Chemical and Biological Engineering

Kimberly A. Gray

Professor of Civil and Environmental Engineering and (by courtesy) Chemical and Biological Engineering

Education

Ph.D. Geography and Environmental Engineering, Johns Hopkins University, Baltimore, MD

M.S. Civil Engineering, University of Miami, Coral Gables, FL

B.A. Biology, minor in Biochemistry, Northwestern University, Evanston, IL

Research Interests

Our work on environmental process deals with the general study of contaminant fate in aquatic systems. Specifically, we use the analytical technique of pyrolysis/GC/MS to trace the removal or transformation of organic compounds in systems such as drinking water treatment, surface waters, or wetlands. We are particularly interested in understanding the coupled effects of organic and metal contaminants in treatment or natural processes.

In the area of radiation-induced catalysis, our work is focused on understanding how radiant energy is converted to chemical energy to drive the degradation of pollutants in complicated mixtures. We study photocatalytic reactions on titanium dioxide by using novel analytical techniques to improve our mechanistic understanding of the process. We also study the radiolytic destruction of contaminants in soils and on oxide surfaces.

Our ecotoxicological research involves the study of PCB dynamics in stream sediments. We are investigating the effects associated with PCBs strong partitioning in biological organisms on ecological structure.

In the area of environmental remediation, we are working on the remediation of a number of highly contaminated brownfield sites on the Southeast side of Chicago.

Selected Publications

1. P. Desario , L. Chen, M.E. Graham, K.A. Gray (2011) “The effect of oxygen deficiency on the photoresponse and reactivity of titania thin films,” JVST A, in press.
2. K.A.Gray (2011). “Five Myths about Nanotechnology in the Current Public Policy Debate: A science and engineering perspective,” in The Nanotechnology Challenge: Creating Legal Institutions for Uncertain Risks (David Dana, editor, Cambridge Press), Sept. 2011, in press.
3. N.M. Dimitrijevic, B. Vijayan, O.G. Poluektov, T. Rajh, K.A. Gray, H. He; P. Zapol, Peter (2011) “Role of Water and Carbonates in the Photocatalytic Transformation of CO₂ to CH₄ on Titania,” JACS, 133:3964-3971.
4. P.A. DeSario, R.M. Gelfand, M.E. Graham, K.A. Gray. (2011) “The effect of Nb substitution on synthesisand photo-response of TiO₂ thin films prepared via reactive magnetron sputtering.” Thin Solid Films, 519:11:3562-356.
5. M. Lindsey, J.L. Schofer, P. Durango-Cohen, K.A. Gray (2011) “The Effect of Residential Location on Vehicle Miles of Travel, Energy Consumption and Greenhouse Gas Emissions: Chicago Case Study,” Transportation Research, Part D, 16:19.
6. B. Vijayan, N.M. Dimitrijevic, J. Wu, K.A. Gray (2010) “The effects of Pt-doping on the structure and visiblelight photoactivity of titania nanotubes,” Jour. Phys. Chem. C, 114, 2126221269.
7. C. Ng, K.A. Gray (2011) “Forecasting the effects of global change scenarios on bioaccumulation patterns in Great Lakes Species,” Global Change Biology, 17, 720-733.
8. M. Lindsey, J.L. Schofer, P. Durango-Cohen, K.A. Gray (2010) “Relationship between Proximity to Transit and Ridership for Journey-to-Work Trips in Chicago,” Transportation Research, Part A, 44:697709 (doi:10.1016/j.tra.2010.07.003).
9. B. Vijayan, N. Dimitrijevic, T. Rajh, K.A. Gray. (2010) “Effect of calcination temperature on photocatalytic reduction and oxidation of hydrothermally synthesized titania nanotube,” Jour. Phys. Chem. C, 14:30:1299413002.
10. K. Schulte, P. Desario, K.A. Gray. (2010) “Effect of Crystal Phase Composition on the Reductive and Oxidative Abilities of TiO₂ Nanotubes under UV and Visible Light,” Applied Catalysis B, 97:3-4:354-360.
11. S. Ciston, R.M. Lueptow, K.A. Gray (2009) “Control of Biofilm Growth on Reactive Ceramic Ultrafiltration Membranes,” Journal of Membrane Science, 342, 263-268.
12. L. Chen, M.E. Graham, K.A. Gray (2009) “Nitrogen stabilized reactive sputtering of optimized TiO_2-x photocatalysts with visible light reactivity,” Journal Vacuum Science & Technology, 27(4):712-715.
13. C. Ng, K.A. Gray (2009) “Tracking bioaccumulation in aquatic organisms: A dynamic model integrating life history characteristics and environmental change,” Ecological Modeling, 220, 12661273.
14. L. Chen, M.E. Graham, G. Li, D. Gentner, K.A. Gray (2009) “Photoreduction of CO₂ by TiO₂ Nanocomposties Synthesized through Reactive DC Magnetron Sputter Deposition,” Thin Solid Films, 517:56415645.
15. G. Li, N.M. Dimigtrijevic, L. Chen, T. Rajh, K.A. Gray (2008). “Photoactive CuO-TiO₂ Nanocomposites Prepared by a Chemical Method,” Jour. Phys. Chem. C, 112, 1904019044.
16. Y. Yao, G. Li, K.A. Gray, R.M. Lueptow (2008) “Single-walled Carbon Nanotube Facilitated Dispersion of Particulate TiO₂ on ZrO₂ Ceramic Membranes,” Langmuir, 24:7072-7075.
17. C.A. Ng, M.B. Berg, D.J. Jude, J. Janssen, P.M. Charlebois, L.A.N. Amaral, K.A. Gray. (2008) “Chemical amplification in an invaded food web: Seasonality and ontogeny in a high biomass, low diversity ecosystem.” Environmental Toxicology and Chemistry, 27:145-154.
18. Y. Yao, G. Li, R.M. Lueptow, K.A. Gray, (2008) “Photoactive TiO₂-Carbon Nanotube Composites: Synthesis and Environmental Application,” Environ. Sci. Techonol., 42:4952-4957.
19. G. Li, N.M. Dimitrijevic, L. Chen, J.M. Nichols, T. Rajh, K.A. Gray (2008) “The Important Role of Tetrahedral Ti⁴⁺ Sites in the Phase Transformation and Photocatalytic Activity of TiO₂ Nanocomposites,” JACS, 130:5402-5403.
20. S. Ciston, R. Lueptow, K.A. Gray, (2008) “Biofilm Attachment Studies on Reactive Ceramic Ultrafiltration Membranes,” Journal of Membrane Science, 320:101-107.
21. G. Li, S.M. Ciston, Z.V. Saponjic, Le Chen, N. Dimitrijevic, T. Rajh, K.A. Gray (2008). “Synthesizing mixed-phase TiO₂ using a hydrothermal method for photo-oxidation and photo-reduction applications,” Journal of Catalysis, 253:105-110.
22. C.K. Ishida, S. Arnon, C. Peterson, J.J. Kelly, K.A. Gray, (2008) “The influence of algal community structure on denitrification rates in periphyton cultivated on artificial substrates,” Microbial Ecology, 56:140-152.

Patents

Photocatalytic Composite (TiO₂/SWCNT) for Organic Chemical Oxidation (provisional patent application NU 27068, filed), Y. Yao, R. Lueptow, K.A. Gray.

Mixed-phase nano-structured TiO₂ composite photocatalyst for energy and energy efficiency applications, (provisional patent application NU 27093 ) G. Li & K.A. Gray.

Reactively sputtered TiO₂ nanocomposite thin films for photoreduction and photooxidation applications under UV and visible light, (provisional patent application NU 28134, filed) L. Chen, M. Graham, K.A. Gray