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Full-Text Articles in Engineering

An Investigation Of The Mechanism Of Advanced Oxidation Processes (Aop) Involving Free Radicals And Charged Species., Yaw-Kuen Lin Dec 1995

An Investigation Of The Mechanism Of Advanced Oxidation Processes (Aop) Involving Free Radicals And Charged Species., Yaw-Kuen Lin

Dissertations

Hydrogen peroxide is a key component in Advanced Oxidation Processes (AOP). Its decomposition at different pH conditions has been studied and some interesting results were observed. When the pH value of hydrogen peroxide solution is less than 9, its rate of decomposition is independent of pH. On the other hand, in the pH range of 9-12.6, its rate of decomposition increases as pH increases, and goes through a maximum value then suddenly decreases with respect to pH. A reaction kinetic model with three rate constants in the form of beta probability function was used to describe the experimental data ...


Comparison Of Reductive Dehalogenation By Microbial Populations On Adsorptive Versus Non-Adsorptive Bioreactor Support Materials, Linda S. Colella Dec 1995

Comparison Of Reductive Dehalogenation By Microbial Populations On Adsorptive Versus Non-Adsorptive Bioreactor Support Materials, Linda S. Colella

Theses

The overall performance of two bioreactors was studied. The reactor with a wood-based activated carbon as a biosupport completely dehalogenated a higher feed concentration of trichlorophenol than that with Manville beads. The carbon reactor was further characterized by the development of adsorption isotherms for most of the class of chlorophenols. Competitive adsorption wag investigated using an anaerobic medium, and a lignite-based carbon was studied for comparison. The order of adsorption strength on both carbons is trichloropenols> dichlorophenols> monochlorophenols, with the wood-based carbon having higher overall adsorption than the lignite-based carbon. The presence of the anaerobic medium decreased the extent of ...


Determination Of Physical Parameters Affecting Biofiltration Of Vocs, Steven Matthew Wojdyla Dec 1995

Determination Of Physical Parameters Affecting Biofiltration Of Vocs, Steven Matthew Wojdyla

Theses

This study dealt with the determination of physical and design parameters affecting the transient behavior of classical biofilters employed in removal of VOCs from airstreams. The column packing material consisted of a mixture of peat and perlite particles (2:3, v:v). The design parameters investigated were the density of the packing material, its porosity, and the void fraction of the filter-bed. The physical parameters investigated were the characteristics of adsorption equilibrium between VOCs and packing material, and the mass transfer coefficients of VOCs to the packing material.

The density of the packing material was found to be 0.679 ...


Activation Of Precipitated Iron Fischer-Tropsch Catalysts, Mehul D. Shroff Dec 1995

Activation Of Precipitated Iron Fischer-Tropsch Catalysts, Mehul D. Shroff

Chemical and Biological Engineering ETDs

The Fischer-Tropsch Synthesis (FTS) is an important step in the manufacture of synthetic fuels from coal. The use of iron catalysts for FTS, though desirable from the standpoint of process economy, is hampered by problems relating to catalyst attrition and carbon buildup. In addition, from a research perspective, there has been a long-standing controversy in the literature with regard to the nature of the active phase.

The effect of activation and reaction treatments on the resulting phase transformations in a commercial, precipitated and spray-dried, Fe2O3 - CuO - K2O Fischer-Tropsch catalyst have been studied. Different catalyst batches ...


Computer-Aided Process Design For Waste Minimization, Konstadinos Abeliotis Oct 1995

Computer-Aided Process Design For Waste Minimization, Konstadinos Abeliotis

Dissertations

Problems related to process design with environmental considerations have been studied in this dissertation. A new heuristic design methodology has been formulated with the objective of minimizing the adverse environmental impact of chemical processes.

This hierarchical methodology starts with the definition and analysis of a process flowsheet followed by quantification of the process environmental loads. The quantification of environmental loads is an essential aspect of this methodology, because it serves as the comparative measure for environmental performance.

If the calculated environmental loads do not satisfy the environmental constraints (e.g., regulatory limits), waste minimization is investigated in the following order ...


Removal Of Vocs From Air By Absorption And Stripping In Hollow Fiber Devices, Tarun K. Poddar Oct 1995

Removal Of Vocs From Air By Absorption And Stripping In Hollow Fiber Devices, Tarun K. Poddar

Dissertations

Large volumes of exhaust air streams contaminated with volatile organic compounds (VOCs) such as toluene, xylene, acetone etc. are discharged into the atmosphere by various industrial facilities. Common technologies for VOC emission abatement e.g., activated carbon adsorption, absorption in a liquid, incineration and catalytic oxidation, have many strengths as well as considerable limitations. In this study, a regenerative absorption-based removal of VOCs from N2 in an inert, nonvolatile, organic liquid flowing in compact hollow fiber devices has been developed. The process eliminates flooding, loading and entrainment encountered in conventional absorption devices.

Contaminated air/N2 stream was fed ...


The Effect Of Chlorine, Sulfur And Phosphorus Compounds On Deactivation Of Palladium Catalysts, Tai-Chiang Yu Oct 1995

The Effect Of Chlorine, Sulfur And Phosphorus Compounds On Deactivation Of Palladium Catalysts, Tai-Chiang Yu

Dissertations

The effects of HCl, H2S, tributyl phosphate (TBP), P2O5, and zinc dialkyldithophosphate (ZDP) as catalyst poisons for methane oxidation over palladium catalysts supported on γ-alumina were investigated in this study. The overall reaction rate of methane oxidation over palladium catalysts can be simplified into a pseudo first order reaction under excess oxidation conditions.

The deactivation of the catalyst poisoned by HCl is attributed to the loss of active sites due to volatilization of PdCl2. H2 treatment at 200 °C can reactivate the catalyst poisoned by HCl at temperatures of up to 300 °C ...


Studies Of Mixing Processes In Gases And Effects On Combustion And Stability, Frank Paul Kozusko Jr. Jul 1995

Studies Of Mixing Processes In Gases And Effects On Combustion And Stability, Frank Paul Kozusko Jr.

Mathematics & Statistics Theses & Dissertations

Three physical models of laminar mixing of initially separated gases are studied. Two models study the effects of the mixing dynamics on the chemical reactions between the gases. The third model studies the structure and stability of a laminar mixing layer in a binary gas. The three models are:

1. Two ideal and incompressible gases representing fuel and oxidizer are initially at rest and separated across an infinite linear interface in a two dimensional system. Combustion, expected as the gases mix, will lead to a rapid rise in temperature in a localized area, i.e. ignition. The mixing of the ...


Biodegradation Of Mixed Wastes : Basic Kinetics And Reaction Engineering For Cyclic Reactor Operation, Kung-Wei Wang May 1995

Biodegradation Of Mixed Wastes : Basic Kinetics And Reaction Engineering For Cyclic Reactor Operation, Kung-Wei Wang

Dissertations

This study dealt with the determination of the detailed kinetics of the biodegradation of mixed substrates by pure cultures, and with reaction engineering studies of bioreactors employed in treatment of substitutable substrates under cyclic operation.

In the first part of the study the degradation of phenol and 4-chlorophenol (4-CP) by two strains of Pseudomonas species was investigated. Strain P. putida 0 was found to be capable of utilizing both phenol and 4-CP as sole carbon and energy sources. This suggests that this strain follows the ortho-cleavage pathway for the aromatic ring. Strain P. putida N could grow on phenol, and ...


Modeling The Fate Of Volatile Organic Compounds In Wastewater Treatment Facilities; Implementation Of Volatilization Models In Envirocad, Vinita Chhahira May 1995

Modeling The Fate Of Volatile Organic Compounds In Wastewater Treatment Facilities; Implementation Of Volatilization Models In Envirocad, Vinita Chhahira

Theses

The 1990 Clean Air Act Amendments have identified wastewater treatment facilities as a major source of volatile organic compound (VOC) emissions. VOCs present in wastewater discharges affect the quality of receiving waters, while emissions to the air affect downwind populations. The primary mechanisms involved in VOC removal from a wastewater treatment facility are volatilization and stripping, biodegradation, and sorption to either suspended or biological solids. Although many models have been developed to predict the fate of VOCs in wastewater treatment facilities, no model completely predicts emissions for an entire wastewater treatment facility. The focus of this work is to incorporate ...


A Comparison Of Anhydrous Ethanol Production From Ethylene And From Corn Utilizing Life Cycle Analysis Methodology, Gregory Morse May 1995

A Comparison Of Anhydrous Ethanol Production From Ethylene And From Corn Utilizing Life Cycle Analysis Methodology, Gregory Morse

Theses

There is currently much concern with the impact on the environment due to industrial processes. One method to assess this impact is to perform a Life Cycle Analysis (LCA) on the process. Life Cycle Analysis is made up of three stages; Life Cycle Inventory Analysis, Life Cycle Impact Assessment, and Life Cycle Improvement Assessment. In this study, Life Cycle Inventory Analysis methodology was applied to two industrial processes for producing anhydrous ethanol. The first process is the fermentation of corn, and the second is the hydration of ethylene using water and a catalyst. Each process was first modeled using the ...


Effect Of Various Mixing Devices And Patterns On Flocculation Kinetics In Water Treatment , Md. Wahid Sajjad Jan 1995

Effect Of Various Mixing Devices And Patterns On Flocculation Kinetics In Water Treatment , Md. Wahid Sajjad

Retrospective Theses and Dissertations

This research was designed to investigate the effects of different mixing variables on flocculation kinetics of kaolinite clay suspension at both warm and cold water temperatures (23°C and 5°C) using alum and ferric nitrate under a number of physico-chemical conditions. The following work was performed during this experimental study: (1) G versus rpm curves for different impellers were developed using calculated power based on measured torque. The torque was measured by a rotating torque meter using a photographic technique. (2) The effects of impeller geometry, rapid mixing intensity and pattern, concentration of coagulant dosing solution, coagulant injection pattern ...


Characterization Of Nylon-11 Degradation, Leslie Christian Mccullough Jan 1995

Characterization Of Nylon-11 Degradation, Leslie Christian Mccullough

Dissertations, Theses, and Masters Projects

No abstract provided.


Characterization Of Pr500 For Use In Resin Transfer Molding, Rhonda Michelle Barksdale Jan 1995

Characterization Of Pr500 For Use In Resin Transfer Molding, Rhonda Michelle Barksdale

Dissertations, Theses, and Masters Projects

No abstract provided.


Fabrication Of Thermoplastic Polymer Composite Ribbon, Donald Allan Sandusky Jan 1995

Fabrication Of Thermoplastic Polymer Composite Ribbon, Donald Allan Sandusky

Dissertations, Theses, and Masters Projects

The goal of this research was to develop a controllable process to convert a thermoplastic powder-coated carbon-fiber towpreg into uniform and consolidated ribbon. The approach comprised four primary activities. (1) The patent and processing literature was studied to evaluate the state of the art. (2) A functional ribbon fabrication technique was developed by scaling-up, in a novel configuration, hardware components found in the literature. (3) The ex parte ribbonizing process was characterized by calibrating equipment, determining steady state and studying cause and effect between process parameters and ribbon quality. (4) Process design and control methods were derived from heat transfer ...


Reaction Kinetics Of Methanol And Mtbe Oxidation And Pyrolysis, Wen-Chiun Ing Jan 1995

Reaction Kinetics Of Methanol And Mtbe Oxidation And Pyrolysis, Wen-Chiun Ing

Dissertations

This study presents experimental data on the decomposition of methanol in several different reaction environments - fuel lean to stoichiometric at a temperature range of 873 and 1073 K and a pressure range of I and 5 atm. Methane fuel is also added in several of the systems studied in order to provide experimental data to understand the methanol addition effect on the methane oxidation.

Computer codes: ThermCal, ThermSrt and ThermCvt have been developed for the thermal property calculations of stable molecules by the Benson group additivity method and of radicals by the NJIT hydrogen bond increment method.

Pressure dependent rate ...


Bubble And Elutriation Control In Fluidized Beds With Electric Fields , Jiun-Shen Wang Jan 1995

Bubble And Elutriation Control In Fluidized Beds With Electric Fields , Jiun-Shen Wang

Retrospective Theses and Dissertations

The mechanisms for controlling elutriation and bubbling effect in a fluidized bed are largely unexplored. Increased understanding of these hydrodynamic effects will help to improve both fluidized bed design and operation;In the present study, an electric field was used as an independent parameter to control the formation of bubbles and the elutriation of fines in a fluidized bed. Various forces which acted on the particles were compared. It was concluded that both the current constriction force and hydrodynamic force dominated the behavior of the bed;The bed expansion increased as much as 15% of the bed height at the ...


Water Reuse In Fermentations , Tzu-Yin Hsiao Jan 1995

Water Reuse In Fermentations , Tzu-Yin Hsiao

Retrospective Theses and Dissertations

This work was undertaken to investigate the feasibility of reusing the process effluent from fermentation processes to minimize the liquid waste. Two fermentations with different characteristics were chosen as model fermentations for development of principles. The first was a yeast fermentation that requires high levels of carbon substrate for production of intracellular lipid. The second was a bacterial fermentation requiring high levels of nitrogen in the medium for production of lysine. The latter is used for commercial production of lysine;In the study of the first model fermentation, Apiotrichum curvatum, an oleaginous yeast, was used as the working culture. Spent ...


Removal Of Vocs From Waste Gas Streams By A Hollow Fiber Permeator, Varinder Pal Malik Jan 1995

Removal Of Vocs From Waste Gas Streams By A Hollow Fiber Permeator, Varinder Pal Malik

Theses

Removal of various VOCs from air/nitrogen feed streams using a novel hollow fiber membrane was studied. Hollow Fiber Module (HFM) used had composite silicone membranes wherein an ultrathin (~ 1μm), nonporous silicone rubber membrane layer had been plasma polymerized on a porous (porosity: 0.4) polypropylene substrate. VOCs studied were toluene, methanol, acetone, methylene chloride and hexane. Primary focus was on single VOCs, although separation of VOC mixtures was also briefly studied. HFM was found to be extremely effective in removing various VOCs from feed streams. Removal of 90-99 % of various VOCs was achieved at low feed flow rates and ...


Determination Of Appropriately Sized Principal Component Models And Their Effect On Detection And Isolation, David M. Himes Jan 1995

Determination Of Appropriately Sized Principal Component Models And Their Effect On Detection And Isolation, David M. Himes

Theses and Dissertations

No abstract provided.


Mechanisms Of Poly(Vinyl Chloride) Pyrolysis In The Presence Of Transition Metals, William Stephen Bryant Jan 1995

Mechanisms Of Poly(Vinyl Chloride) Pyrolysis In The Presence Of Transition Metals, William Stephen Bryant

Dissertations, Theses, and Masters Projects

No abstract provided.


Turbulent Scalar Transport Using Two-Point Statistical Closure Theory , Robert Charles Sanderson Jan 1995

Turbulent Scalar Transport Using Two-Point Statistical Closure Theory , Robert Charles Sanderson

Retrospective Theses and Dissertations

The turbulent transport of a passive scalar (Corrsin's problem with diffusion) and of an active scalar in stably stratified fluids is studied using linear analysis (rapid distortion theory or RDT), Kraichnan's direct interaction approximation (DIA) and direct numerical simulation (DNS). The results are compared with each other and with laboratory experiments. The numerical results compare favorably with the experiments of Sirivat and Warhaft, Budwig, Tavoularis and Corrsin and Stillinger and Itsweire of van Atta's group. The RDT study reveals that much of the qualitative behavior observed in experiments, such as the tendency for the system to evolve ...