Chemical Engineering Commons^™

Mechanisms Of Pathogen Inactivation In Wastewater And Pharmaceutical Applications, Christa L. Meingast

Dissertations, Master's Theses and Master's Reports

Infectious diseases are a significant threat to public health. Though society enacts practices to prevent the spread of these dangerous diseases, challenges remain. Therefore, continual advancements in treatment and prevention are required. Wastewater treatment and viral clearance in pharmaceutical applications are two key health measures that prevent the spread of infections.

A low-cost, low-technology biosolids treatment process was developed to improve wastewater treatment by collecting key information on storage temperature, ammonia, volatile solids, moisture content, pH, and pathogen inactivation in biosolids over long-term storage at two wastewater treatment plants located in northern climates of the United States. Inactivation of pathogens …

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). …

Pelletization Of Cao Catalyst For Biodiesel Production Via Transesterification Of Palm Oil, Warisara Vornuch

Chulalongkorn University Theses and Dissertations (Chula ETD)

This thesis investigates biodiesel production from palm oil by transesterification using extruded CaO catalysts. The preparation parameters of extruded CaO catalysts were investigated including 1) binder type including activated alumina, diatomite and kaolin, 2) calcination temperature at 700, 800 and 900°C, 3) mass ratio of CaO to the binder at 1: 1, 3: 1 and 6: 1. The Effect of catalyst shape of the extruded CaO and the addition of pore forming (polyacrylamide) on the catalytic activity of extruded CaO were also studied using transesterification using methanol to palm oil. The ratio of methanol to palm oil was fixed at …

Comparison Of Pyrolysis Of Live Wildland Fuels Heated By Radiation Vs. Convection, Mohammad-Saeed Safdari, Elham Amini, David R. Weise, Thomas H. Fletcher

Faculty Publications

During wildland fires, which include both planned (prescribed fire) and unplanned (wildfire) fires, live and dead plants may be subject to both radiative and convective heat transfer mechanisms. In this study, the pyrolysis of 14 live plant species native to the forests of the southern United States was investigated using a flat-flame burner (FFB) apparatus under three heating modes in order to mimic pyrolysis of plants during wildland fires. The heating modes were: (1) radiation-only, where the plants were pyrolyzed under a moderate heating rate of 4 °C s−1 (radiative flux of 50 kW m−2); (2) convection-only, where the FFB …

Virus Purification Framework And Enhancement In Aqueous Two-Phase System, Pratik Umesh Joshi

Dissertations, Master's Theses and Master's Reports

Viral infections regularly pose detrimental health risks to humans. Preventing viral infections through global immunization requires the production of large doses of vaccines. The increasing demand for vaccines, especially during pandemics such as COVID-19, has challenged current manufacturing strategy to develop advanced unit operations with high throughput capability. Over the decade, the upstream processing responsible for synthesizing viral products in cell cultures has shown significant success in yielding high titers of viruses and virus-like particles. The progress in the upstream stage has now shifted the bottleneck to the downstream processing (DSP). Overlooked for decades, the DSP responsible for viral product …

The Deactivation Study Of Titanium Dioxide Catalyst In Thermochemical Processes Via Density Functional Theory, Chinanang Ngamlaor

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this study, the investigation of catalytic deactivation of TiO2 by coking was performed using DFT. The effect of the Hubbard U, which was varied as U equal 4 to 6 eV and Van der Waal corrections on electronic properties were also investigated. The effect of temperature in the range of 400-1000°C was also studied. This work aims to understand relatives of coke formation, oxygen vacancy, phase transformation. The increment of the Hubbard U values provide a more accurate quantitative cited by the energy gap from the experimental investigation, the appropriate U value of the A-TiO2 (101) is 4 eV, …

Deactivation Of Manganese Dioxide Electrocatalyst In Zinc-Air Batteries Studied Via Density Functional Theory, Puwit Buapin

Chulalongkorn University Theses and Dissertations (Chula ETD)

Manganese dioxide (MnO2) is the effective electrocatalysts used as a cathode for Zn-Air batteries (ZABs) accounted for the acceleration of the oxygen reduction reaction (ORR). There are various studies on the ORR activity of MnO2 rather than deactivation mechanisms. In this work, the deactivation mechanisms of α-MnO2 and β-MnO2 was investigated by density functional theory and computational hydrogen electrode. It was found that, the phase transformation from the α-MnO2 (211) to β-MnO2 (110) shows that the catalyst deactivation is due to the higher overpotential of β-MnO2 (110) making electrocatalyst efficiency low. For Ov surfaces, it illustrates that the performance is …

The Deactivation Of Gamma-Alumina Based Catalyst During Aqueous Phase Reaction Using Density Function Theory, Phakaorn Aphichoksiri

Chulalongkorn University Theses and Dissertations (Chula ETD)

Nowadays, biomass conversion has become a more attractive process to produce fuels and various high-value chemicals from biological materials. From many kinds of catalysts, the metal-supported gamma-alumina (γ-Al2O3) is a widely used catalyst for various transformation processes, especially in the aqueous phase reaction. Typically, coke formation on γ-Al2O3 causes catalyst deactivation in the thermal reaction process. Moreover, incorporation of aqueous phase medium initiates hydroxylation of γ-Al2O3 and phase transformation of γ-AlOOH, leading to the catalyst deactivation. Not only coke formation and phase transformation are the cause of catalytic deactivation, but the oxygen vacancy, changing the activity of the catalyst, should …

Effect Of Hydrochloric Acid Modification On Different Clay Catalystsfor Esterification Of Ethanol And Acetic Acid, Kwanchanok Netcharoen

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research aims to investigate the catalytic performance and characteristics of different clays with 0.5 M hydrochloric acid modification such as montmorillonite (HA-MMT), montmorillonite modified with Al (HA/Al-MMT), and kaolinite (HA-K) as a solid catalysts for esterification of ethanol and acetic acid. The reaction was performed in a batch reactor at 80oC, molar ratio of ethanol/acetic acid at 1.5, atmospheric pressure, and catalyst 10%wt of acetic acid for 1 hour. It revealed that hydrochloric acid-activated did not affect to the main structure and functional group of clays. All catalysts were tested for the catalytic performance in esterification of ethanol and …

Development Of Graft Copolymers Of Ultrafine Fully Vulcanized Powdered Natural Rubber With Styrene Or Acrylonitrile Monomers, Niratchaporn Rimdusit

Chulalongkorn University Theses and Dissertations (Chula ETD)

Ultrafine fully vulcanized powdered natural rubber (UFPNRs) were prepared by electron beam irradiation of graft copolymers, i.e. DPNR-graft-polystyrene (DPNR-g-PS) and DPNR-graft-polyacrylonitrile (DPNR-g-PAN), followed by spray drying process. The graft copolymers were prepared by grafting with styrene or acrylonitrile monomer onto deproteinized natural rubber (DPNR) via emulsion polymerization. The effects of monomer contents and radiation doses on thermal properties, chemical structure, swelling behaviors, and morphology of UFPNRs, i.e. UFPNR-GST and UFPNR-GAN were investigated. The results found that the highest grafting efficiency of the DPNR-g-PS and the DPNR-g-PAN were obtained at 15 phr of styrene or acrylonitrile content which provided the highest …

Development Of High Performance Ballistic Hard Armor Based On Fibers Reinforced Polybenzoxazine Alloy Filled With Nanoparticles, Phattarin Mora

Chulalongkorn University Theses and Dissertations (Chula ETD)

The multilayered armor based on fabric reinforced polybenzoxazine (poly(BA-a)) nanocomposites was developed in this research. The effect of nano-SiO2 contents on mechanical property and ballistic impact response of poly(BA-a) nanocomposites is determined for using as strike panel. Essential properties of aramid fabric reinforced polybenzoxazine/urethane (poly(BA-a/PU)) composites influenced by multiwalled carbon nanotube (MWCNT) contents is also investigated for using as support panel. From the results, the mechanical property of the nanocomposite was improved with the addition of nanoparticles. The experimental energy absorption (EAbs) and ballistic limit velocity (Vbl) of the nanocomposites were subjected by 7.62×51 mm projectile at velocity of 847 …

The Potential Of Gold Mine Development Project : A Case Study Of Chifunde District In Mozambique, Sara Mario Mabecuane

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research presents the results of the gold exploration activities developed in the district of Chifunde, Province of Tete in Mozambique. The works showed that in the study area there are two types of deposits which are primary and secondary deposits. There was clear evidence that they have undergone high-grade metamorphism of greenschist due to the grenade occurrences in hornblende in the form of porphyroblast which indicated a high probability of gold occurrence inside amphibolic schist. The results of the SGS laboratory revealed that all samples collected in the area contained gold ranging from 1 to 2,500 ppb, whereas in …

Integrative Co2 Capture And Utilization Process For Methanol Production Through Hydrogenation Reaction Of Co2-Rich Aqueous Penta-Ethylene Hexamine, Wachiramon Khuenkaew

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this study, integration of CO2 capture process with CO2 conversion to methanol process was simulated by Aspen Plus 8.8. The integrative carbon capture and utilization of methanol production can be divided into three main units; CO2 capture unit, methanol synthesis unit, and purification unit. A comparative study between conventional methanol production (case I) and CO2-rich Penta-Ethylene Hexamine (PEHA) conversion to methanol (case II and III) was carried out. Process in case II and III has different product purification processes. In the conventional process, monoethanolamine (MEA) was used in absorber to capture CO2 while PEHA was used in case II …

Fabrication And Characterization Of Bacterial Cellulose-Chitosan/Alginate/Gelatin Hydrogel Scaffolds For Application In Cartilage Tissue Engineering, Phasuwit Phassorn Phatchayawat

Chulalongkorn University Theses and Dissertations (Chula ETD)

Biopolymers of bacterial cellulose (BC), chitosan (C), alginate (A) and gelatin (G) were combined to fabricate three-dimensional (3D) hydrogel composite scaffolds for tissue engineering applications. The bacterial cellulose-chitosan/alginate/gelatin (BCC-AG) hydrogel scaffolds were characterized for chemical property by Fourier transform infrared (FT-IR) spectroscopic analysis, morphology by scanning electron microscopy (SEM), mechanical properties, degradability, biocompatibility and potential application in cartilage tissue engineering. Results from Fourier transform infrared (FT-IR) spectroscopy showed some weak interactions among BC, chitosan, alginate and gelatin, but no chemical interaction between those biopolymers was observed. The morphology of BCC-AG hydrogel scaffolds under SEM observation revealed that alginate and gelatin …

Development Of A Method For Quantification Of Toluene Diisocyanate And Methylenediphenyl Diisocyanate Migration From Polyurethane Foam Sample Surface To Artificial Sweat By Hplc-Uv-Ms, Aleksandra Donchenko, Simon Aubin, Sébastien Gagné, Mark Spence, Livain Breau, Jacques Lesage

Études primaires

The US Environmental protection agency (EPA) has published guidance that includes test procedures for evaluating indoor exposure to chemicals from products. One of the test procedures represents the migration test for evaluating potential dermal exposure from home furniture. Such an evaluation involves the chemical measurement of the sweat which is currently unavailable in the literature. The objective of this project was to develop and validate an analytical method for quantification of migration of 4,4′-methylenediphenyl diisocyanate (MDI), 2,6-toluene diisocyanate (2,6-TDI) and 2,4-toluene diisocyanate (2,4-TDI) from a polyurethane (PU) flexible foam to artificial sweat that meets the recommendations of the EPA test …

อิเล็กโทรดีโพสิชันของโครงสร้างนาโนของทองแดงออกไซด์บนแผ่นรองรับทองแดงสำหรับการรีดักชันเชิงไฟฟ้าของไนตรัสออกไซด์, สิรภัทร นิลวิเชียร

Chulalongkorn University Theses and Dissertations (Chula ETD)

งานวิจัยนี้ศึกษาการสังเคราะห์โครงสร้างนาโนของทองแดงออกไซด์บนแผ่นรองรับทองแดงโดยใช้วิธีอิเล็กโทรดีโพสิชันเพื่อให้ทองแดงมีพื้นที่ผิวสูงขึ้นเพื่อใช้เป็นตัวเร่งปฏิกิริยาโลหะทองแดงจากออกไซด์ในการทำปฏิกิริยารีดักชันเชิงไฟฟ้าของแก๊สไนตรัสออกไซด์ จากผลการศึกษาพบว่าปริมาณผลึกทองแดงออกไซด์แปรผันตามความหนาแน่นกระแสไฟฟ้าซึ่งหากมีค่าสูงเกินไปจะส่งผลให้เกิดการเกาะติดของผลึกไม่เต็มพื้นผิว นอกจากนี้ อุณหภูมิของอิเล็กโทรไลต์ที่สูงขึ้นทำให้ปริมาณผลึกเพิ่มขึ้นรวมถึงเกิดผลึกขนาดใหญ่ขึ้นอีกด้วย โดยพบว่าการอิเล็กโทรดีโพสิชันด้วยความหนาแน่นกระแสฟ้า -3.33 มิลลิแอมป์ต่อตารางเซนติเมตรและอุณหภูมิของอิเล็กโทรไลต์ 40 องศาเซลเซียสเป็นสภาวะที่ให้พื้นที่ผิวที่สูงที่สุด การอิเล็กโทรดีโพสิชันที่อุณหภูมิ 50 องศาเซลเซียสก่อให้เกิดผลึกขนาดใหญ่อย่างเห็นได้ชัดส่งผลให้พื้นที่ผิวในการทำปฏิกิริยาต่ำลง สำหรับการทำปฏิกิริยารีดักชันเชิงไฟฟ้าของแก๊สไนตรัสออกไซด์ด้วยตัวเร่งปฏิกิริยาโลหะทองแดงจากออกไซด์นั้น พบว่าความหนาแน่นกระแสไฟฟ้าสำหรับการเกิดแก๊สไนโตรเจนแปรผันตามปริมาณตัวเร่งปฏิกิริยาซึ่งเป็นผลมาจากการควบคุมระยะเวลาในการอิเล็กโทรดีโพสิชัน โดยเวลาอิเล็กโทรดีโพสิชันที่เหมาะสมคือ 30 นาที โดยเกิดปฏิกิริยารีดักชันของแก๊สไนตรัสออกไซด์ที่ศักย์ไฟฟ้าเริ่มต้นประมาณ 0.2 V vs RHE และเกิดปฏิกิริยาการผลิตไฮโดรเจนที่ประมาณ -0.3 V vs RHE และเมื่อศักย์ไฟฟ้าสูงขึ้นทำให้ความหนาแน่นกระแสไฟฟ้าสำหรับการเกิดแก๊สไนโตรเจนสูงขึ้นจนถึงศักย์ไฟฟ้าเท่ากับ -0.12 V vs RHE และลดต่ำลงที่ศักย์ไฟฟ้าที่สูงขึ้น ซึ่งให้ความหนาแน่นกระแสไฟฟ้าสำหรับการเกิดไนโตรเจนสูงสุดเท่ากับ -8.61 มิลลิแอมป์ต่อตารางเซนติเมตร และประสิทธิภาพเชิงฟาราเดย์ของการเกิดไนโตรเจนเท่ากับร้อยละ 98.5±1.7 นอกจากนี้ยังพบว่าตัวเร่งปฏิกิริยาทองแดงจากออกไซด์มีความเสถียรต่อการรีดักชันแก๊สไนตรัสออกไซด์เป็นเวลาอย่างน้อย 7 ชั่วโมง

Structural Analysis Of Deformed Caprock Associated With A Salt Shoulder At Gypsum Valley Salt Wall, Paradox Basin, Colorado, Hanah Draper

Open Access Theses & Dissertations

This study documents the style and distribution of deformation present in Triassic-age gypsic and carbonate caprock associated with the Gypsum Valley Salt Wall Salt Shoulder in the Paradox Basin, Colorado in order to determine the mechanism and timing of deformation. Mapping of gypsic and carbonate capstone facies shows that the caprock layering that was generated during formation has been deformed by large-and-small-scale folding and faulting, brecciation, and boudinage. Deformation within the caprock resulted in widely variable orientations along the length of the salt shoulder, that also varies locally in intensity of deformation and with proximity to the passively rising diapir …