 16641-16645 (1995).

Heterogeneous atmospheric chemistry, free radical reactions in the aqueous phase, modeling complex multiphasic reaction chemistry.

Maria Encarnación Vázquez Suárez-Iha (PD 1993-1994)

Associate Professor of Analytical Chemistry

Department of Chemistry

University of Sao Paulo

Sao Paulo, Brazil

http://www2.iq.usp.br/

http://www.iq.usp.br/wwwdocentes/maevsiha/index.htm

Iha M., Pehkonen S. O., and Hoffmann M. R. (1994) Stability, Stoichiometry, and Structure of Fe(II) and Fe(III) Complexes with Di-2-Pyridyl Ketone Benzoylhydrazone - Environmental Applications. Environmental Science & Technology 28, 2080-2086.

Yigal Erel (Ph.D. 1991; PD 1991-1993)

Associate Professor

Institute of Earth Sciences

The Hebrew University of Jerusalem

Israel

yerel@vms.huji.ac.il

1996	2001	1999

http://sites.huji.ac.il/cfer/yigalerel.htm

Ph.D. California Institute of Technology, 1991

Ph.D. Thesis Title: Transport of Natural Lead and Cadmium in Rivers : Global Flux Implications

Erel Y., Pehkonen S. O., and Hoffmann M. R. (1993) Redox Chemistry of Iron in Fog and Stratus Clouds. Journal of Geophysical Research-Atmospheres 98, 18423-18434.

Isotope systematics of Pb and Sr during granitoid weathering and soil formation processes; dynamic cycles and the bio-availability of Fe, Mn, Cu, Zn, and Mo in surface waters; tracing the transport of anthropogenic Pb in the atmosphere and in  soils using isotopic ratios. Prof. Erel’s research incorporates advanced speciation techniques with isotopic measurements in order to fingerprint reservoirs, to trace pathways, and to study chemical transformations of metals on the earth's surface.  The research provides new approaches to estimate the rate of pollutant transport in porous media and in the atmosphere.  There is an ongoing collaboration with major universities in Europe and in the US.  The research is based on state-of-the art clean laboratory techniques for metal speciation studies.

Simo Pehkonen (Ph.D. 1994)

Associate Professor of Environmental Chemistry

Department of Chemical and Environmental Engineering

Singapore National University

Singapore

chesop@nus.edu.sg

http://www.chee.nus.edu.sg/staff/000731pehkonen.html

1992	2002

Ph.D. Thesis: Redox Chemistry of Iron in Multiphasic Atmospheres

S. O. Pehkonen, R. L. Siefert, and M. R. Hoffmann, "Photoreduction of Iron Oxyhydroxides and Photooxidation of Halogenated Acetic Acids: Implications for Tropospheric Chemistry," Environ. Sci. Technol., 29, 1215-1222 (1995)

Mercury Chemistry in the Atmosphere

Fate of Organophosphorus Pesticide in Aquatic Environments

Copper Corrosion Kinetics in Water Distribution Systems

Associate Professor of Environmental Chemistry

Division of Engineering and Applied Science

Harvard University

Cambridge, MA

smartin@deas.harvard.edu

http://people.deas.harvard.edu/~smartin/

1992	2003

 Ph.D. California Institute of Technology, 1996

Ph.D. Thesis: Photocatalyzed Destruction of Chlorinated Hydrocarbons

S. T. Martin, H. Herrmann, W. Choi and M. R. Hoffmann, "Time-Resolved Microwave Conductivity (TRMC) 1. TiO₂ Photoactivity and Size Quantization," J.Chem. Soc. Faraday Trans., 90, 3315-3322 (1994)

Professor Martin’s research group is involved in a range of projects concerned with understanding and quantifying the chemistry of surfaces in environmental chemical systems. The projects have a unifying theme of: What controls the formation and reactivity of a surface? The rates of new surface formation depend on many molecular and cooperative factors, which jointly and separately influence homogeneous and heterogeneous nucleation. At a microscopic level, surfaces have significant topography, including terraces, ledges, kinks, and other defects. These locations are usually of higher energy and thus have greater reactivity.

Inez Hua (Ph.D. 1996)

Associate Professor of Environmental Engineering,

School of Civil Engineering

Purdue University

hua@ecn.purdue.edu

Ph.D. California Institute of Technology, 1996

Ph.D. Thesis: Aqueous-Phase Sonochemical Degradation of Hazardous Chemicals

Water treatment, fate and transport of chemical contaminants, inorganic and organic environmental chemistry, and groundwater and soil remediation

Wonyong Choi (Ph.D. 1996)

Assistant Professor of Environmental Engineering

Pohang Institute of Science and Technology (Postech), Pohang, Korea

Ph.D. Thesis: Photooxidative and Photoreductive Degradation of Chlorinated Hydrocarbons on Aqueous Titanium Dioxide Colloids

Choi W. Y., Termin A., and Hoffmann M. R. (1994) The Role of Metal-Ion Dopants in Quantum-Sized TiO₂ - Correlation between Photoreactivity And Charge-Carrier Recombination Dynamics. Journal of Physical Chemistry 98, 13669-13679.

Advanced Oxidation Processes (AOPs) for Destructing Pollutants

Environmental Applications of Semiconductor Photocatalysis

Environmental Chemistry, Environmental Photochemistry

Atmospheric Chemistry

Assistant Professor of Atmospheric Chemistry

University of Maryland

http://www.cbl.umces.edu/~siefert/

Ph.D. Thesis: Speciation of Fe in Ambient Aerosol and Cloudwater

R. L. Siefert, S. O. Pehkonen, Y. Erel and M. R. Hoffmann "Photoproduction of H₂O₂ in Aqueous Suspensions of Ambient Aerosol in the Presence of Oxalate" Geochem. Cosmochim. Acta, 58, 3271-3279 (1994)

Professor Siefert's research interests include atmospheric and aquatic chemistry. Specifically, Professor Siefert is interested in the chemical processing of atmospheric aerosols and their role as a source of chemical species (e.g., nutrients) to remote and coastal surface waters. Understanding these atmospheric sources is important since they can control major biogeochemical cycles.

Assistant Professor of Chemistry

Pomona College

Pomona, CA

Ph.D. California Institute of Technology, 1996

Ph.D. Thesis: Fundamental Photoelectrochemical Properties of TiO₂/Water Interfaces: Relevance for Hazardous Waste Remediation

J. M. Kesselman, O. Weres, N. S. Lewis and M. R. Hoffmann, "Electrochemical Production of Hydroxyl Radical at Polycrystalline Nb-doped TiO₂ Electrodes and Estimation of the Partitioning between Hydroxyl Radical and Direct Hole Oxidation Pathways," J. Phys. Chem., 101, 2637-2643 (1997)

Associate Professor of Environmental Engineering

Department of Civil and Environmental Engineering

Ohio State University

Columbus, OH

1994	2002

http://www.ceegs.ohio-state.edu/~lweavers/index.htm

weavers.l@osu.edu

Ph.D. California Institute of Technology, 1997

Ph.D. Thesis Title: Advanced Oxidation Technologies for Water Treatment

Professor Weavers’ group research is multi-pronged with projects in the area of advanced oxidation processes (AOPs), organic contaminants contained on flue gas desulfurization by-product (FGD), and defouling of membranes for water treatment. All of these research areas are related in that they investigate the transformation of organic pollutants. An overarching goal of our research is to understand how the processes work on a fundamental level to determine how to optimize the processes for real world use.

Joon-Wun Kang (PD 1997-1998)

Associate Professor

Department of Environmental Engineering

Yonsei University

Wonju, South Korea

2003

jwkang@dragon.yonsei.ac.kr

J. W. Kang, H. M. Hung, A. Lin and M. R. Hoffmann, "The Sonolytic Destruction of Methyl Tertiary Butyl Ether (MTBE) by Ultrasonic Irradiation: Effects of Ozone and Frequency, Environ. Sci. Technol., 33, 3199-3205 (1999)

Assistant Professor of Environmental Chemistry & Analytical Chemistry

Department of Chemistry

Central Washington University

http://www.cwu.edu/~chem/faculty/johansen/

johansea@cwu.edu

Ph.D. Thesis Title: Aerosol Chemistry over Remote Oceanic Regions

A. M. Johansen, R. L. Siefert and M. R. Hoffmann, "Chemical Composition of Aerosols Collected over the Tropical North Atlantic Ocean," J. Geophys. Res., 105, 15277-15312 (2000)

Professor Johansen studies the transformations of trace metals over remote areas of the open ocean. Continental dust is subjected to in-cloud processing, similar to weathering of rocks, whereby trace elements are released into the aqueous phase of the particle. Speciation of these elements, especially that of iron, may determine the selective uptake by marine organisms which in turn play an important role in the biogeochemical cycling of major elements. Although trace metals are present at low concentrations in the atmosphere, due to rapid redox cycling in solution, e.g. of Cu and Fe, they can contribute significantly to the flow of electrons. I am interested in identifying fundamental compositions and reaction mechanisms important in aerosol chemistry that involve trace metals. My approach is based on the interpretation and modeling of reliable field and laboratory observations. In addition, the other inorganic and organic constituents of aerosols also undergo important redox reactions with trace metals and serve to further understand the history and origin of aerosol particles.

Hui-Ming Hung (Ph.D. 2000)

Research Associate in Environmental Chemistry

Harvard University

hmhung@deas.harvard.edu

1996	2003

http://www.deas.harvard.edu/environmental-chemistry/hmhung.htm

Ph.D. California Institute of Technology, 2000

Ph.D. Thesis Title: Sonochemistry: Mechanisms and Applications

Hung H. M. and Hoffmann M. R. (1999) Kinetics and mechanism of the sonolytic degradation of chlorinated hydrocarbons: Frequency effects. Journal of Physical Chemistry A 103(15), 2734-2739.

Aerosol Phase Transitions and Atmospheric Nanoparticles

Assistant Faculty

Oak Crest Institute of Science

Pasadena, CA

Visiting Associate

Caltech

(Environmental Science and Engineering)

j.moss@oak-crest.org

http://www.its.caltech.edu/~jmoss

http://www.oak-crest.org

Szczepankiewicz S. H., Moss J. A., and Hoffmann M. R. (2002) Electron traps and the Stark effect on hydroxylated titania photocatalysts. Journal of Physical Chemistry B 106, 7654-7658.

Steven Szczepankiewicz (Ph.D. 2001)
Assistant Professor of Chemistry

Department of Chemistry and Biochemistry

Canisius College

Buffalo, NY

http://www2.canisius.edu/~szczepas/

Ph.D. California Institute of Technology, 2001

Ph.D. Thesis Title: Surface Chemistry of TiO₂ Photocatalysts

Szczepankiewicz S. H., Moss J. A., and Hoffmann M. R. (2002) Slow surface charge trapping kinetics on irradiated TiO₂. Journal of Physical Chemistry B 106, 2922-2927.

Research Associate

Department of Chemistry

University of California, Irvine

Irvine CA

1996	2003

Ph.D. California Institute of Technology, 2001

Ph.D. Thesis Title: Photochemical Transformations in Ice

Dubowski Y., Colussi A. J., Boxe C., and Hoffmann M. R. (2002) Monotonic increase of nitrite yields in the photolysis of nitrate in ice and water between 238 and 294 K. Journal of Physical Chemistry A 106, 6967-6971.

Greg Roberts (Ph.D. 2001)

Post-doctoral Fellow

Center for Atmospheric Science

UCSD – Scripps

Caltech Mainz UCSD

greg@borneo.ucsd.edu

Ph.D. California Institute of Technology, 2001

Ph.D. Thesis Title: Cloud Condensation Nuclei in the Amazon Basin

Current Research Interests:

Aerosol-Cloud interactions, CCM instrument development and Unmanned aircraft platforms

Weng-Ki Ching (Ph.D. 2001)

Research Scientist

Ambiocare

Pasadena, CA

2000	2003

  Ph.D. California Institute of Technology, 2001

Ph.D. Thesis Title: Disinfection by Pulsed Power Discharges

Ching W. K., Colussi A. J., Sun H. J., Nealson K. H., and Hoffmann M. R. (2001) Escherichia coli disinfection by electrohydraulic discharges. Environmental Science & Technology 35, 4139-4144.

Hugo Destaillats (PD 1998 – 2001)

Lawrence Berkeley National Laboratory

Indoor Environment Department

Berkeley, CA

HDestaillats@lbl.gov

Associate specialist at the Institute for Environmental Science and Engineering, University of California - Berkeley

Berkeley, CA

Destaillats H., Hung H. M., and Hoffmann M. R. (2000) Degradation of alkylphenol ethoxylate surfactants in water with ultrasonic irradiation. Environmental Science & Technology 34, 311-317.

Scott D. Boyce (PD 1981-1983)

Research Chemist

Rohm & Haas, Co.

Philiadelphia, PA

SBoyce@rohmhaas.com

Boyce S. D., Hoffmann M. R., Hong P. A., and Moberly L. M. (1983) Catalysis of the Autoxidation of Aquated Sulfur-Dioxide by Homogeneous Metal Phthalocyanine Complexes. Environmental Science & Technology 17, 602-611.

James V. McArdle (PD 1981-1983)
Vice President

Analytical Development and Quality Control

Isis Pharmaceuticals

Carlsbad, CA

1982	2003

jmcardle@isisph.com

www.isip.com

Dr. McArdle is Vice President, Analytical Development and Quality Control for Isis Pharmaceuticals. He began his industrial career in the pharmaceutical industry at SmithKline Beecham in 1983. He spent 16 years at SmithKline, including four years at SmithKline’s Tonbridge, England, chemical development site. He eventually had worldwide responsibility for analytical development within the chemical development area at SmithKline. Dr. McArdle joined Isis Pharmaceuticals in August of 1999, and now is contributing to the analytical development of antisense therapeutics. 

Key Paper from Caltech Days:

McArdle J. V. and Hoffmann M. R. (1983) Kinetics and Mechanism of the Oxidation of Aquated Sulfur Dioxide by Hydrogen-Peroxide at Low pH. Journal of Physical Chemistry 87, 5425-5429.

Jed M. Waldman (Ph.D. 1986)

Formerly - Associate Professor

UMDNJ-Robert Wood Johnson Medical School

Department of Community and Environmental Health

Present Position: Chief, Indoor Air Quality Section

California Department of Health Services,

Environmental Health Laboratory Branch

Berkeley, CA

http://www.cal-iaq.org/CV/CV_waldman.htm

Ph.D. California Institute of Technology, 1986

Ph.D. Thesis Title: Depositional Aspects of Pollutant Behavior in Fog

J. M. Waldman, J. W. Munger, D. J. Jacob, R. C. Flagan, J. J. Morgan and M. R. Hoffmann "The Chemical Composition of Acid Fog" Science 218, 677-680 (1982).

Bruce Daube (Research Engineer 1985-1990)

NOAA

Climate Monitoring & Diagnostics Laboratory
Halocarbons & other Atmospheric Trace Species
325 Broadway R/CMDL1
Boulder, CO

1986	1988

http://www.cmdl.noaa.gov/hats/

B. C. Daube, Jr., R. C. Flagan, and M. R. Hoffmann (1987) "Active Cloudwater Collector," United States Patent, Patent Number: 4,697,462; Date: Oct. 6, 1987

Staff Engineer

Environ

San Francisco

Ph.D. California Institute of Technology, 1987

Ph.D. Thesis Title: Co-phthalocyanine Catalyzed Autoxidation of Mercaptans

Leung P. S. K. and Hoffmann M. R., "Kinetics and Mechanism of Autoxidation of 2-Mercaptoethanol Catalyzed by Cobalt(II)-4,4',4'',4'''-Tetrasulfophthalocyanine in Aqueous-Solution," Environmental Science & Technology 22, 275-282 (1988).

Alicia C. Gonzalez (PD 1987-1988)

Analytical Chemist

Metropolitan Water District of Southern California

La Verne, CA

Research Chemist

BASF

Ludwigshafen, Germany

Claudius.Kormann@t-online.de

http://home.t-online.de/home/Claudius.Kormann/index.htm

Ph.D. Thesis Title: Syntheses and Characterization of Quantum Size Metal Oxide Colloid Particles - Photocatalytic Peroxide Production on ZnO and TiO₂

Kormann C., Bahnemann D. W., and Hoffmann M. R. (1988) Preparation and Characterization of Quantum-Size Titanium- Dioxide. Journal of Physical Chemistry 92, 5196-5201.

Colloid Chemistry, Synthesis of Nanoparticulates, Nanotechnology

Andreas Termin (PD 1990 – 1992)

DuPont Pharmaceuticals Research Laboratories

Chemical and Physical Sciences Research & Development

4570 Executive Drive

San Diego, CA

1982

A. Termin, M. R. Hoffmann and R. J. Bing, "A Simplified Method for the Determination of Nitric Oxide (NO) in Biological Solutions," Life Sci., 51, 1621 -1629 (1992)

Amy Hoffman (Ph.D. 1993)

Staff Environmental Chemist

Dames & Moore

Sacramento, CA

1994

Ph.D. California Institute of Technology, 1993

Ph.D. Thesis Title: Photocatalytic Reactions on Quantum-Sized Metal Oxide Colloids

Hoffman A. J., Carraway E. R., and Hoffmann M. R. "Photocatalytic Production of H₂O₂ and Organic Peroxides on Quantum-Sized Semiconductor Colloids," Environmental Science & Technology 28, 776-785 (1994).

Dean Willberg (Ph.D. 1994; PD 1994 -1996)

Moscow, Russia

1994	2003

Ph.D. California Institute of Technology, 2001

Ph.D. Thesis Title: Picosecond Spectroscopy of van der Waals Clusters

D. M. Willberg, P. S. Lang, R. H. Höchemer, A. Kratel and M. R. Hoffmann, "Degradation of 4-chlorophenol and 2,4-dichloroaniline in an Electrohydraulic Discharge Reactor," Environ. Sci. Technol. 30, 2526-2534 (1996)

Axel Kratel (Ph.D. 1996)

Product Manager Borland

Axel Kratel is a senior product manager for Borland's Java^TM technology-based solutions. He sets the direction for Borland's Java technology-based products and solutions. Kratel has extensive experience in enterprise development and has participated in development projects using both formal and XP methodologies. He has held previous positions at SAP and PeopleSoft.

Ph.D. California Institute of Technology, 1996

Ph.D. Thesis Title: Pulsed Power Discharges in Water

Research Engineer

Environmental Technology Division

Aventis Research & Development

Frankfurt, Germany

1994	2004

Ph.D. California Institute of Technology, 1996

Ph.D. Thesis Title: Degradation of Organic Compounds by Acoustic Cavitation and Pulsed-Power Discharges

I. Hua, R. H. Höchemer and M. R. Hoffmann, "The Sonochemical Degradation of p-nitrophenol in a Parallel-Plate Near-field Acoustical Processor," Environ. Sci. Technol., 29, 2790-2796 (1995)

Nicole Peill (Ph.D. 1996)

EdgeComputing Specialist

Akamai

Carson, CA

Ph.D. California Institute of Technology, 1986

Ph.D. Thesis Title: Fiber-Optic Bundled Array Cable Reactors for Heterogeneous Photocatalysis and Waste Stream Remediation

Key Paper from Caltech Days:

N. J. Peill and M. R. Hoffmann, "Chemical and Physical Characterization of a TiO2-Coated Fiber Optic Cable Reactor," Environ. Sci. Technol., 30, 2806-2812 (1996)

Articulate the business value, technical details and superiority of Akamai's services to prospective clients at the executive and director levels, as well as build and maintain client relationships. Responsibilities include: developing business and technical requirements, managing trials, managing regional technical team, communicating product development requirements to the appropriate internal teams, authoring technical documents and proposals, generating ROI analyses, and deflecting competitive threats.

Staff Engineer

Ralph M. Parsons, Inc.

Pasadena, CA

1996

Jeff.Noelte@parsons.com

Ph.D. California Institute of Technology, 2002

Ph.D. Thesis Title: Effects of Surface Chemistry on Deposition Kinetics of Colloidal Hematite (a -Fe₂O₃) in Packed Beds of Silica Sand

Catherine Cornu (Ph.D. 2002)

Health Council
Federal Public Service of Health, Food Chain Safety and Environment
Brussels, Belgium

catherine.cornu@health.fgov.be

http://www.health.fgov.be/CSH_HGR

1998	2002

Ph.D. California Institute of Technology, 2002

Ph.D. Thesis Title: Photocatalysis under Periodic Illumination

Cornu C. J. G., Colussi A. J., and Hoffmann M. R. (2003) Time scales and pH dependences of the redox processes determining the photocatalytic efficiency of TiO₂ nanoparticles from periodic illumination experiments in the stochastic regime. Journal of Physical Chemistry B 107, 3156-3160.

Brian Lim (1979)

Eric Yost (1980)

Kim Lapakko (1980)

Dan Moran (1980)

Neil E. Carriker (PD1977-1979)

Walter S. Combs, Jr. (PD 1976-1977)

Tom Holm (PD 1978-1980)

Environmental Services Manager

North America ASC-EHS Department

H.B. Fuller Company

brian.lim@hbfuller.com

Hoffmann M. R. and Lim B. C. (1979) Kinetics and Mechanism of the Oxidation of Sulfide by Oxygen - Catalysis by Homogeneous Metal-Phthalocyanine Complexes. Environmental Science & Technology 13, 1406-1414.

Eric Yost (1980)

Corporate Environmental Engineer

Hutchinson Technology Incorporated

Hutchinson, MN

eric.yost@hti.htch.com

Hoffmann M. R., Yost E. C., Eisenreich S. J., and Maier W. J. (1981) Characterization of Soluble and Colloidal-Phase Metal-Complexes in River Water by Ultrafiltration - a Mass-Balance Approach. Environmental Science & Technology 15, 655-661.

Kim Lapakko (1980)

Principal Engineer

Minnesota Department of Natural Resources

St. Paul, MN

kim.lapakko@dnr.state.mn.us

Dan Moran (1980) - deceased

Energy Analyst

Wisconsin Energy Bureau

Madison, WI

MORAND@mail.state.wi.us

Thesis: Residential Solar Heating in Minnesota

Neil E. Carriker (PD 1977-1979)

Water Quality Manager

Water Management Division

Tennessee Valley Authority

Clean Water Initiative

Chattanooga, TN

Walter S. Combs, Jr. (PD 1976-1977)

Executive Director of Health
Environmental Health

Rhode Island Department of Health
Providence, RI

2003

waltc@doh.state.ri.us

Tom Holm (PD 1978-1980)

Illinois State Water Survey
Champaign, IL

tomholm@sws.uiuc.edu 

Ph.D. California Institute of Technology, 1978

Ph.D. Thesis Title: Trace Metals in Fresh Water Plankton

Trace Metals Chemistry, Arsenic in Ground-water, Polyphosphate Chemistry