Digital Commons Network^™

Removal Of Trace Organic Contaminants By A Membrane Bioreactor-Granular Activated Carbon (Mbr -Gac) System, Luong N. Nguyen, Faisal I. Hai, Jinguo Kang, William E. Price, Long Nghiem

Long D Nghiem

The removal of trace organics by a membrane bioreactor–granular activated carbon (MBR–GAC) integrated system were investigated. The results confirmed that MBR treatment can be effective for the removal of hydrophobic (logD > 3.2) and readily biodegradable trace organics. The data also highlighted the limitation of MBR in removing hydrophilic and persistent compounds (e.g. carbamazepine, diclofenac, and fenoprop) and that GAC could complement MBR very well as a post-treatment process. The MBR– GAC system showed high removal of all selected trace organics including those that are hydrophilic and persistent to biological degradation at up to 406 bed volumes (BV). However, over an …

Simultaneous Activated Carbon Adsorption Within A Membrane Bioreactor For An Enhanced Micropollutant Removal, Xueqing Li, Faisal I. Hai, Long Nghiem

Long D Nghiem

Significant adsorption of sulfamethoxazole and carbamazepine to powdered activated carbon (PAC) was confirmed by a series of adsorption tests. In contrast, adsorption of these micropollutants to the sludge was negligible. The removal of these compounds in membrane bioreactor (MBR) was dependent on their hydrophobicity and loading as well as the PAC dosage. Sulfamethoxazole exhibited better removal rate during operation under no or low (0.1 g/L) PAC dosage. When the PAC concentration in MBR was raised to 1.0 g/L, a sustainable and significantly improved performance in the removal of both compounds was observed – the removal efficiencies of sulfamethoxazole and carbamazepine …

Topographic Influences On Trends And Cycles In Nutrient Export From Forested Catchments On The Precambrian Shield, Samson G. Mengistu

Electronic Thesis and Dissertation Repository

This dissertation explored topographic controls on spatial and temporal patterns in water yield and nutrient (carbon, nitrogen and phosphorus) export from forested headwater catchments in the Turkey Lakes Watershed in central Ontario, where other factors contributing to differences in water yield and nutrient export, including climate, geology, forest, and soils, are relatively constant. Topographic characteristics, including (a) hydrological flushing potential (expansion of water table into nitrate-N producing areas); (b) hydrological storage potential (area of wetlands, which can alternatively allow water and nutrients to bypass wetlands when storage capacity is filled with water or to trap them when not filled); and …

Modelling Carbon Nanostructures For Filtering And Adsorbing Polycyclic Aromatic Hydrocarbons, Thien Tran-Duc, Ngamta Thamwattana

Dr Ngamta Thamwattana

The discovery of carbon nanostructures, such as graphene and carbon nanotubes, has led to the creation of many novel nano-devices. In this paper, we consider an environmental application of carbon nanostructures for filtering and adsorbing polycyclic aromatic hydrocarbons (PAHs) which are environmental pollutants. We mathematically investigate the adsorption of PAHs onto a graphene sheet and determine the underlying mechanisms of suction of PAHs into a carbon nanotube. We adopt a continuum approach together with the semi-empirical Lennard-Jones potential to determine van der Waals interaction forces and energies. Results obtained here for certain PAHs are well in agreement with existing experimental …

Continuum Modelling For Carbon And Boron Nitride Nanostructures, James M. Hill, Ngamta Thamwattana

Dr Ngamta Thamwattana

Continmuum based models are presented here for certain boron nitride and carbon nanostructures.

Carbon Nanomaterial Based Vapor Sensors., Silpa Kona

Electronic Theses and Dissertations

The discovery of carbon nanotubes and subsequently graphene has led to an interest in carbon materials as sensing elements due to their unique properties. Graphene is a 2-dimensional material that has a large surface area that can be exposed to surface adsorbates from a target gas. This enables studies on the interaction of gas molecules with the graphene surface and subsequent changes in its properties. Graphene also exhibits high conductivity and low noise and has low crystal defects. Due to its high electron mobility at room temperature, graphene exhibits high sensitivity (in tune of detecting ppm) which is a required …

Long-Term Effects Of Rice Rotation, Tillage, And Fertility On Near-Surface Soil Carbon And Nitrogen Cycling, Jill Marie Motschenbacher

Graduate Theses and Dissertations

Rice (Oryza sativa L.)-based cropping systems are different from other row crops due to the flood-irrigation scheme used from about one month after planting to a few weeks prior to harvest. The frequent cycling between anaerobic (i.e., flooding during the growing season) and aerobic (i.e., generally, the remainder of the year) conditions can influence the rate of soil organic matter (SOM) decomposition, which can greatly influence carbon (C) and nitrogen (N) storage and sequestration in the soil over time. Therefore, a study was conducted on a silt-loam soil (fine, smectitic, thermic, Typic Albaqualf) at the Rice Research and Extension Center …

Co2 Injection Into A Deep Saline Aquifer: Porosity Measurements, Numerical Modeling, And Costs Associated With Uncertainty Of Petrophysical Parameters, Michael John Gragg

Masters Theses

Anthropogenic levels of atmospheric greenhouse gases, particularly carbon dioxide (CO₂) have increased rapidly over the last several decades and coincide with rising temperatures globally. One possible solution is to capture CO₂ before it is released into the atmosphere by large point sources, such as fossil fuel power plants. Once captured, the CO₂ can be condensed and transported to a storage facility. Of the available options for storage of condensed CO₂, geologic sequestration in deep saline aquifers is considered the most viable option.

Porosity measurements were obtained for nearly 100 core samples of the Knox …

Silicon/Single-Walled Carbon Nanotube Composite Paper As A Flexible Anode Material For Lithium Ion Batteries, Shulei Chou, Yue Zhao, Jiazhao Wang, Zhixin Chen, Hua-Kun Liu, S. X. Dou

Shulei Chou

Flexible silicon/single-walled carbon nanotube (Si/SWCNT) composite paper was prepared using the pulsed laser deposition (PLD) method to deposit Si onto SWCNT paper. In the composite, Si mainly shows nanoworm-like morphology. Increasing deposition time results in an increased amount of Si microspheres. Electrochemical measurements show that the capacity of the composite paper is improved by the presence of Si. The Si/SWCNT composite with only 2.2% Si shows a capacity of 163 mA h g−1 at a current density of 25 mA g−1 up to 50 cycles, which is more than 60% improvement of the capacity of pristine CNT paper. The Si …

High-Surface-Area -Fe2o3/Carbon Nanocomposite: One-Step Synthesis And Its Highly Reversible And Enhanced High-Rate Lithium Storage Properties, S X. Dou, David Wexler, Jiazhao Wang, Hua-Kun Liu, Konstantin K. Konstantinov, Chao Zhong, Shulei Chou

Shulei Chou

Hollow-structured α-Fe2O3/carbon (HIOC) nanocomposite with a high surface area of around 260 m2 g−1 was synthesized by a one-step, in situ, and industrially-oriented spray pyrolysis method using iron lactate and sucrose solution as the precursors. The small α-Fe2O3 nanocrystals were highly dispersed inside amorphous carbon to form a carbon nanocomposite. Electrochemical measurements showed that the carbon played an important role in affecting both the cycle life and the rate capability of the electrode. The HIOC composites showed the best electrochemical performance in terms of high capacity (1210 mAh g−1 at a current density of 0.1 C), enhanced rate capability and …

Smarter Finance For Cleaner Energy: Open Up Master Limited Partnerships (Mlps) And Real Estate Investment Trusts (Reits) To Renewable Energy Investment, Felix Mormann, Dan Reicher

Faculty Scholarship

This policy proposal makes the case for opening Master Limited Partnerships (MLPs) and Real Estate Investment Trusts (REITs) — both well-established investment structures — to renewable energy investment. MLPs and, more recently, REITs have a proven track record for promoting oil, gas, and other traditional energy sources. When extended to renewable energy projects these tools will help promote growth, move renewables closer to subsidy independence, and vastly broaden the base of investors in America’s energy economy.

Shedding Light On Plant Litter Decomposition: Advances, Implications And New Directions In Understanding The Role Of Photodegradation, Jennifer Y. King, Leslie A. Brandt, E. Carol Adair

Rubenstein School of Environment and Natural Resources Faculty Publications

Litter decomposition contributes to one of the largest fluxes of carbon (C) in the terrestrial biosphere and is a primary control on nutrient cycling. The inability of models using climate and litter chemistry to predict decomposition in dry environments has stimulated investigation of non-traditional drivers of decomposition, including photodegradation, the abiotic decomposition of organic matter via exposure to solar radiation. Recent work in this developing field shows that photodegradation may substantially influence terrestrial C fluxes, including abiotic production of carbon dioxide, carbon monoxide and methane, especially in arid and semi-arid regions. Research has also produced contradictory results regarding controls on …

Wolfpack Gear Inc. Composite Frame Firefighter Backpack, Gabriel Mountjoy, Blair Ridings, Carl Drummond Buchenroth

Mechanical Engineering

No abstract provided.

The Loss Of Carbon Dioxide From Activated Perbenzoate Anions In The Gas Phase: Unimolecular Rearrangement Via Epoxidation Of The Benzene Ring, David G. Harman, Aravind Ramachandran, Michelle Gracanin, Stephen J. Blanksby

Stephen Blanksby

The unimolecular reactivities of a range of perbenzoate anions (X−C6H5CO3-), including the perbenzoate anion itself (X = H), nitroperbenzoates (X = para-, meta-, ortho-NO2), and methoxyperbenzoates (X = para-, meta-OCH3) were investigated in the gas phase by electrospray ionization tandem mass spectrometry. The collision-induced dissociation mass spectra of these compounds reveal product ions consistent with a major loss of carbon dioxide requiring unimolecular rearrangement of the perbenzoate anion prior to fragmentation. Isotopic labeling of the perbenzoate anion supports rearrangement via an initial nucleophilic aromatic substitution at the ortho carbon of the benzene ring, while data from substituted perbenzoates indicate that …

Form And Function Of Clostridium Thermocellum Biofilms, Alexandru Dumitrache, Gideon Wolfaardt, Grant Allen, Steven N. Liss, Lee R. Lynd

Dartmouth Scholarship

The importance of bacterial adherence has been acknowledged in microbial lignocellulose conversion studies; however, few reports have described the function and structure of biofilms supported by cellulosic substrates. We investigated the organization, dynamic formation, and carbon flow associated with biofilms of the obligately anaerobic cellulolytic bacterium Clostridium thermocellum 27405. Using noninvasive, in situ fluorescence imaging, we showed biofilms capable of near complete substrate conversion with a characteristic monolayered cell structure without an extracellular polymeric matrix typically seen in biofilms. Cell division at the interface and terminal endospores appeared throughout all stages of biofilm growth. Using continuous-flow reactors with a rate …

Removal Of Trace Organic Contaminants By A Membrane Bioreactor-Granular Activated Carbon (Mbr -Gac) System, Luong N. Nguyen, Faisal I. Hai, Jinguo Kang, William E. Price, Long Nghiem

William E. Price

The removal of trace organics by a membrane bioreactor–granular activated carbon (MBR–GAC) integrated system were investigated. The results confirmed that MBR treatment can be effective for the removal of hydrophobic (logD > 3.2) and readily biodegradable trace organics. The data also highlighted the limitation of MBR in removing hydrophilic and persistent compounds (e.g. carbamazepine, diclofenac, and fenoprop) and that GAC could complement MBR very well as a post-treatment process. The MBR– GAC system showed high removal of all selected trace organics including those that are hydrophilic and persistent to biological degradation at up to 406 bed volumes (BV). However, over an …

Zawartość Węgla I Siarki W Pyle Pm2,5 I Pm10 W Powietrzu W Centrum Krakowa, Monika Dziugieł, Marek Bogacki, Robert Oleniacz, Marian Mazur

Robert Oleniacz

This paper presents the results of the PM2.5 and PM10 mass concentration measurements in an urban air and results obtained from the additional chemical analysis concerning carbon and sulfur content of the collected dust samples. Dust samples were collected at the measuring point located on the roof of five-storey building at the AGH University of Science and Technology in Krakow, Poland (the center of the urban area of the city). In the scope of this study the relations between the carbon and sulfur content within the collected dust samples were determined in the function of the dust fraction content and …

Estimating Global “Blue Carbon” Emissions From Conversion And Degradation Of Vegetated Coastal Ecosystems, Linwood Pendleton, Daniel C. Donato, Brian C. Murray, Stephen Crooks, W. Aaron Jenkins, Samantha Sifleet, Christopher Craft, James W. Fourqurean, J. Boone Kauffman, Núria Marbà,, Patrick Megonigal, Emily Pidgeon, Dorothee Herr, David Gordon, Alexis Baldera

Department of Biological Sciences

Recent attention has focused on the high rates of annual carbon sequestration in vegetated coastal ecosystems—marshes, mangroves, and seagrasses—that may be lost with habitat destruction (‘conversion’). Relatively unappreciated, however, is that conversion of these coastal ecosystems also impacts very large pools of previously-sequestered carbon. Residing mostly in sediments, this ‘blue carbon’ can be released to the atmosphere when these ecosystems are converted or degraded. Here we provide the first global estimates of this impact and evaluate its economic implications. Combining the best available data on global area, land-use conversion rates, and near-surface carbon stocks in each of the three ecosystems, …

Enhancing The Investor Appeal Of Renewable Energy, Felix Mormann

Faculty Scholarship

This article introduces an investor-oriented framework for the evaluation of renewable energy policy, applies these newly developed criteria to a qualitative comparison of the primary policy instruments, and offers recommendations to enhance the investor appeal of renewable energy in the United States.

The multi-trillion dollar task of scaling renewable energy technologies to mitigate climate change, ensure energy security, and create green jobs is one of the most daunting challenges of the twenty-first century. It is, in fact, too great a challenge for either the public or private sector to shoulder alone. Rather, public policy must catalyze private investment in renewable …

"Roads? Where We're Going We Don't Need Roads:" The Transformation Of The Roadless Rule Into An American Carbon Sink, Sam W. Gieryn

Sam W. Gieryn

Abstract “Roads? Where We’re Going, We Don’t Need Roads:” The Transformation of the Roadless Rule into an American Carbon Sink. By: Sam Gieryn Climate change continues to become a global problem, but for the United States, part of the solution is closer than we think. In the search for an effective means to halt the adverse effects of global warming, scientists discovered the benefits of carbon sequestration from forests. The United States contains nearly 750 million acres of forest, which this paper proposes the nation uses to combat climate change. In 2001, the Clinton Administration took notice of the importance …

Effects Of Invasion By The Common Reed (Phragmites Australis) On Carbon Transformations In A Great Lakes Marsh, Shawn Trevor Duke

Master's Theses and Doctoral Dissertations

The common reed (Phragmites australis) is a highly productive invasive grass that alters the wetland physiochemical environment and produces toxic secondary metabolites. Plant litter decomposition, effects of water level on soil microbes, and soil microbial response to leachate additions were investigated in Phragmites invaded and pre-invaded Typha sites. Less litter mass was lost from Phragmites than Typha in both sites during the initial 144 days. Annual mass loss from both species’ litter was greater in the Phragmites site. Lower water levels resulted in greater CO₂ than CH₄ production in both Phragmites and Typha soils. Higher water …

Simultaneous Activated Carbon Adsorption Within A Membrane Bioreactor For An Enhanced Micropollutant Removal, Xueqing Li, Faisal I. Hai, Long Nghiem

Faisal I Hai

Significant adsorption of sulfamethoxazole and carbamazepine to powdered activated carbon (PAC) was confirmed by a series of adsorption tests. In contrast, adsorption of these micropollutants to the sludge was negligible. The removal of these compounds in membrane bioreactor (MBR) was dependent on their hydrophobicity and loading as well as the PAC dosage. Sulfamethoxazole exhibited better removal rate during operation under no or low (0.1 g/L) PAC dosage. When the PAC concentration in MBR was raised to 1.0 g/L, a sustainable and significantly improved performance in the removal of both compounds was observed – the removal efficiencies of sulfamethoxazole and carbamazepine …

Agenda: Drafting Model Laws On Indoor Pollution For Developing And Developed Nations, University Of Colorado Boulder. Center For Energy & Environmental Security, Colorado Natural Resources, Energy And Environmental Law Review

Drafting Model Laws on Indoor Pollution for Developing and Developed Nations (July 12-13)

On July 12 and 13, 2012, experts convened at Colorado Law to demonstrate the extent to which a model law could help address the global problem of indoor air pollution from inefficient cook stoves. The air pollution that results from inefficiently burning biomass as fuel for cooking has serious health and climatic consequences. The workshop produced two sets of Model Laws and commentaries to help nations solve the problem, and the commentaries were published in the Colorado Natural Resources, Energy, and Environmental Law Review.

Drafting Model Laws On Indoor Pollution For Developing And Developed Nations Workshop, July 12-13, 2012, Boulder, Colorado: Introduction, Lakshman Guruswamy

Drafting Model Laws on Indoor Pollution for Developing and Developed Nations (July 12-13)

11 pages.

"This Essay introduces the framework for deliberation and legislative drafting undertaken at the workshop: Drafting Model Laws on Indoor Pollution for Developing and Developed Nations on July 12-13, 2012, in Boulder, Colorado. There are a number of fundamental premises upon which the workshop was based, and this Essay refers to the most salient among them."-- Excerpted from 24 Colo. Nat. Resources, Energy & Envtl. L. Rev. 319 (2013).

Plant Establishment And Soil Microenvironments In Utah Juniper Masticated Woodlands, Kert R. Young

Theses and Dissertations

Juniper (Juniperus spp.) encroachment into sagebrush (Artemisia spp.) and bunchgrass communities has reduced understory plant cover and allowed juniper trees to dominate millions of hectares of semiarid rangelands. Trees are mechanically masticated or shredded to decrease wildfire potential and increase desirable understory plant cover. When trees are masticated after a major increase in tree population density and associated decrease in perennial understory cover, there is a risk that invasive annual grasses will dominate because they are highly responsive to the increased resource availability that commonly follows removal of the main resource user. To determine if tree mastication increases …

Playing Without Aces: Offset And The Limits Of Flexibility Under Clean Air Act Climate Policy, Nathan D. Richardson

Faculty Publications

The United States Environmental Protection Agency (EPA) continues to move ahead with regulation of greenhouse gas emissions under the Clean Air Act (CAA). Previous work has indicated that basic forms of compliance flexibility—trading—appear to be legally permissible under section III of the CAA. This Article takes a close look at more expansive and ambitious types of flexibility: trading between different kinds of sources, biomass co-firing, and above all, offsets. It concludes that most types of such extended flexibility are either legally incompatible with the CAA, or so legally problematic that EPA is unlikely to adopt them. This has important implications …

Linking Environment To Ecology In Arid Land Consumers : Two Case Studies, Ian W. Murray

Biology ETDs

The physical environment has a profound influence over many aspects of animal ecology, such as governing the pace and timing of phenology and the patterns of activity across space and time. In extreme habitats such as deserts, the most important components of the physical environment are precipitation and temperature. Not only do these vary temporally and spatially, but this variation may influence the life history and ecology of species. My research examines how variance in temperature and precipitation influences the ecology of two species of desert dwelling consumers (desert woodrats and desert tortoises) over differing temporal scales. In Chapter 1, …

Low Energy (E, 2e) Study From The 1t₂ Orbital Of Ch₄, Shenyue Xu, Hari Chaluvadi, Xueguang Ren, Thomas Pfluger, Arne Senftleben, Chuangang Ning, Shuncheng Yan, Peng Zhang, Jie Yang, Xinwen Ma, Joachim Hermann Ullrich, Don H. Madison, Alexander Dorn

Physics Faculty Research & Creative Works

Single ionization of the methane (CH₄) 1t₂ orbital by 54 eV electron impact has been studied experimentally and theoretically. The measured triple differential cross sections cover nearly a 4π solid angle for the emission of low energy electrons and a range of projectile scattering angles. Experimental data are compared with theoretical calculations from the distorted wave Born approximation and the molecular three-body distorted wave models. It is found that theory can give a proper description of the main features of experimental cross section only at smaller scattering angles. For larger scattering angles, significant discrepancies between experiment and …

The State Of Sustainable Transportation At Union College: A Transportation Audit Of Union College Students And Faculty, Benjamin Engle

Honors Theses

Union College has established a Climate Action Plan with the goal of carbon neutrality by 2060 as part of its commitment to sustainability. A significant component of Union’s carbon footprint, however, is student and faculty transportation. The purpose of this research was to analyze the transportation behavior of students and faculty to determine the carbon emissions that result from the use of various transportation methods. Two campus‐wide surveys were conducted; one was distributed to students and the other targeted faculty. For comparison purposes, survey questions were designed to be compatible with, but more focused than, those of a survey conducted …

Putting The Wind At Our Backs: Assessing U.S. Potential For 20% Wind Energy By 2030, Kevin T. Harnett

Honors Theses

The discussion surrounding the future of energy, particularly in the United States, has gained significant momentum in recent years for an obvious reason — it’s daunting. Our dependence on fossil fuels has positioned our nation in an undesirable predicament with a questionable future. With the associated consequences, principally Climate Change, it is essential that energy be addressed as a primary national concern. Renewables need to flip the switch.