Physical Sciences and Mathematics Commons^™

Catechol Oxidation By Ozone And Hydroxyl Radicals At The Air-Water Interface, Elizabeth A. Pillar, Robert C. Camm, Marcelo I. Guzman

Chemistry Faculty Publications

Anthropogenic emissions of aromatic hydrocarbons promptly react with hydroxyl radicals undergoing oxidation to form phenols and polyphenols (e.g., catechol) typically identified in the complex mixture of humic-like substances (HULIS). Because further processing of polyphenols in secondary organic aerosols (SOA) can continue mediated by a mechanism of ozonolysis at interfaces, a better understanding about how these reactions proceed at the air–water interface is needed. This work shows how catechol, a molecular probe of the oxygenated aromatic hydrocarbons present in SOA, can contribute interfacial reactive species that enhance the production of HULIS under atmospheric conditions. Reactive semiquinone radicals are quickly produced upon …

Slides: Understanding The Impacts: Issues Of Research, Cindy Beeler

Water and Air Quality Issues in Oil and Gas Development: The Evolving Framework of Regulation and Management (Martz Summer Conference, June 5-6)

Presenter: Cindy Beeler, U.S. Environmental Protection Agency, Denver, CO

10 slides

Slides: What We Know (And Don't Know) About Air Quality Impacts Of Oil And Gas Development, Anna Karion

Water and Air Quality Issues in Oil and Gas Development: The Evolving Framework of Regulation and Management (Martz Summer Conference, June 5-6)

Presenter: Anna Karion, NOAA/ESRL, University of Colorado/CIRES

35 slides

Slides: Regulating Oil And Gas Emissions In The Denver Julesberg Basin, Garry Kaufman

Water and Air Quality Issues in Oil and Gas Development: The Evolving Framework of Regulation and Management (Martz Summer Conference, June 5-6)

Presenter: Garry Kaufman, Deputy Director, Colorado Air Pollution Control Division

25 slides

A Combined Chemical And Biological Approach To Transforming And Mineralizing Pahs In Runoff Water, Chainarong Sakulthaew, Steve D. Comfort, Chanat Chokejaroenrat, Clifford Harris, Xu Li

School of Natural Resources: Faculty Publications

The water quality of lakes, rivers and streams associated with metropolitan areas is declining from increased inputs of urban runoff that contain polycyclic aromatic hydrocarbons (PAHs). Our objective was to transform and mineralize PAHs in runoff using a combined chemical and biological approach. Using ¹⁴C-labeled phenanthrene, ¹⁴C-benzo(a)pyrene and a mixture of 16 PAHs, we found that ozone transformed all PAHs in a H₂O matrix within minutes but complete mineralization to CO₂ took several weeks. When urban runoff water (7.6 mg C L−1) replaced H₂O as the background matrix, some delays in degradation rates …

Investigation Of Isotope Effects Of Ozone As A Function Of Temperature, Daniel J. Mcmahon

Open Access Theses

Ozone is an important oxidizer in the atmosphere and plays a crucial role as a cleanser, removing various compounds such NOx and SOx. It also is intriguing to those that study stable isotopes as it has a unique signature found in no other oxygen containing molecule. Ozone is observed to fractionate mass independently, which means it does not follow the typical δ 17 O /δ18 O = 0.52 ratio expected for molecules enriched with 17 O and 18 O. The magnitude of ozone's mass independent enrichment has been studied in laboratory experiments and atmospheric observations but its explanation is still …

Modeling Dynamics Of Ozone And Nitrogen Oxides At Summit, Greenland With A 1-D Process-Scale Model, Keenan Anton Murray

Dissertations, Master's Theses and Master's Reports - Open

This work presents a 1-D process scale model used to investigate the chemical dynamics and temporal variability of nitrogen oxides (NO_x) and ozone (O₃) within and above snowpack at Summit, Greenland for March-May 2009 and estimates surface exchange of NO_x between the snowpack and surface layer in April-May 2009. The model assumes the surface of snowflakes have a Liquid Like Layer (LLL) where aqueous chemistry occurs and interacts with the interstitial air of the snowpack. Model parameters and initialization are physically and chemically representative of snowpack at Summit, Greenland and model results are compared to …

Evaluation Of Ozone Trends In Southern Doña Ana County, New Mexico Thru Wind Rose Analysis And Use Of Noaa Hysplit Model, Maria Aurelia Sisneros

Open Access Theses & Dissertations

The objective of this study was to determine whether increasing ozone concentrations in 2012 and 2013 at the Santa Teresa air quality monitor in Doña Ana County, New Mexico were due to a local point source impacting this monitor only or part of a regional phenomenon that affects all the monitors within the Paso del Norte Region. In addition, the study focused on identifying local and regional/long-range source areas contributing transport ozone to the study area (southern Doña Ana County).

The study showed that increasing ozone levels were not unique to the Santa Teresa monitor due to the fact that …

Modeling Of An Upper Midwest Forest Boundary Layer And Vehicle Indoor Air Quality, Phillip Stratton

Master's Theses and Doctoral Dissertations

The key to understanding tropospheric chemistry begins with the hydroxyl and hydroperoxy radicals. Recent research suggests that there is still considerable uncertainty in our understanding of the sources of these radicals and their role as sinks. The work detailed in this thesis describes a computational approach to modeling the hydroxyl and hydroperoxy radicals in a forest environment and attempts to shed further light on the radical budget in a typical Northern Hardwood forest. Additionally, research was conducted with United States Council for Automotive Research in collaboration with Ford, General Motors, and Chrysler to develop a global standard for vehicle indoor …