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Bioventing and biosparging at a site contaminated with JP-4 and TCEHinlein, Erich S 01 January 1999 (has links)
During the 1950's, 60's and 70's, a great number of military and civilian airfields dumped thousands of gallons of fuel, waste oils and solvents into the subsurface environment as part of routine fire training activities. These areas now pose a threat to humans and wildlife. This research investigates bioventing and biosparging as remedial alternatives at Plattsburgh Air Force Base (PAFB) where soils are heavily contaminated with JP-4 and solvents. To begin the investigation, site geology and contaminant constituents were thoroughly characterized. Installation and sampling of soil gas monitoring points confirmed the presence of hydrocarbon and TCE vapors in the vadose zone as well as a gradient of decreasing oxygen and increasing carbon dioxide from the ground surface to the water table indicative of aerobic hydrocarbon degradation. New models were developed and used to determine soil gas constituent mass fluxes during ambient and bioventing/biosparging conditions. Mass fluxes of hydrocarbons, TCE, oxygen and carbon dioxide were calculated during ambient conditions based on the soil gas profiles. Combining this information with contaminant characterization and extent yielded an estimated cleanup time of approximately 150 years. After the initial characterization, the bioventing system, operating above the water table, was activated followed by sampling and analysis of O2, CO2, TCE, and HCs. Following 6 months of operation, compound mass fluxes under the pilot scale bioventing system indicated an increase in the hydrocarbon degradation rate by a factor of 4 for an estimated cleanup time of 37 years. After ending the bioventing phase, the biosparging system, injecting air below the water table, was subsequently activated and the same soil gas constituents measured over a period of 4 months. Compound mass flux results indicated a hydrocarbon degradation rate increase over ambient conditions by a factor of 2 (75 years). A new, near surface soil gas measurement tool was developed allowing sample collection in shallow (1m) soils with high resolution (2cm). Based on the pilot scale bioventing and biosparging results, either one or a combination of both of these remedial alternatives would accelerate the cleanup process at PAFB for a reasonable cost.
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Socioeconomic Dimensions of Urban Greenspace Access and Usage PatternsSimon, Joshua J. January 2020 (has links)
No description available.
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The Invasion Ecology of Ivy (Hedera spp.) in Portland's Forest ParkButler, Eric Paul 26 August 2019 (has links)
Invasive ivy (Hedera spp.) has extensive impacts on Pacific Northwest urban forests, many of which are not yet fully understood. In this study of Forest Park, Portland, Oregon, I evaluated several environmental variables obtained or derived from monitoring datasets at three spatial scales to determine the following: how ivy is spatially distributed; what factors are most correlated with ivy abundance; and how ivy abundance influences shrub community composition. I found that ivy is significantly clustered at all scales with multiple apparent epicenters along the park's urban periphery. Using NMDS ordination, I determined that ivy is a significant factor in the ecosystem in general and the shrub community in particular at all scales. Random Forest regression found different sets of important environmental predictors and shrub associations at each scale, but spatial relatedness and the abundance of Mahonia nervosa consistently emerged from predictor and shrub models, respectively. All this suggests that while ivy has complicated and often site- and scale-specific interactions with its environment, its clustered dispersal pattern may be at least as important as conditions in the ecosystems it invades. However, each of the monitoring datasets had significant limitations. Future research with refined data methods could be used to infer causal relationships, measure changes over time, and model ivy's ability to spread through the Forest Park landscape.
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The influence of plural governance systems on rural coastal livelihoods: the case of Kosi BayMbatha, Nonhlanhla Philile 21 February 2019 (has links)
Thousands of rural households along the South African coast rely on fisheries resources, forest products and agricultural resources in order to support their livelihoods. These customary livelihoods have continued in many rural areas despite restrictive policies and laws during the colonial and apartheid administrations. More contemporary restrictions have emerged in the post-1994 democratic state due to an expansion of the conservation estate and increased efforts to improve compliance in existing protected areas. This conservation drive is due largely to environmental concerns as well as the country’s international and national commitments to enhance biodiversity protection. Statutory conservation governance in rural areas in South Africa often operates in parallel to traditional and customary systems of governance. This results in confusion and conflict emanating from the plurality of governance systems, actors and institutions whose powers, roles and approaches are informed by different norms, discourses, values, images and worldviews. This study seeks to enhance understanding about the conceptual linkages between livelihoods and plural governance systems, using the case study of Kosi Bay, a coastal region in northern KwaZulu-Natal, South Africa. This was done using a case study methodology and empirical research to: a) describe livelihood strategies; b) identify and document statutory, traditional and customary governance structures linked to coastal resource governance; c) explore the norms, discourses, images, values and worldviews that have informed coastal resource governance in this area; d) review and analyse the influences of plural coastal governance systems on livelihood strategies; e) contribute towards conceptual frameworks that link livelihoods and governance and; f) make recommendations for improved livelihoods and governance in rural areas in the South African context and beyond. The study underscores the manner in which legal pluralism and historical context affect and influence governance processes, and demonstrates that the day-to-day livelihoods of rural people are diverse and dynamic, and can be profoundly affected by meta-level and institutional governance processes and practices. It concludes by highlighting the manner in which legal pluralism and historical context significantly affect and influence governance processes that shape rural livelihoods, and provides a set of recommendations for consideration.
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An analysis of the education potential of sites in the Cape Peninsula for secondary school fieldwork in environmental studiesNightingale, Charles S January 1977 (has links)
In South African secondary schools much less fieldwork is undertaken than in a number of other countries despite fieldwork being required by some school syllabuses and the fact that, in many areas, suitable sites are ready to hand. In an attempt to assess the nature of future demands for fieldwork sites, this study reviews developments in education which lead to increasing emphasis on teaching outside the classroom, and the reasons why so little fieldwork is being done are analyzed. A methodology is developed for selecting fieldwork sites taking into account educational priorities and practical constraints. This is worked out in practice by drawing up a fieldwork syllabus for a particular school, and selecting sites in the Cape Peninsula for field studies. Finally, the educational potential of a sample of these sites is indicated by means of exercises prepared for secondary school children.
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Index-based Approach with Remote Sensing for the Assessment of Extreme Weather Impact on Watershed Vegetation DynamicsBellanthudawage, Kushan 01 January 2021 (has links) (PDF)
Spatial technologies such as satellite remote sensing can be used to identify vegetation dynamics over space and time, which play a critical role in earth observations. Biophysical and biochemical features associated with vegetation cover can then be used to elucidate climate change impact such as floods and droughts on ecosystem that may in turn affect watershed-scale water resources management. Unlike single flood or drought event, intermittent extreme weather events may exert more physiological and biological pressures on the canopy vegetation. This study aims to investigate the climate change impacts on canopy vegetation, which occurred from March 2017 to October 2017 in the Santa Fe River Watershed, Florida, the United States of America. First, this study explores the effect of Hurricane Irma on vegetation dynamics via the pre and post landfall conditions in terms of biophysical and biochemical features. The environmental system analysis compares a suite of remote sensing indices: enhanced vegetation index (EVI), leaf area index (LAI), fraction of photosynthetically active radiation (FPAR), evapotranspiration (ET), land surface temperature (LST), gross primary productivity (GPP), and global vegetation moisture index (GVMI) for a holistic assessment. The satellite images from MODIS (Moderate Resolution Imaging Spectroradiometer) were projected from the MODIS Sinusoidal projection to WGS84 geographic coordination systems to conduct the essential spatial analysis. In addition, the evolution of features associated with the vegetation was analyzed in terms of a new indicator, the functional capacity of the different land uses for grassland, evergreen forested, deciduous forested, and agricultural land uses to elevate our understanding of the ecosystem's sustainability and possible recovery processes as a response to damage caused by the Hurricane Irma event. Urban land use and open water space showed a low level of EVI, LAI, FPAR, GVMI, whereas LST and ET were significantly higher compared to the forested and agricultural land uses. Coupling LAI and LST,EVI and GVMI, or EVI and LST confirms the hypotheses of the study, namely that biophysical features pre and post landfall of Hurricane Irma exhibit significant spatial and temporal variations, and integration of pairwise comparisons of biophysical and biochemical features can better portray the impacts driven by the landfall of Hurricane Irma than a single biophysical feature. The functional capacity of the ecosystem can be derived in terms of EVI, LAI, GVMI, and LST analysis over grassland, evergreen forested, deciduous forested, and agricultural land to quantitively reflect the ecosystem response due to landfall of Hurricane Irma. Secondly, emphasis was placed on determining the impacts of alternating adverse flood and drought events on four vegetative land use types via remote sensing and contrasting the vegetation canopy resilience, resistance, and elasticity in intermittent extreme weather events from March to Oct. 2017 in the same subtropical watershed. Nonlinear extreme weather events in sequence discriminated the marginal resilience, resistance, and thus elasticity of four land uses showing high resilience and elasticity in transitions of dry and wet events. It is indicative that thermodynamics driven LST served as the energy source that explains the forcing of variations of these vegetation indices and sustainability indicators.
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Using iPhone Significant Location Data to Improve Air Pollution Exposure EstimationEastman, Elizabeth 01 December 2021 (has links) (PDF)
An accurate estimation of human exposure to ambient air pollution is crucial for air pollution health studies. Time-activity patterns may introduce substantial uncertainties in exposure estimation. As smartphones are becoming increasingly popular and their ownership is becoming ubiquitous in the US. Virtually all smartphones can collect location data, and such data is continuously somewhere. Therefore, it is clear that such stored location data has the potential to be used for characterizing an individual's time-activity patterns for air pollution health studies. However, studies on the accuracy and feasibility of using a smartphone's location data in air pollution exposure estimation are still limited. Here, a pilot study was conducted to evaluate the accuracy of the iPhone's Significant Location (iSL) data, in capturing an individual's time-activity patterns. Specifically, iSL data collected from a single individual were compared with reference GPS data to evaluate the ability of iSL in capturing: 1) all microenvironments the subject visited during the study period; 2) the duration and frequency the subject spent in each microenvironment, if the location is labelled as significant and captured by iSL; and 3) the impact of neglecting time-activity pattern on the subject's air pollution exposure estimates. The results showed a favorable performance of the iSL data, which accurately captured the time the subject spent in 16 microenvironments encompassing 93% of all time during the study period. To further understand the availability of iSL data, an online survey was conducted among 349 participants. Among the surveyed users, 72% have iSL data available which highlighted the potential substantial coverage of iSL data. With the popularity of iPhone, detailed significant location data could be available for a considerable portion of the population, and such iSL data may have great potentials for improving retrospective air pollution exposure estimation.
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Emulsion Characterization Study for Improved Bilgewater Treatment and ManagementDiaz Hernandez, Daniela 01 January 2020 (has links)
The need for proper management of bilgewater to meet discharge regulations (e.g., 15 ppm oil) has revealed the necessity to expand the current understanding of bilgewater emulsions. This study proposed to evaluate emulsion stability under various environmental conditions and to identify governing parameters for emulsion formation. The stabilizing properties of eight-commercial cleaners and two-neat surfactants were evaluated. In situ characterization techniques were used for monitoring emulsion stability. Additionally, a needle-type pH microsensor and fluorescence spectroscopy were used for analyzing mass transfer at the oil-water interface. Water quality of extracted bilgewater showed to highly vary between vessels (e.g., conductivity: 1.74 -- 24 mS/cm, chemical oxygen demand [COD]: 1,279–42,800 mgO2/L, and total suspended solids [TSS]: 256–4,248 mg/L). Emulsion stability was significantly affected by surfactant type, temperature, and salinity. In particular, increase in salinity and temperature greatly reduced emulsion stability by enhancing emulsion coalescence. From the surfactants/detergents tested, emulsion stability was in the order of Type 1 > SDS > B&B > Power green > Solid surge> Calla= PRC > Triton X-100 > 6% AFFF= Blast-off from most to least stable. Suspended solids stabilized emulsions under certain environments, particularly at 0.5 x CMClog. Alkalinity of emulsifiers was found between 3.3 -- 413 mg/L CaCO3 and the presence of unknown additives in the NSBM#4 showed to increase emulsion alkalinity. pH microprofiles demonstrated the diffusion of additives at the interface, which was verified by the increase in bulk-water fluorescence, indicating the diffusion of organic compounds. In addition, the diffused additives enhanced the formation of stable emulsions. Overall, this study presents a systematic investigation of bilgewater emulsion characteristics using multi-faceted experimental approaches from conventional methods to a novel microsensor technique. The effect of environmental parameters on the formation and stability of bilgewater emulsions was evaluated. This work intended to assist in the selection of more suitable bilgewater treatment techniques and the detection of bilgewater conditions triggering emulsion stability.
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Chemically Stabilized Oil-in-water Emulsion Separation Using a Custom Aquaporin-based Polyethersulfone (PES) Forward Osmosis Membrane SystemRicchino, AnnMarie 01 January 2020 (has links)
The stability of oil-in-water emulsions is enhanced by the presence of surfactants in the water, thereby increasing difficulty of remediation. In this study, mineral oil and a standard bilge mix (SBM) were used as model oils for forward osmosis (FO) performance evaluation and two different high-concentration feed solutions (FS) were tested: 10,000 and 100,000 ppm oil/surfactant (9:1 Oil/Surfactant, wt %). It was hypothesized that the charge-charge interactions between the surfactant portion of the micelles and the membrane would play an important role in membrane fouling. Therefore, the effects of both an anionic surfactant (sodium dodecyl sulfate [SDS]) and a nonionic surfactant (Type 1) on fouling propensity as well as water and reverse salt flux (RSF) rates were evaluated. Water flux rates as high as 12.7 and 10.1 LMH (L m-2 h-1) were achieved for emulsion solutions using SDS as the emulsifier and containing mineral oil and SBM at concentrations of 10,000 ppm (9:1, oil/SDS), respectively, over a one-hour run-time. Furthermore, a 98% flux recovery resulting from a three-hour physical membrane cleaning using deionized (DI) water was observed for solutions containing 10,000 ppm mineral oil/SDS when run under FO mode, and an 87% recovery when run under pressure-retarded osmosis (PRO) mode following a 10-hour run time. Salt (NaCl) addition in the FS demonstrated a destabilization effect of the emulsions, which led to increased water permeation across the membrane when the osmotic pressure gradient was restored. These combined qualities endorse potential use of this FO membrane system as a potential low-cost treatment technology for bilgewater.
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Design, Synthesis and Characterization of Biomimetic, Bioinspired and Bio-related Functional Polymers for Atmospheric Water RecoveryAlqassar, Abdullah 01 January 2019 (has links)
Atmospheric water recovery in changing environments has received wide attention in environmental science and engineering communities due to rapid population growth and frequent droughts. This study is focused on the design, synthesis, and characterization of biomimetic, bioinspired, and bio-related functional polymers (b3p) to help resolve the water supply issue especially in arid or semi-arid regions. It is aimed to develop unique synthetic methods to access well-defined polymers with the aid of nanomaterials and metal to produce next generation polymer materials for better atmospheric water recovery. The design of such new b3p is bioinspired by some skin materials of biological species such as frogs, beetles, or spiders. Such synthetic efforts are also coupled with fundamental studies of the polymer functions and structures, providing renewed understanding of how molecular structure and processing parameters associated with different nanomaterials impact macroscopic properties. This research was conducted by using a class of cross-linked hydrophilic copolymers known as hydrogels that exhibit a high fluid absorbency, up to 1,000 times to their own weight. Using free radical polymerization to cross-link two different monomers, such as Acrylamide (Am) and Acrylic Acid (Aa) loaded with Calcium Chloride (CaCl2) and coated with gold nanoparticles (Au-Np's), can produce novel thermally-responsive hydrophilic copolymer (e.g. Poly (Am-co-Aa)/Au-Np's/CaCl2) that was placed inside a controlled structure for testing. The new b3p materials can adsorb water vapor in the evening via a swelling process and discharge water vapor in the morning via a deswelling process to harvest the atmospheric water for recovery and reuse. The new b3p materials demonstrated high average swelling percentage of about 3541% when placed in water under a temperature range of [20-30oC] for 5 hours. The hydrogel loaded with 3.3701 grams CaCl2 was placed in the furnace under relative humidity percentage (RH) range of [80-90%] and can absorb up to 27% of the atmospheric water undergoing the same time. The research concludes that the proposed synthetic method contributes to solving such contemporary challenge in green chemistry to some extent. Further studies are needed to deeply investigate the ability of this new hydrogel to load more dissolved solids such as CaCl2.
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