Engineering Commons^™

A Controlled Release Technique Using Microporous Membranes, Stephanie Farrell

Dissertations

A novel controlled release device based on aqueous-organic partitioning is described. The device comprises a reservoir, bounded by a microporous or porous membrane in the form of a hollow fiber or flat film. The reservoir liquid phase and the pore liquid phase are immiscible. The agent partitions between the phases at the aqueous-organic interface of the reservoir and the pore mouth, and then diffuses through the membrane pore liquid into a surrounding aqueous solution. The partition coefficient significantly influences the rate of release of the agent by reducing the driving force for diffusion across the fluid-filled membrane pore. The performance …

Vapor-Liquid Phase Equilibria Of Nonideal Fluids With A Ge-Eos Model, Socrates Ioannidis

Dissertations

This study dealt with the prediction and correlation of vapor-liquid equilibria behavior of nonideal fluids. The thermodynamic formalism of the G^E-EoS models, which combines the two traditional methods γ-Φ and Φ-Φ used so far for low and high pressure phase equilibria correlations respectively, has been combined with the 1FG^E model, based on one-fluid theory, to produce a more consistent approach to the phase equilibrium problem.

In the first part of our study we examine the predictive abilities of our model for vapor-liquid equilibria of highly nonideal fluids. The results establish the fact that the Huron-Vidal mixing rule …

Solids Suspension And Power Dissipation In Stirred Tanks Agitated By An Impeller Near The Tank Bottom, Ernesto Uehara-Nagamine

Theses

In this work, the effect of very small impeller clearances off the tank bottom, C, on complete solid off-bottom suspension, Njs, was investigated. Four types of impellers were used six-blade flat-disk turbine, six-blade flat-blade turbine, six-blade flat (45 degreees) pitched-blade turbine, and the high efficiency impeller Chemineer HE-3. The effects of the impeller diameter, D, tank diameter, T, and solids loading, X, were quantified. The presence of two impellers was analyzed using impellers of the same type and size.

Typically, Njs and the power consumption were found to decrease with the impeller clearance. However, for lower C/T values, a slight …

Removal Of Volatile Organic Compounds From Contaminated Groundwater By Pervaporation, Sukla Chandra

Theses

Effective removal of non-aqueous phase liquid pools in groundwater and volatile organic compounds (VOCs) from contaminated soils can be achieved by surfactant flushing. This surfactant-rich ground water contains VOCs like trichloroethylene (TCE), dichloroethylene (DCE), etc. Membrane pervaporation technique is employed here to remove TCE from these micellar systems where a very high percentage of the VOC is trapped inside the micellar core. The micellar solution flows through the bore of microporous hydrophobic hollow fibers wherein the micelles break down and release the surfactants and the TCE. The TCE is then removed through the pores and a nonporous thin silicone skin …

Fuel-Rich Combustion Of Ethylene And Air In A Two Stage Turbulent Flow Reactor, Tara Byrnes Salem

Theses

This thesis presents experimental and modeling results from the combustion of ethylene and air in a two stage turbulent flow reactor. This work is motivated by the continuing concern over combustion by-products. The first half of the research effort focused on the validation of the reactor as a perfectly stirred reactor and a plug flow reactor (PSR+PFR) sequence. Using four detailed reaction mechanisms, measured concentrations of carbon oxides, oxygen, and light hydrocarbon concentrations were modeled. Within the accuracy of the data, the mechanism of Mao (1995) yielded the best results. However, it was observed that the success of the reactor …

Removal Of Gasoline-Based Hydrocarbons By Vapor Permeation Membranes, Shivashanker Bagavandoss

Theses

Removal and recovery of evaporated lighter gasoline fractions can be effectively implemented by selectively permeating the hydrocarbons (HCs) and other volatile organic compounds (VOCs) from the vented air streams through nonporous hydrophobic polymeric membranes subjected to vacuum on the permeate side and then condensing these organics from the permeate. Such a vapor permeation process employing spiral-wound membranes has already been commercialized for VOCs. In this study, attention has been focused on removal of hydrocarbons from nitrogen flowing through the bore of microporous hydrophobic hollow fibers with a specially engineered nonporous silicone coating on the outside surface with a view to …

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 …

Emulsion Liquid Membrane Removal Of Arsenic And Strontium From Wastewater : An Experimental And Theoretical Study, Ding-Wei Zhou

Dissertations

The emulsion liquid membrane (ELM) technique has been successfully applied on the removal of arsenic (As) from metallurgical wastewater and the removal of strontium (Sr) horn radioactive wastewater. This study consisted of experimental work and mathematical modeling.

Extraction of arsenic by an emulsion liquid membrane was firstly investigated. The liquid membrane used was composed of 2-ethylhexyl alcohol (2EHA) as the extractant, ECA436OJ as the surfactant, and Exxsol D-8O solvent (or heptane) the diluent. The sulfuric acid and sodium hydroxide solutions were use I as the external and internal phases, respectively. The arsenic removal efficiency reached 92% within 15 minutes in …

Mass Transfer Of Pryene Between A Solid Phase And Oil/Water Suspensions, Sachin Ashok Purekar

Theses

This study dealt with understanding the partitioning of pyrene between water and mineral oil, and the mass transfer of pyrene from solid particles to oil/water suspensions.

It was found that when pyrene is dissolved in mineral oil, the amount transferred to water is negligible even after 10 days of phase contact.

Glass beads and sand were used as model solid phases to simulate soil and PAH (pyrene)-contaminated industrial sludges.

The transfer of pyrene from glass beads to mineral oil when no water phase is present was quantified. Mass transfer coefficients, and their dependence on the rate of environment shaking were …

Removal Of Vocs From Waste Gas Streams By Cyclic Membrane Separation Techniques, Gordana Obuskovic

Theses

In this study, new separation techniques called Flow Swing Membrane Absorption Permeation (FSMABP) and Flow Swing Membrane Permeation (FSMP) were used for the removal of the volatile organic compounds (VOCs). In both cases, processes are cyclic in terms of feed flow while desorption of the VOCs is constantly taking place. The transport mechanism in the FSMABP process is selective permeation followed by absorption of the VOCs into the stagnant nonvolatile absorbent liquid on the shell side of the membrane module and then desorption through a similar polymeric membrane. In the FSMP process, VOCs selectively permeate through the membrane into the …

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 of …

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

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 x 106 g-packing/ …