付記する学位プログラム名: 京都大学卓越大学院プログラム「先端光・電子デバイス創成学」 / 京都大学 / 新制・課程博士 / 博士(工学) / 甲第24624号 / 工博第5130号 / 新制||工||1980(附属図書館) / 京都大学大学院工学研究科電子工学専攻 / (主査)教授 川上 養一, 教授 野田 進, 教授 木本 恒暢 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

Advanced oxidation processes (AOPs) have been used to treat drinking water and wastewater but their application to greywater is limited to photocatalysis. Therefore, three homogeneous AOPs were investigated in this project: Fenton, photo-Fenton, and UVC/H2O2 processes. Alum and ferrous sulphate coagulation were also compared and their supernatants were treated by UVC/H2O2. The process comparisons were based on the removal of chemical oxygen demand (COD), treatment type (physical separation versus chemical oxidation), sludge formation, complexity in operation, required pH, visual aesthetic of effluent and energy requirement. Treating greywaters collected from the researcher's home or laboratory, alum coagulation achieved 73% COD removal and was more effective than ferrous sulphate coagulation (49%) and the Fenton process (45%). The photo-Fenton process removed 83% COD, compared with 87% by overnight settlement and subsequent UVC/H2O2 treatment. Using ferrous sulphate and alum, sequential coagulation and UVC/H2O2 treatment removed 91% and 98% COD, respectively. Overnight settlement generated little sludge and the subsequent UVC/H2O2 treatment removed most organic contaminants by oxidation. All other processes produced a large quantity of chemical sludge from coagulation which requires appropriate disposal. Also, the residual iron in some treated water was not aesthetically desirable. The Fenton and photo-Fenton processes were complex and involved the optimisation of multiple parameters. Their requirement for different procedures according to the greywater type presents a major challenge to process design and operation. Due to the non-selectivity of the hydroxyl radicals (●OH), the UVC/H2O2 process was capable of treating all greywaters collected by the researcher, and its operation was moderate in complexity. The COD removal was modelled as a pseudo first-order reaction in terms of H2O2 dosage: The rate constant (k´) increased linearly up to 10 mM H2O2, above which the excess H2O2 scavenged the ●OH and reduced the rate. The overall kinetics of COD removal followed a second-order equation of r = 0.0637 [COD][H2O2]. In contrast to the literature, operation of UVC/H2O2 in acidic conditions was not required and the enhanced COD removal at the initial pH of 10 was attributed to the dissociation of H2O2 to O2H-. Maintaining the pH at 10 or higher resulted in poorer COD removal due to the increased decomposition rate of H2O2 to O2 and H2O. The performance of the UVC/H2O2 treatment was unaffected for initial pH 3 - 10 with the initial total carbonate concentration (cT) of 3 mM. For initial cT ≥ 10 mM, operating between pH 3 and 5 was essential. After 3 hours of the UVC/H2O2 treatment, the effluent met the requirement of Class B reclaimed water specified by the Environment Protection Authority of Victoria, and less than 1 org/100 mL of Escherichia coli survived. A subsequent treatment such as filtration may be required to meet more requirements for biochemical oxygen demand (BOD5), turbidity and total suspended solids. Since the biodegradability (as BOD5:COD) of the greywater was increased from 0.22 to 0.41 with 2 hours of UVC/H2O2 treatment, its integration with a subsequent biological treatment may be viable to reduce the costs and energy consumption associated with the UVC/H2O2 process.

Made available in DSpace on 2014-06-12T18:01:53Z (GMT). No. of bitstreams: 2 arquivo120_1.pdf: 4032573 bytes, checksum: a9af6ac4684588cbaeb85c3a2acced19 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2010 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Os métodos usualmente empregados na desinfecção de águas contaminadas têm por vezes efeitos secundários indesejados. A cloração, a mais difundida forma de desinfecção, têm como subprodutos os trihalometanos, comprovadamente carcinogênicos. Nesse cenário, os processos alternativos de desinfecção têm desempenhado um papel de destaque. A desinfecção via processo combinado UVC/H2O2 é um exemplo dos chamados Processos Oxidativos Avançados (POA) que têm sido largamente estudados e empregados na inativação de bactérias. No presente trabalho realizaram-se estudos acerca da cinética de inativação da bactéria Pseudomonas aeruginosa via irradiação com luz UVC, contato direto com H2O2 e processo combinado UVC/H2O2 em águas sem turbidez e sem nutrientes. Foi utilizado um sistema composto de um fotorreator anular munido de uma lâmpada germicida acoplado em série com um tanque de reciclo com agitação mecânica em um circuito fechado. Foram empregados diversos modelos cinéticos para descrever a evolução da concentração de bactérias ativas. A eficiência alcançada utilizando-se irradiação com luz UVC foi em média 99,99% em um tempo de irradiação de 252 s. A taxa de inativação mostrou-se independente da concentração inicial de bactérias. O modelo cinético que melhor representou o processo foi o de Hom por possuir um termo associado à não-linearidade com relação ao tempo de irradiação. A eficiência alcançada utilizando-se H2O2 como agente oxidante e a taxa de inativação bacteriana dependeu diretamente da concentração inicial de H2O2, atingindo valores entre 54,85 e 94,87 % em um tempo de contato de 120 min. A baixa eficiência se deve a capacidade da Pseudomonas aeruginosa de produzir catalase. A enzima catalase se mostrou eficiente em inativar a ação do H2O2. Os modelos de Hom, Exponencial de Hom, dos Alvos Múltiplos e o dos Alvos Múltiplos Modificado representaram com boa aproximação os dados experimentais da inativação via H2O2, com uma pequena vantagem para o modelo dos Alvos Múltiplos Modificado. Todos estes modelos têm em comum um termo que representa a não-linearidade com relação ao tempo de contato. A eficiência alcançada utilizando-se o processo combinado UVC/H2O2 dependeu diretamente da concentração inicial de H2O2, atingindo valores entre 98,95 e 99,99 % em um tempo de irradiação de 252 s. O peróxido de hidrogênio teve uma influência negativa na inativação da bactéria devido a dois fatores: a) O H2O2 absorveu parte da energia incidente no espaço reacional na geração de radicais livres; b) A Pseudomonas aeruginosa é catalase-positiva, possuindo resistência à ação do H2O2 e dos radicais hidroxila. Não foi possível analisar a dependência da taxa de inativação em relação à concentração inicial de bactéria

The COVID-19 pandemic has been an unprecedented public health crisis around the world and has created novel needs in the healthcare industry. Primary among these needs is a vast shortage in personal protective equipment (PPE) such as masks and gloves. This is problematic due to the near constant of COVID-19 cases in hospitals around the United States. In an effort to meet the need for more PPE, new disinfection techniques must be found to "recycle" used PPE. UVC light has previously been used by healthcare facilities for years to disinfect surfaces such as stainless steel and are frequently used in operating room sterilization and dentist offices. UVC light's effectiveness on porous materials such as masks has not been substantially investigated prior to the COVID-19 pandemic. This work shows the effectiveness and efficiency of UVC disinfection on porous surfaces for the COVID-19 virus and other bacteria.

<p>The agriculture in Sweden today uses chemical substances to control vermin, weed</p><p>and diseases. This usage shows through polluted subsoil water and trace elements in</p><p>the food we eat. There’s a risk that additional symptoms will arise in the future.</p><p>Our product Sha Jun, developed in 2006-2007, is an attempt to try and minimize the</p><p>need of chemicals in the agriculture. The idea started with the attempt to minimize the</p><p>usage of pesticides on the cropland. It later developed in an attempt to decrease seed</p><p>disinfectant. The spraying with seed disinfectant today is happening with a rate of 1</p><p>tonne/h. They hope one day to reach the speed of 5 tonnes/h. With our product you</p><p>reach speeds of 17.5 tonnes/h. We also eliminate the need to use the dangerous seed</p><p>disinfectant on the seed before it s stored. The market for our product in Sweden</p><p>consists of approximately 800 potential buyers. These include farms over 200 hectares</p><p>and collection centrals. It will also give ecological framers a change to decrease their</p><p>losses in useless crops. This because our method of treatment is environment-friendly.</p>

The agriculture in Sweden today uses chemical substances to control vermin, weed and diseases. This usage shows through polluted subsoil water and trace elements in the food we eat. There’s a risk that additional symptoms will arise in the future. Our product Sha Jun, developed in 2006-2007, is an attempt to try and minimize the need of chemicals in the agriculture. The idea started with the attempt to minimize the usage of pesticides on the cropland. It later developed in an attempt to decrease seed disinfectant. The spraying with seed disinfectant today is happening with a rate of 1 tonne/h. They hope one day to reach the speed of 5 tonnes/h. With our product you reach speeds of 17.5 tonnes/h. We also eliminate the need to use the dangerous seed disinfectant on the seed before it s stored. The market for our product in Sweden consists of approximately 800 potential buyers. These include farms over 200 hectares and collection centrals. It will also give ecological framers a change to decrease their losses in useless crops. This because our method of treatment is environment-friendly.

B-Ga2O3 is one of the emerging semiconductor materials with high breakdown field strength (~ 8 MV/cm) and ultrawide-bandgap (UWBG) 4.9 eV. Therefore, B-Ga2O3 and related compound semiconductors are ideal for power electronics and deep/vacuum ultraviolet-wavelength photodetector applications. High-crystal-quality B-Ga2O3 semiconductor materials epitaxially deposited on the various substrate are prerequisites for realizing any practical application. However, it is still challenging to grow high-crystal-quality V-Ga2O3 layer and to integrate B-Ga2O3 with other semiconductor materials by direct epitaxy. Understanding the epitaxial relationship of the integrated oxide heterostructure and the substrate used helps to shed light on the feasibility of heterojunctions formation for photonic applications, such as the ultraviolet-wavelength photodetectors developed in this thesis. By optimizing pulsed laser deposition (PLD) conditions, such as laser energy, ambient gas, pressure, etc., a single-crystalline oxide heterostructure were successfully integrated into a photonic platform. This included p-NiO/n-B-Ga2O3/a-Al2O3, B-Ga2O3/y-In2O3/a-Al2O3, and B-Ga2O3/TiN/MgO structures. The epitaxial thin film crystallographic and chemical properties were investigated by different characterization techniques. The high-resolution X-ray diffraction (HRXRD) was applied to study the heterostructures’ epitaxial orientation relationship by out-of-plane XRD w-2θ-scan and asymmetric skew ɸ-scan. The lattice-mismatch at the heterostructure interfaces were examined and the crystal quality of the epitaxial thin films were measured by means of full-width at half-maximum (FWHM) fitting. Scanning-TEM energy-dispersive X-ray spectroscopy (STEM-EDX) was applied to qualitatively study the chemical elements’ spatial distribution. Rutherford backscattering spectroscopy (RBS) was applied to study the epitaxial thin film chemical composition, material stoichiometry, and inter-diffusion. The X-ray photoelectron spectroscopy (XPS) was applied to study the conduction and valence band offsets which is essential to determine the types of heterostructures formed. Finally, the p-NiO/n-B-Ga2O3/a-Al2O3 B-Ga2O3/y-In2O3/a-Al2O3, and B-Ga2O3/TiN/MgO epitaxial thin-film were fabricated into ultraviolet-wavelength photodetectors. The wavelength-dependent and power-dependent characterizations were applied to measure the cut-off wavelength and the peak responsivity. The time response characterization was applied to measure the photodetectors’ responses to pulse signals, and the rise and decay times were fitted by a double exponential function.

The lack of biodegradability of PFAS, or per- and polyfluoroalkyl substances, is due to the presence of many strong carbon-fluorine bonds. Two common PFAS that are found in the environment are perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS). This work first studied an innovative pathway for PFAS removal through the adsorption of PFOA and PFOS (pre-concentrating the contaminants) by nanoscale zero-valent iron/reduced graphene oxide (rGO-nZVI) and their subsequent degradation via photocatalysis under UVC light. The GO that was later reduced in nanohybrid production was made utilizing a modified Hummer’s method. The rGO-nZVI nanohybrid was prepared for the first time via thermal reduction at high temperatures. Additionally, the nanohybrid was prepared using the wet chemistry method for comparison. LC/MS/MS analysis was conducted to determine the adsorption efficiencies for PFOA and PFOS using the nanohybrids and their successive removal under UVC light. Chlorinated hydrocarbons are another group of contaminants of concern that should be removed from the subsurface due to their harmful effects. In this study, a more complex mixture of the contaminants including PFAS and chlorinated hydrocarbons was investigated, which is usually found in the superfund and other contaminated sites. Considering the effectiveness of nZVI to remove chlorinated hydrocarbons from the subsurface, engineered nZVI coupled with rGO was utilized to enhance the removal efficiency of the mixture of contaminants, i.e., PFAS comingled with chlorinated hydrocarbons. The synthesized rGO-nZVI nanoparticle showed high adsorption efficiencies for both PFOA and PFOS, i.e., removal of 55.3%, 98.2%, and >99.9% of PFOA of 10, 1, and 0.1 mg/L, and 94.9%, 97.6%, and 85.0% of PFOS of 10, 1, and 0.1 mg/L, respectively, in 3 h. Later degradation of pre-concentrated PFAS under UVC light was also achieved. Using extracted rGO-nZVI, 55.1%, 77.6% of preconcentrated PFOS was degraded starting from 10, and 1 mg/L of initial concentrations before adsorption in the photoreactor at the end of 24 h. In comparison, 68.5% and 47.2% of PFOS and PFOA (starting from 1 mg/L each) was degraded, respectively, using rGO-nZVI directly under UVC light after 24 h. Moreover, it was found that rGO-nZVI had high adsorption capacity of 69.4% and 68.7% respectively for TCE and PFOA in a mixture of these contaminants. Under UVC irradiation, the preconcentrated mixture of TCE and PFOA were both degraded to below the detection limit in 21 h. It was also found that PFOA concentration dropped by 64.3% at 5 h and by 88.7% at 24 h by fresh rGO-nZVI in presence of 10 mg/L TCE. Short-chained PFCAs like PFHpA and PFHxA were found as the intermediates for PFOA degradation using rGO-nZVI under UVC light. Also, under UVC irradiation of a mixture of TCE and PFOA, TCE degradation was supported by the formation of intermediates during the reaction. Because of its composition, photocatalytic activity, large surface area, magnetic properties, and environmental friendliness, the thermal reduced rGO-nZVI particle demonstrated its potential to successfully remove PFAS and comingled chlorinated hydrocarbon from pre-concentration followed by degradation under UVC light. The nanohybrid is promising to be used to repair PFAS-contaminated water bodies.

Made available in DSpace on 2014-12-17T14:05:20Z (GMT). No. of bitstreams: 1 VivianeKSM_TESE.pdf: 2717769 bytes, checksum: dc3d156a1c1b3c1791c93a0e2266556f (MD5) Previous issue date: 2011-12-13 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Chromobacterium violaceum is a free-living bacillus, Gram-negative commonly found in water and sand of tropical and subtropical regions. One of its main characteristic it's the ability to produce the purple pigment named violacein, that shows countless biological activities. In 2003, the genome of this organism was totally sequenced and revealed important informations about the physiology of this bacteria. However, few post-genomics studies had been accomplished. This work evaluated the protein profile of C. violaceum cultivated in LB medium at 28?C that allowed the identification and characterization of proteins related to a possible secretion system that wasn't identified and characterized yet in C. violaceum, to the quorum sensing system, to regulatory process of transcription and translation, stress adaptation and biotechnological potential. Moreover, the response of the bacteria to UVC radiation was evaluated. The comparison of the protein profile, analyzed through 2-D electrophoresis, of the control group versus the treatment group allowed the identification of 52 proteins that arose after stress induction. The obtained results enable the elaboration of a stress response pathway in C. violaceum generated by the UVC light. This pathway, that seems to be a general stress response, involves the expression of proteins related to cellular division, purine and pirimidine metabolism, heat chock or chaperones, energy supply, regulation of biofilm formation, transport, regulation of lytic cycle of bacteriophages, besides proteins that show undefined function. Despite the response present similarities with the classic SOS response of E. coli, we still cannot assert that C. violaceum shows a SOS-like response, mainly due to the absence of characterization of a LexA-like protein in this organism / Chromobacterium violaceum ? um bacilo de vida-livre, Gram-negativo comumente encontrado no solo e nas ?guas de regi?es tropicais e subtropicais. Uma das principais caracter?sticas deste organismo ? sua capacidade de produzir o pigmento violace?na, o qual apresenta in?meras atividades biol?gicas. Em 2003, o genoma deste organismo foi completamente sequenciado e revelou informa??es importantes sobre a fisiologia desta bact?ria. Por?m, poucos estudos p?s-gen?micos tem sido realizados. Este trabalho avaliou o perfil proteico de C. violaceum cultivada em meio LB a 28?C, o que permitiu a identifica??o de prote?nas relacionadas a um poss?vel sistema de secre??o ainda n?o identificado e caracterizado em C. violaceum, ao sistema quorum sensing, a processos regulat?rios da transcri??o e tradu??o, adapta??o ao estresse e ao potencial biotecnol?gico. Al?m disso, a resposta desta bact?ria ? radia??o UVC foi avaliada. A compara??o do perfil prot?ico, analisado por eletroforese 2-D, do controle versus tratado possibilitou a identifica??o de 52 prote?nas que surgiram ap?s a indu??o do estresse. Os resultados obtidos permitiram a elabora??o de uma via de resposta de C. violaceum ao estresse gerado pela luz UVC. Esta via, que parece ser de resposta geral ao estresse, envolve a express?o de prote?nas relacionada ? divis?o celular, metabolismo de purinas e pirimidinas, choque t?rmico ou chaperonas, fornecimento de energia, regula??o da forma??o de biofilme, transporte, regula??o do ciclo l?tico de bacteri?fagos, al?m de prote?nas que ainda n?o apresentam fun??o caracterizada. Apesar da reposta apresentar similaridades com a SOS cl?ssica de E. coli, ainda n?o podemos afirmar que C. violaceum apresenta uma resposta SOS-like, principalmente devido a aus?ncia da caracteriza??o de um prote?na LexA-like neste organismo

Coronapandemin har bidragit till en ökad försäljning av desinficeringsrobotar/UVC-robotar till sjukvården. UVC-roboten SteriPro, som användes i detta arbete, har inte tidigare tillämpats på ett svenskt sjukhus. Målet med arbetet var att fastställa mervärdet av desinficeringsroboten som komplement till befintliga städrutiner på sjukhus, i detta arbete avgränsat till Västmanlands sjukhus i Västerås. Ett mervärde som berör UVC-robotens strålningseffektivitet och användarvänlighet. Provtagningar och analysering av utvalda provpunkter före- och efter de manuella städrutinerna samt efter UVC-robotens desinficeringsprocess utfördes. Även faktorer som berör UVC-robotens användarvänlighet sammanställdes.    Det konstaterades att UVC-roboten reducerade antalet kolonibildande enheter mellan provtagningarna, mellan den manuellt utförda städningen och UVC-robotens desinficeringsprocesser, samt att användarvänligheten påvisade både för- och nackdelar. Slutsatsen angående UVC-robotens övergripande mervärde är att den har god potential att tillämpas inom vården i och med dess goda desinficeringsförmåga och enkla användning. Däremot skapar UVC-robotens avvikande elektriska standard problem för en naturlig integration av UVC-roboten i de befintliga städrutinerna vilket gör att den i nuläget ej är redo för den svenska vården. / The coronavirus pandemic has contributed to increased sales of disinfection robots/UVC-robotsto healthcare. The UVC-robot SteriPro, which was used in this study, has not previously been applied in a Swedish hospital. The aim of the study was to establish the added value ofdisinfection robots as complements to existing cleaning routines at hospitals, in this study at Västmanlands sjukhus in Västerås. An added value that affects the UVC-robot’s radiation efficiency and user-friendliness. Sampling and analysis of selected test points before and after the manual cleaning routines and after the UVC-robot's disinfection process were performed. Factors influencing the usability ofthe UVC-robot were also compiled. It was found that the UVC-robot reduced the number of colony-forming units between samplings, between the manual cleaning and the disinfection processes of the UVC-robot, and that the user-friendliness demonstrated both advantages and disadvantages. The conclusion regarding the UVC-robot’s overall added value is that is has good potential to be applied inhealthcare due to its good disinfection ability and ease of use. However, the UVC-robot’s deviating electrical standard creates problems for a natural integration of the UVC-robot into existing cleaning routines, which means that it is not currently ready for Swedish healthcare.