The basics of convection, mechanical, hydraulic and bubbling mixing used in methane fermentation technologies are discussed. The impact of the intensity of mechanical mixing on the quality and quantity of biogas as well as the course of the fermentation process was evaluated. The influence of the paddle agitator speed rate on quasi-continuous fermentation was investigated. Fermentation was carried out under mesophilic conditions with a hydraulic retention time of 21 days. A 10% increase in biogas production was observed with the increase of the speed of mixing from 60 to 70 min-1 without a significant change in the composition of biogas and other process parameters.
Spinning fluids reactor (SFR) is one of the most efficient gas-liquid contacting system with high potential of application in many fields. The unique solution of SFR is the contacting of two spinning fluids which generated centrifugal force. The aim of this study was to investigate the pressure field distribution on the inner surface of reactors dispersing element. Obtained results confirm the high heterogeneity of the field pressure in the reactor system with a cylindrical wall. This is due to the low tangential force generated by rotating liquid on a cylindrical wall, and pressure drop in the locations of surface irregularities. The change of the sparger element to conical shape element increases the pressure exerted by fluid on the wall. In this case the effects of solid particles and inequality in the fluid flow are negligibly small compared to the measured pressure exerted on the sparger element.
Ionic liquids are widely used in supported ionic liquid membranes technology, especially in gas separation and purification processes. This work characterizes the ability of ionic liquids to wet commercially available porous supports used for such purposes. Characterization of supports and membrane phases was carried out in order to determine factors influencing wetting process. Experimental method based on capillary rise is widely used for porous media characterization (i.e. pore radius, contact angle). Measurements of penetration distance or liquid mass are two main experimental methods, in which the Washburn equation is a basic instrument to analyze the obtained results. However, polymeric porous supports do not meet Washburn assumptions and the method is loaded with human errors, so the sessile drop method was used. The rate of wetting influences swelling effects and therefore changes in permeation path during gas separation processes are observed. Influence of ionic liquids structure on wetting and swelling of porous supports was investigated. The families of 1-alkyl-3-methylimidazolium (Cnmim), ammonium (Nnnnn), 1-alkyl-1-methylpyrrolidinium (CnPyrr) and 1-alkylpyridinium (CnPy) compounds with variable alkyl chain lengths in cation structures and changeable anions were taken into account in wetting and swelling experiments.
The paper focuses on assessing wettability of surfaces modified with ionic liquid solutions. Dialkylimidazolium chlorides have been selected as the test group, because of their immediate availabil-ity and limited previous research. Contact angle of selected ionic liquid solutions have been measured with two methods: capillary rise test and simplified sitting droplet analysis, performed by means of digital camera. During tests the extremely high viscosity of dialkylimidazolium chlorides has been observed to drop rapidly with prolonged exposition to atmospheric moisture and measured experimentally with Karl-Fischer titration and viscosity measurements. Contact angles of selected ionic liquids have been presented.
Supported liquids membranes are very promising products. They have been intensively inves-tigated in last two decades and widely used in many technologies especially in gas separation and purifi-cation processes. A key aspect in obtaining satisfying effectiveness and long membrane lifetime is a proper choice of ionic liquid and polymeric or ceramic support. Properties of both affect the processes of obtaining useful supported ionic liquid membranes. In comparison to polymeric membranes, ceramic ones are slightly thicker, however they are thermally and mechanically more stable. Our research was aimed at sintering fine glass particles of 500 to 45 μm in size in order to prepare porous membranes which can be used as supports for liquid membranes. Dextrin and borax were used as pore-making agents. The membranes, as disks 35 mm in diameter and 3 mm of thickness, were prepared. The porosity was determined using absorption method. It was found, that the porosity could be controlled by changing the applied pressure from 1 to 5 MPa, particle size distribution, sintering temperature, type and amount of pore-enhancing agents.
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Ionic liquids were found to be selective solvents for separation of gases. They are widely used in supported ionic liquid membranes (SILMs) technology, especially in gas separation and purification processes. This work has characterized commercially available porous membranes employed in such purposes. Characterization of supports and membrane phases was carried out in order to determine factors influencing membrane stability. Scanning electron microscopy (SEM) was used to determine morphology of membrane surface. In this work wetting of the polymeric support with [Emim][TfO], [Emim][Tf2N], [Bmim][TfO] and [Bmim][Tf2N] and swelling of the membrane impregnated with ionic liquids have been investigated.
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The effectiveness of water filtration in gravel-sand bed filters has been studied in the rehabilitating swimming pool treatment plant. Apart from instrumental analysis of the water the investigation considered additionally particle size distribution as well as thermal analysis of the sediment collected in the sand bed of depth filters and removed during the process of washing. Variable value of TOC in the washings for each filter indicates indirectly their non-uniform loading. It has been proved that the size of particles in the suspension easily changes as a result of operation of shear stress. Derivatographic research has indicated approximately 30 % presence of organic substances in the sediment. In neither of the investigated samples loss of mass over > 460oC has been observed.
PL
Przebadano efektywność filtracji wody w filtrach ze złożem żwirowo-piaskowym w instalacji basenu rehabilitacyjnego. Obok analizy instrumentalnej wody, w badaniach uwzględniono rozkład wielkości cząstek i analizę termiczną osadu zgromadzonego w złożu piaskowym filtrów wgłębnych i usuwanego podczas płukania. Zmienna wartość TOC w popłuczynach dla każdego z filtrów wskazuje pośrednio na nierównomierne ich obciążenie. Wykazano, że wielkość cząstek w zawiesinie łatwo zmienia się w wyniku działania naprężeń ścinających. Badania derywatograficzne wskazały na około 30% udział substancji organicznych w osadzie. W żadnej z badanych próbek, nie zanotowano ubytku masy powyżej > 460°C.
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The measurements of rheological properties of activated sludge suspension after mechanical disintegration indicate a substantial decrease in viscosity of up to 60%. Together with the decrease of viscosity pseudoplastic properties increased and the flow limit dropped. Similarly, significant changes of rheological properties occurred in the sludge, subjected to methane fermentation. One can observe that the length of fermentation period influences the decrease in viscosity of the sewage sludge. It is postulated to use the measurement of viscosity for the estimation of excessive sludge disintegration ratio as this method is much faster than determination of COD.
PL
Wykonane pomiary właściwości reologicznych osadów nadmiernych poddawanych procesowi dezintegracji mechanicznej wskazują na znaczny spadek lepkości sięgający 60%. Wraz ze stopniem dezintegracji rosły również właściwości pseudoplastyczne oraz malała granica płynięcia. Podobnie istotne zmiany właściwości reologicznych następowały w osadach poddawanych fermentacji metanowej. Z analiz pobieranych próbek po różnym okresie trwania procesu wynika, że czas fermentacji wpływa na zmniejszenie lepkości osadów ściekowych. Pomiar lepkości może być stosowany do oceny stopnia dezintegracji osadu nadmiernego, ponieważ metoda ta jest znacznie szybsza niż oznaczenie ChZT (analiza zalecana przez ATV).
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Ionic liquids (ILs) attract growing attention and the range of their potential application is constantly expanding. To meet not only the technological but also environmental requirements for their implementation to wide-scale use, we undertook an extensive literature study into ILs interaction and sorption onto soils. The available data were compared and subjected to critical review. We also performed sorption batch test of l-methyl-3- octylimidazolium chloride in a broad concentration range onto low pH and forest soil poor in organic matter. The sorption isotherm closely matched the isotherm described previously in the literature as corresponding to double layer sorption. From the sorption isotherm we calculated the partition coefficients (Kd)
W ostatnich latach wzrasta udział pojazdów z silnikami wysokoprężnymi w sprzedaży samochodów osobowych, szczególnie w segmencie aut klasy średniej. W 2005 r. stanowiły one 49% całego europejskiego rynku samochodowego. W Polsce udział diesli wśród nowych samochodów wynosił 31 %.
Laboratory results of an initial study on CO2 removal from gas mixture by means of the air-sparged hydrocyclone (ASH) technology are reported. The CO2 absorption rate into sodium hydroxide aqueous solution was studied on a laboratory and pilot scale. The air flow rate was 900 dm³/min and the alkaline solution flow rate was 15 dm³/min in the case of pilot scale. The influence of CO2 concentration, pH of the liquid phase, the gas flow rate, and the alkaline solution flow rate on the efficiency of the process was investigated. An increase in the alkaline concentration significantly enhanced the CO2 absorption. A very low distribution of bubble sizes enhanced the carbon dioxide absorption, too.
Konieczność usuwania wody z fazy olejowej pojawia się często w przedsiębiorstwach zajmujących się produkcją i utylizacją olejów, włączając wydobycie ropy naftowej (odsalanie) i usuwanie wody z produktów gotowych. Oprócz przemysłu petrochemicznego, problem usuwania wody z produktów olejowych występuje także w przemyśle zajmującym się przerobem tłuszczów.
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Przedstawiono wyniki rozdzielania faz w emulsji typu woda w oleju metodą koalescencji w złożu. Jako wypełnienie stosowano kulki szklane o średnicy od 40 do 250 um. Określono wpływ natężenia przepływu, wysokości złoża i temperatury procesu na efektywność usuwania wody. Najlepsze rezultaty uzyskano dla złoża o średniej wielkości ziaren 75 um. Z uwagi na wysokie opory przepływu przez złoże koalescencję prowadzono w temperaturze 40, 60 i 80 °C. Osiągnięto ponad 90% redukcję zawartości wody dla złoża o wysokości 0,12 m oraz ponad 80% redukcję dla złoża 0,06 m i średniej wielkości kropel wody 3,4 um. Proces najefektywniej przebiegał w temperaturze 80 °C jednak niekorzystnym efektem w tych warunkach był wzrost rozpuszczalności wody w oleju (200-300 ppm).
EN
The results of water from w/o emulsion removal in granular bed coalescer were presented. As a coalescence bed were used glass spheres with 40-250 urn in diameter. Influence of flow volume, thickness of bed and temperature on coalescence effectiveness were determined. The best results were obtained using glass spheres with medium diameter 75 um. Considering high flow resistance through coalescence bed the process was carried out at 40, 60 and 80 °C. Over 90% of water reduction for 0,12 m thick bed and over 80% for 0,06 m thick bed was obtained (medium diameter of water droplets was 3,4 um). The most effective process was passing at 80 °C temperature but high temperature effect on water in oil solubility (200-300 ppm).
Badano mieszaniny asfaltu z PE i EPDM zawierające 1, 3 i 5% tych polimerów. Mieszaniny poddano dodatkowo modyfikacji przez utlenienie PE powietrzem w obecności H2SO4 jako katalizatora. Modyfikowane asfalty w porównaniu z niemodyfikowanymi wykazywały obniżoną penetrację i wrażliwość na temperaturę oraz wzrost indeksu penetracji.
EN
The modification of asphalt by PE and EPDM polymers was studied. Series samples of asphalt modified by PE and EPDM containing 1, 3, 5 mass % of polymers were prepared. The oxidation of PE by air was carried with sulphuric acid as catalyst. The penetration 25 degrees centigrade temperature, penetration index, viscosity at 60 degrees centigrade temperature and viscosity versus temperature were measured. Decrease in penetration, increase in penetration index and decrease temperature sensitivity compared to unmodified asphalt were observed.
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