Grad Students


The Environmental Engineering faculty have a wide range of research interests, and are always seeking well-qualified graduate students to participate on research projects. Please feel free to contact individual faculty members to learn more about their research.


Daven Henze group's research focuses on the role that atmospheric constituents such as ozone, nitrogen oxides (NOx) and particulate matter (aerosols) play in local air quality, long range pollution transport, and climate change. Numerical models of chemical and physical processes in the atmosphere provide valuable estimates of the sources and fates of these species. In addition, space-born measurements and coordinated field campaigns provide an unprecedented wealth of observations related to the chemical state of the atmosphere. A large part of our research stems from chemical data assimilation, the process by which both models and observations are combined to produce estimates of the atmospheric state that are often more complete than those provided by either approach alone. These estimates are used in applications from constraining emissions to optimizing energy system models to achieve specific air quality and climate objectives. This encompasses more specific interests in remote sensing, adjoint sensitivity analysis, inverse problems, and source apportionment.

Z. Jason Ren is leading several projects to recover bioenergy (electricity, H2, biogas, liquid fuels) and resources (fresh water, value-added chemicals) from wastewater, produced water, and other municipal and industrial waste streams. These projects were supported by NSF, ONR, Gates Foundation, and several private sponsors. The goal was to expand environmental engineering from pollution clean-up to sustainable development of energy and environmental systems. More details can be found here.

JoAnn Silverstein has ongoing projects on biological treatment and recovery of nitrogen and phosphorus in water supplies and wastewater. She recently began research on modeling wastewater treatment reliability and resilience as part of the new EPA-funded Center for Comprehensive Optimal and Effective Abatement of Nutrients (CLEAN) using both mass balance based and statistical modeling methods to evaluate the sustainability of centralized, decentralized and on-site treatment systems. Recently she has been involved in the planning, selection and performance evaluation of a new indoor gray water reuse system in a 500-resident dormitory on the Boulder Campus.

Joseph Ryan, the Bennett-Lindstedt Faculty Fellow, and his research group are conducting several projects examining the fate and transport of organic and inorganic contaminants in ground water and surface waters. These projects include studies of the effect of wild fire on the release of mercury from forest soils sponsored by the National Science Foundation (NSF), of the role of mineral and organic particles in the transport of radioactive elements through fractured soils sponsored by the Department of Energy (DOE), of the effect of flooding on the release of mercury from flood plain sediments sponsored by the DOE, an analysis of the release of trace elements from coal ash sponsored by the Tennessee Valley Authority. Ryan is also leading the AirWaterGas Sustainability Research Network sponsored by the NSF, a multi-institution team investigating the environmental effects of oil and gas development in the Rocky Mountain region. More information is available at Prof. Ryan’s webpage and

R. Scott Summers, along with Fernando Rosario-Ortiz and Karl Linden, is active in the development of effective treatment technologies for the production of safe water. Activated carbon adsorption is being assessed for application to a wide range of organic contaminants, such as volatile organic contaminants, those found in the waste discharges of industry, agriculture and municipalities, and naturally occurring organic matter that causes taste and odor issues at parts per trillion levels, as well as reacting to disinfection byproducts (DBPs). In addition, new adsorbents, such a chars, are being developed from indigenously sourced biomass feedstocks. Many of these organic contaminants have been found to be biodegradable under secondary utilization scenarios and new approaches to optimize their removal under drinking water conditions are being developed. Bioprocesses are also being evaluated as pretreatment processes prior to coagulation, adsorption and membrane processes. In our labs we found fluorescence spectroscopy to be a valuable tool in understanding and monitoring of organic matter as it is impacted by coagulation and adsorption and as it reacts to form DBPs. These treatment processes are being evaluated under water quality perturbations caused by climate change, wildfires, floods and deforestation.

Angela Bielefeldt is leading several research projects to improve the education and success of engineering students. These include explorations of service-learning, sustainable engineering, global awareness, ethics, and social responsibility. Student-centered, active learning methods including project based learning and undergraduate research are being explored as effective methods to increase the interest, learning, and retention of engineering students. These projects are collaborative efforts with individuals at institutions around the nation and have been supported by the NSF.

Fernando L. Rosario-Ortiz and his research group specialize in the area of characterization of organic matter, environmental photochemistry and impact of watershed perturbations on water quality and treatability. Ongoing projects include the evaluation of the effects of forest fires on water quality. As part of this project, the water quality of a watershed impacted by a fire has been studied, including evaluating the impact of the fire on water treatment. In addition, the environmental photochemistry of organic matter is studied, including the determination of quantum yields for the formation of different photo-produced intermediates and the impacts of halides and composition of the organic matter. For more information, see Dr. Rosario’s website.

Mark Hernandez is leading research to determine the biological quality of the air we breathe when impacted by natural and man-made disasters. This research employs a suite of modern optical, genetic and toxicological tools to determine the distribution, abundance, activity and identity of biogenic agents suspended in air – both indoors and out. In cooperation with several industrial sponsors and the National Science Foundation, research teams from this forensic environmental microbiology laboratory have monitored the aerobiological quality of air in the quarantined city of New Orleans following Hurricane Katrina, the oil impacted beaches following the Horizon oil spill, as well as numerous buildings following major metropolitan floods. Supported by the Department of Energy, this forensic laboratory also studies the causes and controls of microbially induced corrosion in our aging urban (waste)water infrastructure.

Lupita Montoya is leading several research projects to evaluate and control indoor air quality. One project is exploring the use of active flow control methods, like synthetic jets, for indoor air quality control. Another project is looking at the use of phytoremediation systems to sequester and control gaseous pollutants indoors. A multi-city study is also being conducted to characterize the indoor air quality in Chile, Peru and the US. Another area of research focuses on the study of toxic and immune effects of particular matter, including nanomaterials. These projects have been supported by NSF, NIH and an Innovation Seed grant from the University of Colorado.

Karl G. LindenScott Summers and Al Weimer (ChBE) are leading a large group of researchers at CU in Environmental and Chemical Engineering to develop a new sanitation solution for developing communities. The system is based on concentrated solar energy delivered to a reaction vessel via fiber optic cables. The delivered energy heats the fecal waste to charing temperatures to produce a biochar that can have value as a fuel source and soil amendment. Research advances in concentrated solar energy, energy transmission, biochar production and characterization, and waste stabilization are the focus. More details can be found here.

Marina Vance’s research is focused on better understanding people's exposure to emerging environmental contaminants from everyday activities, especially ultrafine aerosols and incidental or engineered nanomaterials. Her research motivation stems from the fact that inhalation exposure and long-term health effects of ultrafine aerosols (< 100 nm) are still poorly understood when compared to larger aerosols. Specific research areas in the Vance group include: Fate and transport of indoor and outdoor ultrafine aerosols; Measurements and empirical modeling of aerosols emitted by novel sources and consumer products; Characterization of environmental samples for incidental and engineered nanoparticles; Applications of nanotechnology for environmental sustainability.

Karl G. Linden holds a number of research projects on advanced water treatment with UV-based systems. Focus is on discovering the fundamentals of disinfection processes for pathogens such as adenoviruses, Cryptosporidium, and E. coli as well as studying the transformations of emerging chemical contaminants under photolysis and oxidation conditions, and their toxicological fate. More information can be found here.

Shelly Miller's research is focused on improving our understanding of urban air quality. She is motivated by the fact that air pollution causes adverse health effects, including illness and death and by reducing air pollutant exposure, health and well-being can be improved. A novel component of her work is a focus on the indoor environment, where people spend the majority of their time. Since tenure she has expanded her interests and research successes to include ambient air pollution in cities. She is one of the leading researchers on the use of control technologies, and specifically for reducing infectious disease transmission, including ultraviolet germicidal irradiation. She has also been a leader in investigating the influence that building characteristics have on indoor air quality including understanding housing conditions in lower socioeconomic neighborhoods and studying the microbiology in homes. She recently was awarded an US EPA STAR grant to conduct a major field effort to understand health impacts of home weatherization.