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Effect of Soil Filtration and Ozonation in the Change of Baseline Toxicity in Wastewater Spiked with Organic Micro-pollutantsGan, Alexander 07 1900 (has links)
Bioassays for baseline toxicity, which measure toxicants’ non-specific effects, have been shown in previous studies to effectively correlate with the increased presence of pharmaceuticals, personal care products, endocrine-disrupting compounds, and other synthetic organics in treated sewage effluent. This study investigated how the baseline toxicity of anthropogenic compounds-spiked wastewater changed during the treatment of biofiltration and ozone oxidation, as measured by the bioluminescence inhibition of the Vibrio fischeri bacterium. The water quality parameters of dissolved organic carbon, seven common anions, and fluorescence spectroscopy were used to corroborate and collate with the toxicity results. Water quality was evaluated on two bench-scale soil filtration columns, which were configured for pre-ozonation and post-ozonation. Both systems’ soil aerobically removed similar amounts of dissolved organic carbon, and the reduction ranged between 57.7% and 62.1% for the post-ozonation and pre-ozonation systems, respectively. Biological removal of DOC, protein-like, humic-like, and soluble microbial product-like material was highest in the first 28.5 cm of each 114 cm-long system. While bioluminescence inhibition showed that ozonation was effective at lowering baseline toxicity, this study’s bioassay procedure was a very poor indicator of soil filtration treatment; both system’s effluents were significantly more toxic than their non-ozonated influents.
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REDUCING SIZE AND COST OF BIOWALL CONTROL SYSTEMDaniel Andres Allocca Kajsza (6630392) 12 October 2021 (has links)
<div>The control system of the Purdue Biowall (the botanical air filter) prototype has been targeted for replacement to improve the potential for commercialization. This thesis is focused on evaluating and improving the performance of a new control system based on a single board computer, which is slated to replace a much larger and more expensive Building Automation System that is currently being used. This analysis considers size, cost, accuracy of sensors, and data logging.</div><div>The research was conducted in three phases. Initially, an evaluation of an existing control prototype was conducted and several critical hardware failures were identified. Some of the most significant malfunctions were caused by broken wires, incorrect power supply voltage, and a short circuit due to poor soldering. The second phase of work involved improving the hardware and software for the control platform. All the problems found were fixed to make the control system completely operational. Moreover, a Printed Circuit Board (PCB) was designed to replace the breadboard previously used. The third phase of work was evaluating the performance of the new control system. Evaluations at a component level (e.g. individual sensors) and the overall system (e.g. including Biowall control algorithm) were conducted.</div><div>After a complete assessment, it was determined that a cheaper and smaller single board computer control system is able to substitute for the current Building Automation System. The accuracy of the sensors and the data collection were within the values expected. The physical size and cost of the controller was reduced by a factor of 30. The results obtained have identified several areas where further improvement is still needed. An efficient data logging code, replacement of wires, and PCB enhancement are still needed before deploying the new control solution into a building.</div>
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Vitamin E Therapy in IgA Nephropathy: A Double-Blind Placebo-Controlled StudyChan, James C.M., Mahan, John D., Trachtman, Howard, Scheinman, Jon, Flynn, Joseph T., Alon, Uri S., Lande, Marc B., Weiss, Robert A., Norkus, Edward P. 01 October 2003 (has links)
IgA nephropathy is the world's most common primary glomerulonephropathy. Recent evidence in a rat model implicated excessive production of oxygen-free radicals in the pathogenesis and suggested that vitamin E-treatment ameliorated progression. We studied this antioxidant therapy on the glomerular filtration rate (GFR), proteinuria and hematuria in biopsy-proven IgA nephropathy in children. The duration of treatment or placebo was 2 years, with vitamin E treatment consisting of 400 IU/day in children weighing <30 kg, and twice that dose for those >30 kg. We measured GFR at entry, midpoint and exit. At baseline and at 4-month intervals after randomization, urinary protein/creatinine ratios and urinalysis were examined. The mixed model procedure with log transformation was used in data analysis to test treatment difference as well as the potential time effect. Fifty-five patients were randomized and 38 completed at least 1 year of follow-up. At entry, the clinical characteristics were not different between the treatment and placebo groups. There was a trend toward better preservation of GFR in vitamin E-treated versus placebo patients, 127±50 vs. 112±31 ml/min/1.73 m2, respectively (P=0.09). The urinary protein/creatinine ratio was significantly lower in the vitamin E-treated group vs. placebo; 0.24±0.38 vs. 0.61±1.37 (P<0.013). However, there was no difference in the prevalence of hematuria between the groups. Vitamin E treatment in our study patients was associated with significantly lower proteinuria, but no effect on hematuria. While there was a trend toward stabilization of GFR in the vitamin E-treated patients, longterm treatment and follow-up are needed to determine whether antioxidant therapy is associated with preservation of renal function in IgA nephropathy.
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Denitrification in Membrane BioreactorsFonseca, Anabela Duarte 28 September 1999 (has links)
Three membrane bioreactors, a low flux filter (LFF), a diafilter (DF), and an ion-exchange (IE) membrane bioreactor were used to treat water polluted with 50 ppm-N nitrate. The three systems were compared in terms of removal efficiency of nitrate, operational complexity, and overall quality of the treated water.
In the low flux filter (LFF) membrane bioreactor an hemo-dialysis hollow fiber module was used and operated continuously for 29 days with a constant flux of permeate. The performance of the system was constant during the span of the experiment, which demonstrated that when the module was operated under constant low flux of permeate, the membrane filtration process was not affected by fouling. The removal rate of the LFF was 100% since the treated effluent did not contain nitrate or nitrite. The volumetric denitrification rate was 240 g-N day-1 m-3, which is within the range of denitrification rates obtained in tubular membrane modules. The treated effluent contained acetate, the carbon source of the biological process, and other inorganic nutrients, which showed that operating this ultrafiltration module at controlled flux did not improve the retention of these substances in the bioreactor.
The same hemo-dialysis hollow fiber module employed in the LFF system was used in the diafilter (DF) membrane bioreactor. In the DF system, however, the membrane module was used as a contactor that separated the treated water and the bioreactor system, which allowed the transfer of solutes through the membrane porous structure and supported the growth of a biofilm on the membrane surface. The nitrate removal rate of the DF system increased from 76% to 91% during the 17 days assay. Unfortunately, this improvement could be attributed to microbial contamination of the water circuit because significant concentrations of the carbon source, acetate, nutrients, and nitrate were found in the treated effluent. The volumetric denitrification rate of the system was 200 g-N day-1 m-3, and the surface denitrification rate was lower than values previously reported for contactor membrane bioreactors. The results hereby presented do not evidence any advantage of operating the Filtral 20 ® membrane module as a contactor instead of as a filter such as in the LFF system.
On the other hand, the third system herein presented, the IE membrane bioreactor, demonstrated several advantages of a contactor configuration but with a non-porous ion exchange membrane module in place of the Filtral 20 ®. As in a contactor system, the anion membrane provided a surface for biofilm growth, facilitated the transport of nitrate, and prevented mixing of treated water and bioreactor medium. Compared to the two previous systems, the most remarkable result of the IE was the reduction of secondary pollution in the treated water. The concentrations of phosphate and ethanol were zero and less than 1% of the concentration in the bioreactor, respectively. In addition, the IE system was less complex than the two other systems because the ion exchange membrane is non-porous. Therefore, unlike with porous contactors, it was not necessary to control the flux of treated water that could be lost through the bioreactor. The average surface denitrification rate of the IE system was 7.0 g-N day-1 m-2, which is higher than what had been reported for other contactor denitrification systems. However, because of the low surface to volume ratio of the membrane module that was used, the volumetric denitrification rate of the IE system was low, equivalent to 65 g-N day-1 m-3. / Master of Science
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Membrane Separation of 2-Ethyl Hexyl Amine/1-DeceneBawareth, Bander 12 1900 (has links)
1-Decene is a valuable product in linear alpha olefins plants that is contaminated with 2-EHA (2-ethyl hexyl amine). Using organic solvent nanofiltration membranes for this separation is quite challengeable. A membrane has to be a chemically stable in this environment with reasonable and stable separation factor. This paper shows that Teflon AF 2400 and cellulose acetate produced interesting results in 1-decene/2-EHA separation. The separation factor of Teflon AF 2400 is 3 with a stable permeance of 1.1x10-2 L/(m2·h·bar). Likewise, cellulose acetate gave 2-EHA/1-decene separation factor of 2 with a lower permeance of 3.67x10-3 L/(m2·h·bar). A series of hydrophilic membranes were tested but they did not give any separation due to high degree of swelling of 2-EHA with these polymers. The large swelling causes the membrane to lose its diffusivity selectivity because of an increase in the polymer's chain mobility.
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Forces governing the dynamics of fine particles near surfaces and suspended in airRajupet, Siddharth January 2021 (has links)
No description available.
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Developing Design Standards to enable the use of innovative technology in Ohio Public Water SystemsPatterson, Megan E. 06 October 2020 (has links)
No description available.
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Drop Motion and Modeling of the Saturation within Depth Coalescing FilterMehdizadeh, Seyedeh Neda January 2020 (has links)
No description available.
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Field evaluation of three systems for filtering polluted river water for use in subsurface irrigationNsengiyumva, Dominique January 1994 (has links)
No description available.
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The Design of a Biodegradable Stent for Arteriovenous Fistula Maturation and a Carbon Nanotube Membrane for Water FiltrationXu, Chenhao 23 August 2022 (has links)
No description available.
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