Environmental Chemistry Commons^™

Photochemistry Of Quinones And Combustion-Derived Particles, Desiree J. Sarmiento

Electronic Theses and Dissertations

Quinones are ubiquitous species that can be produced from the photochemical aging of combustion-derived particles (CDPs). Polycyclic aromatic hydrocarbons (PAHs) are a major component of CDPs and are precursors to quinones and other oxidized products (OPAHs). My work first expanded on the PAH and OPAH photochemistry research of Dr. John Haynes, who showed that anthracene (ANT) oxidizes into 1,4-naphthoquinone (1,4-NAPQ), 1,4-anthraquinone (1,4-ANTQ), and 9,10-anthraquinone (9,10-ANTQ), and of Dr. Heather Runberg, who demonstrated the ability of ANT and these quinones to generate reactive oxygen species (ROS). Then at the Pacific Northwest National Laboratory (PNNL), I was given the opportunity to investigate …

Evaluating The Efficiency Of Low-Cost Air Quality Sensors At A Suburban Field Site, Olivia Wuttke

Undergraduate Theses, Capstones, and Recitals

Science surrounding the use of low-cost sensors (LCS) to monitor air quality is rapidly expanding to satisfy the need to fill in regional air quality data gaps. This project evaluated the suitability of two types of LCS: Modulair-PM and PurpleAir (SD and Flex models) as efficient means to measure airborne particulate matter. The study involved physical installation of nine co-located sensors at a suburban site in Denver, connectivity troubleshooting as necessary, and data analysis/modeling of data over multiple months (19 weeks). PM data was compared between individual sensors of the same type, as well as across the two different sensor …

Data Set For "Atmospheric Aging Of Combustion-Derived Particles: Impact On Stable Free Radical Concentration And Its Ability To Produce Reactive Oxygen Species In Aqueous Media", Brian Majestic, Heather L. Runberg

Chemistry and Biochemistry: Data Sets

Environmentally persistent free radicals (EPFR) are an emerging pollutant found in soot particles. Understanding how these change as they move through the atmosphere is important to human health. Here, soot was generated in the laboratory and exposed to simulated sunlight. The concentrations and characteristics of EPFR in the soot was recorded. Additionally, formation of hydroxyl radical from the photoactivated soot was measured.

Measurements Of Atmospheric Radicals, Heather L. Runberg

Electronic Theses and Dissertations

Atmospheric particulate matter (PM) is a global health concern. PM_2.5 is formed primarily through combustion processes such as automobile use and industrial activity. Natural sources of PM_2.5 result from events like volcanos and wildfires. Upon inhalation, PM_2.5 is small enough to travel deep into the lungs where it can form reactive oxygen species (ROS), such as hydroxyl radical (OH), causing oxidative damage to pulmonary tissues. PM_2.5 has been linked to cardiopulmonary diseases such as asthma, chronic obstructive pulmonary disease (COPD), and high blood pressure.

PM_2.5 is small enough to remain aloft and travel many hundreds …

Iron Speciation In Pm2.5 From Urban, Agriculture, And Mixed Environments In Colorado, Usa, Joseph R. Salazar, David J. Pfotenhauer, Frank Leresche, Fernando L. Rosario-Ortiz, Michael P. Hannigan, Sirine C. Fakra, Brian Majestic

Chemistry and Biochemistry: Faculty Scholarship

Atmospheric iron solubility varies depending on whether the particles are collected in rural or urban areas, with urban areas showing increased iron solubility. In this study, we investigate if the iron species present in different environments affects its ultimate solubility. Field data are presented from the Platte River Air Pollution and Photochemistry Experiment (PRAPPE), aimed at understanding the interactions between organic carbon and trace elements in atmospheric particulate matter (PM). 24-hr PM2.5 samples were collected during the summer and winter (2016–2017), at three different sites on the Eastern Colorado plains: an urban, agricultural, and a mixed site. Downtown Denver had …

Trends In Heavy-Duty Diesel Emissions And Analyses Of Colorado's Light-Duty Vehicle Inspection And Maintenance Program, Brent G. Schuchmann

Electronic Theses and Dissertations

Emission trends are reported and discussed resulting from the multi-year study of Heavy-Duty Diesel Vehicles (HDDV) at the Port of Los Angeles and at a weigh station in Peralta also in the L.A. basin. Remote sensing data were also collected from the Port of Houston and compared to the data from California. As part of San Pedro Bay Ports Clean Air Action Plan (CAAP) to fast track the turnover rate of cleaner trucks, many truck operators have been subject to modifying their trucks, or have purchased new trucks, with more advanced control technologies to reduce exhaust particulate matter (PM) and …

Analysis And Treatment Of Emerging Polar Contaminants, Daniel E. Connors

Electronic Theses and Dissertations

Two major classes of polar compounds have recently become a major focus as sources of contamination of water systems. Pharmaceuticals and personal care products (PPCPs) enter water through wastewater streams, and many of these compounds survive current wastewater treatment processes. High production volume chemicals (HPVCs), defined as chemicals produced in excess of one million pounds per year have numerous entries into surface and drinking waters due to their ubiquity. The commonality between many of these compounds is their polarity, which makes them water-soluble.

While both PPCPs and HPVCs have been entering into the environment for decades, advances in analyte detection …

Development Of A High-Speed Ultraviolet Spectrometer, Capable Of Real-Time No And Aromatic Hydrocarbon Detection In Vehicle Exhaust (Presentation), Peter J. Popp, Gary A. Bishop, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

Paper presented at the 7th Coordinating Research Council On-Road Vehicle Emissions Workshop, San Diego, CA, April 9-11, 1997.

Epa Overestimates The Benefit Of Biennial Inspection And Maintenance, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

The United States Environmental Protection Agency (EPA) computer model of mobile source emissions is used to estimate the benefits of future emissions control programs. Four input assumptions are discussed, each of which tends to overestimate the benefits of biennial testing programs. The assumptions are: each model year drives the same number of miles; high/superemitters, absent initially, increase linearly with mileage; inspection and maintenance (I/M) readings are invariant, and I/M repairs last forever. States opting for these programs should be aware that the predicted benefits may not materialize.

Carbon Monoxide Amongst Other Chemicals (Presentation), Donald H. Stedman

Fuel Efficiency Automobile Test Publications

Paper presented at the Division of Environmental Chemistry, American Chemical Society National Meeting, New Orleans, LA, March 24-28,1996.

Remote Sensing: A Simpler Way To Reduce Air Pollution, Donald H. Stedman, Gary A. Bishop

Fuel Efficiency Automobile Test Publications

No abstract provided.

Vehicle Measurements For Co, Hc, And No In El Paso, Texas, And Juarez, Mexico, Donald H. Stedman, Yi Zhang, Jon M. Lesko

Fuel Efficiency Automobile Test Publications

No abstract provided.

Playing With Fire: Science And Politics Of Air Pollution From Cars, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

No abstract provided.

On-Road Remote Sensing Of Vehicle Emissions In Monterrey, N. L. Mexico, Gary A. Bishop, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

No abstract provided.

Tucson Intersection Study Of Automobile Emissions, Amber K. Hodgson, Yi Zhang, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

No abstract provided.

Automobile Emissions In Tulsa, Oklahoma, Donald H. Stedman, Peter J. Popp, Paul L. Guenther

Fuel Efficiency Automobile Test Publications

Final Report to the Indian Nations Council of Governments, Tulsa, Oklahoma, 1994

On-Road Carbon Monoxide And Hydrocarbon Remote Sensing In The Chicago Area In 1992, Donald H. Stedman, Yi Zhang, Gary A. Bishop, Stuart P. Beaton, Paul L. Guenther

Fuel Efficiency Automobile Test Publications

No abstract provided.

Determination Of Parameters Influencing The Vehicle Emissions In Greece Using A Remote Sensing System, Kostas Nikolaou, Donald H. Stedman, Stavros Papaioannou, Nikos Zoumakis, Apostolos Kelesis

Fuel Efficiency Automobile Test Publications

Paper presented at the 3rd International Symposium on  Transport and Air Pollution, Avignon, France, June 6-10, 1994.

On-Road Remote Sensing Of Co And Hc Emissions In California, Donald H. Stedman, Gary A. Bishop, Stuart P. Beaton, James E. Peterson, Paul L. Guenther, Iain F. Mcvey, Yi Zhang

Fuel Efficiency Automobile Test Publications

No abstract provided.

On-Road Nox Emissions Intercomparison Of On-Board Measurements And Remote Sensing, James W. Butler, Christine A. Gierczak, Gerald Jesion, Donald H. Stedman, Jon M. Lesko

Fuel Efficiency Automobile Test Publications

No abstract provided.

Remote Sensing Of Vehicle Emissions, Case Study: Thessaloniki, Greece (Presentation), Kostas Nikolaou, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

Presented at the 4th International Conference on Advances in Communication and Control, Rhodes Greece, June 14-18, 1993.

Provo Pollution Prevention Program, Donald H. Stedman, Gary A. Bishop, James E. Peterson, Theresa Hosick

Fuel Efficiency Automobile Test Publications

No abstract provided.

Remote Sensing Of On-Road Vehicle Emissions, Donald H. Stedman, Gary A. Bishop, Paul L. Guenther, James E. Peterson, Stuart P. Beaton, Iain F. Mcvey

Fuel Efficiency Automobile Test Publications

No abstract provided.

On-Road Remote Sensing Of Carbon Monoxide And Hydrocarbon Emissions During Several Vehicle Operating Conditions (Presentation), Lowell L. Ashbaugh, Douglas R. Lawson, Gary A. Bishop, Paul L. Guenther, Donald H. Stedman, Robert D. Stephens, Peter J. Groblicki, Jayendra S. Parikh, Brian J. Johnson, Steve C. Huang

Fuel Efficiency Automobile Test Publications

No abstract provided.

Melbourne Automobile Emissions Study, Donald H. Stedman, Yi Zhang

Fuel Efficiency Automobile Test Publications

No abstract provided.

Remote Sensing Enhanced Motor Vehicle Emissions Control For Pollution Reduction In The Chicago Metropolitan Area: Siting And Issue Analysis, Carol E. Lyons, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

No abstract provided.

On-Road Remote Sensing Of Co Emissions In The Los Angeles Basin, Donald H. Stedman, Gary A. Bishop, James E. Peterson, Paul L. Guenther

Fuel Efficiency Automobile Test Publications

Final report to the California Air Resources Board under Contract No. A932-189.

The University of Denver remote sensor for on-road motor vehicle carbon monoxide emissions was used for eleven days in the Los Angeles Basin in December, 1989. The remote sensor has been incorporated into the 1990 Clean Air Act Amendments as "on-road emissions testing". The device measures the CO/CO₂ ratio for one-half second behind each vehicle, from which the exhaust %CO is calculated. Vehicles were measured in a mix of many driving modes and speeds ranging from deceleration coming up to a red traffic light through idling in …

Automobile Pollution Is A Disease, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

Brief article printed on grocery bags (#27) by Food & Liquor Publications in Benicia, CA.

On-Road Carbon Monoxide And Hydrocarbon Remote Sensing In The Chicago Area, Donald H. Stedman, Gary A. Bishop, James E. Peterson, Paul L. Guenther, Iain F. Mcvey, Stuart P. Beaton

Fuel Efficiency Automobile Test Publications

No abstract provided.

Evaluation Of A Remote Sensor For Mobile Source Co Emissions, Donald H. Stedman, Gary A. Bishop, Marc Pitchford

Fuel Efficiency Automobile Test Publications

EPA Pub 600/4-90/032 (NTIS PB91148320)

Carbon monoxide (CO) emission measurements of thousands of vehicles per day are possible with a recently evaluated remote sensor developed at the University of Denver. Funded by the Environmental Monitoring Systems Laboratory - Las Vegas (EMSL- LV) Innovative Research Program, the evaluation has demonstrated the comparability of volume concentration measurements made by this method with traditional emission monitoring instrumentation. Measurements are made unobtrusively as vehicles pass through an infrared light beam directed across one traffic lane about 25 centimeters above the pavement. A video camera records the vehicle registration number of each vehicle as its …