News & Events

Environmental Engineering seminar: Novel materials for a sustainable water supply: Surface chemistry

Wednesday, February 21, 2018, 9:00AM - 10:00AM

Speaker

Jessica Ray

Postdoctoral Research Fellow, UC Berkeley

Location:

SEEC room N128

4001 Discovery Drive, Boulder

Abstract

Global water demands continue to rise in response to population growth and urbanization, and stresses on freshwater supply by global climate change. As a result, water-strained regions are being forced to consider water reuse applications, shifting the current urban water supply paradigm towards more sustainable practices. Unfortunately, such obstacles as failing water treatment infrastructure, the presence of toxic contaminants, and decreased recharge of water resources jeopardize human and environmental health and pose challenges to the realization of wastewater reclamation strategies. New technologies and approaches are needed to address these challenges.

In this talk, I will highlight three studies employing analytical surface chemistry techniques and novel materials to: (1) improve water treatment efficiency, (2) help predict contaminant fate and transport, and (3) selectively remove pollutants from contaminated waters. First, I developed multifunctional membrane composites designed to increase reverse osmosis membrane lifetime and reduce mineral scaling, organic and biological fouling. By amending the membrane surface with bactericidal nanoparticles and polymers, the membrane surface effectively eliminated all classes of fouling without additional chemical or thermal treatment. The membrane composite was characterized and tested for fouling resistance, water flux, and rejection using a benchtop reverse osmosis system. Second, I investigated iron hydroxide particle formation on mineral and organic-coated substrates using a synchrotron-based X-ray scattering in situ monitoring technique. Iron hydroxides form in natural and engineered aqueous systems and act as adsorbents for geochemical cycling of trace metal contaminants. The iron hydroxide and substrate physicochemical properties were characterized to gain a fundamental understanding of mechanisms directing nucleation which can be used to predict contaminant mobility. Finally, I synthesized and characterized organoclay composites as engineered geomedia to passively treat urban runoff in stormwater infiltration systems. These systems are designed to promote groundwater recharge in urban areas. A suite of fifteen representative urban runoff trace metal and trace organic contaminants were used to assess the composite adsorptive capacity as a function of natural organic matter content. Column studies were also performed to determine the lifetime of the engineered geomedia under complex, simulated stormwater conditions.

By combining thorough surface chemistry analysis with employment of novel materials and techniques, we can help advance water treatment technologies and provide new insights into contaminant fate and transport in efforts to mitigate global water shortages and produce clean drinking water.

Bio

Dr. Jessica Ray is currently a Miller Institute postdoctoral fellow at the University of California, Berkeley in the Department of Civil and Environmental Engineering. She received her B.S. (Department of Chemical Engineering, 2009) and Ph.D. (Department of Energy, Environmental and Chemical Engineering, 2015) from Washington University in St. Louis. As a graduate student, Dr. Ray’s research interests included nanomaterial fate and transport, employing advanced surface chemistry analytical techniques for which she received the Environmental Protection Agency Students to Achieve Results (STAR) Fellowship to support her research. As a member of the Miller Institute and the Reinventing the Nation’s Urban Water Infrastructure (ReNUWIt) Engineering Research Center, Dr. Ray develops low-cost engineered geomedia to treat urban stormwater during aquifer recharge as well as selective adsorption of perfluorinated compounds in contaminated waters.

Directions

See directions: http://www.colorado.edu/even/current-students/graduate-studies/seminar-series