ASU Electronic Theses and Dissertations
This collection includes most of the ASU Theses and Dissertations from 2011 to present. ASU Theses and Dissertations are available in downloadable PDF format; however, a small percentage of items are under embargo. Information about the dissertations/theses includes degree information, committee members, an abstract, supporting data or media.
In addition to the electronic theses found in the ASU Digital Repository, ASU Theses and Dissertations can be found in the ASU Library Catalog.
Dissertations and Theses granted by Arizona State University are archived and made available through a joint effort of the ASU Graduate College and the ASU Libraries. For more information or questions about this collection contact or visit the Digital Repository ETD Library Guide or contact the ASU Graduate College at gradformat@asu.edu.
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Description
Radioactive cesium (137Cs), released from nuclear power plants and nuclear accidental releases, is a problem due to difficulties regarding its removal. Efforts have been focused on removing cesium and the remediation of the contaminated environment. Traditional treatment techniques include Prussian blue and nano zero-valent ion (nZVI) and nano-Fe/Cu particles to remove Cs from water; however, they are not efficient at removing Cs when present at low concentrations of about 10 parts-per-billion (ppb), typical of concentrations found in the radioactive contaminated sites.
The objective of this study was to develop an innovative and simple method to remove Cs+ present at low concentrations by engineering a proteoliposome transporter composed of an uptake protein reconstituted into a liposome vesicle. To achieve this, the uptake protein, Kup, from E. coli, was isolated through protein extraction and purification procedures. The new and simple extraction methodology developed in this study was highly efficient and resulted in purified Kup at ~1 mg/mL. A new method was also developed to insert purified Kup protein into the bilayers of liposome vesicles. Finally, removal of CsCl (10 and 100 ppb) was demonstrated by spiking the constructed proteoliposome in lab-fortified water, followed by incubation and ultracentrifugation, and measuring Cs+ with inductively coupled plasma mass spectrometry (ICP-MS).
The ICP-MS results from testing water contaminated with 100 ppb CsCl, revealed that adding 0.1 – 8 mL of Kup proteoliposome resulted in 0.29 – 12.7% Cs removal. Addition of 0.1 – 2 mL of proteoliposome to water contaminated with 10 ppb CsCl resulted in 0.65 – 3.43% Cs removal. These removal efficiencies were greater than the control, liposome with no protein.
A linear relationship was observed between the amount of proteoliposome added to the contaminated water and removal percentage. Consequently, by adding more volumes of proteoliposome, removal can be simply improved. This suggests that with ~ 60-70 mL of proteoliposome, removal of about 90% can be achieved. The novel technique developed herein is a contribution to emerging technologies in the water and wastewater treatment industry.
The objective of this study was to develop an innovative and simple method to remove Cs+ present at low concentrations by engineering a proteoliposome transporter composed of an uptake protein reconstituted into a liposome vesicle. To achieve this, the uptake protein, Kup, from E. coli, was isolated through protein extraction and purification procedures. The new and simple extraction methodology developed in this study was highly efficient and resulted in purified Kup at ~1 mg/mL. A new method was also developed to insert purified Kup protein into the bilayers of liposome vesicles. Finally, removal of CsCl (10 and 100 ppb) was demonstrated by spiking the constructed proteoliposome in lab-fortified water, followed by incubation and ultracentrifugation, and measuring Cs+ with inductively coupled plasma mass spectrometry (ICP-MS).
The ICP-MS results from testing water contaminated with 100 ppb CsCl, revealed that adding 0.1 – 8 mL of Kup proteoliposome resulted in 0.29 – 12.7% Cs removal. Addition of 0.1 – 2 mL of proteoliposome to water contaminated with 10 ppb CsCl resulted in 0.65 – 3.43% Cs removal. These removal efficiencies were greater than the control, liposome with no protein.
A linear relationship was observed between the amount of proteoliposome added to the contaminated water and removal percentage. Consequently, by adding more volumes of proteoliposome, removal can be simply improved. This suggests that with ~ 60-70 mL of proteoliposome, removal of about 90% can be achieved. The novel technique developed herein is a contribution to emerging technologies in the water and wastewater treatment industry.
ContributorsHakim Elahi, Sepideh (Author) / Conroy-Ben, Otakuye (Thesis advisor) / Abbaszadegan, Morteza (Committee member) / Fox, Peter (Committee member) / Arizona State University (Publisher)
Created2018
Description
This dissertation investigates the mechanisms that lead to fouling, as well as how an understanding of how these mechanisms can be leveraged to mitigate fouling.
To limit fouling on feed spacers, various coatings were applied. The results showed silver-coated biocidal spacers outperformed other spacers by all measures. The control polypropylene spacers performed in-line with, or better than, the other coatings. Polypropylene’s relative anti-adhesiveness is due to its surface free energy (SFE; 30.0 +/- 2.8 mN/m), which, according to previously generated models, is near the ideal SFE for resisting adhesion of bacteria and organics (~25 mN/m).
Previous research has indicated that electrochemical surfaces can be used to remove biofilms. To better elucidate the conditions and kinetics of biofilm removal, optical coherence tomography microscopy was used to visualize the biofouling and subsequent cleaning of the surface. The 50.0 mA cm-2 and 87.5 mA cm-2 current densities proved most effective in removing the biofilm. The 50.0 mA cm-2 condition offers the best balance between performance and energy use for anodic operation.
To test the potential to incorporate electrochemical coatings into infrastructure, membranes were coated with carbon nanotubes (CNTs), rendering the membranes electrochemically active. These membranes were biofouled and subsequently cleaned via electrochemical reactions. P. aeruginosa was given 72h to develop a biofilm on the CNT-coated membranes in a synthetic medium simulating desalination brines. Cathodic reactions, which generate H2 gas, produce vigorous bubbling at a current density of 12.5 mA cm-2 and higher, leading to a rapid and complete displacement of the biofilm from the CNT-functionalized membrane surface. In comparison, anodic reactions were unable to disperse the biofilms from the surface at similar current densities.
The scaling behavior of a nanophotonics-enabled solar membrane distillation (NESMD) system was investigated. The results showed the NESMD system to be resistant to scaling. The system operated without any decline in flux up to concentrations 6x higher than the initial salt concentration (8,439 mg/L), whereas in traditional membrane distillation (MD), flux essentially stopped at a salt concentration factor of 2x. Microscope and analytical analyses showed more fouling on the membranes from the MD system.
To limit fouling on feed spacers, various coatings were applied. The results showed silver-coated biocidal spacers outperformed other spacers by all measures. The control polypropylene spacers performed in-line with, or better than, the other coatings. Polypropylene’s relative anti-adhesiveness is due to its surface free energy (SFE; 30.0 +/- 2.8 mN/m), which, according to previously generated models, is near the ideal SFE for resisting adhesion of bacteria and organics (~25 mN/m).
Previous research has indicated that electrochemical surfaces can be used to remove biofilms. To better elucidate the conditions and kinetics of biofilm removal, optical coherence tomography microscopy was used to visualize the biofouling and subsequent cleaning of the surface. The 50.0 mA cm-2 and 87.5 mA cm-2 current densities proved most effective in removing the biofilm. The 50.0 mA cm-2 condition offers the best balance between performance and energy use for anodic operation.
To test the potential to incorporate electrochemical coatings into infrastructure, membranes were coated with carbon nanotubes (CNTs), rendering the membranes electrochemically active. These membranes were biofouled and subsequently cleaned via electrochemical reactions. P. aeruginosa was given 72h to develop a biofilm on the CNT-coated membranes in a synthetic medium simulating desalination brines. Cathodic reactions, which generate H2 gas, produce vigorous bubbling at a current density of 12.5 mA cm-2 and higher, leading to a rapid and complete displacement of the biofilm from the CNT-functionalized membrane surface. In comparison, anodic reactions were unable to disperse the biofilms from the surface at similar current densities.
The scaling behavior of a nanophotonics-enabled solar membrane distillation (NESMD) system was investigated. The results showed the NESMD system to be resistant to scaling. The system operated without any decline in flux up to concentrations 6x higher than the initial salt concentration (8,439 mg/L), whereas in traditional membrane distillation (MD), flux essentially stopped at a salt concentration factor of 2x. Microscope and analytical analyses showed more fouling on the membranes from the MD system.
ContributorsRice, Douglas, Ph.D (Author) / Perreault, Francois (Thesis advisor) / Abbaszadegan, Morteza (Committee member) / Fox, Peter (Committee member) / Lind-Thomas, Mary Laura (Committee member) / Arizona State University (Publisher)
Created2019
Description
This dissertation aims at developing novel materials and processing routes using alkali activated aluminosilicate binders for porous (lightweight) geopolymer matrices and 3D-printing concrete applications. The major research objectives are executed in different stages. Stage 1 includes developing synthesis routes, microstructural characterization, and performance characterization of a family of economical, multifunctional porous ceramics developed through geopolymerization of an abundant volcanic tuff (aluminosilicate mineral) as the primary source material. Metakaolin, silica fume, alumina powder, and pure silicon powder are also used as additional ingredients when necessary and activated by potassium-based alkaline agents. In Stage 2, a processing route was developed to synthesize lightweight geopolymer matrices from fly ash through carbonate-based activation. Sodium carbonate (Na2CO3) was used in this study to produce controlled pores through the release of CO2 during the low-temperature decomposition of Na2CO3. Stage 3 focuses on 3D printing of binders using geopolymeric binders along with several OPC-based 3D printable binders. In Stage 4, synthesis and characterization of 3D-printable foamed fly ash-based geopolymer matrices for thermal insulation is the focus. A surfactant-based foaming process, multi-step mixing that ensures foam jamming transition and thus a dry foam, and microstructural packing to ensure adequate skeletal density are implemented to develop foamed suspensions amenable to 3D-printing. The last stage of this research develops 3D-printable alkali-activated ground granulated blast furnace slag mixture. Slag is used as the source of aluminosilicate and shows excellent mechanical properties when activated by highly alkaline activator (NaOH + sodium silicate solution). However, alkali activated slag sets and hardens rapidly which is undesirable for 3D printing. Thus, a novel mixing procedure is developed to significantly extend the setting time of slag activated with an alkaline activator to suit 3D printing applications without the use of any retarding admixtures. This dissertation, thus advances the field of sustainable and 3D-printable matrices and opens up a new avenue for faster and economical construction using specialized materials.
ContributorsAlghamdi, Hussam Suhail G (Author) / Neithalath, Narayanan (Thesis advisor) / Rajan, Subramaniam D. (Committee member) / Mobasher, Barzin (Committee member) / Abbaszadegan, Morteza (Committee member) / Bhate, Dhruv (Committee member) / Arizona State University (Publisher)
Created2019
Description
Iodine and silver ions (Ag+), added as silver fluoride (AgF) or silver nitrate (AgNO3), are currently being used as a biocide to control the spread of bacteria in the water storage tanks of the International Space Station (ISS). Due to the complications of the iodine system, NASA is interested to completely replace iodine with silver and apply it as an antibacterial surface coating on stainless steel (SS) surfaces for biofouling control in extended space missions. However, Ag+ is highly soluble and rapidly dissolves in water, as a result, the coated surface loses its antibacterial properties. The dissolution of NPs into Ag+ and subsequent solubilization reduces its effectivity or extended period application. This study focuses on the in-situ nucleation of silver nanoparticles (AgNP) on stainless steel followed by their partial passivation by the formation of a low solubility silver sulfide (Ag2S), silver bromide (AgBr), and silver iodide (AgI) shell with various concentrations for an increased long-term biofouling performance and a slower silver release over time. Antibacterial activity was evaluated using Pseudomonas aeruginosa. The highest bacterial inactivation (up to 75%) occurred with sulfidized AgNPs as opposed to bromidized (up to 50%) and iodized NPs (up to 60%). Surface analysis by scanning electron microscopy (SEM) showed considerably fewer particles on AgBr and AgI compared to Ag2S-coated samples. Silver iodide was not tested in additional experiments due to its drawbacks and its poor antibacterial performance compared to sulfidized samples. Compared to pristine AgNPs, Ag release from both sulfidized and bromidized NPs was significantly low (16% vs 6% or less) depending on the extent of sulfidation or bromidation. Experiments were also carried out to investigate the effect of passivation on biofilm formation. Biofilm growth was smaller on surfaces treated with 10-3 M Na2S and 10-3 M NaBr compared to the surface of pristine AgNPs. Overall, sulfidation appears to be the most effective option to control biofilm formation on stainless steel. However, future research is needed to verify the effectiveness of sulfidized AgNPs on other metals including Inconel 718 and Titanium 6Al-4V used in the spacecraft potable water systems.
ContributorsRanjbari, Kiarash (Author) / Perreault, Francois (Thesis advisor) / Abbaszadegan, Morteza (Committee member) / Islam, Mohammed R (Committee member) / Arizona State University (Publisher)
Created2021