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Showing 51 to 56 of 56 (0.043 seconds)Spelling suggestions: "subject:"bioreaktor"" "subject:"bioreaktori""
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Denitrification in a Low Temperature Bioreactor System : Laboratory column studiesNordström, Albin January 2014 (has links)
Denitrification is a microbially-catalyzed reaction which reduces nitrate to N2 through a series of intermediate nitrogen compounds. Nitrate is a nutrient and its release into the environment may lead to eutrophication, depending on the amount that is released and the state of the recipient. The release of nitrate from the mining industry in Kiruna (Sweden) has been identified as an eutrophication risk, and a denitrifying bioreactor is to be constructed at the site to reduce the nitrate release.Since the denitrification rate decreases with temperature and the temperature in Kiruna during large parts of the year drops below 0˚C, the denitrifying bioreactor therefore has to be designed for the site-specific environment in terms of flow rate and hydraulic residence time. Laboratory column studies are used to study and determine the nitrate removal rate in a low temperature environment (5˚C) with pine wood chips as reactive matrix/ electron donor; the input solution had an average concentration of 35 mg NO3-N/L and a high sulfate concentration. Nitrate removal was studied as a function of hydraulic residence time and temperature. Parameters that were monitored include pH, alkalinity and concentrations of ammonium, nitrite and sulfate in the effluent from the columns. On three occasions, samples were gathered along the flow path in the columns (concentration profiles) such that changes in nitrate, nitrite, and occasionally ammonium concentration could be studied in relation to each other. The study concluded that a denitrifying bioreactor utilizing pine wood chips as the reactive matrix is a suitable option for nitrate treatment in a low temperature (5˚C) environment. Under the conditions of the study, effluent nitrate, nitrite, and ammonium concentrations are below limits established in legislation. Nitrate removal rates are given for zero-order nitrate reduction and overall first-order nitrate reduction, as the concentration profiles revealed a decrease in nitrate removal rate as nitrate concentration dropped below 3 mg NO3-N/L. / Nitrat är ett näringsämne som kan orsaka övergödning vid utsläpp, beroende på halterna och recipienten. Växterna som tar upp kväve kommer så småningom att dö och sjunka mot botten där de förmultnar. Förmultningen kräver syre, och vid ökad växtlighet så ökar även konsumtionen av syre då det finns mer organiskt material att bryta ned. Detta leder i slutändan till syrefria områden, där djurliv och växtlighet är mer begränsade. Nitratutsläpp från gruvindustrin i Kiruna har blivit identifierad som en potentiell övergödningsrisk och en denitrifierande bioreaktor ska därmed installeras för att minska utsläppen. Denitrifikation är en mikrobiell reaktion som reducerar nitrat till kvävgas genom en serie av intermediära kväveföreningar. En denitrifierande bioreaktor använder sig utav denitrifikation för att minska nitratkoncentrationer i vatten som passerar genom bioreaktorn som består av huvudsakligen; (1) bakterierna som sköter denitrifikationen, och (2) en kolkälla som fungerar som ”mat” till de denitrifierande bakterierna, Hastigheten varvid nitrat omvandlas till kvävgas genom denitrifikation, minskar med temperatur och den denitrifierande bioreaktorn måste därmed anpassas till omgivningen där den ska placeras med avseende på uppehållstid i reaktorn. Uppehållstiden måste vara tillräcklig för att minska nitratkoncentrationen till önskad nivå, men samtidigt så får uppehållstiden inte vara för lång då andra ämnen kan reagera och bilda ofördelaktiga produkter vid låga nitratkoncentrationer. Kolonnstudier i en låg-tempererad miljö (5˚C) är ett första steg för att studera hastigheten av nitratförbrukning i en sådan omgivning, och används i detta arbete med träflis av tall som kolkälla. Parametrar som påverkar, och varierar som ett resultat av, denitrifikation (exempelvis pH och sekundära föroreningar) övervakas. Hastigheten av nitratförbrukning som fås från kolonnstudierna kan sedan används som riktlinjer för konstruktionen av en denitrifierande bioreaktor i fältskala i Kiruna. Studiens slutsats är att en denitrifierande bioreaktor med träflis av tall som reaktivt medium är ett fungerande alternativ för nitrat reducering i en lågtempererad miljö (5˚C) då nitrat effektivt reduceras till under gränsvärden fastslagna i lag. Även andra potentiella biprodukter (exempelvis nitrit och ammonium) som kan resultera från den miljö som den denitrifierande bioreaktorn ger upphov till är under de gränsvärden som finns fastslagna i lag.
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Instrumentierte Strömungsfolger zur Prozessdiagnose in gerührten Fermentern / Instrumented Flow Followers for Process Analysis of Stirred FermentersReinecke, Sebastian Felix 08 May 2014 (has links) (PDF)
Advanced monitoring of the spatio-temporal distribution of process parameters in large-scale vessels and containers such as stirred chemical or bioreactors offers a high potential for the investigation and further optimization of plants and embedded processes. This applies especially to large-scale fermentation biogas reactors where the process performance including the biological processes highly depend on mixing parameters of the complex bio-substrates. Sufficient mixing is a basic requirement for a stable operation of the process and adequate process performance. However, this condition is rarely met in agricultural biogas plants and the process efficiency is often reduced dramatically by inhomogeneities in the agitated vessels. Without a doupt, investigation and monitoring of biochemical parameters, such as the fermentation rate, pH distribution as well as O2 and CO2 concentration is of great importance. Nevertheless, also understanding of non-biological parameters, such as fluid dynamics (flow velocity profiles, circulation times), suspension mixing (homogeneity, location of dead zones and short-circuits) and heat transfer (temperature profiles), is necessary to analyze the impact of mixing on the biological system and also to improve the process efficiency.
However, in most industrial scale applications the acquisition of these parameters and their spatial distributions in the large-scale vessels is hampered by the limited access to the process itself, because sensor mounting or cable connections are not feasible or desired. Therefore, state of the art instrumentation of such reactors is commonly limited to few spatial positions where it is doubtfully assumed that the measured parameters are representative for the whole reaction mixture.
In this work, a concept of flow following sensor particles was developed. The sensor particles allow long-term measurement of spatially distributed process parameters in the chemically and mechanically harsh environments of agitated industrial vessels. Each sensor particle comprises of an onboard measurement electronics that logs the signals of measurement devices, namely temperature, absolute pressure (immersion depth, axial position) and 3D acceleration. The whole electronics is enclosed in a robust neutrally buoyant capsule (equivalent diameter 58.2 mm; sphericity 0.91), to allow free movement with the flow.
The sensor particles were tested in pilot fermenters under comparable flow conditions of biogas fermenters. The experiments proved the applicability of the sensor particles and the robustness to resist the harsh environments of mixing processes. Moreover, the results show the capabilities of the sensor particles to monitor the internal conditions of the vessel correctly and thus deliver significant information about the flow regime. Therefore effects of liquid rheology, vessel geometry, impeller speed and axial impeller position on the macro-mixing process were properly detected. Evaluation of the impeller efficiency and the mixing processes was done based on mixing homogeneity, location of dead zones, axial velocity profiles, circulation time distributions as well as average circulation times, acceleration spectra and temperature profiles that were extracted from the measured data. Furthermore, it is shown, that parameters of mixing models such as circulation number, impeller head, PECLÉT-number and variance of suspended solid particles can be estimated from the measured data.
The main achievement of this work is therefore the development and validation of instrumented flow followers for the investigation of macro-mixing effects in agitated vessels. The sensor particles show potential for employment to real applications such as biogas fermenters or large bioreactors and to monitor and improve the mixing and heating regimes.
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| 53 |
Anaerobní membránový bioreaktor (AnMBR) pro čištění odpadních vod potravinářského průmyslu / Anaerobic membrane bioreactor (AnMBR) for food industry wastewater treatment.Polášek, Daniel Unknown Date (has links)
The most significant environmental problems related to the food industry is water consumption and pollution, energy consumption and waste production. Most of the water that does not become a part of the products ultimately leaves plants in the form of wastewater, which is often very specific and requires adequate handling / treatment / disposal. For the purpose of this thesis, brewery industry was chosen, because of its very long tradition in the Czech history and culture. Anaerobic technologies are applied for still wider range of industrial wastewater treating. In general anaerobic membrane bioreactors (AnMBRs) can very effectively treat wastewater of different concentration and composition and produce treated water (outlet, permeate) of excellent quality, that can be further utilised. At the same time, it can promote energy self-sufficiency through biogas production usable in WWTPs / plants. Main disadvantages include unavoidable membrane fouling and generally higher CAPEX / OPEX. Within the framework of Ph.D. studies and related research activities, immersed membrane modules for anaerobic applications were selected and lab-scale tested (designed and assembled laboratory unit), an AnMBR pilot plant was designed, built and subsequently tested under real conditions - at Černá Hora Brewery WWTP (waste waters from the brewery and associated facilities). The pilot AnMBR and the technology itself has been verified over more than a year (5/2015 – 11/2016) of trial operation - the initial and recommended operational parameters have been set up, minor construction adjustments / modifications and measurement & regulation optimizations have been made, the recommended membrane cleaning and regeneration procedure has been verified. Last, but not least, conclusions and recommendations of the trial operation were summarised - some key findings and recommendations for further operation, use and modifications of the existing AnMBR pilot plant are presented.
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| 54 |
Instrumentierte Strömungsfolger zur Prozessdiagnose in gerührten FermenternReinecke, Sebastian Felix 06 December 2013 (has links)
Advanced monitoring of the spatio-temporal distribution of process parameters in large-scale vessels and containers such as stirred chemical or bioreactors offers a high potential for the investigation and further optimization of plants and embedded processes. This applies especially to large-scale fermentation biogas reactors where the process performance including the biological processes highly depend on mixing parameters of the complex bio-substrates. Sufficient mixing is a basic requirement for a stable operation of the process and adequate process performance. However, this condition is rarely met in agricultural biogas plants and the process efficiency is often reduced dramatically by inhomogeneities in the agitated vessels. Without a doupt, investigation and monitoring of biochemical parameters, such as the fermentation rate, pH distribution as well as O2 and CO2 concentration is of great importance. Nevertheless, also understanding of non-biological parameters, such as fluid dynamics (flow velocity profiles, circulation times), suspension mixing (homogeneity, location of dead zones and short-circuits) and heat transfer (temperature profiles), is necessary to analyze the impact of mixing on the biological system and also to improve the process efficiency.
However, in most industrial scale applications the acquisition of these parameters and their spatial distributions in the large-scale vessels is hampered by the limited access to the process itself, because sensor mounting or cable connections are not feasible or desired. Therefore, state of the art instrumentation of such reactors is commonly limited to few spatial positions where it is doubtfully assumed that the measured parameters are representative for the whole reaction mixture.
In this work, a concept of flow following sensor particles was developed. The sensor particles allow long-term measurement of spatially distributed process parameters in the chemically and mechanically harsh environments of agitated industrial vessels. Each sensor particle comprises of an onboard measurement electronics that logs the signals of measurement devices, namely temperature, absolute pressure (immersion depth, axial position) and 3D acceleration. The whole electronics is enclosed in a robust neutrally buoyant capsule (equivalent diameter 58.2 mm; sphericity 0.91), to allow free movement with the flow.
The sensor particles were tested in pilot fermenters under comparable flow conditions of biogas fermenters. The experiments proved the applicability of the sensor particles and the robustness to resist the harsh environments of mixing processes. Moreover, the results show the capabilities of the sensor particles to monitor the internal conditions of the vessel correctly and thus deliver significant information about the flow regime. Therefore effects of liquid rheology, vessel geometry, impeller speed and axial impeller position on the macro-mixing process were properly detected. Evaluation of the impeller efficiency and the mixing processes was done based on mixing homogeneity, location of dead zones, axial velocity profiles, circulation time distributions as well as average circulation times, acceleration spectra and temperature profiles that were extracted from the measured data. Furthermore, it is shown, that parameters of mixing models such as circulation number, impeller head, PECLÉT-number and variance of suspended solid particles can be estimated from the measured data.
The main achievement of this work is therefore the development and validation of instrumented flow followers for the investigation of macro-mixing effects in agitated vessels. The sensor particles show potential for employment to real applications such as biogas fermenters or large bioreactors and to monitor and improve the mixing and heating regimes.
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| 55 |
Fluidic microchemomechanical integrated circuits processing chemical informationGreiner, Rinaldo, Allerdissen, Merle, Voigt, Andreas, Richter, Andreas January 2012 (has links)
Lab-on-a-chip (LOC) technology has blossomed into a major new technology fundamentally influencing the sciences of life and nature. From a systemic point of view however, microfluidics is still in its infancy. Here, we present the concept of a microfluidic central processing unit (CPU) which shows remarkable similarities to early electronic Von Neumann microprocessors. It combines both control and execution units and, moreover, the complete power supply on a single chip and introduces the decision-making ability regarding chemical information into fluidic integrated circuits (ICs). As a consequence of this system concept, the ICs process chemical information completely in a self-controlled manner and energetically self-sustaining. The ICs are fabricated by layer-by-layer deposition of several overlapping layers based on different intrinsically active polymers. As examples we present two microchips carrying out long-term monitoring of critical parameters by around-the-clock sampling. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
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Stabil och antibiotikafri läkemedelsproduktion i rekombinant Escherichia coliBenevides, Kristina, Broström, Oscar, Elison Kalman, Grim, Swenson, Hugo, Vlassov, Andrei, Ågren, Josefin January 2017 (has links)
Den här rapporten presenterar ett antibiotikafritt, stabilt och kromosombaserat expressionssystem för läkemedelsproduktion i Escherichia coli på beställning av företaget Affibody AB. E. coli-stammen BL21(DE3) valdes som värdorganism för expressionssystemet. Systemet består av en genkassett som innehåller en T7-promotor, en 5′-UTR från genen ompA och en terminatorsekvens från RNA-operonet rrnB. Fyra kopior av genkassetten ska integreras i pseudogenerna caiB, yjjM, hsdS och yjiV. En datormodell som modellerar det egentliga kopietalet i cellerna har skapats i mjukvaran MATLAB, vilket visar att det uppskattas vara maximalt 32 kopior av genkassetten per cell på grund av replikation av kromosomen. Ett högt pH i fermentorn; att använda fed-batch och blandade kolhydratkällor; och att använda stammen BL21(DE3) minskar acetatproduktionen i cellen. En lägre acetatproduktion kan leda till en högre produkthalt. En proteinutbytesmodell för mjukvaran MATLAB har konstruerats för att uppskatta koncentrationen av Affibody®-molekylen i en E. coli cell.
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