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Emissions of hexavalent chromium from hard chromium plating operations
Title
Emissions of hexavalent chromium from hard chromium plating operations.
Creator
Hall, Mitchell Scott, Wayson, Roger L., Engineering
Abstract / Description
University of Central Florida College of Engineering Thesis; This research addressess emissions of hexavalent chromium mist from hard chromium electroplating operations. Most of these emissions are typically captured by a ventilation stack and directed to a pollution control device; those which escape capture are called fugitive emissions. Releases of toxic materials such as hexavalent chromium must be reported annually to the Environmental Protection Agency (EPA) under provisions of the...
Show moreUniversity of Central Florida College of Engineering Thesis; This research addressess emissions of hexavalent chromium mist from hard chromium electroplating operations. Most of these emissions are typically captured by a ventilation stack and directed to a pollution control device; those which escape capture are called fugitive emissions. Releases of toxic materials such as hexavalent chromium must be reported annually to the Environmental Protection Agency (EPA) under provisions of the Superfund Amendments and Reauthorization Act (SARA) Title III of 1986 via the Toxic Release Inventory (TRI), Form R. The objectives were: (1) to provide estimates of fugitive hexavalent chromium emissions for the completion of Form R; and (2) to develop a predictive model for stack and fugitive emissions versus process and ventilation parameters. The database for stack emissions included published results from EPA studies. Fugitive release data were generated by field characterization at two operating facilities. Supplemental data for stack releases were also obtained during this field activity. The fugitive releases were documented to represent a small portion of the total atmospheric discharge; in most instances, the fugitive releases were less than the detection capability of the smapling/analytical protocols. Stack releases were successfully correlated with a measure of production activity (ampere-hours), production capacity (mass of chromium in the process bath), tank dimensions (plating bath surface area), and ventilation efficiency (ventilation slot area). This effort was supported by the EPA in the form of a cooperative agreement with the American Electropaters and Surface Finishers Society (AESF).
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Date Issued
1992
Identifier
CFR0008174, ucf:53062
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFR0008174
APPLICATION OF ABSORPTIVE TREATMENTS ON TRAFFIC NOISE BARRIERS IN FLORIDA
Title
APPLICATION OF ABSORPTIVE TREATMENTS ON TRAFFIC NOISE BARRIERS IN FLORIDA.
Creator
Chua, Chin Boon, Wayson, Roger, University of Central Florida
Abstract / Description
In this thesis, the parallel barrier analysis feature in the Federal Highway Administration Traffic Noise Model (FHWA TNM), which is based on RAYVERB was used to explore the effects of multiple reflections due to single and parallel barriers and the use of absorptive treatment. Database was developed from the data collected from previous research efforts was used to generate a best fit equation model that can be used as a predetermining tool to determine the magnitude of parallel barrier...
Show moreIn this thesis, the parallel barrier analysis feature in the Federal Highway Administration Traffic Noise Model (FHWA TNM), which is based on RAYVERB was used to explore the effects of multiple reflections due to single and parallel barriers and the use of absorptive treatment. Database was developed from the data collected from previous research efforts was used to generate a best fit equation model that can be used as a predetermining tool to determine the magnitude of parallel barrier insertion loss. The best fit equation model was then used to test against measured/model result and TNM prediction results for its validity. Absorptive materials were also studied such that 3 top of them were selected and recommended for Florida highway barrier use. It was found that the top three absorptive treatments for use on Florida highway barriers have been determined to be cementitous material, metal wool and glass fiber. These materials can be used to reduce the sound reflections for single and parallel barriers. The developed best fit equation model from this research is Deg = -2.17NRC - CW0.42 + 1.97eln(BH) + RH0.29 + DBB0.27; the prediction results give moderately high R2 value of 0.55 if compared to the results from database. Prediction results from best fit equation model was also found to be consistent with the results from the measure/modeled results, providing further proof of the validity of the model. However, if compared results from equation model, TNM and measured/model (measured and model compared results using ANSI method), TNM was shown to provide higher insertion loss degradation. It was found that the most effective placement of absorptive material was the pattern which covers the barrier from the bottom up; it was also found that only about 60% from the bottom of the barrier area requires covering with high NRC absorptive treatment (NRC greater than 0.8) without sacrificing insertion loss. Also, if the barrier area near the top includes an easily obtainable NRC value of 0.4, only 40% to 50% of the bottom barrier needs absorptive treatment with a higher, more expensive NRC rating. These findings can substantially reduce the cost of conventional absorptive barrier which have full coverage of high NRC absorptive treatment. This research has begun important improvements in noise barrier design, additional work can be continued to further verify all the findings in this thesis such that easier and better equation model can be developed to calculate insertion loss degradation and cheaper absorptive barrier with less absorptive material usage can be built.
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Date Issued
2004
Identifier
CFE0000008, ucf:46127
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0000008
A DERIVATION OF AN EMPIRICAL EQUATION FOR ESTIMATING THE ACOUSTICAL SHADOW ZONE LENGTH OF ROADWAY NOISE BARRIERS
Title
A DERIVATION OF AN EMPIRICAL EQUATION FOR ESTIMATING THE ACOUSTICAL SHADOW ZONE LENGTH OF ROADWAY NOISE BARRIERS.
Creator
Arner, Wayne, Wayson, Roger, University of Central Florida
Abstract / Description
The objective of this research was to derive an empirical equation that estimates the acoustical shadow zone length (SZL) of roadway noise barriers. The acoustical shadow zone is the area behind a noise barrier of reduced sound levels, generally to some stated level at or near background. The ability to predict the SZL can be used as a method to evaluate the performance, and possibly the design, of roadway noise barriers. The current federally required roadway noise model is the Federal...
Show moreThe objective of this research was to derive an empirical equation that estimates the acoustical shadow zone length (SZL) of roadway noise barriers. The acoustical shadow zone is the area behind a noise barrier of reduced sound levels, generally to some stated level at or near background. The ability to predict the SZL can be used as a method to evaluate the performance, and possibly the design, of roadway noise barriers. The current federally required roadway noise model is the Federal Highway Administration (FHWA) Traffic Noise Model (TNM). TNM uses insertion loss (IL) to evaluate the effectiveness of a barrier. Insertion loss is the difference in sound level between the "no barrier" and the "with barrier" case. One major limitation with TNM is that the reported IL does not take into account how background noise levels influence the mitigated sound levels. Background noise can be defined as the noise present at a barrier location in the absence of roadway noise. The shadow zone represents a region behind the noise barrier where the barrier is effective at reducing noise levels and takes into account how background noise affects the IL and thus the SZL. The inclusion of background noise becomes significant in evaluating barrier effectiveness because as the distance from the barrier increases, background noise begins to overtake roadway noise as the dominate noise source. The derivation of the empirical equation began by collecting in-situ noise measurements at 18 noise barrier locations across Florida. The measured noise data was supplemented by noise data obtained from computer modeling. After a sufficient quantity of measured and modeled IL data was obtained, a contour of equal IL (IL = 5 dB) was plotted for each barrier location. The area defined by the contour is called the shadow zone. All the SZLs were statistically compared to several variables that were expected to influence it. Regression modeling showed that the background noise level, noise barrier height, the distance from the roadway to the noise barrier, and percent of heavy truck traffic volume were statistically significant as useful predictors of SZL. Two empirical equations were derived, one from linear regression and one from polynomial regression, and are referred to as the Shadow Zone Equations.
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Date Issued
2006
Identifier
CFE0001464, ucf:47096
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0001464
VERIFICATION OF FAA'S EMISSIONS AND DISPERSION MODELING SYSTEM (EDMS)
Title
VERIFICATION OF FAA'S EMISSIONS AND DISPERSION MODELING SYSTEM (EDMS).
Creator
Martin, Anjoli, Wayson, Roger, University of Central Florida
Abstract / Description
Air quality has been a major environmental concern for many years. Recently the issue of airport emissions has presented growing concerns and is being studied in much more depth. Airport emissions come from a variety of point, line and area sources, making emissions modeling for airports very complex and more involved. Accurate air quality models, specific to airport needs, are required to properly analyze this complex array of air pollution sources created by airports. Accurate air quality...
Show moreAir quality has been a major environmental concern for many years. Recently the issue of airport emissions has presented growing concerns and is being studied in much more depth. Airport emissions come from a variety of point, line and area sources, making emissions modeling for airports very complex and more involved. Accurate air quality models, specific to airport needs, are required to properly analyze this complex array of air pollution sources created by airports. Accurate air quality models are needed to plan for increased growth of current airports and address concerns over proposed new ones. The Federal Aviation Administration's (FAA) Emissions and Dispersion Modeling System (EDMS) is a program that is the required model for assessing emissions from airport sources. This research used EDMS Version 4.21, which incorporates the EPA dispersion model AERMOD, to model detailed airport data and compare the model's predicted values to the actual measured carbon monoxide concentrations at 25 locations at a major U.S. airport. Statistics relating the model characteristics as well as trends are presented. In this way, a thorough investigation of the accuracy of the EDMS modeled values of carbon monoxide was possible. EDMS modeling included two scenarios, the first scenario referred to as practice detail included general airport information that a modeler could find from the airport being studied and the second scenario referred to as research detail utilized very detailed information from observer logs during a three day observation period. Each of the modeling scenarios was compared to the field measured data and to each other. These comparisons are important to insure the model is adequately describing emissions sources at airports. Data analysis of this study was disappointing since measured levels of CO were generally higher than modeled values. Since EDMS is continually changing and improving perhaps these results can help enhance future models.
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Date Issued
2006
Identifier
CFE0001282, ucf:46903
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0001282
PREDICTING AIR QUALITY NEAR ROADWAY INTERSECTIONS THROUGH THE APPLICATION OF A GAUSSIAN PUFF MODEL TO MOVING SOURCES
Title
PREDICTING AIR QUALITY NEAR ROADWAY INTERSECTIONS THROUGH THE APPLICATION OF A GAUSSIAN PUFF MODEL TO MOVING SOURCES.
Creator
Kim, Brian, Wayson, Roger, University of Central Florida
Abstract / Description
With substantial health and economic impacts attached to many highway-related projects, it has become imperative that the models used to assess air quality be as accurate as possible. The United States (US) Environmental Protection Agency (EPA) currently promulgates the use of CAL3QHC to model concentrations of carbon monoxide (CO) near roadway intersections. This model uses steady-state and macroscopic methods to model the physical phenomena (e.g., emission rates, atmospheric dispersion, etc...
Show moreWith substantial health and economic impacts attached to many highway-related projects, it has become imperative that the models used to assess air quality be as accurate as possible. The United States (US) Environmental Protection Agency (EPA) currently promulgates the use of CAL3QHC to model concentrations of carbon monoxide (CO) near roadway intersections. This model uses steady-state and macroscopic methods to model the physical phenomena (e.g., emission rates, atmospheric dispersion, etc.) occurring at intersections. These methods are not straightforward and unintuitive for the users. Therefore, this project investigated the possibility of developing a model that is theoretically more realistic and flexible than CAL3QHC. The new model entitled, Traffic Air Quality Simulation Model (TRAQSIM), uses a microscopic approach by modeling vehicle movements and dispersion in a simulation environment. Instead of steady-state plume equations used in the CAL3QHC model, TRAQSIM uses a discrete puff methodology that can be used to model time-based dispersion of pollutants. Most of the components incorporated into TRAQSIM have been drawn from existing methodologies and therefore, are not new. However, the combination of these different methods into a single integrated model is new and presents a novel approach to such a model. Initial verification and sensitivity/trend studies of the model indicate that TRAQSIM uses reasonable/realistic traffic parameters and behaves intuitively correct. A validation study showed that TRAQSIM produces good results when compared to actual measured data with an overall R2 value of 0.605 for 11 scenarios comprising 264 data points. Although most statistical parameters showed CAL3QHC agrees better overall with measured data (R2 value of 0.721), the comparisons were mixed on a scenario-by-scenario basis; that is, CAL3QHC showed better results for 6 scenarios and TRAQSIM showed better results for 5 scenarios. Additional tests with larger datasets, which were beyond the scope of this work, could be conducted to obtain more definitive conclusions and allow further development of TRAQSIM. While CAL3QHC is a mature model that has been developed over many years, TRAQSIM is new and has much more potential for improvement. The physical parameters used in TRAQSIM allow it to be more directly (more logically) improved than the approximations used in CAL3QHC. In addition, although the fundamental-level modeling in TRAQSIM make it a more complex model internally, it is much more intuitive for the user to understand and use.
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Date Issued
2004
Identifier
CFE0000316, ucf:46306
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0000316
MODELING OF ATMOSPHERIC REFRACTION EFFECTS ON TRAFFIC NOISE PROPAGATION
Title
MODELING OF ATMOSPHERIC REFRACTION EFFECTS ON TRAFFIC NOISE PROPAGATION.
Creator
El-Aassar, Ahmed, Wayson, Roger, University of Central Florida
Abstract / Description
Traffic noise has been shown to have negative effects on exposed persons in the communities along highways. Noise from transportation systems is considered a nuisance in the U.S. and the government agencies require a determination of noise impacts for federally funded projects. There are several models available for assessing noise levels impacts. These models vary from simple charts to computer design models. Some computer models, i.e. Standard Method In Noise Analysis (STAMINA), the Traffic...
Show moreTraffic noise has been shown to have negative effects on exposed persons in the communities along highways. Noise from transportation systems is considered a nuisance in the U.S. and the government agencies require a determination of noise impacts for federally funded projects. There are several models available for assessing noise levels impacts. These models vary from simple charts to computer design models. Some computer models, i.e. Standard Method In Noise Analysis (STAMINA), the Traffic Noise Model (TNM) and the UCF Community Noise Model (CNM), have been used to predict geometric spreading, atmospheric absorption, diffraction, and ground impedance. However, they have largely neglected the atmospheric effects on noise propagation in their algorithms. The purpose of this research was to better understand and predict the meteorological effects on traffic noise propagation though measurements and comparison to acoustic theory. It should be noted that this represents an approach to incorporate refraction algorithms affecting outdoor noise propagation that must also work with algorithms for geometric spreading, ground effects, diffraction, and turbulence. The new empirical model for predicting atmospheric refraction shows that wind direction is a significant parameter and should be included in future modeling for atmospheric refraction. To accomplish this, the model includes a "wind shear" and "lapse rate" terms instead of wind speed and temperature as previously needed for input of the most used models. The model is an attempt to explain atmospheric refraction by including the parameters of wind direction, wind shear, and lapse rate that directly affect atmospheric refraction.
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Date Issued
2006
Identifier
CFE0001505, ucf:47140
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0001505