Environmental Chemistry Commons^™

Extreme Value Theory Analysis Of High Emitter Trends Across Four Us Cities From 1995 To 2021, M. Matti Maricq, Gary A. Bishop

Fuel Efficiency Automobile Test Publications

Extreme value theory provides a direct means to characterize the distribution of high emitters within a vehicle fleet and calculate statistical confidence intervals for comparisons. Defining a “high emitter” as the maximum emitter in a random sample of N vehicles implies in the limit of large N that high emitters follow an extreme value distribution, comprised of three distinct domains. The analysis of over twenty years of roadside remote sensing emissions measurements in Chicago, Denver, Los Angeles and Tulsa reveals clear differences between gasoline vehicle high emitter distributions across pollutants (hydrocarbons (HC), carbon monoxide (CO) and nitric oxide (NO)), but …

Verification Of Real-Time Smoke Simulations: A Case Study On Early Summer North American Wildfire Events, Daniel Bonilla

Pitzer Senior Theses

As wildfire intensity and frequency escalate in times of unprecedented climate change and severe droughts, it is important to enhance forecasting models that accurately and efficiently predict wildfire smoke movement. NOAA’s experimental Rapid-Refresh Forecasting System with Smoke and Dust (RRFS-SD) aims to improve upon the High-Resolution Rapid Refresh- Smoke (HRRR-Smoke), by extending the domain to include all of North America and incorporating new developments in physics and wildfire parameterizations. Our work explores the process of adding satellite Aerosol Optical Depth (AOD) data, through AERONET, as an additional method of verification of the RRFS-SD experimental model. Using a case study on …

New Psychoactive Substances Detected In Wastewater Samples Collected Along The Interstate Highway Rest Areas In Kentucky, Durga Prasad Kodati

Murray State Theses and Dissertations

The rapid emergence and proliferation of new psychoactive substances (NPS) pose significant challenges to public health and law enforcement. The potential for abuse and toxicity of these substances, which are intended to mimic the effects of controlled drugs, has been raising concerns as these compounds are designed to evade being regulated. There are traditional methods of tracking NPS, such as seizures and forensic toxicology, but they are delayed and seldom effective because these substances continue to evolve rapidly. Wastewater-based epidemiology (WBE) has emerged as a promising tool for real-time surveillance of drug consumption. The primary objective of this research was …

A Colorimetric Sensor Array For Differentiating Emerging Material Contaminants Based On Surface Chemistry, Ifunanya Chiamaka Ede

All Master's Theses

Emerging materials contaminants, such as microplastics (MPs) and engineered nanoparticles (ENPs), are now recognized to contaminate oceans, seas, freshwater, and drinking water through many different exposure pathways. The extent of the materials' water contamination problem has only begun to be properly appreciated in the last decade. While comprehensive global data on the exact quantity of nano- and microcontaminants in drinking water is challenging to ascertain, studies have shown that microplastics and nanoparticles can now be found in drinking water sources worldwide.  Indeed, a well-publicized recent study has shown that 93% of bottled water around the world contains microplastic contamination.

Detecting …

Zinc Or Swim: Investigating Zinc Pollution From Restoration Materials, Megan R. Jensik

Honors Undergraduate Theses

Zinc is an essential nutrient, but can be toxic at high concentrations, negatively affecting various biological functions. Gabions are galvanized metals coated in zinc that are used for many human purposes, including coastal restoration efforts attempting to avoid using plastic materials. However, gabions can degrade in marine environments, potentially leaching metal into the water and soil. There is a knowledge gap regarding the occurrence and impacts of zinc pollution in the areas where these gabions are deployed, including the Indian River Lagoon (IRL). To address this, sediment samples were collected from the IRL and analyzed for their physical and chemical …

Investigating The Thermal Stratification Patterns Of A Shallow Polymictic Boreal Shield Lake And The Effectiveness Of Models In Predicting Shallow Lake Thermal Profiles, Matthew Roberts

Theses and Dissertations (Comprehensive)

Thermal stratification is a core process of lakes which plays a critical role in shaping the ecological dynamics of lakes, influencing major processes like nutrient cycling and oxygen availability. For shallow polymictic lakes, thermal stratification patterns present some unique differences due to the complex and variable nature of these lakes. In this thesis, I examined thermal stratification in a shallow polymictic lake in northwestern Ontario during the ice-free season of 2019 to investigate the frequency, duration, and driving factors of thermal stratification. The lake underwent 146 separate stratification events, with a median duration of 2 hours per event, with a …

Geochemical Assessment Of Sediment Flux In A Sediment Core From A Tidal Flat In A Tropical Estuary, Olumide Ajulo

Master's Theses or Doctor of Nursing Practice

Sediment flux in estuaries is influenced by both natural processes and anthropogenic activities. Understanding the historical and current trends in sediment flux inputs and geochemical composition are essential for evaluating the estuary’s response to natural and human-induced changes and for developing effective environmental management strategies. The tropical Wouri Estuary in Cameroon receives water and sediment inputs from three main rivers draining urban, industrial, and agricultural areas, as well as different rock terrains. The complex inputs into the estuary can significantly affect sediment flux, consequently impacting the ecosystem. Thereby making an understanding of the temporal variations in sediment inputs in the …

High Throughput, Solid Sample Analysis With Cone-Based Mass Spectrometric Ionization Sources, Emily J. Wiggins

Theses and Dissertations

The widespread presence of environmental and consumer-product contaminants (e.g. trace metals, opium alkaloids) has underscored the need for rapid, reliable, and high-throughput analytical techniques that are capable of handling complex solid samples. While traditional mass spectrometric (MS) methods tend to have high sensitivity and accuracy, they often require labor-intensive and time-consuming sample preparation steps that limit throughput and field applicability. This thesis investigates the use of 3D-Printed Cone Spray Ionization-Mass Spectrometry (3D-PCSI-MS) as an ambient ionization technique for the direct screening of contaminants from solid matrices, eliminating the need for traditional sample preparation and allowing for real-time analysis.

In …

Generational Exposures To Cerium Oxide Nanoparticles And Perfluorooctanesulfonic Acid Affect The Performance Of Daughter Plants, Preston Clubb

Graduate Theses/Dissertations

The effects of parental stress on the performance of next generation exposed to another contaminant were investigated. Wheat was exposed to cerium oxide nanoparticles (CeO2-NPs) in first and second generations and exposed to perfluorooctanesulfonic acid (PFOS) in the third generation. Phenotypic or metabolic responses were assessed at 21-day (short-term exposure) or 90-day (long-term exposure) exposure periods. Biomass production, chlorophyll content, enzyme activity, and membrane damage were measured at short-term exposure, while elemental and PFOS concentrations, and grain metabolites were analyzed in long-term exposure. Results showed that continued exposures to CeO2-NPs and PFOS enhanced chlorophyll content but reduced concentrations of important …

One Peak, Two Peaks: On The Effects Of Enhanced Evaporation In An Ammonium Sulfate And Succinic Acid Aerosol System, Julia Reynolds

Honors Theses

Aerosols, defined as suspensions of liquid or solid particles in a gaseous medium, are ubiquitous in both indoor and outdoor environments. They have significant impacts ranging from public health concerns to climate dynamics. In laboratory settings, aerosols are most often generated through a technique known as atomization. The atomization or nebulization is from dilute, aqueous solutions of various chemical compositions. This process typically produces a unimodal, lognormal particle size distribution with exceedingly rare exceptions. Colleagues in a different laboratory (Dr. Freedman’s Group at Pennsylvania State University), however, mentioned they observed a bimodal size distribution, a distribution with more than one …

Lc-Ms Discriminates Between Effects Of Sulfur Nanoparticles Vs Molybdenum Disulfide Nanoparticles On Lettuce (Lactuca Sativa), Mary Fakunle

Graduate Theses/Dissertations

Nanotechnology is gaining attention in agriculture, majorly due to their potential benefits in farming practices. Sulfur and molybdenum disulfide nanoparticles are reported to enhance plant growth, protection, and nutrient delivery. However, there is a need to understand how nano-fertilizers affect the metabolites and nutritional benefits of plants. Here, lettuce was cultivated under greenhouse in one of three treatments: control, 50 ppm S NPs, and 20 ppm MoS2 NPs. A method was developed on Liquid Chromatography – Mass Spectrometry (LC-MS) instrument to quantify the concentration of amino acids and antioxidants in the harvested lettuce plants. Inductively Coupled Plasma – Mass Spectrometry …

Evaluation Of Practical Methods To Determine If A Karst Creek Is Gaining Or Losing: Case Study Of Leith Creek, Elizabeth Jones

Graduate Theses/Dissertations

Karst landscapes are abundant in Missouri, with features such as caves, springs, and sinkholes that form through the dissolution of limestone. Leith Creek is a small stream in Polk County, Missouri fed by two springs and the shallow unconfined Springfield Plateau aquifer, a highly karstified aquifer which is made up of limestone and minor interbedded shale-mudstone units. To determine if Leith Creek is gaining or losing, stream flow, water chemistry and temperature sensors were monitored. Stream flow results required multiple visits to take measurements while temperature sensors required two visits, one to install the dataloggers and another to remove the …

Extended Inter-Laboratory Characterization Of The New Coastal Seawater Dissolved Organic Matter Reference Material Trm-0522, Alexander J. Craig, Lydia Babcock-Adams, Maxime C. Bridoux, Charlotte Brun, Juliana D'Andrilli, Aleksandar I. Goranov, Patrick G. Hatcher, Oliver Lechtenfeld, Hang Li, Rebecca Matos, Garrett Mckay, Amy M. Mckenna, Madelyn Miller, Sasha Wagner, Margot E. White, Alexander Zherebker, Jeffrey A. Hawkes

Chemistry & Biochemistry Faculty Publications

Dissolved organic matter (DOM) reference materials are critical to ensuring reliable comparability of measurements across experiments and between labs. TRM-0522, isolated in 2022 from 45 m deep seawater off of Sweden’s west coast, fills the niche of a previously unavailable coastal marine DOM reference material. After its isolation, we detailed a limited number of metrics for TRM-0522, initially disclosing Orbitrap high-resolution mass spectrometry, nuclear magnetic resonance, carbon proportion, absorbance, and fluorescence data. With TRM-0522 becoming more widely used, a variety of labs have generated different metrics that help to characterize and define the chemical properties of this coastal reference material. …

Deciphering The Chemistry Of Condensed Aromatic "Black" Carbon And Nitrogen In Amazonian Anthrosols, João Vitor Dos Santos, Aleksandar I. Goranov, Laís G. Fregolente, Marcia C. Bisinoti, Zhenhuan Sun, Klaus Schmidt-Rohr, Patrick G. Hatcher

Chemistry & Biochemistry Faculty Publications

Amazonian anthrosols are renowned for their high fertility and dark color, properties primarily attributed to the abundance of condensed aromatic carbon (ConAC) in the soil organic matter. ConAC, commonly referred to as black carbon, play a key role in the stability and nutrient retention of these soils. However, the processes governing the formation of ConAC and its transformation into oxygenated derivatives remain poorly understood. In this study, we used multiple analytical platforms to investigate the chemistry of ConAC-rich humic acids (HA) extracted from Terra Mulata de Indio, a type of Amazonian anthrosol. The results reveal that ConAC are predominantly …

Oxidation Camouflages Terrestrial Organic Matter To Appear Marine-Like, Aleksandar I. Goranov, Susan J. Carter, Ann Pearson, Patrick G. Hatcher

Chemistry & Biochemistry Faculty Publications

The export of terrestrial organic matter (TOM) to the ocean has been traditionally viewed to be minimal or only of significance in near-coastal continental margins. The broadly accepted explanation for the widespread loss of terrestrial lignin biomarkers and apparent disappearance of the <-25‰ stable carbon isotopic signature (δ¹³C) of TOM is that TOM is almost fully degraded before reaching the open ocean. Oceanic carbon (δ¹³C value ≥ -22‰) is therefore thought to be derived primarily from algae. However, an alternative explanation for the different molecular and δ¹³C signatures in terrestrial and marine environments may be that oxidative processing transforms TOM to appear marine-like. To test this hypothesis, we subjected eight TOM samples to a strong oxidation gradient. At carbon losses typical of TOM degradation during transport and sedimentation (above 60%), the differentiators of provenance disappeared, leaving a residue that was marine-like both chemically (aliphatic- and nitrogen-rich) and isotopically (δ¹³C enrichment of 4 to 9‰). This challenges the validity of conventional two-endmember mixing models, suggesting that a much larger fraction than previously estimated of the organic matter found in the ocean may originate from terrestrial sources, impacting global models of carbon cycling and sequestration.

Twenty Years Of Global Stratospheric Fluorine Inventories From Atmospheric Chemistry Experiment Fourier Transform Spectrometer (Ace-Fts) Measurements, N. Raymond, P. Bernath, C. Boone, M. Chipperfield

Chemistry & Biochemistry Faculty Publications

We present fluorine inventories calculated for twenty years (2004–2023) and five latitude bands (82°–60°N, 60°–30°N, 30°N–30°S, 30°–60°S, and 60°–82°S) at altitudes from the surface up to 55 km. The inventories were calculated using the Atmospheric Chemistry Experiment Fourier transform spectrometer (ACE‐FTS) version 5.2 retrievals of the volume mixing ratios (VMRs) of 15 fluorine‐containing species. Of these 15 species, 3 are product gases: HF, COF₂, COCIF, and 12 are source gases: SF₆, PFC-14 (CF₄), CFC-11 (CCl₃F), CFC-12 (CCl₂F₂), CFC-113 (CCIF₂CCl₂F), HCFC-22 (CHF₂CL), HCFC-141b(C₂H₃Cl₂F), HCFC-142b ( …

Cfd Analysis Of Hydrodynamic Cavitation Through An Orifice: Influence Of Different Inlet Pressures And Number Of Orifice Holes, Lemthong Chanphavong, Vongsavanh Chanthaboune, Keophousone Phonhalath

ASEAN Journal on Science and Technology for Development

Hydrodynamic cavitation (HC) is considered an energy-efficient process with high potential for utilization in many chemical processes. This study presents a computational fluid dynamics (CFD) analysis of cavitating flow through an orifice with a constant flow area. The Reynolds-Averaged Navier-Stokes (RANS) equations, coupled with turbulence and cavitation models, are employed to capture the complex flow behaviors. The effects of inlet pressures and number of orifice-holes on cavitation behavior are investigated. Result of the numerical simulation is validated with the existing experimental data from the literature. The CFD study revealed that cavitation initiates just behind the inlet edge of the orifice …

A Potentially Fruitful Path Toward A Cleaner And Safer Environment: Mxenes Uses In Environmental Remediation, Ali Mohammad Amani, Milad Abbasi, Atena Najdian, Farzaneh Mohamadpour, Seyed Reza Kasaee, Hesam Kamyab, Shreeshivadasan Chelliapan, Hanieh Ardeshiri, Lobat Tayebi, Ehsan Vafa, Sarah Mosleh-Shirazi, Alireza Jahanbin, Saravanan Rajendran, Daniel Simancas-Racines

Electrical & Computer Engineering Faculty Publications

The rapid industrialization of the world has resulted in severe environmental pollution, necessitating the development of new materials such as pollution remediation. Two-dimensional (2D) MXenes have emerged as a promising family of materials due to their unique physicochemical properties, making them ideal for environmental remediation. The article sheds light on the new opportunities of MXenes in the removal of organic and inorganic contaminants, including organic dyes, pharmaceuticals, heavy metals, radionuclides, and gas pollutants. MXenes also show excellent performance in photocatalytic degradation, adsorption, and microbial inactivation with environmental safety. Moreover, their application in recovering valuable elements from waste streams is also …

Catalytic Innovation For Sustainable Styrene Production: Green Chemistry Strategies Utilizing Octahedral Ruthenium (Ii) Complexes Supported By A Single Bipyridine Ligand, Kennedy G. Musso, Brandon Quillian, Clifford Padgett, Jose Jimenez

College of Graduate Studies: Theses & Dissertations

This study investigates: 1) the synthesis and reactivity of the mono- substituted systems, [κ²-(t-bipy)Ru(NCMe)2(Ph)(PR3)][BArF'] supported by different ancillary ligands PR3 = (P(OCH3)3 and P(CH3)3) and a single bidentate ligand, 4,4′-di-tert-butyl-2,2′-bipyridine (t-bipy), and 2) UV/heat formation of di-PR3 and tri-PR3 systems supported by a single bidentate ligand to better understand the mechanism of styrene production. Utilizing [(η6-p-cymene)RuI(µ-I)]2 (1), the complexes (η6-p-cymene)RuI2(P(OCH3)3) (2) and (η6-p-cymene)RuI2(P(CH3)3) (3) were synthesized and phenylated to produce (η6-p-cymene)RuI(Ph)(PR3) (6; PR3 = P(OCH3)3 and 7; PR3 = P(CH3)3). Complex 4, (η6-p-cymene)RuCl2(P(CH3)3), was also synthesized and phenylated to produce (η6-p-cymene)RuClPh(P(CH3)3) (5) to understand the impact of chloride versus iodine …

Quantifying Inositol Phosphate Dephosphorylation To Understand The Role Of Recalcitrant Organic Phosphorus Forms On Harmful Algal Blooms In Freshwater Systems, Iffat Tasnim

College of Graduate Studies: Theses & Dissertations

Organophosphorus such as phytic acid, a surrogate species of inositol phosphate (IP), may serve as a source for orthophosphate (OP) in freshwater. In absence of OP, competent aquatic microorganisms upregulate the production of specialized enzymes to obtain growth-sustaining OP from organic phosphorus (org-P) forms. The contribution of recalcitrant org-P to the OP pool has been overlooked due to the lack of capable tools to measure OP production from org-P accurately. The objective of this study was to quantify OP production from phytic acid (a surrogate form of recalcitrant org-P) to assess the contribution of recalcitrant org-P forms to the total …