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Full-Text Articles in Environmental Engineering

Assessment Of Physicochemical Characteristics, Thermal Stability And Release Profile Of Ascorbic Acid Microcapsules Obtained By Complex Coacervation, Michele Cristina Rodrigues Da Cruz, João Luiz Andreotti Dagostin, Camila Augusto Perussello, Maria Lúcia Masson Jan 2019

Assessment Of Physicochemical Characteristics, Thermal Stability And Release Profile Of Ascorbic Acid Microcapsules Obtained By Complex Coacervation, Michele Cristina Rodrigues Da Cruz, João Luiz Andreotti Dagostin, Camila Augusto Perussello, Maria Lúcia Masson

Articles

The aim of this study was to determine the physicochemical characteristics, thermal stability and release profile of ascorbic acid (AA) microcapsules obtained by complex coacervation. Gelatin and gum arabic were used as wall materials in concentrations of 2.5, 5.0 and 7.5 g% (w/v). The coacervate microcapsules were freeze-dried and assessed for physicochemical characteristics, thermal behavior and stability during 60 days of storage. The release profile was evaluated at different pH values (1.1, 2.2, 5.4, 7.4, 9.6 and 12). The encapsulation efficiency ranged from 27.3 to 93.8%. The microcapsules of AA presented good characteristics for application in food matrices, such as …


Pathogen And Indicator Organism Inactivation And Quantification For Low-Cost Low-Tech Biosolids Treatment, Karina Eyre Jan 2019

Pathogen And Indicator Organism Inactivation And Quantification For Low-Cost Low-Tech Biosolids Treatment, Karina Eyre

Dissertations, Master's Theses and Master's Reports

Biosolids are a by-product of municipal wastewater treatment which, when treated to reduce pathogens, can be land applied as a fertilizer. Class A biosolids must contain low pathogen levels and are unrestricted in their use. This thesis describes methods to identify pathogen and indicator organism (PIO) inactivation mechanisms and PIO inactivation rates for use in low-cost low-tech Class A processes. Procedures to control the levels of spiked bacteria and viruses, total solids, volatile fatty acids, pH, and temperature in biosolids are described for their use in laboratory experiments. Methods for coliphage in biosolids as a surrogate for total enteric viruses …


Improved Methods For The Quantification Of Viable Ascaris Suum And Application To Biosolids, Tanner Keyzers Jan 2019

Improved Methods For The Quantification Of Viable Ascaris Suum And Application To Biosolids, Tanner Keyzers

Dissertations, Master's Theses and Master's Reports

The current method for detection of Ascaris ova in biosolids and wastewater has several drawbacks including being labor and time intensive as well as being difficult to quantify viable ova that have larvated during treatment. The goal of this thesis was to improve several methods for the detection and quantification of Ascaris ova during long term-storage of biosolids including improvement of quantifying viable ova using a heat and bleach treatment to promote movement of larvae inside of ova, and comparison of the traditional microscopic method with qPCR and PMA-qPCR to prevent the false-positive results. Improved methods to promote movement of …


Prevention Of Harmful Algal Blooms By The Mitigation Of Phosphorus Nutrient Loading Via Filtration By Steel Wool And Activated Carbon, Ronald Simpson, Sara Kidd, Samantha Zidd Jan 2019

Prevention Of Harmful Algal Blooms By The Mitigation Of Phosphorus Nutrient Loading Via Filtration By Steel Wool And Activated Carbon, Ronald Simpson, Sara Kidd, Samantha Zidd

Williams Honors College, Honors Research Projects

Harmful Algal Blooms (HABs) are a devastating ecological and economic consequence of the abundance of nutrient-rich agricultural runoff entering aquatic ecosystems (Baker et al. 2014). Bio-available phosphorus from synthetic fertilizers is one of the major nutrients contributing to this global issue. Previous studies indicated that dissolved phosphorus can be removed from an aqueous environment when passed through a composite mixture of granular steel wool particles and activated carbon (Erickson, Gulliver, and Weiss, 2007). In this project, we conducted experiments using higher quality concentration measurements to determine what grades of steel wool (SW-0000, SW-000, SW-00) and types of activated carbon (granulated …


Microcontroller Based Granular Urea Application Attachment For Rice Transplanter, Md Towfiqur Rahman, Md Monjurul Alam, Md Mosharraf Hossain, Muhammad Rashed Al Mamun Jan 2019

Microcontroller Based Granular Urea Application Attachment For Rice Transplanter, Md Towfiqur Rahman, Md Monjurul Alam, Md Mosharraf Hossain, Muhammad Rashed Al Mamun

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Transplanting and fertilizer application for rice production in Bangladesh are tedious, time consuming and laborious task, and mostly done manually. Mechanical transplanting of rice becoming popular in the country in recent years and few machines have been developed for granular urea deep placement, however, having some limitations. Placing granular urea precisely along with rice transplanting, an attempt was under taken to design and fabricate an electronic control granular urea applicator to be attach with a 4-row walk behind type rice transplanter. Fabrication of the electronic granular urea applicator was done in the workshop of the Department of Farm Power and …


Waste Management Of Highway Right Of Way Areas In Southeast Georgia, David M. Penn Ii Jan 2019

Waste Management Of Highway Right Of Way Areas In Southeast Georgia, David M. Penn Ii

College of Graduate Studies: Theses & Dissertations

Maintenance of highway right of way (ROW) areas has become problematic during the last several years due to the high cost, and little to no economic return associated with disposing vegetation waste that is continuously generated on all highways and interstates across the state of Georgia. The Georgia Department of Transportation (GDOT) was interested in evaluating the feasibility of replacing ROW vegetation of highways throughout the state with high-value alternatives such as switchgrass (Panicum virgatum L. ‘Alamo’), big bluestem (Andropogon gerardii) and woodland sunflower (Helianthus divaricatus). Preliminary objective involved measuring and mapping SOC and soil N concentrations in the highway …


Methods To Improve The Remediation Of Polycyclic Aromatic Hydrocarbons (Pahs) In Aerobic And Anaerobic Environments, Brian Wartell Dec 2018

Methods To Improve The Remediation Of Polycyclic Aromatic Hydrocarbons (Pahs) In Aerobic And Anaerobic Environments, Brian Wartell

Dissertations

Oil spills occur regularly in terrestrial environments and crude oil can contain many compounds that are highly resistant to degradation. Among these compounds are high levels of polycyclic aromatic hydrocarbons (PAHs) which are not only toxic but can also be carcinogenic and/or mutagenic. The first chapter of this dissertation includes an extensive review chapter on the variables affecting the anaerobic degradation of hydrocarbons, with a particular focus on PAHs. Electron acceptors, electron donors, temperature, salinity, pH all play key roles in determining the possibility effective of effective degradation occurring. Thus, by addressing solutions, such as biostimulation, improving environmental variables for …


Community-Scale Water Treatment Systems In The Dominican Republic, Jonathan Racey, Annabelle Papai, Elise Fischer, Becca Johnson Dec 2018

Community-Scale Water Treatment Systems In The Dominican Republic, Jonathan Racey, Annabelle Papai, Elise Fischer, Becca Johnson

Engagement & Service-Learning Summit

Engagement and Service-Learning Summit: Reciprocal and Sustainable Partnerships


Assessing Biofiltration Without Ozonation For Removal Of Trihalomethane Precursors In Drinking Water At The Beaver Water District Drinking Water Treatment Plant, Sana Ajaz Dec 2018

Assessing Biofiltration Without Ozonation For Removal Of Trihalomethane Precursors In Drinking Water At The Beaver Water District Drinking Water Treatment Plant, Sana Ajaz

Graduate Theses and Dissertations

Biofiltration without pre-ozonation has the capability to remove natural organic matter (NOM) fractions that serve as precursors of disinfection byproducts (DBPs), which include the four regulated trihalomethanes (THMs) and dichloroacetonitrile (DCAN). Rapid small-scale column tests (RSSCTs) and Pilot Plant filters operated at empty-bed contact times (EBCTs) of 4, 8, and 16 minutes were used to evaluate the performance of nutrient-amended (free ammonia and phosphorus) biofiltration for THM and DCAN precursor removal, as measured using formation potential (FP) tests. NOM surrogates – which include dissolved organic carbon (DOC), specific ultraviolet absorbance (SUVA254) and fluorescence-PARAFAC components – were measured weekly throughout the …


Urban Agriculture And Small Farm Water Use: Case Studies And Trends From Cache Valley, Utah, Tyler Pratt, L. Niel Allen, David E. Rosenberg, Andrew A. Keller, Kelly Kopp Oct 2018

Urban Agriculture And Small Farm Water Use: Case Studies And Trends From Cache Valley, Utah, Tyler Pratt, L. Niel Allen, David E. Rosenberg, Andrew A. Keller, Kelly Kopp

Publications

The landscape of water in Utah is changing due to population growth, conversion of agricultural land to urban development, and increasing awareness of water scarcity. At the same time, Utah is experiencing a growing number of urban and small farms, but knowledge of water use in this sector is limited. Better understanding of what occurs at the field level on urban and small farms can aid state water use estimates and conservation efforts, and assist farmers in moving towards wiser water management. For the 2015 growing season, we performed irrigation evaluations for 24 urban and small farms in Cache Valley, …


Cover Crops Have Negligible Impact On Soil Water In Nebraska Maize–Soybean Rotation, J. Burdette Barker, Derek M. Heeren, Katja Koehler-Cole, Charles Shapiro, Humberto Blanco-Canqui, Roger W. Elmore, Christopher A. Proctor, Suat Irmak, Charles A. Francis, Tim M. Shaver, Ali T. Mohammed Aug 2018

Cover Crops Have Negligible Impact On Soil Water In Nebraska Maize–Soybean Rotation, J. Burdette Barker, Derek M. Heeren, Katja Koehler-Cole, Charles Shapiro, Humberto Blanco-Canqui, Roger W. Elmore, Christopher A. Proctor, Suat Irmak, Charles A. Francis, Tim M. Shaver, Ali T. Mohammed

Department of Agricultural and Biological Systems Engineering: Faculty Publications

One perceived cost of integrating winter cover cropping in maize (Zea mays L.) and soybean [Glycine max (L.) Merr.] rotation systems is the potential negative impact on soil water storage available for primary crop production. The objective of this 3-year study was to evaluate the effects of winter cover crops on soil water storage and cover crop biomass production following no-till maize and soybean rotations. Locations were near Brule (west-central), Clay Center (south-central), Concord (northeast), and Mead (east-central), Nebraska, United States. Treatments included crop residue only (no cover crop) and a multi-species cover crop mix, both broadcast-seeded before …


Plant Community Composition, Floristic Quality, And Establishment Of Roadside Revegetation In Nebraska, Usa, Jonathan M. Soper Jul 2018

Plant Community Composition, Floristic Quality, And Establishment Of Roadside Revegetation In Nebraska, Usa, Jonathan M. Soper

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Roadside revegetation poses a challenge and opportunity for biodiversity conservation, as the land area occupied by roadsides is not expected to decline in the future. In the context of roadside revegetation activities in rural regions dominated by agricultural land uses, revegetation efforts can establish plant communities that offer unique species that would otherwise be absent on the landscape. To determine the efficacy of roadside revegetation efforts in 1) providing plant communities of high biodiversity value and 2) meeting the expectations of roadside revegetation managers for establishment, we quantified botanical composition, floristic quality, and success in seeding efforts to meet manager …


Cross Photoreaction Of Glyoxylic And Pyruvic Acids In Model Aqueous Aerosol, Sha-Sha Xia, Alexis J. Eugene, Marcelo I. Guzman Jul 2018

Cross Photoreaction Of Glyoxylic And Pyruvic Acids In Model Aqueous Aerosol, Sha-Sha Xia, Alexis J. Eugene, Marcelo I. Guzman

Chemistry Faculty Publications

Aerosols of variable composition, size, and shape are associated with public health concerns as well as with light-particle interactions that play a role in the energy balance of the atmosphere. Photochemical reactions of 2-oxocarboxylic acids in the aqueous phase are now known to contribute to the total secondary organic aerosol (SOA) budget. This work explores the cross reaction of glyoxylic acid (GA) and pyruvic acid (PA) in water, the two most abundant 2-oxocarboxylic acids in the atmosphere, under solar irradiation and dark thermal aging steps. During irradiation, PA and GA are excited and initiate proton-coupled electron transfer or hydrogen abstraction …


The Effect Of Destoning And Enzymatic Pretreatments On The Biofuel Production From Olive Cake, Patrick Tai Jul 2018

The Effect Of Destoning And Enzymatic Pretreatments On The Biofuel Production From Olive Cake, Patrick Tai

Master's Theses

More than 16,000 tons of olive cake was produced in the United States in 2017. Olive cake is a by-product of olive oil extraction, which has limited animal feed potential, and poses an environmental threat when landfilled due to its high organic load and polyphenol content. This residue has potential for biofuel (bioethanol and biomethane) production because it is rich in polysaccharides such as pectin, hemicellulose, and cellulose. Yet, olive cake contains olive stones that can impede its conversion to biofuel. Therefore, two methods of destoning, centrifugation and screening by horizontal screw press, were first compared. Both methods removed an …


Effect Of Bioaugmentation Product Biowish® Aqua™ On Nitrogen Removal In Wastewater, Patrick Cassidy Kalvass Jun 2018

Effect Of Bioaugmentation Product Biowish® Aqua™ On Nitrogen Removal In Wastewater, Patrick Cassidy Kalvass

Master's Theses

Biological nutrient removal (BNR) from wastewater, and specifically nitrogen removal, is a growing concern to wastewater dischargers such as municipalities. Excess nutrients in effluent can create problems such as eutrophication, toxicity to aquatic life, and dissolved oxygen depletion in receiving waters. BNR systems have been installed in many locations with success, but their operation presents operational and financial demands greater than conventional biological treatment. Nitrogen removal is typically performed in sequential autotrophic nitrification and denitrification, which increases needed energy input, operational complexity, and therefore cost. Simultaneous nitrification-denitrification (SNdN) achieved in a single system has also been successfully implemented, however operational …


Radical Social Ecology As Deep Pragmatism: A Call To The Abolition Of Systemic Dissonance And The Minimization Of Entropic Chaos, Arielle Brender May 2018

Radical Social Ecology As Deep Pragmatism: A Call To The Abolition Of Systemic Dissonance And The Minimization Of Entropic Chaos, Arielle Brender

Student Theses 2015-Present

This paper aims to shed light on the dissonance caused by the superimposition of Dominant Human Systems on Natural Systems. I highlight the synthetic nature of Dominant Human Systems as egoic and linguistic phenomenon manufactured by a mere portion of the human population, which renders them inherently oppressive unto peoples and landscapes whose wisdom were barred from the design process. In pursuing a radical pragmatic approach to mending the simultaneous oppression and destruction of the human being and the earth, I highlight the necessity of minimizing entropic chaos caused by excess energy expenditure, an essential feature of systems that aim …


Chloride Salt Inhibition On Lipid Production In Wastewater-Grown Algae For Biofuel Production, Will Richardson May 2018

Chloride Salt Inhibition On Lipid Production In Wastewater-Grown Algae For Biofuel Production, Will Richardson

Biological and Agricultural Engineering Undergraduate Honors Theses

Algae are increasingly being recognized as useful organisms for many applications in today’s world. Their ability to remove nitrogen, phosphorus, and trace metals from water while adding oxygen to water makes them an attractive tertiary treatment technology in municipal wastewater treatment facilities. At the same time, algae produce lipids and carbohydrates that are useful for biofuel production, and they are not a human food crop unlike many biofuel feedstocks. In this study the effect of increased chloride concentrations in wastewater was assessed on the ability of two species of algae, Chlorella vulgaris and Scenedesmus dimorphus, to function as a …


Transcriptomics To Develop Biochemical Network Models In Cyanobacteria, Bridget E. Hegarty, Jordan Peccia, Ratanachat Racharaks Apr 2018

Transcriptomics To Develop Biochemical Network Models In Cyanobacteria, Bridget E. Hegarty, Jordan Peccia, Ratanachat Racharaks

Yale Day of Data

Through targeted genetic manipulations guided by network modeling, we will create a flexible, cyanobacteria-based platform for the production of biofuel-precursors and valuable chemical products. To build gene-metabolite predictive models, we have characterized Synecococcus elongatus sp. UTEX 2973’s (henceforth, UTEX 2973) gene expression and metabolite production under a number of environmental conditions.


Hawai'i Wildlife Fund V. County Of Maui, Lowell J. Chandler Apr 2018

Hawai'i Wildlife Fund V. County Of Maui, Lowell J. Chandler

Public Land & Resources Law Review

In Hawai’i Wildlife Fund v. County of Maui, the Ninth Circuit held that the plain language of the Clean Water Act provides jurisdiction over indirect discharges of pollutants from a point source into groundwater that is shown to be connected to navigable waters. The court found that studies confirmed pollutants entering the Pacific Ocean were fairly traceable to the County of Maui’s sewage disposal wells. In affirming the district court’s ruling, the Ninth Circuit held that Maui County violated the Clean Water Act by discharging pollutants into a navigable water without the required permit. The court also concluded the …


Functional Trait Differences Between Native Bunchgrasses And The Invasive Grass Bromus Tectorum, Huiqin H.E., Thomas A. Monaco, Thomas A. Jones Mar 2018

Functional Trait Differences Between Native Bunchgrasses And The Invasive Grass Bromus Tectorum, Huiqin H.E., Thomas A. Monaco, Thomas A. Jones

Forage and Range Research Laboratory Publications

We conducted 30- and 60-d greenhouse experiments to compare functional traits of Bromus tectorum (invasive annual grass) and four perennial bunchgrasses under well-watered or drought conditions. Even under drought, B. tectorum experienced significantly less stress (i.e., higher xylem pressure potential and greater shoot water content, water use per day and water-use efficiency) and biomass production than the perennial grasses after 30 d. However, after 60 d, its superiority was reduced under infrequent watering. Differences among perennial grasses were more pronounced for physiological traits under infrequent watering and for morphological traits under frequent watering. Elymus multisetus (fastgrowing species) had a higher …


The Tensile Root Strength Of Emergent Coastal Macrophytes, Lauris Olivia Hollis Mar 2018

The Tensile Root Strength Of Emergent Coastal Macrophytes, Lauris Olivia Hollis

LSU Doctoral Dissertations

Spartina patens is a dominant emergent macrophyte in fresh, intermediate, and brackish marshes along the Atlantic and Gulf coasts of United States where its biomechanical properties are a key component of wetland health and resilience. Its root biomass and tensile root strength are essential for anchorage, erosion protection, and are important determinants of soil strength. Nutrients and the herbicide atrazine are suspected of negatively impacting this wetland plant and others. The objectives of this study were to: 1) ascertain the tensile root strength of five emergent coastal macrophytes in coastal estuaries, and 2) test the effects of nutrient addition, atrazine …


Integrated Analysis Of The Value Of Wetland Services In Coastal Adaptation; Methodology And Case Study Of Hampton-Seabrook Estuary, New Hampshire, Paul Kirshen, Semra Aytur, David M. Burdick, Diane Foster, Tom Lippmann, Ellen Douglas, Sydney Nick, Chris Watson Jan 2018

Integrated Analysis Of The Value Of Wetland Services In Coastal Adaptation; Methodology And Case Study Of Hampton-Seabrook Estuary, New Hampshire, Paul Kirshen, Semra Aytur, David M. Burdick, Diane Foster, Tom Lippmann, Ellen Douglas, Sydney Nick, Chris Watson

Jackson Estuarine Laboratory

The present impacts from coastal storms and high tides grow significantly over time due to SLR even over the relatively short period to 2060. Hydrodynamic model simulations of storm surge with and without sea level rise scenarios show that although flooding and inundation increases with increasing subtidal forcing and higher sea level, dissipation of the tide and storm surge in the estuary channel somewhat limits the maximum inundation that might otherwise be expected in the back marsh areas. The estuary is dominated by high marsh, which lies high in the intertidal zone and by 2060 it will convert to mostly …


Pressure-Driven Stabilization Of Capacitive Deionization, Landon S. Caudill Jan 2018

Pressure-Driven Stabilization Of Capacitive Deionization, Landon S. Caudill

Theses and Dissertations--Mechanical and Aerospace Engineering

The effects of system pressure on the performance stability of flow-through capacitive deionization (CDI) cells was investigated. Initial data showed that the highly porous carbon electrodes possessed air/oxygen in the micropores, and the increased system pressure boosts the gases solubility in saline solution and carries them out of the cell in the effluent. Upon applying a potential difference to the electrodes, capacitive-based ion adsorption occurs in competition with faradaic reactions that consume oxygen. Through the addition of backpressure, the rate of degradation decreases, allowing the cell to maintain its salt adsorption capacity (SAC) longer. The removal of oxygen from the …


Modeling Canopy Effect In The Great Lakes Cladophora Model, Ankita Bakshi Jan 2018

Modeling Canopy Effect In The Great Lakes Cladophora Model, Ankita Bakshi

Dissertations, Master's Theses and Master's Reports

Cladophora glomerata is a filamentous green alga native to the Great Lakes. However, its nuisance growth in phosphorus rich waters negatively affects the lakes’ aesthetic and water quality. The Great Lakes Cladophora Model (GLCM) v1, developed in 1982, was the first mechanistic model to simulate Cladophora growth basing phosphorus availability and environmental conditions followed by Cladophora Growth Model and GLCM v2. In this study, the light and temperature mediation factors for Cladophora net growth are revised as a necessary step prior to the development of a self-shading algorithm. The concept of a fixed-value, maximum achievable biomass (carrying capacity) employed in …


Rice Hull Bioreactor For Recirculating Aquaculture, Marlon A. Greensword Aug 2017

Rice Hull Bioreactor For Recirculating Aquaculture, Marlon A. Greensword

LSU Doctoral Dissertations

The engineering of floating media biofilters has been optimized over the years. The backwashing process has made them more energy and water efficient. Likewise, moving bed bioreactors (MBBR) are gaining interest and popularity because they are relatively affordable to build. Yet, developing countries’ aquaculture production remains largely excluded from the advances made in recirculating aquaculture systems (RAS). This discrepancy is partially driven by the high costs of media such plastic beads and Kaldnes (KMT) media, commonly used in MBBR.

This dissertation evaluates the usability and profitability of rice hulls (RH), an abundant by-product in many developing nations, as a sinking …


Full-Water Column Turbulence Parameterization Of Stratified Waters In Southern Lake Michigan, Kyla A. Prendergast, Cary D. Troy, David Cannon Aug 2017

Full-Water Column Turbulence Parameterization Of Stratified Waters In Southern Lake Michigan, Kyla A. Prendergast, Cary D. Troy, David Cannon

The Summer Undergraduate Research Fellowship (SURF) Symposium

Full water column mean flow and turbulence structure was characterized at two stratified locations in Lake Michigan (a. Muskegon, MI; b. Michigan City, IN) in order to better understand the filtration potential of invasive quagga mussels. Invasive quagga mussels in Lake Michigan are filter feeders and can dramatically alter clarity as well as the biological/chemical characteristics of the water column. This filtering capacity is highly contingent on turbulence characteristics throughout the water column, which is poorly understood in the Great Lakes. Using velocity, temperature, and turbulence data collected from these locations, the structure of the water column turbulence was modeled …


Geometry-Based Mass Grading Of Mango Fruits Using Image Processing, M. A. Momin, Md Towfiqur Rahman, M. S. Sultana, C. Igathinathane, A. T. M. Ziauddin, T. E. Grift Jun 2017

Geometry-Based Mass Grading Of Mango Fruits Using Image Processing, M. A. Momin, Md Towfiqur Rahman, M. S. Sultana, C. Igathinathane, A. T. M. Ziauddin, T. E. Grift

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Mango (Mangifera indica) is an important, and popular fruit in Bangladesh. However, the post-harvest processing of it is still mostly performed manually, a situation far from satisfactory, in terms of accuracy and throughput. To automate the grading of mangos (geometry and shape), we developed an image acquisition and processing system to extract projected area, perimeter, and roundness features. In this system, images were acquired using a XGA format color camera of 8-bit gray levels using fluorescent lighting. An image processing algorithm based on region based global thresholding color binarization, combined with median filter and morphological analysis was developed …


Oxidation Of Substituted Catechols At The Air-Water Interface: Production Of Carboxylic Acids, Quinones, And Polyphenols, Elizabeth A. Pillar, Marcelo I. Guzman Apr 2017

Oxidation Of Substituted Catechols At The Air-Water Interface: Production Of Carboxylic Acids, Quinones, And Polyphenols, Elizabeth A. Pillar, Marcelo I. Guzman

Chemistry Faculty Publications

Anthropogenic activities contribute benzene, toluene, and anisole to the environment, which in the atmosphere are converted into the respective phenols, cresols, and methoxyphenols by fast gas-phase reaction with hydroxyl radicals (HO(•)). Further processing of the latter species by HO(•) decreases their vapor pressure as a second hydroxyl group is incorporated to accelerate their oxidative aging at interfaces and in aqueous particles. This work shows how catechol, pyrogallol, 3-methylcatechol, 4-methylcatechol, and 3-methoxycatechol (all proxies for oxygenated aromatics derived from benzene, toluene, and anisole) react at the air-water interface with increasing O3(g) during τc ≈ 1 μs contact time and contrasts their …


Quantifying Cyanide Inhibition Of Nitrification And Developing Cost-Effective Treatment Processes, Germano M. Salazar-Benites Apr 2017

Quantifying Cyanide Inhibition Of Nitrification And Developing Cost-Effective Treatment Processes, Germano M. Salazar-Benites

Civil & Environmental Engineering Theses & Dissertations

All wastewater treatment plants that operate multiple hearth furnaces (MHF) and are required to nitrify must manage the inhibitory effects of free cyanide (HCN, CN-) in the scrubber return flows due to inhibitory impacts on nitrifying bacteria.

HRSD Boat Harbor Treatment Plant (BHTP) a 25 MGD facility consisting of primary and secondary treatment, employs an anoxic selector process for nitrification and partial denitrification and operates a MHF. There is a desire to improve TN removal performance at BHTP due to an annual mass-based bubble permit limit on a combined discharge from seven HRSD plants, and there are no discharge limitations …


Characterization Of Ecological Water Stress In The U.S. Great Lakes Region Using A Geospatial Modeling Approach, Sara Alian Jan 2017

Characterization Of Ecological Water Stress In The U.S. Great Lakes Region Using A Geospatial Modeling Approach, Sara Alian

Dissertations, Master's Theses and Master's Reports

Anthropocentric water resources management affects aquatic habitats by changing streamflow regime. Understanding the impacts of water withdrawal from different sources and consumption by various economic sectors at different spatial and temporal scales is key to characterizing ecologically harmful streamflow disturbances. To this end, we developed a generic, integrative framework to characterize catchment scale water stress at annual and monthly time scales. The framework accounts for spatially cumulative consumptive and non-consumptive use impacts and associated changes in flow due to depletion and return flow along the stream network. Application of the framework to the U.S. Great Lakes Region indicates that a …