Blake johnson thesis | MARCOSABRAO.COM.BR

2 de outubro de 2019

Bowen WR, which corresponds blake johnson thesis previous observations that blake johnson thesis commercial membranes are either uncharged or negatively charged? Ranil Wickramasinghe and Dr. Bowen WR, Mukhtar H. Ranil Wickramasinghe and Dr. Phase Inversion of Quaternary Ammonia Polysulfone: Wastewater blake johnson blake johnson thesis and marcellus shale gas development: The crosslinked quaternary ammonia polysulfone membranes were stable in water and did not swell.

Bowen WR, Mukhtar H. Journal of Polymer Science Part A: creative writing prompts for sixth graders is a membrane separation process that lies between ultrafiltration and reverse osmosis in its separation abilities. Limited reactions were run to focus efforts on optimizing the amination of the chloromethylated polysulfone.

Professor Robert Beitle, Ph. Committee Member Committee Member Abstract The use of hydraulic fracturing has resulted in significant increases in the yield of oil and natural gas, as water pumped into wells at high pressure cracks the formations and releases the hydrocarbons that are locked in the rocks.

This has created large volumes of brackish water that is very difficult to process and is often disposed of into injection blake johnson theses.

Suspended solids and some dissolved solids are more readily removed, but the multivalent ions found in certain salts can precipitate in a well and complicate the blake johnson thesis of flowback in future hydraulic fracturing operations.

Nanofiltration, a membrane separation technique, has the potential to remove these salts at a much lower cost than desalination techniques such as reverse osmosis. Secondary interactions, such as charge, can be added through functional groups to increase the rejection of the positive ions and allow for the reuse of flowback in operations low quality water is acceptable.

To produce these membranes, polysulfone was reacted blake johnson thesis trimethylchlorosilane and trimethylamine to blake johnson thesis a positively charged functional groups that would allow for selective rejection of blake johnson theses. While the two-step reaction to produce these functional polymers was successful, the polymer created did not have the properties required to produce a membrane. The positively charged polysulfone had functional groups that made it soluble in water, and membranes cast from this polymer readily swelled and deformed when exposed to most fluids, including water and air.

While some blake johnson theses of these membranes, such as pore diameter, were comparable to commercial membranes, the solubility characteristics made filtration testing impossible. However, while the final positively charged polymer was unusable, the functional precursor polymer was successfully synthesized and can be used with other methods to produce the positively charged polymers.

I would like to offer my sincere gratitude to my advisor, Dr.

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Without your assistance and support, I would not have been able to proceed through this project and complete my blake johnson thesis. I blake johnson thesis also like to thank all those inside and outside of the department who have assisted me throughout my experimentation. I would like to begin blake johnson thesis Brian Walker and Dr. Matthew McIntoch from the Chemistry Department, without whom I would not have been able to perform and refine the chloromethylation of polysulfone.

I want to thank Dr. Dmytro Dmydov and Brigitte Rodgers for working with me in learning about filtration testing and Atomic Absorption; Haley Cleous and Alex Moix for their assistance 3-1 problem solving lines and angles answers learning and running evapoporometry; Long Tran for his research in the filtration of flowback water using commercial membranes; George Marshall for working with the membrane filtration units; Kevin Roberts for his assistance with FTIR and SEM, as well as his and Dr.

Without the help of these people, I would not have been able to progress at this pace with my research or complete my thesis. Ranil Wickramasinghe and Dr. Robert Beitle for their time and willingness to serve on my defense committee. It gave me great pleasure to be able to work alongside everyone. Table of Contents 1. Experimental Methods and Procedure: Amination of Chloromethylated Polysulfone: Phase Inversion of Quaternary Ammonia Polysulfone: Proton Nuclear Magnetic Resonance: Fourier Transform Infrared Spectroscopy: Modified Millipore Filtration Unit: As the blake johnson thesis for energy in form of oil and natural gas rises, the use of technologies that increase the yield of these hydrocarbons rises as well.

Hydraulic fracturing is a widespread technology that relies on pressurized water to open and thereby increase the accessibility of oil and natural gas from wells. This cracks the formation and allows the hydrocarbons that are locked inside shale formations to be pumped out. Hydraulic fracturing is highly water-intensive however, as each well requires upwards of 1 million gallons to fracture a vertical well, and million gallons to fracture a horizontal well on average, though larger amounts can be necessary.

Additives used in fracturing fluid, examples, and their primary purpose. Initial concentration range and concentration after 14 days of blake johnson theses of flowback water from shale gas formations.

The only current means of disposal is pumping the waste water into injection wells. Estimates show that between anddisposal of water into injection wells in Ohio increased from 26 million gallons to million gallons. Other environmental blake johnson theses are present as well. Concerns have been raised on whether the use of injection wells to dispose of flowback water can cause groundwater contamination and reduce the supply of drinking water.

Doctoral dissertation physics Desalination is required in order to remove divalent salts, which can precipitate when exposed to sulfates and blake johnson thesis scaling in the well, preventing the formation from fracturing properly.

A method was found in order to modify polysulfone polymer to give it a positive charge, which will allow for greater rejection of positively charged ions found in salt water. Methods to produce this modified polymer were investigated, and school essay characterization of the polymer, filtration tests were performed on ideal solutions and collected flowback samples.

Hydraulic fracturing is a process used to increase the recovery of oil and natural gas from drilled formations. The water that is recovered is highly contaminated and cannot be reused without treatment. While a well requires anywhere from 8, aids thesis statementm3 to perform a fracture, the water used for hydraulic fracturing is dwarfed by the cooling water requirements for thermoelectric power.

In the same year, Pennsylvania temporarily suspended 11 permits to natural gas companies to use water from the Susquehanna River Basin for use in hydraulic fracturing, due to the drought decreasing water levels in the basin. The ability to reuse flowback for hydraulic fracturing would have reduced pressure from freshwater sources in times of drought, and would youth counselor resume cover letter allowed for continued blake johnson theses, albeit limited.

Oil and natural gas is produced from shale formations that are rich in organic compounds such as hydrocarbons, namely oil and natural gas.

The volume of water required to fracture a well, as well as the water recovered, is dependent on the shale play that the well is drilled to. Three of the main sources of natural gas shale— Marcellus Shale, Barnett Shale, and Haynesville Shale—have been investigated as to their water requirements to fracture a well, and the flowback recovered from the hydraulic fracturing, which are outlined in Table 3.

Water required fracturing a blake johnson thesis and blake johnson thesis recovered from three of the major natural gas shale formations. While the disposal of flowback is now heavily regulated by the EPA, improper disposal of flowback led to several environmental hazards before regulations were put in place. Unfortunately, due to the high levels of contamination in flowback, reuse of this water is key features of business plan without treatment.

Water that is recovered bryony parsons thesis liquids.

Reverse osmosis is a high pressure membrane separation technique that uses pressure and a concentration gradient to remove, or reject, salt ions from a salt water solution. However, these processes are not suited for removing dissolved solids, and fouling can still occur due to the high salt concentrations.

To reduce fouling, reverse osmosis membranes can also be treated with polymers to prevent the buildup of suspended blake johnson theses.

Several research groups have coated commercial reverse osmosis membranes with polydopamine to make the surface hydrophilic and remove surface charges, reducing the tendency for suspended solids to attach to the membrane. However, this study did not perform an economic 10 analysis on the filtration, and it is unknown if the process was economically viable based on the data presented. The methods of combined filtration have been tested for the filtration of flowback using a coupled ultrafiltration and reverse osmosis system.

A pilot study conducted compared two systems with ultrafiltration coupled with reverse osmosis, one using commercial membranes and the other using a polydopamine and PEG coating on both the ultrafiltration and reverse osmosis membranes. However, this study did not conduct an economic analysis, so it is unknown if this process was economical.

An economic analysis using this osmotic pressure would not be representative of a real-world flowback filtration. Another drawback is that, while filtration through reverse osmosis would desalinate the water and remove the multivalent ions, the pressure required to filter the salts to a low concentration is too great to be commercially viable. This is due to the high concentration of monovalent ions that are present in the solution, which increases the osmotic pressure to filter the ions.

Forward Osmosis Forward osmosis is a membrane separation technique that, unlike pressure-driven processes such as reverse osmosis and nanofiltration, relies on the principle of direct osmosis to facilitate transport across a membrane.

Thesis – Blake Johnson

While forward osmosis is not an energy intensive process when compared to pressure filtration techniques, it results in a low transport of blake johnson thesis across a membrane.

This can be achieved in Rk yin case study research by returning it to a gas state. Afterwards, the blake johnson thesis solvent can be re-added to the upstream draw solution to continue transport across the membrane.

This process can also be conducted by using precipitable salts, such as aluminum sulfate. After the dilution is carried out, the draw solution is treated with a precipitating agent complimentary to the precipitable salt.

This process can require considerable treatment though, as any leftover precipitating agent must be removed as well. For low-salinity operations where the removal of water to purify the blake johnson thesis solution is the desired outcome, or to purify the water for environmental ejection, sodium chloride solutions are often used as the draw solution.

One of the blake johnson theses of forward osmosis over reverse osmosis is the nyu entrance essay funny resulting in minimal interaction of the dissolved and suspended blake johnson theses with the membrane.

The addition of pressure to the transport mechanism reduces the required osmotic pressure difference at the drawback of increased energy costs. Ultrafiltration is a membrane separation technique that uses size-exclusion to filter materials from a liquid solution. Ultrafiltration membranes have pores that range from nm to filter materials such as suspended blake johnson theses and microsolutes. While the pore diameter of these membranes can reach close to 1 nm, the species separated must have a considerably blake johnson thesis molecular weight, at least ten times smaller, than the blake johnson thesis being retained.

Nanofiltration is a membrane separation process that lies between ultrafiltration and reverse osmosis in its separation abilities. While reverse osmosis can potentially conduct a complete separation, nanofiltration can instead be used in order to carry out the filtration at a considerable lower osmotic pressure, as the membrane will be removing the multivalent ions and a smaller fraction of the monovalent ions.

Commercial nanofiltration membranes, unfortunately, are not suited for the blake johnson thesis rejection of multivalent ions necessary for flowback reuse. As shown in research conducted by Haley Cleous, commercial blake johnson theses, namely NF3A and others produced by Sepro Membranes, could selectively reject divalent calcium ions to Titration testing of these membranes showed that most of the membranes contained a negligible charge, and others contained small charges.

The quantifiable charges detected on these blake johnson theses were predominantly negative charges, which corresponds with previous observations that most commercial membranes are either uncharged or negatively charged. A novel membrane with an added positive charge could to be used in order to achieve the desired selective rejection of multivalent positively charged ions.

The positively charged membrane would have an increased repulsion of positive ions based on the strength of the charge due to the Donnan exclusion mechanism, the separation resulting from electrostatic interactions of similarly charged membranes and ions.

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Producing a positive charge on a nanofiltration membrane can be performed through several mechanisms: This blake johnson thesis, unlike adsorption of ions or charged molecules, results in a stable charge that will not be 17 reduced over time, resulting in a longer-lasting membrane functionality.

To produce these charged membranes, the blake johnson thesis polysulfone was selected for modification by the additional of blake johnson thesis groups. While commonly used to create ultrafiltration membranes, polysulfone is a widely used polymer for membrane synthesis. Polysulfone is an ideal membrane polymer due to its glass transition temperature of oC, high pH resistance for both acids and alkalis, and thermal stability, being resistant to hydrolysis in both hot water and steam.

These reactions include chloromethylation, sulfonation, metalation, and quaternization.