Current Search:  environmental engineering (x)

View All Items

  • CSV Spreadsheet
(1 - 7 of 7)
The effects of altered traffic signs upon vehicular driving modes and consequent fuel conservation and environmental benefits, as measured by vehicular noise-imprints
Title
The effects of altered traffic signs upon vehicular driving modes and consequent fuel conservation and environmental benefits, as measured by vehicular noise-imprints.
Creator
Pfarrer, Mark Daniel, null, null, Engineering
Abstract / Description
Florida Technological University College of Engineering Thesis; The hypothesis is that the recorded noise-imprints of a vehicle at an intersection can be used to identify and accurately time the driving modes of deceleration, idle, slow cruise, and acceleration. This is proven by analyzing and comparing noise-imprints of vehicles at an uncontrolled intersection marked first with a 'stop' sign, and then by a 'yield' and an experimental 'dead slow' sign. By relating the duration of each driving...
Show moreFlorida Technological University College of Engineering Thesis; The hypothesis is that the recorded noise-imprints of a vehicle at an intersection can be used to identify and accurately time the driving modes of deceleration, idle, slow cruise, and acceleration. This is proven by analyzing and comparing noise-imprints of vehicles at an uncontrolled intersection marked first with a 'stop' sign, and then by a 'yield' and an experimental 'dead slow' sign. By relating the duration of each driving mode to known relations, the overall efficiency of an intersection can be characterized. A new technique for studying various types of traffic conditions at intersections is the result. Initial noise-imprint analysis and comparison shows that a 'yield' sign is to be preferred over a 'stop' sign to decrease travel time, air pollution emissions, gasoline consumption, and wear-and-tear on the car. The experimental 'dead slow' sign is used as a demonstration of the noise-imprint technique upon an unknown situation. The efficiency of a 'dead slow' sign proved to be less than that of a 'yield' sign, but still greater than that of a 'stop' sign.
Show less
Date Issued
1976
Identifier
CFR0003525, ucf:52986
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFR0003525
An Improved Biosolid Gasifier Model
Title
An Improved Biosolid Gasifier Model.
Creator
McLean, Hannah, Cooper, David, Randall, Andrew, Lee, Woo Hyoung, University of Central Florida
Abstract / Description
As populations increase and cities become denser, the production of waste, both sewage sludge and food biomass, increases exponentially while disposal options for these wastes are limited. Landfills have minimal space for biosolids; countries are now banning ocean disposal methods for fear of the negative environmental impacts. Agricultural application of biosolids cannot keep up with the production rates because of the accumulation of heavy metals in the soils. Gasification can convert...
Show moreAs populations increase and cities become denser, the production of waste, both sewage sludge and food biomass, increases exponentially while disposal options for these wastes are limited. Landfills have minimal space for biosolids; countries are now banning ocean disposal methods for fear of the negative environmental impacts. Agricultural application of biosolids cannot keep up with the production rates because of the accumulation of heavy metals in the soils. Gasification can convert biosolids into a renewable energy source that can reduce the amount of waste heading to the landfills and reduce our dependence on fossil fuels. A recently published chemical kinetic computer model for a fluidized-bed sewage sludge gasifier (Champion, Cooper, Mackie, (&) Cairney, 2014) was improved in this work based on limited experimental results obtained from a bubbling fluidized-bed sewage sludge gasifier at the MaxWest facility in Sanford, Florida and published information from the technical literature. The gasifier processed sewage sludge from the communities surrounding Sanford and was operated at various air equivalence ratios and biosolid feed rates. The temperature profile inside of the gasifier was recorded over the span of four months, and an average profile was used in the base case scenario. The improved model gave reasonable predictions of the axial bed temperature profile, syngas composition, heating value of the syngas, gas flow rate, and carbon conversion. The model was validated by comparing the simulation temperature profile data with the measured temperature profile data. An overall heat loss coefficient was calculated for the gasification unit to provide a more accurate energy balance. Once the model was equipped with a heat loss coefficient, the output syngas temperature closely matched the operational data from the MaxWest facility.The model was exercised at a constant equivalence ratio at varying temperatures, and again using a constant temperature with varying equivalence ratios. The resulting syngas compositions from these exercises were compared to various literature sources. It was decided that some of the reactions kinetics needed to be adjusted so that the change in syngas concentration versus change in bed temperature would more closely match the literature. The reaction kinetics for the Water-Gas Shift and Boudouard reactions were modified back to their original values previously obtained from the literature.
Show less
Date Issued
2015
Identifier
CFE0005663, ucf:50199
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0005663
Optimization of Block Layout and Evaluation of Collection Mat Materials for Polyacrylamide Treatment Channels
Title
Optimization of Block Layout and Evaluation of Collection Mat Materials for Polyacrylamide Treatment Channels.
Creator
McDougal, Alicia, Chopra, Manoj, Nam, Boo Hyun, Wang, Dingbao, University of Central Florida
Abstract / Description
Construction sites are frequently cited as major sources of pollution that degrade the quality of surface water. The highly erodible topsoil is transported off site by stormwater runoff causing negative effects downstream. Research has shown that the small particles, which are the most susceptible to erosive forces, have more pollutants associated with them than larger soil particles. Currently, in the state of Florida, it is not permissible to discharge water to a receiving water body if the...
Show moreConstruction sites are frequently cited as major sources of pollution that degrade the quality of surface water. The highly erodible topsoil is transported off site by stormwater runoff causing negative effects downstream. Research has shown that the small particles, which are the most susceptible to erosive forces, have more pollutants associated with them than larger soil particles. Currently, in the state of Florida, it is not permissible to discharge water to a receiving water body if the turbidity is more than 29 Nephelometric Turbidity Units (NTUs) above background or higher than background for an outstanding Florida water body. The removal of fine suspended sediment from water can be achieved by filtration, settling, and the use of chemical coagulants. Polyacrylamide (PAM), a coagulant, has been shown to be effective in removing fine suspended particles from water via coagulation and flocculation. The Stormwater Management Academy at the University of Central Florida has researched the use of PAM and collection mats in a treatment channel to meet state discharge requirements. In this study, turbid water using sediment from typical Florida soils was simulated and passed through a channel. The channel contained polymer blocks in a configuration previously determined to be the most effective. An important component of the treatment system is the floc collection. This research examined three types of collection mats, namely jute, coconut fiber and polypropylene mix to collect the flocs. This thesis presents the results of this investigation.The results for the sandy soil tests showed an average removal efficiency prior to the collection mat starting at 71% and decreasing to 44% at the end of the tests. The 20-foot coconut mat maintained an average removal efficiency of 90%. The turbidity due to silty-sandy soil was decreased with an average removal efficiency prior to the collection mat ranging from 50% to 65%. The average removal efficiency for the 20-foot coconut mat started at 85%and decreased to 60% during the tests. The turbidity due to crushed limestone showed an average removal efficiency prior to the collection mat ranging from 81% down to 69% over time. The average results from the 20-foot coconut mat ranged from 65% to 80%. Turbidity was tested on the samples under two conditions, a 30 second settling time and completely mixed. Statistical results show a significant decrease (?=0.05) in turbidity between the mixed and settled samples.Statistical analyses were performed on the collected data, which concluded that the capability of the mat to reduce turbidity can be repeated with a 95% confidence interval. The 20-foot length coconut mat had the highest turbidity removal efficiency for every soil type examined. Further statistical analysis showed that the achieved turbidity reduction was significantly different (?=0.05) for the various materials. It was observed that generally, each type of mat clogged during testing indicating that longer collection mats be used, possibly lining the entire channel. Recommendations from this study are to provide a settling area after the collection mats and line the entire length of the channel with the collection mat selected.
Show less
Date Issued
2014
Identifier
CFE0005210, ucf:50628
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0005210
A STUDY OF CENTRAL FLORIDA NONROAD VOC AND NOX EMISSIONS AND POTENTIAL ACTIONS TO REDUCE EMISSIONS
Title
A STUDY OF CENTRAL FLORIDA NONROAD VOC AND NOX EMISSIONS AND POTENTIAL ACTIONS TO REDUCE EMISSIONS.
Creator
Radford, Michael, Cooper, C. David, University of Central Florida
Abstract / Description
Ground-level ozone is harmful to the human respiratory system, as well as the environment. The national EPA 8-hour ozone standard for ground-level ozone was reduced from 85 parts per billion (ppb) to 75 ppb in 2008, and trends from previous years show that some of the counties in Central Florida could be in danger of violation. Violation means "non attainment" status; in which the county is ordered by EPA to develop specific implementation plans to reduce its emissions. The objective of this...
Show moreGround-level ozone is harmful to the human respiratory system, as well as the environment. The national EPA 8-hour ozone standard for ground-level ozone was reduced from 85 parts per billion (ppb) to 75 ppb in 2008, and trends from previous years show that some of the counties in Central Florida could be in danger of violation. Violation means "non attainment" status; in which the county is ordered by EPA to develop specific implementation plans to reduce its emissions. The objective of this study was to compile an emissions inventory of volatile organic compounds (VOCs) and nitrogen oxides (NOx) from nonroad equipment in Osceola, Seminole, and Orange Counties (OSO) in Central Florida, and to develop possible action steps to reduce those emissions. This is important because VOC and NOx emissions are precursors to ground-level ozone. Thus, compiling emissions inventories is important to identify high VOC and NOx emitters. Mobile and point sources have long been the highest emitters of VOC and NOx and have therefore been targeted and monitored since the Clean Air Act of 1970, but the nonroad sources (such as construction and lawn equipment) have only been regulated since the 1990s. Using the NONROAD and NMIM modeling programs, the highest nonroad emitters of VOC for Central Florida were found to be lawn/garden equipment, and boating equipment, emitting a combined percentage of 77% of the total nonroad mobile source VOC. Construction equipment contributed 67% of the total nonroad mobile source emissions of NOx in Central Florida. The components of these categories were also analyzed to find the largest individual sources of VOC and NOx. Of the individual sources, lawn mowers and outboard boat engines were found to be the largest sources of VOCs. Of the NOx sources, all the construction equipment components had a relatively similar level of NOx emissions. Next, action steps were developed to reduce emissions, focusing on the high emitters, along with an estimated cost and feasibility for each measure. Of these steps, implementing a ban on leafblowers, and reducing use of lawn mowers, edgers, trimmers, etc. seemed to be the most effective for reducing VOCs. Although these are effective measures, the cost and feasibility of both pose challenges. The best action step for reducing NOx emissions in construction equipment seemed to be by simply reducing idling of equipment on job sites. This also poses challenges in feasibility and enforcement by management. Further, constant on/off cycles could result in decreasing the useful life of the older construction equipment. Finally, a survey was conducted with various construction managers and companies to find out the typical equipment and quantity needed for land clearing/grubbing, as well as the typical use, idling time, and total project time for each piece of equipment on a 10-acre site, under various conditions. The purpose of the study was to develop a rough estimate for the average amount of VOC and NOx emissions that will be produced per acre of land clearing activities, and to estimate the emissions reductions and cost savings if idling of the equipment was reduced.
Show less
Date Issued
2009
Identifier
CFE0002850, ucf:48064
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0002850
A COMPARATIVE ANALYSIS OF GREEN ROOF DESIGNS INCLUDING DEPTH OF MEDIA, DRAINAGE LAYER MATERIALS, AND POLLUTION CONTROL MEDIA
Title
A COMPARATIVE ANALYSIS OF GREEN ROOF DESIGNS INCLUDING DEPTH OF MEDIA, DRAINAGE LAYER MATERIALS, AND POLLUTION CONTROL MEDIA.
Creator
Kelly, Matt, Cooper, C. David, University of Central Florida
Abstract / Description
Population growth has lead to an increase in development and impervious areas in urban settings. Post-development conditions cause several problems for stormwater management such as limited space for stormwater storage systems and the conveyance of pollution picked up by runoff to near by water bodies. Green Roofs with cisterns have been shown to attenuate the peak flow of storm events and reduce the pollution load leaving a site and entering nearby water bodies. The purpose of this research...
Show morePopulation growth has lead to an increase in development and impervious areas in urban settings. Post-development conditions cause several problems for stormwater management such as limited space for stormwater storage systems and the conveyance of pollution picked up by runoff to near by water bodies. Green Roofs with cisterns have been shown to attenuate the peak flow of storm events and reduce the pollution load leaving a site and entering nearby water bodies. The purpose of this research is to expand the available research data on green roofs with cisterns by investigating the water quality and hydrology effects of different green roof designs including depth of media, an additional pollution control layer beneath the growth media, and different drainage layer materials. Furthermore, a comparison study is performed on the cistern water quality, direct filtrate water quality, and control roof filtrate water quality. Results show that phosphorus concentrations are lower when using a pollution control layer beneath the growing media, and that evapotransporation and filtrate factor values from the 4-inch media and the 8-inch media are approximately equal for one year. However, hydrograph results show that the 8-inch media design has a lower peak flow and longer attenuation when compared to the 4-inch media design for a single storm event. Furthermore, the drainage layer material has no significant effect on the water quality or hydrology of the green roof discharge. The data also emphasizes the importance and effectiveness of the incorporation of a cistern into a green roof system.
Show less
Date Issued
2008
Identifier
CFE0002107, ucf:47552
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0002107
Development of a chemical kinetic model for the combustion of a synthesis gas from a fluidized-bed sewage sludge gasifier in a thermal oxidizer
Title
Development of a chemical kinetic model for the combustion of a synthesis gas from a fluidized-bed sewage sludge gasifier in a thermal oxidizer.
Creator
Martinez, Luis, Cooper, David, Randall, Andrew, Vasu Sumathi, Subith, University of Central Florida
Abstract / Description
The need for sustainability has been on the rise. Municipalities are finding ways of reducing waste, but also finding ways to reduce energy costs. Waste-to-energy is a sustainable method that may reduce bio-solids volume while also producing energy. In this research study bio-solids enters a bubbling bed gasifier and within the gasifier a synthesis gas is produced. This synthesis gas exits through the top of the gasifier and enters a thermal oxidizer for combustion. The thermal oxidizer has...
Show moreThe need for sustainability has been on the rise. Municipalities are finding ways of reducing waste, but also finding ways to reduce energy costs. Waste-to-energy is a sustainable method that may reduce bio-solids volume while also producing energy. In this research study bio-solids enters a bubbling bed gasifier and within the gasifier a synthesis gas is produced. This synthesis gas exits through the top of the gasifier and enters a thermal oxidizer for combustion. The thermal oxidizer has an innovative method of oxidizing the synthesis gas. The thermal oxidizer has two air injection sites and the possibility for aqueous ammonia injection for further NOx reduction. Most thermal oxidizers already include an oxidizer such as air in the fuel before it enters the thermal oxidizer; thus making this research and operation different from many other thermal oxidizers and waste-to-energy plants.The reduction in waste means less volume loads to a landfill. This process significantly reduces the amount of bio-solids to a landfill. The energy produced from the synthesis is beneficial for any municipality, as it may be used to run the waste-to-energy facility. The purpose of this study is to determine methods in which operators may configure future plants to reduce NOx emissions. NOx mixed with volatile organic compounds (VOC) and sunlight, produce ozone (O3) a deadly gas at high concentrations.This study developed a model to determine the best methods to reduce NOx emissions. Results indicate that a fuel-rich then fuel-lean injection scheme results in lower NOx emissions. This is because at fuel-rich conditions not all of the ammonia in the first air ring is converted to NOx, but rather a partial of the ammonia is converted to NOx and N2 and then the second air ring operates at fuel-lean which further oxidizes the remaining ammonia which converts to NOx, but also a fraction to N2. If NOx standards reach more stringency then aqueous ammonia injection is a recommended method for NOx reduction; this method is also known as selective non-catalytic reduction (SNCR).The findings in this study will allow operators to make better judgment in the way that they operate a two air injection scheme thermal oxidizer. The goal of the operator and the organization is to meet air quality standards and this study aims at finding ways to reduce emissions, specifically NOx.
Show less
Date Issued
2014
Identifier
CFE0005528, ucf:50301
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0005528
THE EFFECTS OF PHOSPHATE AND SILICATE INHIBITORS ON SURFACE ROUGHNESS AND COPPER RELEASE IN WATER DISTRIBUTION SYSTEMS
Title
THE EFFECTS OF PHOSPHATE AND SILICATE INHIBITORS ON SURFACE ROUGHNESS AND COPPER RELEASE IN WATER DISTRIBUTION SYSTEMS.
Creator
MacNevin, David, Taylor, James, University of Central Florida
Abstract / Description
The effects of corrosion inhibitors on water quality and the distribution system were studied. This dissertation investigates the effect of inhibitors on iron surface roughness, copper surface roughness, and copper release. Corrosion inhibitors included blended poly/ortho phosphate, sodium orthophosphate, zinc orthophosphate, and sodium silicate. These inhibitors were added to a blend of surface water, groundwater, and desalinated brackish water. Surface roughness of galvanized iron, unlined...
Show moreThe effects of corrosion inhibitors on water quality and the distribution system were studied. This dissertation investigates the effect of inhibitors on iron surface roughness, copper surface roughness, and copper release. Corrosion inhibitors included blended poly/ortho phosphate, sodium orthophosphate, zinc orthophosphate, and sodium silicate. These inhibitors were added to a blend of surface water, groundwater, and desalinated brackish water. Surface roughness of galvanized iron, unlined cast iron, lined cast iron, and polyvinyl chloride was measured using pipe coupons exposed for three months. Roughness of each pipe coupon was measured with an optical surface profiler before and after exposure to inhibitors. For most materials, inhibitor did not have a significant effect on surface roughness; instead, the most significant factor determining the final surface roughness was the initial surface roughness. Coupons with low initial surface roughness tended to have an increase in surface roughness during exposure, and vice versa, implying that surface roughness tended to regress towards an average or equilibrium value. For unlined cast iron, increased alkalinity and increased temperature tended to correspond with increases in surface roughness. Unlined cast iron coupons receiving phosphate inhibitors were more likely to have a significant change in surface roughness, suggesting that phosphate inhibitors affect stability of iron pipe scales. Similar roughness data collected with new copper coupons showed that elevated orthophosphate, alkalinity, and temperature were all factors associated with increased copper surface roughness. The greatest increases in surface roughness were observed with copper coupons receiving phosphate inhibitors. Smaller increases were observed with copper coupons receiving silicate inhibitor or no inhibitor. With phosphate inhibitors, elevated temperature and alkalinity were associated with larger increases in surface roughness and blue-green copper (II) scales.. Otherwise a compact, dull red copper (I) scale was observed. These data suggest that phosphate inhibitor addition corresponds with changes in surface morphology, and surface composition, including the oxidation state of copper solids. The effects of corrosion inhibitors on copper surface chemistry and cuprosolvency were investigated. Most copper scales had X-ray photoelectron spectroscopy binding energies consistent with a mixture of Cu2O, CuO, Cu(OH)2, and other copper (II) salts. Orthophosphate and silica were detected on copper surfaces exposed to each inhibitor. All phosphate and silicate inhibitors reduced copper release relative to the no inhibitor treatments, keeping total copper below the 1.3 mg/L MCLG for all water quality blends. All three kinds of phosphate inhibitors, when added at 1 mg/L as P, corresponded with a 60% reduction in copper release relative to the no inhibitor control. On average, this percent reduction was consistent across varying water quality conditions in all four phases. Similarly when silicate inhibitor was added at 6 mg/L as SiO2, this corresponded with a 25-40% reduction in copper release relative to the no inhibitor control. Hence, on average, for the given inhibitors and doses, phosphate inhibitors provided more predictable control of copper release across changing water quality conditions. A plot of cupric ion concentration versus orthophosphate concentration showed a decrease in copper release consistent with mechanistic control by either cupric phosphate solubility or a diffusion limiting phosphate film. Thermodynamic models were developed to identify feasible controlling solids. For the no inhibitor treatment, Cu(OH)2 provided the closest prediction of copper release. With phosphate inhibitors both Cu(OH)2 and Cu(PO4)·2H2O models provided plausible predictions. Similarly, with silicate inhibitor, the Cu(OH)2 and CuSiO3·H2O models provided plausible predictions.
Show less
Date Issued
2008
Identifier
CFE0002001, ucf:47621
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0002001