Membrane Science Commons^™

Surface Modified Polypropylene Membranes For Treating Hydraulic Fracturing Produced Waters By Membrane Distillation, Tharaka Hawpe Gamage

Graduate Theses and Dissertations

Membrane distillation is an emerging technology for treating hydraulic fracturing flowback and produced waters. Suppression of membrane fouling by inorganic and polar and non-polar organic compounds is a challenge. Here polyhydroxyethyl methacrylate, polyacrylic acid, polvinylallyl imidazolium bromide and polyvinylhexyl imidazolium bromide chains have been grafted from the membrane surface. Fouling is initially due to adsorption of organic compounds followed by scale formation. When challenged with produced water, membranes modified with polvinylallyl imidazolium bromide chains provided the greatest resistance to fouling. For EC pretreated produced water and synthetic produced water that contained mainly inorganic species, the flux decline was much less.

Fabrication Of Composite Membranes For Solar-Thermal Desalination, Andrew Mason, Mahdi Mohammadighaleni, Siamak Nejati

UCARE Research Products

With rising human populations, the demand for freshwater is an ever-growing problem. One emerging technology to combat this problem is membrane distillation (MD). MD has several advantages for water desalination such as:

•100% rejection of solute (salt, heavy metals, etc.) •Mergeable with other affordable energy sources (solar heat, electric resistance, etc.)

However, at the moment the specific energy consumption (SEC) of MD is very high due to low water production rates and large energy inputs to heat water. In a solar-assisted design for MD, the high cost of solar collectors (~$200/m2) inhibits low cost of water production in comparison to …

Integrity Testing Of Gas Permeable Silicone Filters, Maggie M. Baker, Thomas P. Humann, Kevin J. Yerina

Biomedical Engineering

This report investigates the most reasonable, cost efficient, and reliable ways to integrity test a filter made from a permeable silicone membrane for future biomedical and pharmaceutical applications. The goal of the project was to create a fixture that a pharmaceutical company can use to quickly and reliably test the integrity of the filter. A variety of methods are outlined to test the integrity of the filter, after a series of quantitative tests, a single method was established that meet the requirements most thoroughly. The method that was determined to be most effective involves a series of components including a …

A Comparison Of Fiber Mat Thickness Measurement Techniques Using Laser Interferometry And Water Displacement, Ryan Seabeck

Williams Honors College, Honors Research Projects

Polymer fiber mats may often be very thin which leads to complications in measuring thickness. The thickness of fiber mats, however, is crucial in understanding their behavior. Thickness affects how well the mat works as a filter as well as the pressure drop across the mat, and herein lies the need for accurate measurement techniques. Currently two of the available techniques for measuring mat thickness are by laser interferometry[1] and by buoyancy force when submerged in water[2]. Instead of measuring the buoyancy force in this experiment, an enclosure intended to measure the thickness via water displacement was …

Filtration Apparatus Design For Oil-Water Separation Using Membranes And Sponges, Alec Jerger

Williams Honors College, Honors Research Projects

It can be difficult to separate water and oil emulsions through traditional filtration. Therefore, investigations of filtering using thermo-responsive (TR) polymers, in this case poly(vinyl methyl ether) (PVME), was conducted. It’s hypothesized that below its lower critical solution temperature (LCST), PVME has an affinity for water while oil substances do not. Above the LCST the opposite will be true. To verify this hypothesis, iterations of filtration designs were created to provide optimum control over the parameters to measure flow. The final optimized experimental apparatus was a Chromaflex glass column which was air tight and controlled all parameters besides fluid flow. …

Methods For Film Coating Electrospun Fibers, Kristopher Dejean

Williams Honors College, Honors Research Projects

Electrospinning uses high voltages to form polymer nanofiber membranes. These membranes have potential for use in filtration, tissue engineering, drug delivery, and catalysis. The nonwoven fiber mat is malleable but has a low tensile strength compared to a solid film of the same polymer. Joining the fibers with a thin film is desired to balance the strength and flexibility. Three methods of producing a film on fiber membrane were tested. The techniques are spraying then melting, spin coating, and dip coating. Electrospinning setup conditions, solvent ratios, damage to fibers, and spin coating speeds were determined. Research was abruptly stopped and …

A Thermodynamic And Feasibility Study Of Green Solvents For The Fabrication Of Water Treatment Membranes, Xiaobo Dong

Theses and Dissertations--Chemical and Materials Engineering

Nonsolvent induced phase separation (NIPS) has been widely used to fabricate polymeric membranes. In NIPS, a polymer is dissolved in a solvent to form a dope solution, which is then cast on a substrate and immersed in a nonsolvent bath, where phase inversion occurs. Petroleum-derived organic solvents, such as N-Methyl-2-Pyrrolidone (NMP) and Dimethylacetamide (DMAc), have been traditionally used to fabricate polymeric membranes via NIPS. However, these solvents may have negative impacts on environmental and human health; therefore, using greener and less toxic solvents, preferably derived from biomass, is of great interest to make membrane fabrication sustainable. In this dissertation, two …

Microfiltration Membrane Pore Functionalization Approaches For Chloro-Organic Remediation To Heavy Metal Sorption, Mohammad Saiful Islam

Theses and Dissertations--Chemical and Materials Engineering

Microfiltration polyvinylidene fluoride (PVDF) membranes have distinct advantage for open structure in terms of high internal surface area and ease of access in the pore domain. Functionalization of PVDF membranes with different functional groups (-COOH, -OH, -SH) enables responsive (pH, temperature) properties to membrane, tuning of effective pore size, controlling permeate flux. PVDF microfiltration membrane functionalization with suitable responsive polymer such as poly acrylic acid (PAA) to incorporate carboxyl (-COOH) group enables further modification of functionalized PAA-PVDF membranes for different application ranging from catalysis, bio reactor to heavy metal sorption platform. As a catalytic reactor bed, this PAA-PVDF membranes are …

Polymeric Nanocomposite Membranes With Phosphorene Based Pore Fillers For Fouling Control, Joyner Eke

Theses and Dissertations--Chemical and Materials Engineering

Phosphorene is a two-dimensional material exfoliated from bulk phosphorus. Specifically, relevant to the field of membrane science, the band gap of phosphorene provides it with potential photocatalytic properties, which could be explored in making reactive membranes able to control the accumulation of compounds on the surface during filtration, or fouling. Another reason phosphorene is a promising candidate as a membrane material additive is due to its catalytic properties which can potentially destroy foulants on the membrane surface.

The first goal of this study was to develop an innovative and robust membrane able to control and reverse fouling with minimal changes …

Methods For Film Coating Electrospun Fibers, Kristopher Dejean

Williams Honors College, Honors Research Projects

Electrospinning uses high voltages to form polymer nanofiber membranes. These membranes have potential for use in filtration, tissue engineering, drug delivery, and catalysis. The nonwoven fiber mat is malleable but has a low tensile strength compared to a solid film of the same polymer. Joining the fibers with a thin film is desired to balance the strength and flexibility. Three methods of producing a film on fiber membrane were tested. The techniques are spraying then melting, spin coating, and dip coating. Electrospinning setup conditions, solvent ratios, damage to fibers, and spin coating speeds were determined. Research was abruptly stopped and …

Towards Efficient Water Treatment: Mechanism Of Colloidal Fouling Of Ultrafiltration Membranes, Ikenna Henry Ozofor

Dissertations, Master's Theses and Master's Reports

This research study first reviewed challenges of conventional and membrane separation systems for water treatment. Though membrane separation systems appeared superior to the conventional counterparts for water and wastewater treatment, wider applications of membrane systems have been limited by some factors, most notably is membrane fouling. Experimental studies were therefore conducted to achieve the goal of this research, which is to investigate how feed properties affect fouling of ultrafiltration (UF) membranes by colloids.

Feed salinity, pH, and nanoparticle concentration were the variables studied to unravel how different UF membranes are fouled by model silica colloids (with average diameter of 25nm). …

Bimetallic Nanoparticles Integrated Membranes For Groundwater Remediation: Synthesis, Characterization And Applications, Hongyi Wan

Theses and Dissertations--Chemical and Materials Engineering

The detoxification of chlorinated organics from groundwater, such as trichloroethylene (TCE), tetrachloroethylene (PCE), polychlorinated biphenyl (PCB) and carbon tetrachloride (CTC), is a challenging area. Reductive dechlorination has been investigated using iron and iron-based nanoparticles, such as bare Fe, sulfidized Fe (S-Fe) and palladized Fe (Pd-Fe). However, issues including particle agglomeration, difficulties in recycling and particle leaching have been reported to hinder the application and wide usage of these techniques. The integration of nanoparticles and membranes can address these issues because of the large surface area, stability, and the potential for versatile functionalities. In this study, commercial polyvinylidene difluoride (PVDF) microfiltration …

Nanostructured Metal Thin Films As Components Of Composite Membranes For Separations And Catalysis, Michael J. Detisch

Theses and Dissertations--Chemical and Materials Engineering

Novel metallic thin film composite membranes are synthesized and evaluated in this work for improved separations and catalysis capabilities. Advances in technology that allow for improved membrane performance in solvent separations are desirable for low molecular weight organic separation applications such as those in pharmaceutical industries. Additionally, the introduction of catalytic materials into membrane systems allow for optimization of complex processes in a single step. By adding a nanostructured metallic thin film to its surface, a polymer membrane may be modified to exhibit these improved properties. Using magnetron sputtering, thin metal films may be deposited on commercially available membranes to …

The Development Of Temperature And Ph Responsive Hydrogels And Membranes For Selective Sorption Of Perfluoroorganics And Nanoparticle Integrated Catalytic Degradation Of Pcb, Anthony Saad

Theses and Dissertations--Chemical and Materials Engineering

The functionalization and use of responsive and catalytic polymeric membranes and materials were explored for contaminant capture and degradation. While membranes have a wide variety of uses across multiple industries, the inclusion of materials that are temperature and pH responsive in the membrane pore domain yields a wide range of applications and possibilities for water treatment. Temperature and pH responsive polymers, as well as controlled nanostructured materials, were synthesized in membrane pores for advanced adsorption-desorption and catalytic treatment of emerging organic contaminants in water. In this study, supported by the NIEHS, poly-N-isopropylacrylamide (PNIPAm) was used as a model thermo-responsive polymer, …

Dynamic Study Of Mo/Zsm-5 Catalyst For Ch4 Dehydroadomation, Hadi Yahya Almusawa

Graduate Theses, Dissertations, and Problem Reports

Methane dehydroaromatization (CH₄-MDA) is a highly promising venture for natural gas utilization/exploitation, i.e., direct conversion of methane (CH₄) to liquid aromatics (benzene) and hydrogen. This process is a catalytic reaction and therefore, is subject to all the advantages and constraints of catalysis. This study discussed the structure and reactivity of Mo/ZSM-5 zeolite catalysts and their effect on the active conversion of methane to valuable aromatic products such as benzene: 1) The preparation and characterization of Mo/ZSM-5, which are crucial steps in any catalytic reaction process since a better performing catalyst consequently leads to better outcomes; 2) …

Preparation And Characterization Of Ceramic Nanofiltration Membrane Prepared From Hazardous Industrial Waste, Shereen Kamel Amin, Mai Hassan Roushdy, Heba Mohamed Abdallah, Ahmed Mostafa, Magdi Fouad Abadir

Chemical Engineering

Kiln rollers, which are widely used in ceramic tiles production, are usually subjected to surface grinding to remove the contaminations. The resulted fine powder is considered useless waste and a hazardous source of environmental pollution particularly as it contains health‐threatening fine free silica. In the present paper, the grind waste from kiln rollers was reused as raw material in the fabrication of nanofiltration cerramic membrane. The samples of produced ceramic membranes were formed into disks by adding 15% (by weight) organic binder solution with 2% concentration, then pressed at 35 MPa, dried and fired at temperatures range from 1100°C to …

Preparation Of Ceramic Membranes From Sludge Waste, Mai H. Roushdy

Chemical Engineering

Ceramic tiles industry produces industrial waste wit large amount which become a worldwide problem. Ceramic sludge produced from ceramic tiles wastewater treatment plant is routinely discarded as a useless waste. The aim of this paper is to recycle the ceramic sludge waste to be used as raw material for ceramic membrane production. The ceramic sludge was collected, dried, and characterized by mineralogical composition (XRD), thermal analysis (DTA and TGA), and chemical composition determination (XRF). The support ceramic membrane samples were formed, pressed, dried then fired using temperatures from 1050 to 1200 °C for 1 to 3 hours. Verification parameters were …

Applications Of Ionic Liquids In Membrane Separation, Mohanad Kamaz

Graduate Theses and Dissertations

Ionic liquids represent an emerging attractive material in membrane technology. The central theme of this doctoral dissertation is to develope novel membranes using ionic liquids. Two different approaches were used to prepare ionic liquid membranes including the immobilization of ionic liquid within the membrane pores or the use of pressure assembly method to deposit a selective ionic liquid layer on the top membrane surface.

In chapter 2, imidazolium ionic liquids with three different alkyl halides were successfully synthesized and used to prepare supported ionic liquid membranes (SILMs). SILMs preraper were tested for aqueous and nonaqueous applications. For nonaqueous applications, the …

Development Of Forward Osmosis Based Separations: A Novel Approach In Membrane Technology, Yu-Hsuan Chiao

Graduate Theses and Dissertations

Tackling the worldwide severe water shortage, the membrane technology is considered to be the most efficient approach and hence, used widely as a cost-effective sustainable solution. “Forward osmosis (FO)” has been the major attention in recent time. FO uses osmotic pressure as the driving force to draw the water passing the membrane and achieve the desired separation performance. In general, it is considered to be a process with tremendous potential to resolve the present-day water shortage with extremely low energy consumption. However, the challenges of membrane and draw solution regeneration associated with FO processes must be conquered prior to their …

Influence Of Single And Multiple Histidine Residues And Their Ionization Properties On Transmembrane Helix Dynamics, Orientations And Fraying, Fahmida Afrose

Graduate Theses and Dissertations

Since aromatic and charged residues are often present in various locations of transmembrane helices of integral membrane proteins, their impacts on the molecular properties of transmembrane proteins and their interactions with lipids are of particular interest in many studies. In this work, I used solid-state deuterium NMR spectroscopy in designed model peptide GWALP23 [GGALW(LA)6LWLAGA] with selective deuterium labels to addresses the pH dependence and influence of single and multiple “guest” histidine residues in the orientation and dynamic behaviors of transmembrane proteins. The mutations include Gly to His (G2/22 to H2/22), Trp to His (W5/19 to H5/19) and Leu to His …