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Carnevali, Sofia. "Unsteady aspects of sodium-water reaction : water cleaning of sodium containing equipments." Compiègne, 2012. http://www.theses.fr/2012COMP2034.
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Cette thèse s’insère dans le cadre des réacteurs rapides à caloporteur sodium (RNRNA) pour lesquels la connaissance approfondie de la réaction chimique entre le sodium et l’eau représente un challenge important aussi bien pour les opérations de traitement du sodium mises en oeuvre durant l’exploitation ou le démantèlement des installations actuelles que pour la filaire SFR (Sodium Fast Reactor) qui est un des concepts de référence envisagé pour les réacteurs de IV génération (R4G). Le sodium est utilisé dans ce type de réacteurs comme réfrigérant primaire du fait de ses propriétés thermiques et neutroniques. Toutefois, le sodium réagit énergiquement avec l’eau (en produisant principalement de l’hydrogène et de la soude) : la compréhension et la maîtrise de cette réaction représentent un enjeu majeur pour la sûreté des réacteurs. Jusqu’à aujourd’hui, le caractère explosif du contact entre sodium et eau était attribué à la réaction secondaire entre l’hydrogène (produit par la réaction sodium-eau) et l’oxygène présent dans l’air. Une importante recherche bibliographique a été conduite et plusieurs expériences ont démontré la présence de réaction explosive aussi bien en présence qu’en absence d’air. Par conséquence, les phénomènes explosifs ne sont pas forcement liés à la présence d’oxygène. La reprise de l’analyse des essais réalisés au CEA, a permis d’avoir une meilleure compréhension phénoménologique de la réaction. L’importance de la vaporisation de l’eau et son potentiel explosif ont été mis en évidence. D’autres essais ont été réalisés dans le cadre de cette thèse pour compléter la compréhension des aspects dynamiques de la réaction. L’étude et l’application aux résultats expérimentaux avec le modèle actuellement utilisé au CEA a bien démontré la nécessité de développer un modèle physique capable de prévoir les effets de pression qui suivent l’interaction entre le sodium et l’eau. Un modèle physique a donc été proposé sur la base des phénomènes identifiés pendant la première partie de cette thèse. Les résultats sont en très bon accord avec les données expérimentales. En conclusion, la complexité de l’interaction entre le sodium et l’eau, qui implique des phénomènes en cinétique rapide en même temps chimiques et thermodynamiques a représenté un important challenge. Ceci a abouti à une meilleure compréhension phénoménologique de la réaction et à la proposition d’un modèle physique tenant compte des aspects thermochimiques et dynamiques, capable d’évaluer les effets explosifs de l’interaction<br>Sodium fast Reactor (FSR) is one of the most promising nuclear reactor concepts in the frame of Generation IV systems to be commercialised in the next decades. One important safety issue about this technology is the highly exothermal chemical reaction of sodium when brought in contact with liquid water. This situation is likely, in particular during decommissioning, when sodium needs to be firstly converted (‘destroyed’) into non reactive species. This is achieved by water washing : the major products are then gaseous hydrogen and corrosive soda. Today, such operations are performed in confined chambers to mitigate the consequences of any possible abnormal conditions. It has for long been believed that the main safety problem was the combustion of hydrogen in the surrounding air despite some pioneering works suggested that even without air the reaction could be explosive. It is extremely important to clarify the phenomenology of sodium-water interactions since available knowledge does not allow a robust extrapolation of existing data/model to full scale plants. The primary objective of this work is to identify and assess the details of the phenomenology, especially at the sodium/water interface, to isolate the leading mechanisms and to propose a robust and innovative modelling approach. A large body of yet unreleased experimental data extracted from the files of the French Commissariat à l’Energie Atomique (CEA) was collated and analysed on the basis of “explosion” physics. Some additional experiments were also performed to fill some gaps, especially about the kinetics of the reaction. The results strongly suggest that the fast expansion of gas producing a blast wave in certain conditions is a kind of vapour explosion. It also appears that any potential hydrogen-air explosion should be strongly mitigated by the large quantity of water vapour emanating also from the reaction zone. The limitations of existing modelling approaches are clearly identified and alternatives are proposed and offer a better perspective of extrapolation to full scale installations
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Mallon, James M. "Floc structure and the improvement of chemical water cleaning." Thesis, Queen's University Belfast, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.324839.
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Cornelissen, Alex. "The chemistry and technology of water cleaning by flocculation." Thesis, Queen's University Belfast, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.387927.
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Graube, Franziska, Sebastian Grahl, Slawomir Rostkowski, and Michael Beckmann. "Optimisation of water-cannon cleaning for deposit removal on water walls inside waste incinerators." Sage, 2016. https://tud.qucosa.de/id/qucosa%3A35547.
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Deposits in municipal waste incinerators are very inhomogeneous in structure and constitution. They cause corrosion and reduce the efficiency, so they need to be removed frequently. Among other systems, operators use water cannons for the deposit removal. Two different removal mechanisms of water-cannon cleaning are suggested: A direct shattering of the deposit by the impact of the water jet, as well as the cracking caused by thermal stresses where droplets cool the deposits. As the contribution of each of the aforementioned mechanisms to the overall cleaning efficiency is unknown, we performed empirical investigations to determine the dominating effect. In a first experimental setup focusing on thermal stress, cold droplets were applied onto hot deposits taken from a waste incinerator. Results showed that the cleaning effect strongly depends on the deposit thickness and structure, so that the deposits could be categorised in three different groups. A second measurement campaign focused on the influence of deposit material, deposit temperature and water jet momentum. It could be shown that both deposit material and temperature have a significant effect on the cleaning efficiency, whereas an increase in water jet momentum only led to modest improvements. The combination of these two parameter studies implies that the influence of the thermal stress outweighs that of the momentum. This knowledge is applicable to the cleaning setup by increasing the temperature gradient.
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Dang, Thien Ngon. "Autonomous water-cleaning machine using solar energy in shrimp ponds." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-99264.
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Limited water exchange shrimp culture technology is commonly used today in many shrimp farms in Vietnam to reduce water usage, input of diseases and discharge of nutrient-rich effluents into environment as well as to increase the production per unit area. However, a remaining problem in this technology is that the water quality in shrimp ponds will be reduced due to limitation of water exchange for a long period. The accumulation of inorganic components such as waste feed, bacterial deposits or other biological debris at the pond bottom will lead to low dissolved oxygen, high ammonia-nitrogen level, high fecal coliform bacteria and high turbidity which cause a severe degradation of water quality and detriment to shrimp growth and survival. To solve this remaining problem, an autonomous water-cleaning machine for shrimp ponds was designed to control the waste accumulation in the pond. This is an effective solution to replace manual cleaning methods for water quality management in shrimp farming in the coastal area of the Mekong delta of Vietnam. Especially, this technique can be used for biosecure shrimp production systems according to GMP standards to meet the objectives for sustainable development of shrimp aquaculture in Vietnam<br>Kỹ thuật nuôi tôm không thay nước đang được sử dụng rộng rãi ở các trại nuôi tôm Việt Nam vì giúp giảm lượng nước sử dụng, hạn chế thải nước vào môi trường và giúp tăng diện tích nuôi trồng tôm. Tuy nhiên, bản thân kỹ thuật này cũng tạo nên một sản phẩm chất thải là phân tôm, thức ăn và chế phẩm sinh học xử lý nước dư thừa. Chất thải này dần dần tích tụ dưới đáy ao tạo thành lớp bùn độc, rất thiếu ôxy và chứa nhiều chất gây hại như ammonia, nitrite, hydrogen sulfide. Để tránh làm giảm diện tích ao nuôi do chất thải tích tụ làm tôm lảng tránh và tăng mật độ tôm nuôi trồng, thiết bị tự hành thu gom chất thải làm sạch nước trong vuông nuôi tôm đã được nghiên cứu, thiết kế và chế tạo thành công. Thiết bị đã thay thế các hoạt động làm sạch chất thải thủ công của con người, không sử dụng các nguồn năng lượng gây ô nhiễm, giảm nhu cầu về điện góp phần phát triển sản xuất tôm sạch đạt chuẩn GMP và phát triển bền vững ở các tỉnh ven biển miền Tây Việt Nam
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Cederlund, Birger. "Product Development; Water-cleaning Device for the Boat Wash, Miniwash." Thesis, KTH, Marina system, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-102031.
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Antifouling paints are a big enemy to the marine ecosystem. Many tons of copper, zinc and other harmful substances are released into the environment each year, in Sweden alone. This study concentrates on the mechanical antifouling method, using boat washes instead, which is a more sustainable alternative. It comes with reduced fuel consumption, increased speed, and moreover, no need for grinding and painting the hull each year. As long as paint residues remain on hulls, but the boat washes are used instead of new paint, it is desired to collect what is scraped of the hulls. By collecting paint flakes and particles accumulated in organic material, the environmental impact is reduced further. The scope of this Master’s thesis is to design a collection device for the portable boat wash Miniwash. A collection device with a cleaning system was developed using the pump effect from the brushes along with an extra pump to press the contaminated water through a bag filter taking most of the particles. One can expect as much as 70% of the harmful particles can be taken care of, according to the filter manufacturer, based on given conditions and filter bag pore sizes. By always having a flow of 8 cubic meters per hour through the cleaning system, it is assumed that not much of the cleaning water will escape, not passing through The bag filter.
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Metlitz, Matthew S. "Design for an invertible water bottle to facilitate cleaning and promote sustainable water bottle usage." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/92200.
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Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2014.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (pages 57-58).<br>The goal of this thesis is to explore the design of a reusable water bottle that can be inverted to expose the inside. Being able to directly touch the entire inside of the product could facilitate cleaning and consequently promote sustainable water bottle usage. Existing cleaning solutions and various water bottles were evaluated for benchmarking, and a water bottle usage survey revealed that most respondents clean their reusable bottles on a weekly to monthly basis, with 35.5% of respondents indicating that they had thrown out a bottle since it was clean. Observing volunteers in water bottle cleanliness perception test revealed that being able to physically contact and see the inside of the bottle while cleaning were most important. Two iterations of sketch models were created, demonstrating that a pouch-like design with a drawstring attached between the inside of the pouch and the water bottle top to aid invertibility was the most feasible solution. The final water bottle design, created as a CAD model, consists of three components: a top, a bottom, and an invertible pouch made of a soft plastic. The invertible pouch is held in place and made watertight between the bottom and top components that resemble a standard reusable water bottle design.<br>by Matthew S. Metlitz.<br>S.B.
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Lindahl, Mattias, Niclas Svensson, Bo Svensson, and Erik Sundin. "Industrial cleaning with Qlean Water : a case study of printed circuit boards." Linköpings universitet, Industriell miljöteknik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-88920.
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Many manufacturing companies are looking for ways to substitute environmentally problematic cleaning methods for surface treatments with more environmentally friendly ones. In this paper, one potential solution is described. The Qlean method, based on cleaning with highly pure water (in this paper defined as Qlean Water), is a novel cleaning method. This method, now utilized at one plant at a leading major international electronic company, has substituted previous chemical-based methods for cleaning printed circuit boards prior to lacquering. This paper presents, based on that company's primary data, a comparative study using environmental analysis and economic life cycle cost review between cleaning with Qlean Water and conventional cleaning. The focus is on the environmental and economic performance of the two alternatives. The conclusion is that Qlean Water offers both a significant economic and environmental cost reduction and a better product. This is the case even though all identified economic benefits derived from using Qlean Water, e.g. that the quality and technical lifetime have been extended for the printed circuit boards with the Qlean Water cleaning method, are not considered in the economic analysis.
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Wan, Yiyang. "Bio-Inspired Material Surfaces with Self-cleaning, Micromanipulation and Water Collection." Thesis, University of North Texas, 2019. https://digital.library.unt.edu/ark:/67531/metadc1505257/.
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Geckos are famous for the skill of switchable adhesion that they use to stick on various surface while keep their fingers super clean. In the dissertation, a unique mechanism was discovered to explain gecko self-cleaning phenomena. Using atomic force microscopy (AFM), we managed to compare the microparticle-substrate adhesion and the microparticle-seta adhesion with a single seta bonded to the AFM cantilever. A dynamic effect was approved that high pulling-off speed could increase the microparticle-substrate adhesion and thus the self-cleaning appears at high moving speed. Based on the self-cleaning theory, a gecko-inspired N-doped graphene surface with switchable adhesion was achieved, which was designed into a bio-inspired micromanipulator with a success rate over 90%. When electrical bias was applied on this biomimetic surface, the charge concentration induced an electrical double layer (ELD) on the convex surfaces, which attracts polar water molecules to form a water bridge on it, significantly enhancing the adhesion on the wrinkled graphene surface, mimicking the capillary force on beetle feet. Therefore, the bio-inspired adhesive surface can be controlled with speed, electrical bias, humidity and different material surfaces. The water attraction phenomenon on the polarized surface was further tested for the potential application of water collection and evaporation in microsystems.
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Marangoni, Federico. "Filter cleaning with liquid droplets." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017.
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L’obiettivo del lavoro svolto è quello di identificare una modalità economica ed applicabile per la pulizia e rigenerazione di filtri di profondità, in particolare nella filtrazione di solidi da correnti gassose. Si ha attualmente mancanza di un tale metodo, che consentirebbe di poter rigenerare il filtro senza che debba essere necessariamente sostituito.
Il lavoro consiste in un approccio sperimentale che studia una singola fibra impolverata da particelle solide. Sono stati proposti dei modelli che descrivono le interazioni tra particella, fibra e liquido. Da questo è stato ricavato un criterio teorico per determinare la riuscita o meno della rimozione di una singola particella solida adesa ad una fibra posta verticalmente e sottoposta al passaggio di un film di liquido con un determinato spessore.
L’apparato sperimentale predisposto permette il fissaggio della fibra, sulla quale vengono fatte scorrere le gocce del liquido di pulizia. Tali gocce sono osservate nella discesa con una fotocamera ad alta frequenza. L'appartato sperimentale ha permesso di variare i principali parametri sperimentali e di testare diverse combinazioni fibra-particelle.
Il parametro chiave nella pulizia è stato individuato nella forza di adesione, dipendente dal liquido utilizzato per la pulizia. Dal punto di vista geometrico, la geometria più affine alla pulizia si è rivelata la geometria cilindrica di piccolo diametro a sfavore di una geometria planare.
L’utilizzo di gocce di liquido più grandi e l’uso di un numero elevato di gocce permette di migliorare il livello di pulizia: entrambi i fattori possono restituire un vantaggio nella pulizia ma si contrappongono al costo materiale del liquido.
Nel complesso, la metodologia di pulizia proposta si è rivelata promettente, con ampie possibilità di essere estesa a filtri industriali.
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Wang, Tao. "Flow and cleaning behaviour of stationary coherent liquid jets impinging on vertical walls." Thesis, University of Cambridge, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.648883.
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Lo, Ka Meng. "A novel design of underwater vehicle-manipulator systems for cleaning water pool." Thesis, University of Macau, 2010. http://umaclib3.umac.mo/record=b2494142.
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Isberg, Ulrika & Karin Nilsson. "Life Cycle Assessment and Sustainability Aspects of Solvatten, a Water Cleaning Device." Thesis, KTH, Industriell ekologi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-127693.
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Solvatten is a water cleaning device for households in developing countries. As a Master Thesis forthe Master of Science in Engineering Programme at Kungliga Tekniska Högskolan a Life CycleAssessment of Solvatten has been conducted. The primary aim was to investigate the environmentalimpacts of Solvatten and compare it with two other common methods of accessing safe water;boiling and bottled water. Information has been gathered by contacting manufacturers and suppliersand analysed in the computer software SimaPro. The stand-‐alone LCA of Solvatten showed that theproduct gives almost no impact on ecosystem quality and human health. As the product mostly ismade of different plastic materials (i.e. fossil fuels), Solvatten has its highest impact in the damagecategory of resources. Hence, most of Solvatten’s environmental impact comes from the materialsand production processes of the black container and the transparent lid. The disposal phase ofSolvatten has been left out of the data analysis as there is a large uncertainty in waste scenarios ofdeveloping countries. Instead, a comparison was made between three different waste scenarios;landfill, incineration, and recycling with European standards. It is clear that recycling is the bestalternative, and Solvatten should show their corporate social responsibility by organizing this. Thecomparative studies conducted for Solvatten, boiling water with firewood and buying bottled waterindicated that due to Solvatten’s long lifetime, the environmental impact for Solvatten is lower. Alsodiscussed in the report are the economic and social aspects of Solvatten, which are a great advantagefor Solvatten since both time and money can be saved. Solvatten is concluded to be a goodalternative for accessing safe water.<br>Solvatten är en produkt för att rena vatten i hushåll i utvecklingsländer. En livscykelanalys avSolvatten har gjorts som examensarbete för civilingenjörsprogrammet på Kungliga TekniskaHögskolan. Det främsta målet med analysen var att utreda Solvattens miljöpåverkan samt att jämföraden med två andra sätt att få tag på rent vatten; kokning och flaskvatten. Information har samlats ingenom att kontakta producenter och leverantörer och sedan analyserat med datorprogrammetSimaPro. Den fristående LCA:n av Solvatten visade att produkten nästan inte ger någon inverkan påekosystem kvalité och hälsa. Eftersom produkten mestadels är gjord utav olika plastmaterial (d.v.s.fossila bränslen), visar analysen högst påverkan i kategorin för råvaror (eng: resources). Den störstadelen av Solvatten’s miljöpåverkan kommer ifrån materialen och produktions processerna för densvarta delen av dunken samt de genomskinliga locken. Avfallshanteringen för Solvatten fickutelämnas ur dataanalysen, då osäkerheten kring olika metoder för avfallshantering är för stor iutvecklingsländer. Istället gjordes en jämförelse mellan tre olika avfallsscenarion; deponering,förbränning och återvinning med europeiska standarder. Det är tydligt att återvinning är det bästaalternativet, och att Solvatten AB borde visa sitt samhällsansvar genom att organisera detta. Denjämförande studien mellan Solvatten, kokning och flaskvatten indikerar att Solvatten har den lägstamiljöpåverkan, på grund av produktens långa livslängd. Rapporten diskuterar även Solvattenshållbarhet ur ekonomiska och sociala perspektiv. De visar att Solvatten har stora fördelar i att bådetid och pengar kan sparas. Slutsatsen är att Solvatten är ett bra alternativ för att få tillgång till rentvatten.
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Isberg, Ulrika, and Karin Nilsson. "Life Cycle Assessment and Sustainability Aspects of Solvatten, a Water Cleaning Device." Thesis, KTH, Industriell ekologi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-127694.
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Solvatten is a water cleaning device for households in developing countries. As a Master Thesis forthe Master of Science in Engineering Programme at Kungliga Tekniska Högskolan a Life CycleAssessment of Solvatten has been conducted. The primary aim was to investigate the environmentalimpacts of Solvatten and compare it with two other common methods of accessing safe water;boiling and bottled water. Information has been gathered by contacting manufacturers and suppliersand analysed in the computer software SimaPro. The stand-‐alone LCA of Solvatten showed that theproduct gives almost no impact on ecosystem quality and human health. As the product mostly ismade of different plastic materials (i.e. fossil fuels), Solvatten has its highest impact in the damagecategory of resources. Hence, most of Solvatten’s environmental impact comes from the materialsand production processes of the black container and the transparent lid. The disposal phase ofSolvatten has been left out of the data analysis as there is a large uncertainty in waste scenarios ofdeveloping countries. Instead, a comparison was made between three different waste scenarios;landfill, incineration, and recycling with European standards. It is clear that recycling is the bestalternative, and Solvatten should show their corporate social responsibility by organizing this. Thecomparative studies conducted for Solvatten, boiling water with firewood and buying bottled waterindicated that due to Solvatten’s long lifetime, the environmental impact for Solvatten is lower. Alsodiscussed in the report are the economic and social aspects of Solvatten, which are a great advantagefor Solvatten since both time and money can be saved. Solvatten is concluded to be a goodalternative for accessing safe water.<br>Solvatten är en produkt för att rena vatten i hushåll i utvecklingsländer. En livscykelanalys avSolvatten har gjorts som examensarbete för civilingenjörsprogrammet på Kungliga TekniskaHögskolan. Det främsta målet med analysen var att utreda Solvattens miljöpåverkan samt att jämföraden med två andra sätt att få tag på rent vatten; kokning och flaskvatten. Information har samlats ingenom att kontakta producenter och leverantörer och sedan analyserat med datorprogrammetSimaPro. Den fristående LCA:n av Solvatten visade att produkten nästan inte ger någon inverkan påekosystem kvalité och hälsa. Eftersom produkten mestadels är gjord utav olika plastmaterial (d.v.s.fossila bränslen), visar analysen högst påverkan i kategorin för råvaror (eng: resources). Den störstadelen av Solvatten’s miljöpåverkan kommer ifrån materialen och produktions processerna för densvarta delen av dunken samt de genomskinliga locken. Avfallshanteringen för Solvatten fickutelämnas ur dataanalysen, då osäkerheten kring olika metoder för avfallshantering är för stor iutvecklingsländer. Istället gjordes en jämförelse mellan tre olika avfallsscenarion; deponering,förbränning och återvinning med europeiska standarder. Det är tydligt att återvinning är det bästaalternativet, och att Solvatten AB borde visa sitt samhällsansvar genom att organisera detta. Denjämförande studien mellan Solvatten, kokning och flaskvatten indikerar att Solvatten har den lägstamiljöpåverkan, på grund av produktens långa livslängd. Rapporten diskuterar även Solvattenshållbarhet ur ekonomiska och sociala perspektiv. De visar att Solvatten har stora fördelar i att bådetid och pengar kan sparas. Slutsatsen är att Solvatten är ett bra alternativ för att få tillgång till rentvatten.
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Beech, Scott Jay. "Oil removal for produced water treatment and micellar cleaning of ultrafiltration membranes." Thesis, Texas A&M University, 2006. http://hdl.handle.net/1969.1/4249.
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Produced water is a major waste produced from oil and natural gas wells in the state of Texas. This water could be a possible source of new fresh water to meet the growing demands of the state after treatment and purification. This thesis describes a research project that evaluated the treatment of brine generated in oil fields (produced water) with ultrafiltration membranes. The characteristics of various ultrafiltration membranes for oil and suspended solids removal from produced water were studied to test whether they could be used in a pretreatment method. The research measured the effect of pressure and flow rate on performance of three commercially available membranes for treatment of oily produced water. Oil and suspended solids removal were measured by using turbidity and oil in water measurements taken periodically. The study also analyzed the flux through the membrane and any effect it had on membrane performance. The research showed that an ultrafiltration membrane provided turbidity removal of over 99% and oil removal of 78% for the produced water samples. The results indicated that the ultrafiltration membranes would be useful as one of the first steps in purifying the water. Membrane cleaning of produced water-fouled membranes by micellar solutions was investigated. A neutral pH and ambient temperature micelle solution for effective cleaning of oily water-fouled membranes was developed and studied. The performance of cleaning solutions on ultrafiltration membranes was investigated on laboratory size membrane testing equipment. Different micro emulsion solutions were studied to evaluate the effect of solution properties on cleaning performance. Three types of multiple membranes were studied, each having the same polyvinylidene fluoride (PVDF) material but with different nominal separation or flux characteristics. The data showed that the use of a micelle solution to clean the produced water-fouled membranes was a feasible and effective method. The study showed with further adjustment of the micelle solution the cleaning effectiveness could be optimized to provide double the effectiveness of current industry methods for membranes fouled by produced water.
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Lundström, Hannah, and Emil Hagström. "A field study in Kenya of insolation parameters to make water drinkable in the household water treatment unit SOLVATTEN." Thesis, Uppsala universitet, Institutionen för teknikvetenskaper, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-176986.
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SOLVATTEN is a household water cleaning device that cleans water with solar energy using filtration, pasteurization and UV sterilization. A field study of the necessary amount of solar insolation that is required to make water drinkable has been carried out in Kenya using a new type of indicator developed by Solvatten AB. This new indicator will complement the old one, which only registers the temperature, with new features to store information about temperature and insolation. The indicators have been calibrated for energy and temperature and a Matlab program has been developed to analyze the information registered by the indicators. The program handles the time shifting that occurs since the indicator only saves the data at some point during a quarter of an hour. It also handles temperature correction and does a suitable curve fitting using polyfit and spline. The experiments have been divided into two parts, one where the relationship between UV and total solar insolation has been studied and one where we have taken water samples and studied the limiting factors of temperature, UV and total insolation for drinkable water. Previous studies have showed that the water in SOLVATTEN gets clean at 55 C. To reach this temperature the required UV245-400 and UV190-570 insolation is 83.0 Wh/m2 and 307 Wh/m2 according to our tests. The required total insolation is 2680 Wh/m2. From our measurement it can be seen that it is possible for water to be clean at 53 °C. During our artificial tests where we pre-heated the water and thus decreased the total insolation, we never got below 8.2 Wh/indicator which correspond to 1940 Wh/m2 of total insolation at 55 °C. The limit for clean water shown from earlier tests by Solvatten AB is 8 Wh/indicator. Even when the temperature was lower than 55 °C and we got clean water, the insolation was never below this value. This means that it is the temperature that is the limiting factor; however the synergy effect with the insolation is essential for the cleaning process. When it is cloudy the amount of UV that SOLVATTEN receives will be lower compared to the total insolation. With more clouds the temperature will drop and rise many times, while the insolation continues to increase. This means that more clouds will give more total insolation. The shortest time it took to reach 55 °C was 1 hours and 45 minutes at an optimal angle to the sun.<br>SOLVATTEN är en vattenreningslösning för hushåll som kombinerar filtrering, uppvärmning samt UV-strålning för att döda bakterier. Det är en 11 liters plastdunk, där ena sidan är genomskinlig, och efter att den har exponerats i solen mellan 2- 6 timmar är vattnet rent. En fältstudie har genomförts i Kenya för att undersöka exakt hur mycket solinstrålning som krävs för att vattnet ska bli rent. Idag finns det en väl fungerande indikator som mäter vattnets temperatur men en ny indikator har tagits fram av Solvatten AB som även mäter solinstrålningen och kan lagra den tillsammans med vattentemperaturen. Indikatorerna har kalibrerats för att få rätt energi och temperatur och ett Matlab-program har utvecklats för att kunna analysera informationen. För att kunna ta fram exakta värden används funktionerna polyfit och spline för att kurvanpassa datan. Programmet tar även hänsyn och korrigerar för de fel som kan uppkomma då tiden sparas. Dessa tidsfel uppkommer då indikatorerna endast skriver informationen någon gång under en kvart. Fältstudien är uppdelad i två delar, en där relationen mellan UV och total instrålning har studerats och en där vattenprover har tagits för att undersöka vilken som är den begränsande faktorn för rent vatten; temperatur, UV eller total instrålning. Tidigare studier har visat att SOLVATTEN blir rent vid 55 C. För att lyckas uppnå denna temperatur har det i vår studie krävts 83.0 Wh/m2 av UV245-400 och 307 Wh/m2 av UV190-570. När det gäller den totala instrålningen har det behövts 2680 Wh/m2. Vi har sett att det är möjligt för vattnet att bli rent vid 53 °C. Under våra tester då vi förvärmde vattnet och på sätt fick mindre instrålning, lyckades vi aldrig få under 8.2 Wh/indikator vilket motsvarar 1940 Wh/m2 av totala instrålningen, detta vid 55 °C. Tidigare tester av Solvatten AB visar att det behövs 8 Wh/indikator för att uppnå rent vatten och då vi aldrig lyckades få in mindre instrålning än så tyder det på att det är temperaturen som är den begränsande faktorn. Dock är instrålningen nödvändig då det är synergieffekten mellan värme och instrålningen som uppnår rent vatten vid så låga temperaturer. Om det är mycket moln på himlen sjunker och ökar temperaturen många gånger medan solinstrålningen fortsätter att ackumuleras. Detta betyder att den instrålade energin som når SOLVATTEN blir högre då det krävs längre exponeringstid för att nå 55 °C. Dock har vi sett att mängden UV inte ökar lika mycket som den totala instrålningen men ett generellt förhållande av hur UV och total instrålning förändras vid molnigt väder är dock svårt att kunna få fram. Den kortaste tiden för att uppnå rent vatten är 1 timme och 45 minuter då SOLVATTEN har haft en optimal vinkel mot solen.
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Verma, Pankaj. "Water saving comparison study between innovative and conventional cleaning systems for CSP technologies." Thesis, Högskolan Dalarna, Energiteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:du-28397.
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Garsow, Ariel V. "Effectiveness of Cleaning-In-Place (CIP) using Ozonated Water for Inactivation of Biofilms." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1555589708451643.
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Thakur, Sandeep. "Cleaning flax fibre; extracting and identifying antimicrobials and measuring water absorption of plant stems." ASABE-CSBE Joint conference 2014, Montreal, 2014. http://hdl.handle.net/1993/30686.
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Decorticated flax contains a significant amount of shive content, which limits applications of flax fibre. Separation of shives from the fibre is essential to improve the quality of flax fibre. Pneumatic method and a Sorter were implemented to meet the above objective. Terminal velocities of individual flax fibre and shive particles were investigated and their width, length, and mass were recorded. A sorting method was used for separation of short and long fibre for two grades of fibre: Grade 1 and Grade 2, with initial fibre purities of 51% and 15%, respectively. The ranges of terminal velocities for shive and fibre particles were 1.13 to 4.09 m/s and 0.51 to 1.07 m/s, respectively, which were significantly different. Fibre purity of approximately 80% for Grade 1 and 66% for Grade 2 were recorded from sorting, which were a significant improvement when compared to the initial purities. This study demonstrated the potential of the pneumatic and sorting methods for improving fibre quality.
With the increase in resistant strains of microorganisms to antibiotics, researchers have started to explore plant parts to discover new antimicrobials. Since medieval times all portions of plants were used medicinally. Plant tissues, including stems, possess secondary metabolites (SMs), which have known antimicrobial properties. The purpose of this study was to investigate: the presence of antimicrobial compounds in stem extracts of canola, flax, hemp, and sweet clover; and study sorption-desorption behavior of their powdered stem material. GC-MS analysis of all extracts showed the presence of many SMs, including fatty acids, terpenoids, steroids, and sterols, etc. Many of the SMs found in the extracts have previously shown antimicrobial activity against a broad spectrum of organisms according to literature. Water sorption isotherms of stems showed a typical IUPAC Type II sigmoid curve similar to natural fibres. Equilibrium moisture content (EMC) of canola and sweet clover was significantly higher than flax and hemp at 95% RH, which were all higher than the fibre saturation point of wood (27%). The preliminary investigation via GC-MS showed promising results and water absorptivity results of stems can be used as the initial key property for many applications.<br>October 2015
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Melamane, Xolisa. "Cleaning of fouled membranes using enzymes from a sulphidogenic bioreactor." Thesis, Rhodes University, 2004. http://hdl.handle.net/10962/d1015764.
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Maintenance of membrane performance requires inevitable cleaning or defouling of fouled membranes. Membrane cleaning using enzymes such as proteases, lipases, α-glucosidases from a sulphidogenic bioreactor was investigated. At first, dilute and concentrated enzyme extract were prepared form the sulphidogenic pellet. Enzyme assays on 0.5 % azocaisen, 1 % triacetin and 1 mg/ml ρ-nitrophenyl-α-D-glucopyranoside were performed using the concentrated enzyme extract (0 – 200 mg/ml). For membrane fouling, an abattoir effluent was obtained from Ostritech Pty (Ltd), Grahamstown, South Africa. The effluent was characterised for presence of potential foulants such as lipids, proteins, amino acids and carbohydrates. Static fouling of polysulphone membranes (0.22 μm, 47 mm) was then performed using the abattoir effluent. Cleaning of the fouled membranes was also performed using at first the dilute and then the concentrated form (200 mg/ml) of enzyme extracts. Qualitative and quantitative biochemical analysis for proteins, lipids and carbohydrates was performed to ascertain the presence of foulants on polysulphone membranes and their removal by dilute or concentrated enzyme extracts. The ability of dilute enzyme extracts to remove proteins lipids, and carbohydrates fouling capillary UF membrane module; their ability to restore permeate fluxes and transmembrane pressure after cleaning/defouling was also investigated. Permeate volumes from this UF membrane module were analysed for protein, amino acids, lipids, and carbohydrates concentrations after fouling and defouling. Fouling was further characterized by standard blocking, cake filtration and pore blocking models using stirred UF cell and polyethersulphone membranes with MWCO of 30 000, 100 000 and 300 000. After characterization of fouling, polyethersulphone membranes with MWCO of 30 000 and 300 000 were defouled using the concentrated enzyme extract (100 mg ml). Enzyme activities at 200 mg/ml of enzyme concentration were 8.071 IU, 86.71 IU and 789.02 IU for proteases, lipases and α-glucosidases. The abattoir effluent contained 553 μg/ml of lipid, 301 μg/ml of protein, 141 μg/ml of total carbohydrate, and 0.63 μg/ml of total reducing sugars. Proteins, lipids and carbohydrates fouling polysulphone membranes after a day were removed by 23.4 %, when a dilute enzyme was used. A concentrated enzyme extract of 200 mg/ml was able to remove proteins, lipids and carbohydrates up to 5 days of fouling by 100 %, 82 %, 71 %, 68 % and 76 % respectively. Defouling of dynamically fouled capillary ultrafiltration membranes using sulphidogenic proteases was successful at pH 10, 37°C, within 1 hour. Sulphidogenic proteases activity was 2.1 U/ml and flux Recovery (FR %) was 64. Characterization of fouling revealed that proteins and lipids were major foulants while low concentration of carbohydrates fouled polyethersulphone membranes. Fouling followed standard blocking for 10 minutes in all the membranes; afterwards fouling adopted cake filtration model for membranes with 30 000 MWCO and pore blocking model for membranes with 300 000 MWCO. A concentration of 100 mg/ml of enzyme extract was able to remove fouling from membranes with MWCO of 30 000. Defouling membranes that followed pore blocking model i.e. 300 000 MWCO was not successful due to a mass transfer problem. From the results of defouling of 30 000 and 300 000 MWCO it was concluded that defouling of cake layer fouling (30 000 MWCO) was successful while defouling of pore blocking fouling was unsuccessful due to a mass transfer problem. The ratio of enzymes present in the enzyme extract when calculated based on enzymatic activity for proteases, lipases and α-glucosidases was 1.1 %, 11 % and 87.9 %. It was hypothesized that apart from proteases, lipases, α and β-glucosidases; phosphatases, sulphatases, amonipeptidases etc. from a sulphidogenic bioreactor clean or defoul cake layer fouling by organic foulants and pore blocking fouling provided the mass transfer problem is solved. However, concentration of enzymes from a sulphidogenic bioreactor has not been optimized yet. Other methods of concentrating the enzyme extract can be investigated for example use of organic solvents.
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Kadewa, Wilfred William. "Small-scale constructed wetland for onsite light grey water treatment and recycling." Thesis, Cranfield University, 2010. http://dspace.lib.cranfield.ac.uk/handle/1826/4572.
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This study focused on the investigation of the impact of household cleaning and personal care products on the quality of grey water and the assessment and optimisation of grey water treatment by a novel constructed wetland design. The prototype wetland design which comprised three-stage cascading beds (0.27 m 2 by 0.20 m deep) with sand media, (d10: 1.0 mm and d90: 4.0 mm) was tested for treatment performance to meet non-potable reuse standards in three versions, unplanted open beds, unplanted covered beds, and planted beds (comprising mixtures of Iris pseudacorus, Iris chrysographes, Carex elata Aurea and Mentha aquatica). The prototypes were benchmarked against a standard single-pass wetland (6 m 2 by 0.7 m) planted with Phragmites australis. Performance was measured in terms of removal of conventional water quality determinant parameters, as well as Total coliforms and E coli, and surfactants. Microbial dynamics were also monitored during the study by looking at variations in microbial compositions with time for the different wetlands. All the wetland versions effectively removed more than 98 % turbidity and organics meeting the most stringent reuse wastewater reuse standards of < 2.0 NTU and < 10 mg BOD5/L respectively. The influent grey water had low BOD:COD ratio ranging from 0.27 – 0.45, which is indicative of low biodegradability. The comparison of the cascade wetland performances showed the following: open beds > planted = covered, with the open beds version meeting reuse standards virtually throughout the monitoring period, despite recurrence of schmutsdecke in the top bed. All wetland technologies supported viable populations of microorganisms. Only phospholipid fatty acids (PLFAs) of lower carbon chain length (< C20) had concentrations greater than 1 mol %, in all the wetlands beds, confirming that the majority of the PLFAs in the media were from contribution of microbial organisms and not plant organic matter. Characterisation of microbial organisms was carried out to understand the constructed wetlands functioning and thus the treatment processes. The household products showed nutrient deficiency signifying low treatability. Product branding did not show correlation with any water quality parameters. In terms of toxicity, laundry and cleaning products were more inhibiting to soil microorganisms than were personal care products.
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Jachim, Jenny Ann. "The examination of the effect of three water soluble fluxes on biased comb patterns exposed to high humidity or condensing environments." Thesis, Georgia Institute of Technology, 1994. http://hdl.handle.net/1853/19573.
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Hayward, Emily. "Investigating fouling and cleaning during the filtration of Gum Arabic to save water and reduce energy." Thesis, University of Bath, 2016. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.698953.
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Tadic, Dihon Misha. "Investigation of cavitating and pulsed high-pressure water jet devices for process scale removal /." [St. Lucia, Qld.], 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe17660.pdf.
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Zasadowski, Dariusz. "REMOVAL OF LIPOPHILIC EXTRACTIVES AND MANGANESE IONS FROM SPRUCE TMP WATER BY FLOTATION." Licentiate thesis, Mittuniversitetet, Institutionen för tillämpad naturvetenskap och design, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-16088.
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Dissolved and Colloidal substances (DisCo) and metals are released from wood during thermomechanical pulp (TMP) production. The mechanical treatment causes that these components have a tendency to accumulate in process waters, as the water circulation systems in integrated paper mills are being closed. Disturbances such as pitch depositions on the paper machine (pitch problems), specks in the paper, decreased wet and dry strength, interference with cationic process chemicals, and impaired sheet brightness and friction properties appear in the presence of DisCo substances. The presence of transition metal ions such as manganese results in higher consumption of bleaching chemicals (hydrogen peroxide) and lowers the optical quality of the final product, and addition of complexing agents, such as EDTA or DTPA, to prevent this is needed. The never ending trends to decrease water consumption and increase process efficiency in pulp and paper production stress that it is very important both to know the effects of wood substances on pulping and papermaking and to be able to remove them in an efficient way. Carried out investigations presented in this thesis show that the lipophilic extractives can be removed from TMP press water to high extent. A 90% decrease in turbidity and a 91% removal of lipophilic extractives from TMP press water can be obtained by addition of a cationic surfactant as foaming agent during flotation. Additionally, fibres located in TMP press water are not removed with the foam fraction but purified. A retained concentration of hydrophilic extractives in the process water indicates that the flotation is selective. Moreover, by introduction of a new recoverable surface active complexing agent, a chelating surfactant, manganese ions in the form of chelates can be successfully removed from the pulp fibres and separated from the process water in the same flotation process. iii The findings presented above indicate new possibilities for internal water cleaning and decreased emissions to water if flotation technology is applied in an integrated mechanical pulp mill.<br>ReGain/FORE
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Atallah, Charbel. "Surface Modification and In-process Steam Cleaning of Ceramic Membranes Used In the Treatment of Wastewaters Containing Bituminous Fines." Thesis, Université d'Ottawa / University of Ottawa, 2019. http://hdl.handle.net/10393/39786.
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Synthetic membranes have a high separation efficiency, small footprint, low energy consumption and ease of operation, making them an attractive alternative to traditional separation operations. For this reason, membranes have been extensively studied for the treatment and recycling of bitumen-containing wastewaters. Such wastewaters include petroleum produced water, residual pipeline cleaning solutions and contaminated water from oil spills. Ceramic membranes are preferred in these applications over polymeric membranes because they are highly resistant to solvents and can be operated at high temperatures over a wide range of pH. Fine clays and silicates, coated with bitumen, are significant foulants for membrane filtration systems. These foulants possess acidic, basic and amphoteric groups, leading to the presence of both positive and negative surface charges. Ceramic membranes in aqueous media have a pH dependent surface charge. It was hypothesized that these surface charges are responsible for the high fouling of ceramic membranes that is observed when treating wastewaters containing bituminous fines.
The overall objective of this research was to reduce fouling and increase the lifetime of ceramic membranes in treating oil sands produced water; an example of a wastewater containing bituminous fines. This goal was achieved through the surface modification of the ceramic membrane’s selective layer, as well as by the implementation of a novel in-place steam regeneration technique. All membrane filtration tests were performed with field samples of oil sands produced water that were supplied to CanmetMINING (NRCan) by three Canadian oil sands companies.
Organosilanes are silicon-based monomers that can possess a wide array of chemical functionality due to their organic moieties. They are capable of reacting with oxide surfaces, and have seen extensive use as surface modification agents for ceramic membranes in various applications. To maintain desirable hydrophilic properties without surface charges, highly hydrophilic and non-ionic polyethylene oxide (PEO) based organosilanes were identified. These PEO-silanes were then used to modify ceramic membranes of several different selective layer materials, and the thermal stability of the silane layer was studied using FTIR, SEM, zeta potential and contact angle measurements. The modification procedure with PEO-silanes was first applied to lab-scale membrane disks, and subsequently to commercial scale multilumen membrane tubes that were tested in a pilot-scale system at CanmetMINING. Results obtained from both sets of experiments were promising and demonstrate that ceramic membranes can be surface modified in a way that successfully renders them fouling resistant to the bituminous fines present in these wastewaters. Upon surface modification, foulants were more readily released from the membrane surface, resulting in an enhanced flux and separation performance.
A novel steam regeneration technique was also applied as a means of bituminous fouling alleviation. This technique was tested in the CanmetMINING pilot-scale system and consisted of periodically injecting steam into the membrane lumen feed channels during operation. Direct steam injection rapidly heated foulant cake layers, and water droplets in the saturated steam caused surface abrasions that ultimately resulted in the scouring of bitumen away from the membrane surface. Membrane fluxes when steam regeneration was active were up to 4 times higher when compared to tests where only traditional permeate backflushing was used.
The fouling remediation techniques developed in this work have broad potential applicability in ceramic membrane filtration systems aimed at treating all wastewaters containing bituminous compounds, such as process waters in general and contaminated water from oil spills.
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Patel, Ankit Arvind. "Novel P-(SBMA) Grafted Glass Fiber Filters and Glass Slides for Oil-Water Separation and Underwater Self-Cleaning Applications." University of Akron / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=akron1353362655.
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Dong, Bingfeng. "Application of Water/Wastewater Treatment in Trace Organic Compounds Removal and Other Industry Sectors." Diss., The University of Arizona, 2014. http://hdl.handle.net/10150/333205.
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Wastewater reuse is fast becoming an imperative issue based on the developments in water/wastewater engineering coupled with increasing pressures on water resources. Trace organic compounds (TOrCs) that exist in water/wastewater, are a serious threat once they were released in the environment. During the past decade, there has been much progress toward understanding the occurrence, fate and toxicology of trace organic pollutants that enter the environment in treated wastewater. The objective of the first part of this research was to evaluate the combined effects of sequential anaerobic/aerobic digestion on residual TOrCs, concentrating on chemicals that are responsible for observed estrogenic/androgenic activities in biosolids. Full-scale digestion was simulated using bench-scale bioreactors in which the primary independent variables were retention time, temperature, and oxygen loading during aerobic digestion. Treatment-dependent changes in estrogenic/androgenic activity and concentrations of specific Endocrine disrupting compounds (EDCs) were measured. Results suggest that standard mesophilic anaerobic digestion increases the total estrogenic/androgenic activity of sludge while aerobic digestion was effective in the reduction of estrogenic/androgenic activity as a supplementary treatment stage. The second part of the study was focused on the fate of TOrCs and estrogenic activity in water and sediment of the Santa Cruz River, which is effluent dependent except during infrequent periods of rainfall/runoff in Tucson area. Several sampling campaigns were carried out from 2011 to 2013. Results suggest that some organic TOrCs, including those that contribute to estrogenic activity, were rapidly attenuated with distance and time of travel in the Santa Cruz River. Indirect photolysis of estrogenic compounds through the river might play an important role for the observation of estrogenic activity changes in the SCR. Hydrophobic TOrCs may accumulate in river sediments during dry weather periods. Riverbed sediment quality is periodically improved through storm-related scouring during periods of heavy rainfall and runoff. Wastewater effluent can be applied to the algal biodiesel industry based on regional water stress across the world. In the third part of the research, reclaimed wastewater was explored for this purpose, simultaneously satisfying the needs for water, macronutrients such as nitrogen and phosphorus, and micronutrients necessary for growth of microalgae. At the same time, algal growth in conventionally treated wastewater will improve water quality through the same nutrient removal processes and perhaps by lowering residual levels of trace organics that are an impediment to potable reuse. Results showed that metals levels in most municipal wastewaters are unlikely to disrupt growth, at least by metals tolerant microalgae like Nannochloropsis salina. Cells can grow without inhibition on nutrients from treated municipal wastewater or a centrate stream derived from wastewater treatment. The results also suggest while wastewater provides a suitable nutrient source for algal growth, there is simply not enough municipal wastewater available to support a meaningful biofuels industry without water recycling and nutrient recovery/reuse from spent algae. The last part of the dissertation was the application of water/wastewater treatment techniques, specifically advanced oxidation processes (AOPs) in other industrial sectors. In the integrated circuit production industry, chemical formulations used for megasonic cleaning typically contain hydroxides, peroxides and carbonates, which can affect particle removal efficiency and feature damage. The role of carbonates and ammonia in modulating the oxidation power of megasonic irradiated alkaline solutions through the scavenging of hydroxyl radicals by varying levels of carbonates, bicarbonates, ammonia and solution temperatures on net generation of hydroxyl radicals for applications in semiconductor industry was investigated in this study. The simulation of actual megasonic cleaning process was carried out at acoustic frequency of ~ 1 MHz and different power densities. Carbonate ions were better scavengers of hydroxyl radicals than bicarbonate ions. The effect of bulk solution temperature revealed that the rate of generation of hydroxyl radicals at a power density of 8 W/cm² increased with temperature from 10-30°C, which suggests an increase of transient cavitation with temperature.
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Wang, Yimin. "Pretreatment, Morphology and Properties of Organosilane Anti-Corrison Coatings." University of Cincinnati / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1186412600.
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Peck, Oliver. "An investigation into the strength and thickness of biofouling deposits to optimise chemical, water and energy use in industrial process cleaning." Thesis, University of Bath, 2017. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.723340.
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Biofouling is both a human health hazard and detrimental to process efficiency. Biofilm growth is inevitable on exposed surfaces, so an informed approach to cleaning and timely management are essential. Chemicals can readily kill cells, but the biofilm structure must be removed to prevent re-growth and maintain sterility. Chemical agents also pose health and environmental risks, but the typical alternative is to pump unsustainable volumes of cleaning solution through pipelines for mechanical cleaning. The aim of this research was to apply green cleaning principles to biofouling removal in industry, reducing the amount of chemicals, water and energy used in cleaning. Biofilms of Escherichia coli and Burkholderia cepacia were grown on polyethylene, glass and stainless steel 304, in single and mixed species cultures. Fluid dynamic gauging (FDG) utilises hydrodynamics to measure both the thickness and attached strength of the biofilms and therefore the optimum water usage for removal can be estimated, and is both relatively simple and inexpensive to operate. As well as using a static culture method, a drip flow reactor was built to develop biofilms under flow conditions. The use of FDG offers an original way of monitoring both the attachment strength and thickness of mixed species biofilms, and drip flow is an alternative to traditional biofilm growth methods for analysis of removal behaviours, with particular relevance to food production environments. The adhesive and cohesive strengths of both single and mixed species biofilms increased up to 14 days’ growth, and as previous studies suggest that this will be sustained over longer periods under flow conditions, cleaning prior to peak strength would be prudent – at later stages the risk of pathogens developing and contaminating the process would likely become too great, particularly if the biofilm is experiencing significant detachment which increasingly occurs with age. The development of greater, sustained thickness over time can also pose problems with heat transfer and enhanced pressure drop. Protein, a key component of the extracellular matrix, showed a strong correlation with the adhesive strength of mixed species biofilms. Biofilms grown on polyethylene attached more strongly in the early stages of growth than those on glass or steel, which may be due to the greater hydrophobicity of the surface. Chemicals can be used most effectively to weaken the outer layers, and sodium hypochlorite was also shown to be useful for weakening surface adhesion – the required shear stress for 95% removal was reduced by approximately 60% for 5 and 10-day old biofilms. There are more risks associated with chlorine-based disinfectants than the alternative, peracetic acid, although finding a suitable low concentration would be simple using this method. There is no simple solution, complicated further by the unpredictability of the species present in industrial biofouling. The best way of minimising the risk of spoiling and contamination would be to clean surfaces with regularity, in the region of every 5 days rather than after a more prolonged period, which would also serve to minimise the resources used by preventing biofilms from becoming too strongly attached or too thick. A chemical input would need to be determined by testing for the optimum concentration necessary for a suitable effect, thus eliminating excess use, and thereby reducing water and energy use in the process. Taking a multispecies sample from a process flow could offer a more realistic approximation of industrial biofilms. Surface coatings to prevent adhesion are the focus of much research, and could be an alternative to reactive methods.
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Bernazzani, Daniel. "The Effect of Disinfectants, Cleaning, and Drying Practices on Oriental Rugs Flooded with Contaminated River Water: Public Health and Policy Implications." Antioch University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=antioch1339427719.
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Tsompou, Andriani. "THE ROLE OF WATER PURITY IN EMULSIFICATION AND REMOVAL OF OIL FROM SOLID SURFACES." Thesis, Malmö universitet, Malmö högskola, Institutionen för biomedicinsk vetenskap (BMV), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-43851.
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Detergents are broadly used in our everyday life for cleaning and washing procedures. They are however, a source of water pollution and can have a negative effect on human health and the environment. To reduce their negative impact, a new trend of using only pure water for washing and cleaning applications is being implemented. However, a scientific basis needs to be established first, as the mechanisms and the effectiveness of this method are not fully understood. In this work, we aim to investigate the effect of water purity on the removal of oil from surfaces and the stability of colloidal systems. To do that, two purified water grades are compared with non-purified tap water and 10 mM NaCl solution. Results from measurement of oil film mass before and after water contact and Quartz Crystal Microbalance with Dissipation (QCM-D) indicate that purified water grades can wash a surface more efficiently than non-purified water grades. Contact angle measurements show that pure water facilitates the cleaning process while spreading of oil on plastic surfaces indicates that electrostatic interactions have an important role in the system. Visual observations of o/w emulsions, show that purified water grades redisperse the oil better. We hypothesize that the mechanism behind the cleaning and washing without detergents relies on the electrostatic interactions. To further investigate the effect of salt on cleaning mechanisms, we performed zeta potential measurements. Results indicate that salt has a negative effect on the stability of the particles.
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Maková, Petra. "Hospodaření s vodou na plaveckém stadionu Lužánky." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2013. http://www.nusl.cz/ntk/nusl-226167.
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Grey water is sewage water from bath, bathtub, sinks, washing machines and washers. This water can be cleaned to white water usefull for irrigation, flashing toilets, cleaning cars and for cleaning. This master´s thesis deals with management of water and their possibilities. First part contains description about possibilities of saving drinking water and their the most effective saving. Next part consists study of technological link for grey water cleaning and calculation of saving water with rate of return.
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Peng, Hui. "The treatment of bilge water using a MF/UF hybrid membrane system: Membrane fouling, cleaning and the effect of constituents on flux decline." Thesis, University of Ottawa (Canada), 2002. http://hdl.handle.net/10393/6110.
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Bilge water accumulates in recesses and bilges onboard ships. Depending on the type of design and age, ships can generate large volumes of bilge water. This wastewater is a mixture of fresh water and seawater containing various contaminants. Typical contaminants may include fuels, oils, greases, detergents, solvents, rusts, paints, insulation material and a wide variety of other substances. Bilge water is a very challenging wastewater to treat due to large variations in production rates and the complex nature of the wastes in solution. Membrane based Oily Water Separators (OWS) are being increasingly used throughout the world for the treatment of oily wastewater. This work focused on two areas of study: (1) Effects of selected components found in bilge water on membrane performance, and (2) Pilot scale testing using a Microfiltration/Ultrafiltration (MF/UF) hybrid system. The studies are aimed at determining suitable membrane materials and optimum operating conditions such as trans-membrane pressure (TMP) and backflushing for permeate flux enhancement. (Abstract shortened by UMI.)
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Goldman, Joshua E. "Relationship between biofilm removal and membrane performance using Dunedin reverse osmosis water treatment plant as a case study." [Tampa, Fla.] : University of South Florida, 2007. http://purl.fcla.edu/usf/dc/et/SFE0002162.
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Hagberg, Anna. "Industrial wastewater treatment and other environmental problems in Wuhan : Is Swedish technology a solution?" Thesis, Uppsala University, Department of Earth Sciences, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-88828.
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<p>År 2000 startades ett samarbete mellan Wuhan i Kina och Borlänge Energi i Sverige. De två parterna bestämde år 2005 tillsammans med IVL, Svenska Miljöinstitutet, att samarbeta inom följande områden; hållbar energiproduktion, hållbar avfallsproduktion samt grundandet av ett miljöteknikcentrum i Wuhan. Miljöteknikcentrumet är till för att vara en plattform för svensk miljöteknik och expertis. Som ett första steg inför grundandet av ett miljöteknikcentrum gjordes en undersökning för att se inom vilka sektorer svensk miljöteknik kan etableras.</p><p>Undersökningen var inriktat på industriell avloppsvattenrening i Wuhan; bedömning av vilka typer av industrier/företag som har problem med avloppsvattenreningen och i vilken utsträckning det finns svenska tekniklösningar på problemen. Undersökningen genomfördes genom intervjuer med myndigheter och en del utvalda företag. Det var svårt att få fram information om vilka företag som inte följer de kinesiska gränsvärdena, varför en del besök gjordes till företag som lever upp till gränsvärdena. På grund av detta togs även andra problem med miljön som företagen hade upp. Några kommunala reningsverk besöktes och intervjuades också för att få en bättre bild av den kommunala vattenreningssituationen. En generell beskrivning av Wuhans miljösituation utfördes också samt en beskrivning av de viktigaste miljömyndigheterna och institutionerna.</p><p>Wuhans största utmaning är att konstruera reningsverk till alla de 3.5 miljoner som fortfarande släpper sitt avloppsvatten rätt ut till sjöar och floder, snarare än att ytterligare rena det industriella avloppsvattnet. Behandlingsgraden av det industriella avloppsvattnet har nått 97 % medan behandlingsgraden av det kommunala avloppsvattnet endast nått 70 %.</p><p>Besök vid de utvalda företagen och kommunala reningsverk ledde till slutsatsen att svensk teknik och expertis kan införas i följande områden: hantering av slam från reningsverk, byggandet av förbränningsanläggningar för sopor och hur man löser problemet med att rena luften från gaser som SO2 och dioxiner. De flesta företagen kunde följa de kinesiska gränsvärdena för utsläpp av avloppsvatten men mycket kan göras för att förbättra företagens tekniker ytterligare. Detta utförs dock nästan aldrig eftersom det är en ekonomisk fråga. Det är möjligt för Wuhan att sätta lokala, hårdare gränsvärlden för att tvinga företagen att förbättra sina reningstekniker ytterligare.</p><br><p>In 2000 a co-operation between Wuhan in China and Borlänge Energi in Sweden started. The two parts decided in 2005 together with IVL, the Swedish Research Institute, to co-operate in the fields of sustainable energy production, sustainable waste management and the establishment of an Environmental Technology Centre, supplying Swedish environmental expertise to companies in Wuhan. As a first step for the establishment of an Environmental Technology Centre in Wuhan, an investigation was made to find out in which sectors Swedish environmental technology could be established.</p><p>The investigation took aim at observing the industrial wastewater treatment in Wuhan and to see which types of companies that have problems with the wastewater treatment and if there existed Swedish technology that could solve the problems. The investigation was performed through interviews with the authorities and some selected companies. It was difficult to get information about companies that did not comply with the National Chinese wastewater standards. This meant that some of the visits were made to companies that comply with the standards, also taking into consideration other problems with the environment that the companies might have. Visits were also paid to municipal wastewater treatment plants to get an overview over the municipal wastewater treatment situation. An overall survey of the environmental situation in Wuhan was also made and a presentation of the most important environmental departments and institutions is given.</p><p>The greatest challenge for Wuhan is to construct wastewater treatment plants for the around 3.5 million people that still discharge their wastewater directly to rivers and lakes, rather than to improve the industrial wastewater treatment further. The treatment rate of the industrial wastewater has reached 97%, but the municipal wastewater treatment rate has only reached 70%.</p><p>After the visits to the selected companies and municipal wastewater treatment plants the conclusion was made that Swedish technologies and expertise can be applied to the following areas; handling sludge from the wastewater treatment plants, construction of waste incineration plants and handling flue gas and dioxins. Most of the visited companies could follow the wastewater standards. Although much can be done to improve their technologies further, this is not done since it is too expensive. It is possible for Wuhan to apply stricter local wastewater treatment standards. This could be used as a tool to make companies invest more money in improvements of their technologies.</p>
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Bosch, Tanya. "Development of a degreasing and anti-fogging formulation for wet wipe application for automotive glass surfaces." Thesis, Nelson Mandela Metropolitan University, 2012. http://hdl.handle.net/10948/d1013177.
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It was the objective of this project to provide a glass cleaner formulation for a wet wipe application with cleaning and anti-fogging properties. This glass cleaner formulation was developed for automotive glass i.e. interior of windscreens. This formulation relates to a glass cleaner with a composition comprising of: (a) a blend of amphoteric surfactants; (b) a solvent system with a combination of glycol ethers; and (c) an aqueous solvent system. This glass formulation must provide good cleaning properties while also providing good wetting and sheeting properties to assist with anti-fogging properties. The objectives were obtained using 2 specific approaches: The first was by using a blend of 2 amphoteric surfactants in an alkaline medium, allowing the glass surface to become more hydrophilic which will also assist with reduction of surface tension on the glass surface. The second was by using the glycol ethers that have good coupling properties and surface tension reducing properties. The formulation was evaluated using commercial standard test methods as per the industry. A predictive model was successfully obtained for each of the five criteria that were evaluated using the 25 formulations derived from the statistical design. There were variables and variable interactions that were antagonistic for some of the criteria which were found to be synergistic for others. To achieve satisfactory cleaning, the fogging rating had to be compromised.
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Stark, Alyssa Yeager. "The Effect of Water on the Gecko Adhesive System." University of Akron / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=akron1405334677.
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Heber, Dominici Victoria Blanca. "Design Improvement of a Water Recirculation System for a Cooling Process in a Tobacco Manufacturing Plant." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019.
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In the industrial sector, it is possible to observe unexpected behaviours of processes, which were not anticipated in the design stage. Such is the case of a secondary cooling process existing within a tobacco manufacturing plant, which was initially designed to cool and recover clean process water with chilled water for posterior recirculation into the main cooling process. It has been observed that under the design flowrates the plate and frame heat exchanger where the process water is cooled is rapidly clogged by suspended solids coming from the main cooling process, resulting in both high maintenance costs and frequent product ion downtime due to necessary intervention for mechanical cleaning.
The aim of this thesis project is to evaluate and design process improvements providing sustainable solutions, reducing the operative costs existing nowadays and avoiding any damage on the plate and frame heat exchanger.
Any process design solution asks for a capital investment, which was also considered in the overall analysis of the alternatives within this study.
Within the evaluation of the possible modifications, solid/liquid separation was mostly studied, together with the selection and design of an appropriate heat exchanger for the given process. After a preliminary screening, a reduced number of alternatives were analysed in detail to assess their possible application. Few alternatives to solving the problem have been studied, in spite of having a wide variety of options.
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Ambrus, Adam. "ResPublica/Civitas Socialis – Strachotín, l. p. 2017." Master's thesis, Vysoké učení technické v Brně. Fakulta architektury, 2017. http://www.nusl.cz/ntk/nusl-316299.
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Mion, Ligiani. "Avaliação de coliformes totais residuais em creches de suínos após lavagem, desinfecção e vazio sanitário." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2017. http://hdl.handle.net/10183/158085.
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A colonização por micro-organismos patogênicos em creches de suínos é um fator importante na disseminação de doenças e surtos no rebanho. O controle desses patógenos se dá principalmente por medidas de biosseguridade, como a prática da limpeza, desinfecção e vazio sanitário das instalações. O presente estudo avaliou a carga bacteriana após o processo de limpeza e desinfecção, durante o período de 3 dias de vazio sanitário, em duas creches de suínos, pelo uso de placas de contato com meio seletivo para coliformes totais. As contagens bacterianas foram analisadas considerando três fatores (água, detergente e desinfetante) em dois níveis para cada (água: fria/quente, detergente e desinfetante: presença/ausência). Foram usadas 4 baias em cada tratamento, 4 pontos de cada baia e cada ponto foi amostrado em triplicata. Foi feita a média de crescimento bacteriano das 3 placas e pontuada em escala de 5 escores. Após limpeza e desinfecção, no primeiro dia de vazio sanitário, houve efeito da interação da água com o detergente (P<0,05), em que o uso do detergente aumentou a chance de diminuir a contaminação quando usado com água quente, mas não com água fria. Na ausência de detergente, a água fria foi mais eficaz em reduzir a contaminação do que a água quente. Houve, também, efeito da interação do detergente com o desinfetante (P<0,05), em que a presença de ambos foi mais eficaz em reduzir a contaminação do que na sua ausência ou quando apenas um dos dois foi utilizado. No terceiro dia, foi verificado que a ausência de desinfetante diminuiu a chance de reduzir a contaminação (P < 0,0001) em comparação com o uso de detergente. A água quente não representou ganho adicional quando comparada a água fria. As evidências aqui observadas reiteram a importância da lavagem, desinfecção e vazio sanitário na redução da carga bacteriana em creche de suínos. A metodologia usada no presente trabalho pode servir como um sistema simples de monitoria dos processos de lavagem e desinfecção de instalações usadas para criação de suínos.<br>The colonization by pathogenic microorganisms in nursery pig units is an important factor in the spread and outbreaks of diseases in the herds. Pathogens are mainly controlled by biosecurity measures, such as cleaning, disinfection and downtime on facilities. The present study evaluated the bacterial load after the cleaning and disinfection process, during the three days of vacancy, in two pig nurseries, by the use of contact plates selective for enterobacteria. Data were analyzed considering three factors (water, detergent and disinfectant) in two levels (water: cold / hot, detergent and disinfectant: presence / absence). Were used 4 pen for each treatment, and 3 plates for 4 points of the pen. A mean of the 3 bacterial growths was calculated and scored on a 5 point scale. After cleaning and disinfection, there was no detergent - water effect (P <0.05) with cold water. In the absence of detergent, cold water was more effective in reducing contamination than hot water. There was also an effect of the interaction of detergent and disinfectant (P <0.05), where a presence of both was more effective in reducing contamination than in its absence or when only one was used. On the third day, it was found that the absence of disinfectant decreased a chance of reducing contamination (P <0.0001) when compared with the use of detergent. Addition of detergent decreased the chance of contamination when combined with disinfectant, as detergent helps in removing dirt and exposes bacteria which were protected by organic matter and biofilms. The use of hot water did not how advantage when compared with cold water. As there was a fall on contamination between the 1st and 3rd day, the time of action of the disinfectant must be considered to calculate the time of vacancy to permit the action on surviving microorganisms. The results of the present work reinforce the importance of cleaning, disinfection and downtime to reduce bacterial load in swine nurseries. The methodology used in this work may serve as a practical system for monitoring cleaning and disinfection of pig facilities.
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Falta, Jan. "Konstrukce čistící jednotky centrálního protitlakého válce flexotiskového stroje." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2017. http://www.nusl.cz/ntk/nusl-318718.
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This master´s thesis is focused on design and manufacturing of prototype of central impression cylinder cleaning unit. This thesis contains explaining of basic principle of flexographic printing and preview of types of flexographic printing presses. There are explained patented cleaning units and main claims of every patented cleaning unit. In the next part of this thesis, there are some conceptual designs, from which was chosen the final design for manufacturing. In the next part of this work, there are detailly described each of the parts of cleaning unit. Prototype of the cleaning unit was manufactured and tested in the SOMA Engineering s.r.o. Lanškroun. Cleaning unit will simplify the work of operators and reduce time, needed to clean the central impression drum in comparison with manually cleaning.
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Rincon, Troconis Brendy Carolina. "Blister Test for Measurements of Adhesion and Adhesion Degradation of Organic Polymers on AA2024-T3." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1366072959.
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Lawing, Andrew S. (Andrew Scott). "Gas-phase cleaning of silicon wafer surfaces." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/38852.
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Bawono, Ali Aryo [Verfasser], Stephan [Akademischer Betreuer] Freudenstein, Yiik Diew [Gutachter] Wong, En-Hua [Gutachter] Yang, and Stephan [Gutachter] Freudenstein. "The Functional Performance of Engineered Cementitious Composites Material for Electrified Roadway Application in Singapore : Skid resistance, surface water drainage, noise, and self-cleaning / Ali Aryo Bawono ; Gutachter: Yiik Diew Wong, En-Hua Yang, Stephan Freudenstein ; Betreuer: Stephan Freudenstein." München : Universitätsbibliothek der TU München, 2020. http://d-nb.info/1241246785/34.
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Gupta, Vipul. "Deposition and Characterization of Hydrophobic Coatings." BYU ScholarsArchive, 2012. https://scholarsarchive.byu.edu/etd/3859.
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Hydrophobic coatings find application in various sectors of the economy including to electronics, textiles, optical devices, and in scientific and commercial equipment. These different applications demand that different hydrophobic coatings posses a range of properties that may include smoothness or roughness, thicknesses on the order of a monolayer or a micron, robustness or the ability to dissolve quickly, transparency or opacity, water resistance or water permeability, electrical conductivity, oleophobicity, etc. However, whatever the final/desired properties, deposition via dry-deposition processes offers significant advantages, including greater reproducibility, increased environmental friendliness, and cost effectiveness on an industrial scale. Herein I explore the chemical vapor deposition of silanes and the characterization of a commercial, hydrophobic coating to better prepare and understand hydrophobic coatings on different materials. One of the characterization techniques I used frequently in these studies is X-ray photoelectron spectroscopy (XPS). Accordingly, in Chapter 2 of this thesis I discuss this technique vis-à-vis the chemical shifts it detects, which reflect the oxidation states of materials being probed. In particular, I discuss a recommendation made over a decade ago by Gion Calzaferri for 'fixing' the problem of oxidation numbers as applied to organic materials and show how XPS confirms his suggestion. In Chapter 3 I introduce hydrogen as an etch/cleaning gas for silicon wafers. I first show that, like argon and oxygen plasmas, hydrogen plasmas will effectively clean silicon wafers. However, I then show that hydrogen plasma treatment leads to a silicon surface that is chemically different than those prepared with the other plasmas and that undergoes silanization to a greater extent -- the resulting surfaces have higher water contact angles and thicknesses. In Chapter 4 I study the deposition of a potential barrier layer for water, which was prepared from an aza silane: N-n-butyl-aza-2,2-dimethoxysilacyclopentane (1) in a molecular layer deposition (MLD)-like process using either water or ammonium hydroxide as the second half reactant. This molecule has the interesting property of undergoing self-limiting growth, where the termination of this growth is accelerated by use of an ammonium hydroxide catalyst. Interestingly, films of 1 are considerably thicker on nylon than on silicon, which is explained by nylon acting as a water reservoir in the reaction. In Chapter 5 I show the careful characterization of the hydrophobic coating on an Apple iPod nano, which was probed by ToF-SIMS, wetting, and XPS. I could identify that the coating is only applied to the touchscreen of the device. SIMS suggested that the fluorinated coating contains oxygen, which should add to its biodegradability. Finally, in Chapter 6 I make recommendation for future work in these areas.
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Jedličková, Tereza. "Technicko-technologický audit úpravny vody." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2019. http://www.nusl.cz/ntk/nusl-391933.
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The aim of the submitted diploma thesis is the implementation and evaluation of the technical and technological audit of water management systems of water treatment plants – concretely Plzeň Water Treatment Plants. Part of its audit is a description of potable water production, including the evaluation of the TEA Water treatment plant, evaluation of quality assurance of raw and produced drinking water, analysis of costs and pricing costing, personnel evaluation, care of the plant and draft measures for better working of the whole system. The work also focuses on the characteristics, history and the past reconstruction and more detailed description of the individual cleaning stages of the selected water treatment plant in Pilsen. The audit itself was preceded by the study of current legislation, namely the Law No. 274/2001 Coll. and Decree No. 428/2001 Coll. The diploma thesis also describes performing laboratory analyzes in an accredited laboratory of Plzeň Water Treatment Plants.
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Han, Yong-Pil 1962. "HF vapor etching and cleaning of silicon wafer surfaces." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/32698.
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Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 1999.<br>Includes bibliographical references.<br>The objectives of this project are to understand the reaction mechanisms for oxide etching by both HF/H2 0 and HF/alcohol processes and to develop a vapor phase HF cleaning process to remove metallic contamination and native oxide on a silicon surface. Although the HF vapor process has been studied intensively for past several decades, the commercial application has not been very successful due to the unknown nature of the process. This study, performed at MIT, has emphasized on finding possible applications to the semiconductor industry as a replacement to the aqueous phase cleaning processes. The ultimate purpose of this project is to demonstrate feasibility of the HF vapor process for a vacuum compatible and clustered cleaning process. In this study, the etching experiments were carried out in a stainless steel vacuum chamber connected to a vacuum wafer transfer system. Samples were introduced through a load lock chamber and transferred to the HF vapor reaction chamber. The base pressure of the system was maintained under 10-7 Torr. The system can handle sample sizes between 1 cm square and 10 cm diameter silicon wafers. The etching rates were measured by an in situ ellipsometer installed on the HF vapor reactor. Ellipsometric measurements suggest that oxide etching can occur without a condensed layer or with a condensed layer on the oxide surface. The etching rates of oxide in the condensed regime were very high (3,000-12,000 A/min) compared to the gas phase regime (0-300 A/min). The etching regime in which a condensed layer is formed is a function of not only the partial pressures of HF and H 20 in the feed gas, but also a function of the mass transport of the products from the sample in the gas phase. We have categorized two different etching regimes: the gas phase regime and the condensed phase regime. In the gas phase etching regime, reactant molecules are adsorbed on the oxide surface in sub-monolayer, monolayer, or multilayer films. In the multilayer adsorption regime, the etching rate is usually low (typically 0-400 A/min) and is linearly proportional to the partial pressure of HF and H20. The etching rate in this regime is greatly affected by the temperature of the substrate. The mass transfer rate limits the etch rate of oxide in the multilayer adsorption regime. In the submonolayer or monolayer adsorption regime the etching rate is described by Langmuir- Hinshelwood kinetics. The etching rate is governed by surface kinetics in this regime. Advantages of this etching regime are: 1) smoother etched surface, 2) low selectivity to TEOS, 3) haze-free etched surface, 4) no metal attack, 5) perfect removal of native oxide, and 6) vacuum compatible process. The HF vapor process in this regime is an ideal process for contact cleaning and polymer removal after metal or via etching. Electrostatic charge on the wafer surface affects the etching reaction significantly in the non-condensed regimes. A positively charged surface enhanced the etching reaction in the submonolayer and monolayer etching regimes. Direct ionization of HF on the oxide surface is responsible for the enhancement in this regime. A negatively charged surface mainly enhanced the etching in the multilayer regime. A thicker multilayer, induced by the formation of fluorosilicate, is responsible for the etching enhancement in this regime. We have demonstrated a successful removal of sodium from both oxide and silicon surfaces using HF/H2 0, HF/IPA, and HF/H20/SiF4 processes in reduced pressure operation. All experiments were performed in a vacuum environment and in-situ XPS was used to measure the surface concentration of sodium. The sodium contamination on oxide surface was successfully removed by both HF/H 20 and HF/IPA processes. The HF/H 20 process could not remove all of sodium contamination on a silicon surface. The addition of SiF4 in the HF/H 20 process greatly enhances the cleaning effect, reducing Na contamination below the detection limit of our XPS, even on a silicon surface. Based on our study, we have reported a true gas phase and vacuum compatible HF vapor process, operated in the monolayer adsorption regime at elevated temperature. A successful removal of RIE residue was performed with a combined cleaning procedure of HF vapor and ashing process. This combined process is a perfect dry cleaning process for contact cleaning method. This process sequence is ideal for a vacuum cluster configuration in which a single wafer is processed at a time and is not exposed in the ambient.<br>by Yong-Pil Han.<br>Ph.D.
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Krauß, Michael. "The Influence of Management Strategies on the Water Productivity in Dairy Farming and Broiler Production." Doctoral thesis, Humboldt-Universität zu Berlin, 2017. http://dx.doi.org/10.18452/18560.
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Die Wasserproduktivität in der Tierhaltung ist von vielen Faktoren abhängig. Die Futterproduktion hat den größten Anteil am Wasserbedarf von tierischen Produkten. Weitere Einflussfaktoren sind die Leistung, die Reproduktion und der Gesundheitsstatus der Tiere, das Management und die Haltungsbedingungen. In dieser Arbeit sollte untersucht werden, wie sich diese Faktoren auf die Wasserproduktivität von Milch und Geflügelfleisch in Nord-Ost-Deutschland auswirken. Zehn unterschiedliche Futtermittel wurden hinsichtlich ihres Wasserbedarfes untersucht. Aus diesen Futtermitteln wurden die Rationen für die Tiere erstellt. Die Milchleistung der Kühe wurde zwischen 4.000 und 12.000 kg Milch pro Kuh und Jahr in 2.000 kg Schritten variiert. Für jedes Leistungsniveau wurden zwölf verschiedene Fütterungsstrategien untersucht, welche auf der Erhöhung einzelner Bestandteile der Ration basieren. Der Wasserbedarf von Leitungswasser im Stall wurde mit 38 Wasserzählern ermittelt. Für die Wasserproduktivität des Geflügelfleisches wurden vier verschieden intensive Mastverfahren untersucht.
Die Wasserproduktivität steigt mit steigender Milchleistung der Kühe. Das Maximum wird bei 10.000 kg Milch pro Kuh und Jahr und Rationen mit einem hohem Gras- bzw. Maissilageanteil erreicht.
Die Kühe, die im automatischen Melksystem gemolken wurden, nahmen mehr Tränkwasser zu sich, als die Kühe im Fischgrätenmelkstand. Dies ist durch die höhere Milchleistung bedingt. Im automatischen Melksystem wurden im Mittel 28,6 Liter Reinigungswasser pro Kuh und Tag benötigt. Für die Reinigung des Fischgrätenmelkstandes wurden 33,8 Liter pro Kuh und Tag genutzt.
Die untersuchten Broilermastverfahren zeigten keine Unterschiede hinsichtlich der Wasserproduktivität. Die intensivere Aufzucht und bessere Futterverwertung wurde durch eine niedrigere Wasserproduktivität des Futters kompensiert.
Der Anteil des technischen Wassers macht in der Milchkuh- und Broilerhaltung nur einen kleinen Teil am Gesamtwasserbedarf aus.<br>Livestock production is the main user of water resources in agricultural production. Water is used in animal production for producing feed, watering the animals, and cleaning and disinfecting barns and equipment. The objective of this dissertation was to quantify the effects of management strategies, such as feeding, intensity of production and the replacement process on the water productivity of milk and poultry meat in Germany.
Water productivity in milk and broiler production systems was calculated based on the methodology of Prochnow et al. (2012). Own measurements of the drinking and cleaning water demand in milk production were conducted in a dairy cow barn. The study was based on site conditions of North-East Germany with common variations in farm operations.
The feed production is the main contributor to water input in dairy and poultry production. The water productivity of milk increased with an increasing milk yield. The most beneficial conditions related to water productivity in dairy farming were found to be with a milk yield of approximately 10,000 kg fat corrected milk and a grass silage and maize silage based feeding. The total technical water use in the barn makes only a minor contribution to water use. Former regression functions of the drinking water intake of the cows were reviewed and a new regression function based on the ambient temperature and the milk yield was developed. In broiler production the intensification of the fattening systems did not increase water productivity.
An increase of water productivity in animal production can be achieved with various management strategies with their specific influence on the production process. The feed management should be a focus of the strategies.
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Xia, Changlei. "Biomass-Derived Activated Carbon Through Self-Activation Process." Thesis, University of North Texas, 2016. https://digital.library.unt.edu/ark:/67531/metadc849716/.
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Self-activation is a process that takes advantage of the gases emitted from the pyrolysis process of biomass to activate the converted carbon. The pyrolytic gases from the biomass contain CO2 and H2O, which can be used as activating agents. As two common methods, both of physical activation using CO2 and chemical activation using ZnCl2 introduce additional gas (CO2) or chemical (ZnCl2), in which the CO2 emission from the activation process or the zinc compound removal by acid from the follow-up process will cause environmental concerns. In comparison with these conventional activation processes, the self-activation process could avoid the cost of activating agents and is more environmentally friendly, since the exhaust gases (CO and H2) can be used as fuel or feedstock for the further synthesis in methanol production. In this research, many types of biomass were successfully converted into activated carbon through the self-activation process. An activation model was developed to describe the changes of specific surface area and pore volume during the activation. The relationships between the activating temperature, dwelling time, yield, specific surface area, and specific pore volume were detailed investigated. The highest specific surface area and pore volume of the biomass-derived activated carbon through the self-activation process were up to 2738 m2 g-1 and 2.209 cm3 g-1, respectively. Moreover, the applications of the activated carbons from the self-activation process have been studied, including lithium-ion battery (LIB) manufacturing, water cleaning, oil absorption, and electromagnetic interference (EMI) shielding.