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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Treatment and using of greywater in sorting wastewater system as a resource / Rening av och resursutvinning ur gråvatten från sorterande avloppssystem

Seifu, Maza Seyuom January 2022 (has links)
Det här projektet redogör för olika behandlingstekniker för gråvatten och för tillämpningar för olika ändamål inom återanvändning. Syftet är att föreslå en lämplig processdesign för behandling av gråvatten i stadsmiljö, på Loudden, Norra Djurgårdsstaden (NDS). Undersökningen grundar sig på relevant litteratur och på fyra demo-sites där gråvatten behandlas och återanvänds i olika tillämpningar. Gråvattendata samlades in och ett genomsnitt beräknades för att karakterisera gråvatteninflödet. Flödet från gråvattnet beräknades utifrån den dagliga vattenförbrukningen i Sverige om 140 liter/person/dag. Fyra behandlingsprocesser valdes ut. Behandlingsprocesserna kombinerades med förbehandling vilket är standard för att skydda efterföljande process steg. Två av dessa behandlingsprocesser modifierades eftersom de, var och en för sig, inte skulle vara tillräckliga för att minska föroreningar och säkra applikationen för slutanvändaren. De fyra processenheternas prestanda utvärderades utifrån två kriterier:  EU:s kvalitetskriterier  för  återvunnet  vatten  under  klass C samt driftsparametrar. En lista som rangordnar de viktigaste variablerna skapades för att sortera fram det bästa teknikvalet. En utvärderingsprocess visade på designernas lämplighet för den behandling som krävs. "Process Combination 1" valdes på grund av dess robusta prestanda och uppvisade inte några betydande nackdelar. Den består av ett fingaller, en submerged membrane bioreactor och ett kloreringssteg. Processdesignen  innehåller värmeåtervinning och tillämpningar  för  återanvändning  inom processindustri samt bevattning för planteringar inom området. De tekniska och ekonomiska beräkningarna baserades på det karakteriserade gråvattnet och den konstruerade flödet. Investeringskostnaden för den föreslagna processdesignen hamnar på 31 miljoner kronor. Den genererar en årlig inkomst på 5 miljoner kronor och kommer, enligt nuvärdesmetoden och med en ränta på 5 %, att vara fullt betald efter 9 år. / This project presents greywater (GW) treatment techniques and reuse applications for different purposes. The aim is to suggest a suitable process design for treating GW in the urban city environment, Loudden, Norra Djurgårdsstaden (NDS). The research studied relevant literature and four demo sites where GW is treated and reused in various applications. GW data were collected, and an average was used to emulate a GW inflow characteristic. The GW flow was constructed based on estimated daily water consumption in Sweden of approximately 140 liter/person/day. Four treatment process units were selected. The treatment processes units were combined with pre- treatment, a standard treatment to protect the system. Two of these treatment processes were modified because, individually, they would not be sufficient to reduce contaminants and secure the end-user application. The performance of the four process units was evaluated based on two criteria: EU quality criteria for reclaimed water under class C and operating parameters. A list ranking the most critical variables was created to sort out the best process unit. An evaluation process showed the suitability of the designs for the required treatment. "Process Combination 1" was chosen because of its robust performance and did not present any significant drawbacks. It consists of a fine screen, a submerged membrane bioreactor, and a chlorination step. A process design including heat recovery and reuse applications for irrigation of the plantation fiels in the area and process industry was established. The characterized inflow and constructed GW flow were then used for technical and economic calculations. The estimated investment cost for the proposed process design was approximately SEK 31 million. It generates an annual income of SEK 5 million and will, according to the Net Present Value method, with an interest rate of 5%, be fully paid after 9 years.
62

Management strategy of landfill leachate and landfill gas condensate

Zhao, Renzun 15 October 2012 (has links)
Studies were conducted to evaluate the impact of landfill leachate discharge on the operation of waste water treatment plants (WWTPs). Two aspects of interferences were found: one is UV quenching substances, which are bio-refractory and able to penetrate the biological treatment processes, consequently interfere the UV disinfection in WWTPs. The other one is organic nitrogen, which can pass the nitrification-denitrification process and contribute to the effluent total nitrogen (TN). Also, treatability study was conducted for landfill gas (LFG) condensate. In a laboratory study, leachate samples were fractionated into humic acids (HA), fulvic acids (FA) and Hydrophilic (Hpi) fractions, the specific UV254 absorbance (SUVA254) of the three fractions follows: HA > FA > Hpi. However, the overall UV254 absorbance of the Hpi fraction was important because there was more hydrophilic organic matter than humic or fulvic acids. It was found that the size distribution of the three fractions follows: HA > FA > Hpi. This indicates that membrane separation following biological treatment is a promising technology for the removal of humic substances from landfill leachates. Leachate samples treated in this manner could usually meet the UV transmittance requirement of the POTWs. Also, nitrogen species in landfill leachates under various stabilization states were investigated. Although the effect of landfill stabilization state on the characteristics of organic matter and ammonia is well documented, there are few investigations into the landfill leachate organic nitrogen under different stabilization stages. Ammonia was found to leach out slower than organic matter and can maintain a constant level within the first a couple of years (< 10 years). The concentration and biodegradability of organic nitrogen were found to decrease with landfill age. A size distribution study showed that most of organic nitrogen in landfill leachates is < 1 kDa. The protein concentration was analyzed and showed a strong correlation with the organic nitrogen. Different slopes of regression curves of untreated and treated leachates indicate that protein is more biodegradable than the other organic nitrogen species in landfill leachates. XAD-8 resin was employed to isolate the hydrophilic fraction of leachate samples, hydrophilic organic nitrogen was found to be more biodegradable/bioavailable than the hydrophobic fractions. Furthermore, biological and physical-chemical treatment methods were applied to a landfill biogas (LFG) condensate to explore the feasible treatment alternatives for organic contaminant and arsenic removal efficiency. Sequencing batch reactor (SBR) showed effectiveness for the degradation of organic matter, even in an environment containing high levels of arsenic. This indicated a relatively low toxicity of organic arsenic as compared to inorganic arsenic. However, for arsenic removal, oxidation-coagulation, including biological oxidation, conventional oxidation and advanced oxidation followed by ferric salt coagulation, and carbon adsorption were not effective for what is believed to be tri-methyl arsenic. Among these, advanced oxidation-coagulation showed the best treatment efficiency (15.1% removal). Only reverse osmosis (RO) could reduce the arsenic concentration to an acceptable level to meet discharge limits. These results implied high stability and low toxicity of organic arsenic. / Ph. D.
63

Tratabilidade de águas residuárias de indústrias petroquímicas - estudo de caso. / Treatability of petrochemical industries wastewaters - case study.

Hilsdorf, Antonio Sérgio de Carvalho 02 September 2008 (has links)
O tratamento de águas residuárias industriais, submetido constantemente a cargas de choque, é pouco estudado no Brasil, sendo limitado o grau de conhecimento que se tem no mundo sobre os mecanismos de remoção de disruptores endócrinos nos sistemas de tratamento físico-químicos e biológicos. O presente trabalho traz um estudo de caso, envolvendo uma indústria com uma composição de produtos muito diversificada, com despejos líquidos de unidades isoladas de qualidades diversas e que tem como uma das principais matérias-primas, nonil fenóis, conhecidos disruptores endócrinos. Os mecanismos de remoção de carga orgânica e a avaliação da toxicidade da água residuária ao processo biológico de tratamento foram estudados em escala de laboratório, enquanto que a sua tratabilidade por coagulação, floculação, flotação com ar dissolvido seguido de sistema de lodos ativados, em escala piloto. Avaliou-se, também, a aplicabilidade do tratamento biológico com carvão ativado em pó. A grande variação qualitativa e quantitativa da água residuária bruta requer uma unidade de equalização com tempo de detenção de pelo menos 30 horas. O maior responsável por esta variação de qualidade é o processo da unidade química, cujo efluente é proveniente de lavagens de tanques e reatores. Apesar da reduzida eficiência de remoção de DQO obtida com a coagulação, floculação e flotação com ar dissolvido (20 a 30%), constatou-se que este tratamento é essencial para a redução da toxicidade ao processo biológico. A dosagem de coagulante e o pH ótimos variam conforme a característica do despejo e devem ser determinadas diariamente. No sistema biológico, observou-se uma remoção significativa da DQO do efluente bruto gerado na indústria, não apenas por biodegradação, mas também por volatilização e adsorção. Os testes de bancada evidenciaram remoções de DQO por arraste com ar de 47 a 77 % e por adsorção no lodo biológico, de 42%. Apesar dos constantes choques de carga orgânica e de poluentes tóxicos, conseguiu-se atingir o estado estacionário com variações máximas da concentração de sólidos em suspensão voláteis no tanque de aeração entre 20 e 30%. Neste período, a idade do lodo situou-se em torno de 25 a 30 dias e o tempo de detenção hidráulico foi de 3,8 dias. A eficiência média de remoção de DQO neste período foi de 86%. Os testes com a unidade piloto demonstraram que a utilização de carvão ativado em pó (CAP) produz resultados satisfatórios, comprovando a redução de poluentes tóxicos da água residuária e refletindo em uma significativa melhora na biodegradabilidade do efluente, com aumento da concentração de sólidos em suspensão voláteis no tanque de aeração (de 1380 mg/L para 3820 mg/L) e redução da amplitude de variação da DQO do efluente tratado que passou de 600 a 3200 mgO2/L para o sistema sem CAP para 300 a 600 mgO2/L para o sistema com CAP. Notou-se, também, com a adição de CAP, melhoria na sedimentação do lodo. Pode-se concluir também que o sistema de tratamento atendeu a legislação atual do Estado de São Paulo, com uma remoção média de 80% da DBO5. / Wastewater treatment systems continuously receiving shock loads and the behavior of contaminants under unsteady state conditions are not very well documented in our country, with limited degree of knowledge in the world on the removal of specific pollutants like endocrine disrupting chemicals (EDC) in physical chemical and biological wastewater treatment systems. The present work brings a case study regarding an industry which wastewaters were generated from plants with multiproducts and campaign production with variable composition, and with nonylphenols as one of their raw materials which is known as an endocrine disrupting chemical. The organic load and toxicity removal mechanisms of the wastewater to the biological treatment were studied in bench scale whilst their treatability was evaluated through coagulation, flocculation, dissolved air flotation followed by activated sludge, in pilot scale. The feasibility of the addition of powdered activated carbon to the biological system was also studied. The large qualitative and quantitative variability of the wastewater requires an equalization time of at least 30 hours. The main responsible for this variability in quality is the chemical unit process which wastewaters are originated from reactors and tanks cleanings. Although the low efficiency in COD removal obtained with coagulation, flocculation and dissolved air flotation (20 to 30%), it was found that this process is essential to the toxicity reduction for the biological process. Optimum pH and coagulant dose vary with the wastewater characteristics, and must be determined on a daily basis. On the biological system, it was observed important raw wastewater COD elimination not only through biodegradation, but also through volatilization and adsorption. Bench tests revealed COD elimination of 47 to 77% by air stripping and 42% by adsorption onto the biological sludge. Despite of constant organic and toxic shock loads, it had been possible to reach the steady state during which the maximum variation on the volatile suspended solids concentration was 20 to 30%. During this period, sludge age was around 25 to 30 days, and the hydraulic detention time was 3,8 days. Average efficiency on COD removal in this period was 86%. Tests results with PAC dosage on the pilot plant showed satisfactory, proving the reduction of toxic compounds from the wastewater and resulting in biodegradability improvement. The increase of volatile suspended solids in the aeration tank was from 1380 mg/L to 3820 mg/L, and reduction in the range of variation of remaining treated water COD from 600 to 3200 mgO2/L (system without CAP) down to 300 to 600 mgO2/L (system with CAP). The improvement on the sludge sedimentation with PAC addition was also remarkable. One can also conclude the treatment system attained the current legislation of the State of São Paulo, with 80% BOD5 removal.
64

Nanotubes de carbonne ultracourts pour la bioimagerie / Ultrashort carbon nanotubes for bioimaging applications

Faes, Romain 18 February 2014 (has links)
Les travaux de recherche effectués lors de cette thèse portent sur l’obtention de nanotubes de carbone ultracourts et leur biofonctionnalisation pour une utilisation comme biomarqueur proche infrarouge. Des dispersions de nanotubes de carbone en milieux aqueux ont été formulées à l’aide de différents tensioactifs. Un traitement chimique oxydant préalable et/ou l’application d’ultrasons aux nanotubes ont permis de réduire leur longueur de façon significative, la sélection des plus courts étant effectuée par ultracentrifugation en gradient de densité. Les différentes fractions sélectionnées à l’issu de ce processus ont été caractérisées par spectroscopie Raman et spectroscopie d’absorption ainsi que par microscopie à force atomique. Il est ainsi montré la sélection de nanotubes d’une longueur inférieure à 20 nm. Nous montrons également leur fonctionnalisation à l’aide d’anticorps monoclonaux et leur visualisation par imagerie photothermique hétérodyne. Des résultats prometteurs ont été obtenus avec la fixation spécifique de nanotubes de carbone ultracourts sur des cellules. Ces travaux ouvrent de nombreuses perspectives en bioimagerie et en particulier l’étude de la plasticité synaptique au sein de neurones vivants. / This thesis reports the achievement of ultrashort carbon nanotubes and their biofunctionalization for applications as near-infrared biomarker. Dispersions of carbon nanotubes in aqueous media have been formulated with various surfactants. Oxidizing chemical treatments combined with the application of ultrasounds allowed significant shortening of the carbon nanotubes. Sorting and selection of the shortest nanotubes was done by density gradient ultracentrifugation. The different fractions selected at the end of this process have been characterized by Raman spectroscopy, UV-vis absorption spectroscopy and atomic force microscopy. Selection of nanotubes of a length below 20 nm is demonstrated. We also show functionalization by antibodies and the visualization of ultrashort functionalized nanotubes by photothermal heterodyne imaging. Promising results were obtained with the specific binding of ultrashort carbon nanotubes to cells. This work open route towards bioimaging applications and in particular towards the study of the synapsis plasticity within alive neurons.
65

Aproveitamento da fibra do epicarpo do coco baba?u em comp?sito com matriz ep?xi: estudo do efeito do tratamento da fibra

Franco, Francisco Jos? Patr?cio 07 August 2010 (has links)
Made available in DSpace on 2014-12-17T14:06:55Z (GMT). No. of bitstreams: 1 FranciscoJPF.pdf: 1681554 bytes, checksum: 4238148885bafd3e26a8d8ca7de20466 (MD5) Previous issue date: 2010-08-07 / Nowadays the environmental issues are increasingly highlighted since the future of humanity is dependent on the actions taken by man. Major efforts are being expended in pursuit of knowledge and alternatives to promote sustainable development without compromising the environment. In recent years there has been a marked growth in the development of reinforced composite fiber plants, as an alternative for economic and ecological effects, especially in the substitution of synthetic materials such as reinforcement material in composites. In this current study the chemical- physical or (thermophysics )characteristics of the babassu coconut fiber, derived from the epicarp of the fruit (Orbignyda Phalerata), which the main constituents of the fiber: Klason lignin, insoluble, cellulose, holocellulose, hemicellulose and the content of ash and moisture will be determined. A study was conducted about the superficial modification of the fibers of the epicarp babassu coconut under the influence of chemical treatment by alkalinization, in an aqueous solution of NaOH to 2.5% (m/v) and to 5.0% to improve the compatibility matrix / reinforcement composite with epoxy matrix. The results of the changes occurred in staple fibers through the use of the techniques of thermogravimetric analyses (TG) and differential scanning calorimetry (DSC). The results found on thermal analysis on samples of fiber without chemical treatment (alkalinities), and on fiber samples treated by alkalinization show that the proposed chemical treatment increases the thermal stability of the fibers and provides a growth of the surface of area fibers, parameters that enhance adhesion fiber / composite. The findings were evaluated and compared with published results from other vegetable fibers, showing that the use of babassu coconut fibers has technical and economic potential for its use as reinforcement in composites / Atualmente as quest?es ambientais ganham destaque cada vez mais acentuado, j? que o futuro da humanidade est? dependente das a??es tomadas hoje pelo homem. Grandes esfor?os est?o sendo despendidos na busca de conhecimentos e solu??es alternativas sustent?veis que promova o desenvolvimento sem comprometimento do meio ambiente. Nos ?ltimos anos tem havido um crescimento acentuado no desenvolvimento de comp?sitos refor?ados por fibras vegetais, como uma alternativa econ?mica e ecol?gica, principalmente, na substitui??o de materiais sint?ticos, como material de refor?o em comp?sitos. No presente trabalho foram analisadas as caracter?sticas qu?mico-f?sicas de fibra oriundas do epicarpo do coco baba?u (Orbignyda Phalerata), sendo determinados os principais teores dos constituintes da fibra: lignina Klason insol?vel, celulose, holocelulose, hemicelulose e os teores de cinzas e de umidade. Foi realizado um estudo da modifica??o superficial das fibras do epicarpo do coco baba?u sob efeito de tratamento qu?mico por alcaliniza??o, em solu??o aquosa de NaOH a 2,5% (m/v) e a 5,0% (m/v), visando melhorar a compatibiliza??o matriz/refor?o em comp?sito com a matriz de ep?xi. Os resultados das modifica??es ocorridas nas fibras foram estudados atrav?s de t?cnicas de termogravimetria (TG) e de calorimetria explorat?ria diferencial (DSC). Os resultados encontrados nas an?lises t?rmicas em amostras de fibras sem tratamento qu?mico e em amostras de fibras tratadas por alcaliniza??o mostram que o tratamento qu?mico proposto aumentou a estabilidade t?rmica das fibras e proporcionou um crescimento na ?rea superficial das fibras, par?metros que melhoram a ades?o fibra/comp?sito. Os resultados obtidos foram avaliados e comparados com resultados publicados de outras fibras vegetais, mostrando que a utiliza??o das fibras de coco baba?u tem potencialidades t?cnicas e econ?micas para o seu uso como refor?o de comp?sitos
66

Tratabilidade de águas residuárias de indústrias petroquímicas - estudo de caso. / Treatability of petrochemical industries wastewaters - case study.

Antonio Sérgio de Carvalho Hilsdorf 02 September 2008 (has links)
O tratamento de águas residuárias industriais, submetido constantemente a cargas de choque, é pouco estudado no Brasil, sendo limitado o grau de conhecimento que se tem no mundo sobre os mecanismos de remoção de disruptores endócrinos nos sistemas de tratamento físico-químicos e biológicos. O presente trabalho traz um estudo de caso, envolvendo uma indústria com uma composição de produtos muito diversificada, com despejos líquidos de unidades isoladas de qualidades diversas e que tem como uma das principais matérias-primas, nonil fenóis, conhecidos disruptores endócrinos. Os mecanismos de remoção de carga orgânica e a avaliação da toxicidade da água residuária ao processo biológico de tratamento foram estudados em escala de laboratório, enquanto que a sua tratabilidade por coagulação, floculação, flotação com ar dissolvido seguido de sistema de lodos ativados, em escala piloto. Avaliou-se, também, a aplicabilidade do tratamento biológico com carvão ativado em pó. A grande variação qualitativa e quantitativa da água residuária bruta requer uma unidade de equalização com tempo de detenção de pelo menos 30 horas. O maior responsável por esta variação de qualidade é o processo da unidade química, cujo efluente é proveniente de lavagens de tanques e reatores. Apesar da reduzida eficiência de remoção de DQO obtida com a coagulação, floculação e flotação com ar dissolvido (20 a 30%), constatou-se que este tratamento é essencial para a redução da toxicidade ao processo biológico. A dosagem de coagulante e o pH ótimos variam conforme a característica do despejo e devem ser determinadas diariamente. No sistema biológico, observou-se uma remoção significativa da DQO do efluente bruto gerado na indústria, não apenas por biodegradação, mas também por volatilização e adsorção. Os testes de bancada evidenciaram remoções de DQO por arraste com ar de 47 a 77 % e por adsorção no lodo biológico, de 42%. Apesar dos constantes choques de carga orgânica e de poluentes tóxicos, conseguiu-se atingir o estado estacionário com variações máximas da concentração de sólidos em suspensão voláteis no tanque de aeração entre 20 e 30%. Neste período, a idade do lodo situou-se em torno de 25 a 30 dias e o tempo de detenção hidráulico foi de 3,8 dias. A eficiência média de remoção de DQO neste período foi de 86%. Os testes com a unidade piloto demonstraram que a utilização de carvão ativado em pó (CAP) produz resultados satisfatórios, comprovando a redução de poluentes tóxicos da água residuária e refletindo em uma significativa melhora na biodegradabilidade do efluente, com aumento da concentração de sólidos em suspensão voláteis no tanque de aeração (de 1380 mg/L para 3820 mg/L) e redução da amplitude de variação da DQO do efluente tratado que passou de 600 a 3200 mgO2/L para o sistema sem CAP para 300 a 600 mgO2/L para o sistema com CAP. Notou-se, também, com a adição de CAP, melhoria na sedimentação do lodo. Pode-se concluir também que o sistema de tratamento atendeu a legislação atual do Estado de São Paulo, com uma remoção média de 80% da DBO5. / Wastewater treatment systems continuously receiving shock loads and the behavior of contaminants under unsteady state conditions are not very well documented in our country, with limited degree of knowledge in the world on the removal of specific pollutants like endocrine disrupting chemicals (EDC) in physical chemical and biological wastewater treatment systems. The present work brings a case study regarding an industry which wastewaters were generated from plants with multiproducts and campaign production with variable composition, and with nonylphenols as one of their raw materials which is known as an endocrine disrupting chemical. The organic load and toxicity removal mechanisms of the wastewater to the biological treatment were studied in bench scale whilst their treatability was evaluated through coagulation, flocculation, dissolved air flotation followed by activated sludge, in pilot scale. The feasibility of the addition of powdered activated carbon to the biological system was also studied. The large qualitative and quantitative variability of the wastewater requires an equalization time of at least 30 hours. The main responsible for this variability in quality is the chemical unit process which wastewaters are originated from reactors and tanks cleanings. Although the low efficiency in COD removal obtained with coagulation, flocculation and dissolved air flotation (20 to 30%), it was found that this process is essential to the toxicity reduction for the biological process. Optimum pH and coagulant dose vary with the wastewater characteristics, and must be determined on a daily basis. On the biological system, it was observed important raw wastewater COD elimination not only through biodegradation, but also through volatilization and adsorption. Bench tests revealed COD elimination of 47 to 77% by air stripping and 42% by adsorption onto the biological sludge. Despite of constant organic and toxic shock loads, it had been possible to reach the steady state during which the maximum variation on the volatile suspended solids concentration was 20 to 30%. During this period, sludge age was around 25 to 30 days, and the hydraulic detention time was 3,8 days. Average efficiency on COD removal in this period was 86%. Tests results with PAC dosage on the pilot plant showed satisfactory, proving the reduction of toxic compounds from the wastewater and resulting in biodegradability improvement. The increase of volatile suspended solids in the aeration tank was from 1380 mg/L to 3820 mg/L, and reduction in the range of variation of remaining treated water COD from 600 to 3200 mgO2/L (system without CAP) down to 300 to 600 mgO2/L (system with CAP). The improvement on the sludge sedimentation with PAC addition was also remarkable. One can also conclude the treatment system attained the current legislation of the State of São Paulo, with 80% BOD5 removal.
67

Redukce korozních vrstev mosazi pomocí nízkotlakého nízkoteplotního plazmatu / Brass Corrosion Layers Reduction by Low-Pressure Low-Temperature Plasma

Řádková, Lucie January 2015 (has links)
This thesis presents results of the corrosion layers removal which could be found on the archaeological artefact surfaces. The low pressure low temperature plasma reduction was used for this purpose. Brass samples were chosen for this study. Two different ways have been used to form model corrosion layers. Several sets of corrosion layers were prepared in laboratory in two different corrosion atmospheres, namely ammonia atmosphere and atmosphere of hydrochloric acid. These samples were placed into desiccator. Small quantities of sand were added to some sets of samples so samples with sandy incrustation were prepared. The corrosion layers had been usually formed during four weeks. The second way, which was used to prepare model corrosion layer, was the natural corrosion in soil or compost. In this case, the corrosion layers had been formed approximately 2 years. The samples were treated in the low pressure (150 Pa) cylindrical Quartz reactor (90 cm long and 9.5 cm in diameter) with a pair of external copper electrodes connected via the matching network to a radiofrequency generator (13.56 MHz). The flows of working gases were set by independent mass flow controllers. Whole system was continuously pumped by the rotary oil pump which was separated from the discharge reactor by liquid nitrogen trap with aluminium chips eliminating dust and reactive species from the gas flow. Each sample was placed on a glass holder at the reactor center. Plasma was generated in pure hydrogen or in mixture of hydrogen and argon. Total flow of working gas was 50 sccm. Different ratios of gas mixture were tested, the ratio 30 sccm hydrogen and 20 sccm argon flows was the best. RF discharge was used in a continuous and pulsed regime. Pulsed mode was carried out with various duty cycle at the frequency of 1000 Hz. There were two ways of temperature monitoring. The sample temperature during the treatment was monitored by a K-type thermocouple installed inside the sample in the first case. Thermometer optical probe was connected to the sample surface by a small stainless plate and allowed continuous sample temperature monitoring in the second way. Safe object temperature for copper and copper alloys is 100–120 °C. To avoid exceeding this temperature, power control or the duty cycle in pulse mode were automatically controlled if thermometer optical probe was used. Plasma chemical treatment is based on generation of reactive atomic hydrogen in plasma discharge. The main reactions during reduction were reactions between oxygen and chloride contained in the corrosion layer and the hydrogen ions and neutral atoms generated in the plasma. These reactions create an unstable OH radical, which emits light in the region of 306–312 nm. This radiation was detected by the optical emission spectroscopy using Ocean Optics HR4000 spectrometer with 2400 gr/mm grating. Data obtained from this method were used to calculate rotational temperatures and integral intensity of OH radicals that were used for the process monitoring. Corrosion layer was not completely removed during the reduction, but due to the reactions which occur in the plasma corrosion layer became brittle and after plasma chemical treatment can be removed easily. The SEM-EDS material analyses were carried out before and after treatment of some samples. Some samples were analysed by XRD analysis. EDS analysis showed that amount of oxygen and chloride was decreased, mainly at 400 W pulse mode.
68

Recycling of uPVC window profile waste

Kelly, Adrian L., Coates, Philip D., Rose, R.M., Weston, S. January 2007 (has links)
No / Methods of recycling unplasticized polyvinyl chloride (uPVC) window frame waste were investigated. The quality of untreated granular waste was compared to that of waste treated by a range of contaminant removal processes including melt filtration and dissolution. Processability of each recyclate was evaluated by using a highly instrumented single screw extruder that enabled melt viscosity and process variation to be monitored in real time. Product quality measurements such as mechanical properties and surface defects were made on extruded strip, and the nature of the stabilizers present was determined. The mechanical properties of recyclates were found to be comparable to or better than those of virgin material in all cases and conformed to industry standards for window profile. Contaminant removal stages significantly reduced the amount of large surface defects detected in extrudate. Processability was comparable to that of virgin compounds, but melt viscosity varied among different batches of recyclate, depending on the source and composition of the original PVC formulation.
69

Challenges and opportunities with shared data for Water Treatment Plants / Utmaningar och möjligheter med delade data mellan vattenverk

Bredhe, Johanna, Hashi, Abdulahi Ismail January 2022 (has links)
The Swedish water sector faces many challenges in terms of climate change, worn out facilities and distribution systems as many of them were built in the 50-, 60- and 70s, but also increased cyber security concerns. Collaborations between different actors are therefore required to address these challenges. This thesis work's purpose is to examine the opportunities a collaboration between water treatment plants could bring for the water sector to achieve a more sustainable drinking water production. The purpose is also to examine the most efficient way to establish a collaboration between them through digital means. A workshop and several interviews with representatives from different water treatment plants were conducted to gather information on possibilities of data/information sharing between them, but also to make a security classification of data/information generated at the water treatment plants. The representatives included process engineers, process technicians, security associates and an associate at Svenskt vatten, an interest organization for the water sector. The result showed that data/information sharing is already taking place in the sector under limited conditions. Smaller VA organizations have more challenges due to lack of skilled workers, partners and time. It is difficult for many in the sector to know where to turn to when in need of help, particularly for smaller VA organizations who usually are the ones with fewer contact networks. It is not to say that only smaller VA organizations are affected but they are more likely to lack contact with other water organizations. The majority of water treatment plants agree on that data/information on treatment processes would be allowed to share under limited conditions. The information classification is a matter for each plant due to different security realities which determines the information classification. This makes it difficult to decide on what parameters could be shared by every water treatment plant. This needs to be investigated further in order to determine what data/information could be shared by most water treatment plants on a platform. Most participants thought that a platform of some kind would be the best solution to simplify data/information sharing between water treatment plants. The suggested platform is a good start for making contacts between water treatment plants and has the potential to enable storage and sharing of data/information in the future. / Den svenska VA sektorn står inför många utmaningar så som klimatförändringar, slitna anläggningar och distributionsnät då många av dem byggdes under 50-, 60- och 70-talet. Även oron kring cybersäkerheten ökar. Samarbeten mellan olika aktörer krävs för att lösa dessa utmaningar. Syftet med examensarbetet är att undersöka de möjligheter som samarbeten mellan vattenverk skulle medföra för att nå en mer hållbar dricksvattenproduktion. Syftet är också att undersöka det mest effektiva sättet att få till ett samarbete mellan vattenverken med digitala medel. En workshop och flertalet intervjuer genomfördes med olika representanter från vattenverk för att samla information om möjligheten med att dela data/information mellan dem. Men också för att göra en säkerhetsklassning av data/information som genereras på vattenverken. Representanterna inkluderade processingenjörer, processtekniker, säkerhetsansvariga samt en medarbetare från Svenskt vatten, en intresseorganisation för vattensektorn. Resultatet visade att delning av data/information redan sker inom sektorn, dock under begränsade former. Mindre VA organisationer har fler utmaningar på grund av brist på anställda med rätt kompetens, samarbetspartners och tid. Många inom sektorn har utmaningar när det kommer till att söka och få hjälp, särskilt för de mindre VA organisationerna som vanligtvis har färre kontakter. Men de är inte bara de små som är påverkade av detta problem, men det är vanligare att de inte har kontakter med andra VA organisationer. De flesta vattenverken ansåg att data/information från reningssteg skulle vara möjligt att dela under begränsade former. Informationssäkerhetsklassning är en enskild fråga för varje vattenverk som baseras på de hot som varje vattenverk står inför. Detta medför att det är svårt att bestämma vilken data/information som kan delas av varje vattenverk. Detta område behöver vidare utredas innan ett beslut kan fattas om vilken data/information alla vattenverk ska dela på en plattform. De flesta deltagarna tyckte att en plattform av något slag skulle vara lösningen för att förenkla delning av data/information mellan vattenverken. Den föreslagna plattformen är en bra start för vattenverk att skapa kontakter och har potentialen att möjliggöra lagring och delning av data/information i framtiden.
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Effect of Thermal and Chemical Treatment of Soy Flour on Soy-Polypropylene Composite Properties

Guettler, Barbara Elisabeth 06 November 2014 (has links)
Soy flour (SF), a by-product of the soybean oil extraction processing, was investigated for its application in soy-polypropylene composites for interior automotive applications. The emphasis of this work was the understanding of this new type of filler material and the contribution of its major constituents to its thermal stability and impact properties. For this reason, reference materials were selected to represent the protein (soy protein isolate (SPI)) and carbohydrate (soy hulls (SH)) constituents of the soy flour. Additional materials were also investigated: the residue obtained after the protein removal from the soy flour which was called insoluble soy (IS), and the remaining liquid solution after acid precipitation of the proteins, containing mostly sugars and minerals, which was called soluble sugar extract (SSE). Two treatments, potassium permanganate and autoclave, were analyzed for their potential to modify the properties of the soy composite materials. An acid treatment with sulfuric acid conducted on soy flour was also considered. The soy materials were studied by thermogravimetric analysis (TGA) under isothermal (in air) and dynamic (in nitrogen) conditions. SPI had the highest thermal stability and SSE the lowest thermal stability for the early stage of the heating process. Those two materials had the highest amount of residual mass at the end of the dynamic TGA in nitrogen. The two treatments showed minimal effect on the isothermal thermal stability of the soy materials at 200 ??C. A minor improvement was observed for the autoclave treated soy materials. Fourier transformed infrared (FTIR) spectroscopy indicated that the chemical surface composition differed according to type of the soy materials but no difference could be observed for the treatments within one type of soy material. Contact angle analysis and surface energy estimation indicated differences of the surface hydrophobicity of the soy materials according to type of material and treatment. The initial water contact angle ranged from 57 ?? for SF to 85 ?? for SH. The rate of water absorption increased dramatically after the autoclave treatment for IS and SPI. Both materials showed the highest increase in the polar surface energy fraction. In general, the major change of the surface energy was associated with change of the polar fraction. After KMnO4 treatment, the polar surface energy of SF, IS and SPI decreased while SH showed a slight increase after KMnO4 treatment. A relationship between protein content and polar surface energy was observed and seen to be more pronounced when high protein containing soy materials were treated with KMnO4 and autoclave. Based on the polar surface energy results, the most suitable soy materials for polypropylene compounding are SPI (KMnO4), SH, and IS (KMnO4) because their polar surface energy are the lowest which should make them more compatible with non-polar polymers such as polypropylene. The soy materials were compounded as 30 wt-% material loading with an injection moulding grade polypropylene blend for different combinations of soy material treatment and coupling agents. Notched Izod impact and flexural strength as well as flexural modulus estimates indicated that the mechanical properties of the autoclaved SF decreased when compared to untreated soy flour while the potassium permanganate treated SF improved in impact and flexural properties. Combinations of the two treatments and two selected (maleic anhydride grafted polypropylene) coupling agents showed improved impact and flexural properties for the autoclaved soy flour but decreased properties for the potassium permanganate treated soy flour. Scanning electron microscopy of the fractured section, obtained after impact testing of the composite material, revealed different crack propagation mechanisms for the treated SF. Autoclaved SF had a poor interface with large gaps between the material and the polypropylene matrix. After the addition of a maleic anhydride coupling agent to the autoclaved SF and polypropylene formulation, the SF was fully embedded in the polymer matrix. Potassium permanganate treated SF showed partial bonding between the material and the polymer matrix but some of the material showed poor bonding to the matrix. The acid treated SF showed cracks through the dispersed phase and completely broken components that did not bind to the polypropylene matrix. In conclusion, the two most promising soy materials in terms of impact and flexural properties improvement of soy polypropylene composites were potassium permanganate treated SF and the autoclaved SF combined with maleic anhydride coupling agent formulation.

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