Environmental Engineering Commons^™

Techno-Economic And Life Cycle Assessment Of Hydrothermal Processing Of Microalgae For Biofuels And Co-Product Generation, Andrew P. Bessette

Civil & Environmental Engineering Theses & Dissertations

Traditional processing methods of algae to biofuels require dewatering after harvesting of the algae before the lipids can be extracted. This is typically the most energy intensive and therefore the most expensive step. Old Dominion University (ODU) has successfully utilized a flash hydrolysis (a kind of hydrothermal) process where proteins are solubilized into the liquid phase of product and the remainder lipid-rich, low nitrogen product is separated into a solid phase. The solid phase (lipid-rich) is then an ideal candidate for biofuel feedstock and the liquid phase, or hydrolysate, can be used for coproducts such as a source of nutrients …

Simplified, Alternative Formulation Of Numerical Simulation Of Proton Exchange Membrane Fuel Cell, Russell L. Edwards

Mechanical & Aerospace Engineering Theses & Dissertations

Three-Dimensional proton exchange fuel cell (PEMFC) operation in steady-state is simulated with computational fluid dynamics / multiphysics software that is based upon the finite-element method. PEMFC operation involves the simultaneous simulation of multiple, interconnected physics involving fluid flows, heat transport, electrochemical reactions, and both protonic and electronic conduction. Modeling efforts have varied by how they treat the physics occurring within and adjacent to the membrane-electrode assembly (MEA). Several approaches treat the MEA as part of the computational domain, solving multiple, and coupled conservation equations via the CFD approach within the 3 regions of the MEA. The thickness dimensions of the …

The Evaluation Of Enhancing Biological Phosphorus Removal And Improving Settleability Using Mainstream Hydrocyclones For External Selection, Amanda Carrie Ford

Civil & Environmental Engineering Theses & Dissertations

Hydrocyclones, which receive mixed liquor tangentially, separate lighter solids from more dense solids through their tapered shape. Increasing the velocity of liquid as it moves downward allows for the selection of a desired solids fraction. Limited research has been conducted utilizing 20 m³hr^-1 hydrocyclones, with the intent of improving settleability and biological phosphorus removal (Bio-P) for mainstream processes. Improved settleability would allow for increased capacity in the secondary clarifiers which prevents the loss of biomass and subsequent treatment disruption, especially during wet weather scenarios. In addition, treatment intensification can be accomplished by maintaining a higher mixed liquor …

Micropollutant-Free Nutrient Recovery: Adsorption Of Micropollutants On Ion Exchangers And Biosolids-Derived Biochar, Yiran Tong

Dissertations (1934 -)

The presence of excessive nutrients in treated wastewater effluent is a growing concern in terms of water quality and ecological balance. Thus, removal of nutrients is of great interest. Moreover, the removed nutrients can be recovered in forms amenable for agricultural reuse, which yields a sustainable supply of nonrenewable phosphorus that can be used to support global food production. As nutrient recovery gains interest, it is essential that the products be free of harmful contaminants. One class of contaminants of great concern is organic micropollutants. To help address these issues, this study evaluated the fate and impact of micropollutants during …

Predicting Effects Of Climate Change And Sea Level Rise On Hydrologic Processes In A Mid-Atlantic Coastal Watershed, Rui Li

Civil & Environmental Engineering Theses & Dissertations

This dissertation assessed impacts of Climate Change (CC) and Sea Level Rise (SLR) on coastal hydrologic processes using the Lynnhaven River watershed as a test bed. The watershed is part of Chesapeake Bay Watershed and hydraulically connected with mid-Atlantic Ocean. Six CC scenarios were considered in terms of eight Regional Climate Models’ predictions for three Intergovernmental Panel on Climate Change (IPCC) emission assumptions, namely, B1, A1B, and A2, for two future periods, namely 2046 to 2065 and 2081 to 2099. The ensemble means of downscaling results from four methods were used to represent the future climates. On the other hand, …

Modeling Effects Of Rainwater Harvesting Systems On Water Yield Increase And Non-Beneficial Evaporation Reduction To Sustain Agriculture In A Water-Scarce Region Of China, Tennille Wade

Civil & Environmental Engineering Theses & Dissertations

The northwestern region of China, which has an arid/semiarid climate, relies heavily on agriculture to provide food for the growing population. Climate change is affecting water availability in the region, causing long periods of drought and water scarcity followed by shorter periods of heavy rainfall and excess water availability. The ridge and furrow rainwater harvesting systems (RFRWHS) are a means of solving the problem of water scarcity; the systems can replenish soil moisture, reduce non-beneficial evaporation from bare soils, and increase surface water yield. In such a region, the hydrologic cycle is dominated by soil evaporation, leading to minimal surface …

Artificial Recharge Of Groundwater As A Management Tool For The Kabul Basin, Afghanistan, Mohammad Farid Masoom

LSU Master's Theses

Decades of war and political instability, consecutive droughts, population increase and displacement, caused serious infrastructural damages to water resources of Afghanistan. The main source of water supply for people in Afghanistan is groundwater. However, over-exploitation of groundwater has led to groundwater level declines in most parts of the country. Kabul, the largest city of Afghanistan, is the capital city with a population of 4.5 million and the fifth fastest-growing city in the world. The city has observed groundwater level declines of 5-10 meters (m) since 1980. Decline of about 30 m has also been observed in one of the monitoring …

Selection Of Energy Systems In Aquaculture Through A Decision Support Tool Considering Economic And Environmental Sustainability, Youngwoon Kim

USF Tampa Graduate Theses and Dissertations

Aquaculture had already been distinguished as an important component of global food security and economics. However, aquaculture has expanded at the cost of natural resources and the environment. The vulnerability of the aquaculture industry due to the consequences of global environmental changes and energy price fluctuations has been addressed in various studies. The identification, planning, and implementation of sustainable energy systems are important to ensure the long term economic and environmental sustainability of aquaculture.

This research investigated sustainable energy systems for aquaculture using a life cycle approach, allowing for the identification of the most sustainable energy options under different geographical …

A Surprising Symbiosis: Examining The Mutualism In Department Of Defense Conservation Partnerships, Andrew J. Lankow

Theses and Dissertations

Because of the DoD’s unique and significant role in the conservation of natural resources, military leaders and natural resource managers need a trail guide to frame interagency collaboration in a way that shapes productive partnerships. The purpose of this research was to examine successful DoD conservation partnerships in order to identify key success factors (KSFs) and the most prominent challenges faced, and how those characteristics enable the accomplishment of each partner’s objectives. The research questions were answered through a comprehensive literature review and the use of the multiple-case study method. 19 key informants from three installations participated in semi-structured interviews, …

Cost And Performance Difference Of High Performance Sustainable Buildings, Philip A. Ramsey

Theses and Dissertations

Varying legislation and executive orders coupled with needs for energy resiliency have led the United States Air Force to pursue sustainable construction. The limited understandings of initial costs to implement these changes have contributed to poor project cost estimating and changed implementation of legal requirements. A student t-test for populations with unequal variance was accomplished on the final normalized contract cost of 1628 Air Force Military Construction (MILCON) projects executed between 2002 and 2017. Future design considerations for net zero energy buildings were compiled from a net zero energy residential community in Fontana, California. There was no statistically significant difference …

Impact Of Substrate To Inoculum Ratio On Methane Production In High Solids Anaerobic Digestion (Hs-Ad) Of Food Waste, Yard Waste, And Biosolids, Phillip James Dixon

USF Tampa Graduate Theses and Dissertations

High solids anaerobic digestion (HS-AD) is an alternative for managing the organic fraction of municipal solids waste (MSW), which produces mainly methane (CH4) and fertilizer as byproducts. HS-AD offers a potentially more economically and environmentally sustainable option compared with landfilling or incineration waste-to-energy facilities. However, HS-AD is a complex process requiring specific microbial communities working together symbiotically. Previous studies have found that the substrate to inoculum (S/I) ratio affects CH4 production and yield in HS-AD reactors by affecting substrate mass and energy transfer as well as microbial activity. In this thesis, biochemical methane potential (BMP) assays were used to investigate …

Field Testing Of Affordable Well Head Protection For Locally Manufactured, Self-Supply Pitcher Pumps On Manually Driven Tubewells In Madagascar, Michal Usowicz

USF Tampa Graduate Theses and Dissertations

Lack of water access is an issue of global importance. The WHO and UNICEF’s Joint Monitoring Program estimated that in 2015 71% of the world’s population used a safely managed drinking water source and 89% of the world’s population used an improved water source within a 30-minute round trip of home. Madagascar’s national statistics lags far behind these global statistics with 54% of the population using improved water sources, 31% using unimproved water sources, and 16% with no service at all.

This research studied water access in Madagascar with self-supply Pitcher Pumps attached on hand-driven tubewells. The term self-supply in …

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 …

Comparison Of Functional Porous Organic Polymers (Pops) And Natural Material Zeolite For Nitrogen Removal And Recovery From Synthetic Urine, Yan Zhang

USF Tampa Graduate Theses and Dissertations

Urine comprises around 1% of domestic sewage volume but holds 80% of total nitrogen. Source separation is a sustainable way to wastewater management than traditional way due to low energy cost and preventing certain pollutants into wastewater treatment plants. Currently, removing and recovering nitrogen from source-separated urine has attracted more and more interests. Of them, ion exchange was used for removal and recovery of nitrogen in the form of ammonia from synthetic urine for potential application as a fertilizer in agriculture. No previous research studies were conducted to investigate the removal and recovery of nitrogen from hydrolyzed urine by ion …

Design And Implementation Of A Ferrocement Improved Cookstove In Rural Panama, Josh Donegan

USF Tampa Graduate Theses and Dissertations

Household air pollution contributes to the premature death of more than 4 million people annually. Improved cookstoves are one technological intervention that can potentially reduce exposure to household air pollution. However, improved cookstove implementation programs need to consider measures to increase sustainability and promote long-term adoption. The objectives of this research were 1) to develop and implement a new ferrocement cookstove for Peña Blanca, a rural indigenous community in the Ngäbe-Bugle region of Panama, 2) to evaluate its potential sustainability in comparison to the most common cooking technologies observed in the community, 3) to prepare a construction manual for the …

Physical And Chemical Interactions Affecting U And V Transport From Mine Wastes, Sumant Avasarala

Civil Engineering ETDs

This research investigates the physical and chemical interactions that affect the transport of uranium (U) and vanadium (V) from uranium mine waste sites by integrating laboratory experiments and reactive transport modelling with various spectroscopy, microscopy, and diffraction techniques. The document consists of results from three related studies. In the first study (Chapter 3), the reactive transport of U and V was investigated by sequentially reacting mine wastes collected from Blue Gap/Tachee Claim-28 mine site, AZ with 10mM NaHCO₃ (7.9) and 10mM CH₃COOH (3.4) during continuous flow through column experiments. Under both of these conditions (pH 3.4 and …

The Effect Of Ms2 Bacteriophage On The Activity And Performance Of Activated Sludge, Sean M. Stuntz

Theses and Dissertations

As a medical waste product, the MS2 bacteriophage has been discharged into wastewater distribution and treatment networks. To categorize its impact to suspended growth treatment methods, this research investigated the effect of the MS2 bacteriophage on activated sludge through a series of respirometry tests. The effects of MS2 bacteriophage at a concentration of 3.2x10⁸ PFU/mL were assessed by determining peak O₂ consumption, cumulative O₂ consumption, molar CO₂/O₂ ratios, and shape factors. None of the MS2 samples caused statistically significant effects on the peak or cumulative O₂ consumption. The molar CO₂/O_{2 …}

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 …

Climate-Driven Crop Yield And Yield Variability And Climate Change Impacts On The U.S. Great Plains Agricultural Production, Meetpal Singh Kukal, Suat Irmak

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Climate variability and trends affect global crop yields and are characterized as highly dependent on location, crop type, and irrigation. U.S. Great Plains, due to its significance in national food production, evident climate variability, and extensive irrigation is an ideal region of investigation for climate impacts on food production. This paper evaluates climate impacts on maize, sorghum, and soybean yields and effect of irrigation for individual counties in this region by employing extensive crop yield and climate datasets from 1968–2013. Variability in crop yields was a quarter of the regional average yields, with a quarter of this variability explained by …

Decision Support System For The Design And Planning Of Low-Impact Development Practices: The Case Of Seoul, Jae-Yeol Song, Eun-Sung Chung, Soo Hyun Kim

Civil and Environmental Engineering Faculty Publications and Presentations

This study presented the conceptual framework of the water-management analysis module (WMAM) to derive effective physical specifications for the design and planning of low-impact development (LID) practices using the storm-water management model (SWMM). This decision-support system can be used for six LID types and has the following key capabilities: determining relevant LID design parameters within the SWMM that critically influence the hydrological cycle components using a simple sensitivity analysis and determining the best hydrological values for LID planning specification. This study analyzed a highly urbanized university campus as a case study to determine the design and planning specifications for an …