Temat: membranes regeneration - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Methods for regeneration and storage of ceramic membranes
Autorzy:: Zielińska, A.
Powiązania:: https://bibliotekanauki.pl/articles/106051.pdf
Data publikacji:: 2018
Wydawca:: Centrum Badań i Innowacji Pro-Akademia
Tematy:: ceramic membranes
fouling
membranes regeneration
membrana ceramiczna
regeneracja membran
Opis:: Ceramic membranes are among one of the most promising candidates for membrane applications, owing to their excellent resistance to mechanical, chemical, and thermal stresses. These advantages make them an attractive filter material. An additional benefit which is extremely important for the industry, is their possibility of continuous operation at high efficiency while maintaining constant transmembrane pressure. Due to the inorganic material from which they are made, ceramic membranes have the possibility of being cleaned by steam sterilization and are resistant to micro-organisms. Although, due to low production costs, ceramic membranes are one of the most cost-effective membrane filtration technologies they are prone to substantial fouling. When used, a layer of contaminants is formed on the active surface, often reducing or completely filling the membrane pores resulting in fouling and concentration polarization. These phenomena cause a decreased efficiency of the process, which leads to the need for the membrane to be replaced with a new one. However, ceramic membranes have the possibility of being regenerated through a series of activities and the use of various chemical agents. The use of regenerated membranes would provide the opportunity to reduce exploitation costs. Although membrane regeneration does not guarantee a return to the initial parameters, it does allow for the recovery of high permeation flow. The aim of the research was to compare operating parameters of the ceramic membranes after multiple use and longtime storage with different condition of storage.
Źródło:: Acta Innovations; 2018, 28; 72-81
2300-5599
Pojawia się w:: Acta Innovations
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Methods of chemical regeneration of polymeric membranes
Metody i sposoby chemicznej regeneracji membran polimerowych
Autorzy:: Suchecka, T.
Grądkowski, M.
Powiązania:: https://bibliotekanauki.pl/articles/256525.pdf
Data publikacji:: 2016
Wydawca:: Sieć Badawcza Łukasiewicz - Instytut Technologii Eksploatacji - Państwowy Instytut Badawczy
Tematy:: membrane filtration
fouling
regeneration of membranes
CIP station
filtracja membranowa
regeneracja membran
stacja CIP
Opis:: The study addresses problems concerning reducing the effects of fouling, accompanying cross flow filtration. Mechanisms of fouling production depend on the properties of the fluids being filtered, the characteristics of the membranes, and the conditions of the filtration processes. This mechanism relies upon the accumulation of particles and colloids, microorganisms, and salts on the surface and in the pores of the membrane. This results in a dramatic flux decline and retention of the membrane. One of the most effective and significant way to reduce fouling is by choosing an appropriate membrane and the optimal process conditions adjusted for the fluid characteristics. However, this does not solve the problem entirely. Fouling may be either reversible or irreversible. In some cases, depending on the structure of membrane, reversible fouling can be removed by backwashing. In the other cases, it is required to use chemical purification of the membranes. Its efficiency depends on the cleaning reagent activity, ionic strength, concentration, and pH, as well as temperature, pressure, time, and the flow rate of cleaning solution. The introduction of the reactants is performed in order to loosen the structure and dissolve the deposit, to maintain the foulant in the solution and to prevent its re-embedding on the membrane surface. Better results of cleaning can be achieved by improving the conditions for the transport of the reaction products from the membrane into the solution. It is mostly controlled by the flow rate of the cleaning solution, but it must also take into account the temperature and time of cleaning, which affect the mass transfer and chemical reaction. This is achieved by means of a suitably designed cleaning-in-Place (CIP). Mobile pilot installation of CIP was prepared by the Institute for Sustainable Technologies - National Research Institute in Radom. It is designed to develop, verify and optimize the CIP procedures in terms of pilot and test membrane systems.
W artykule omówiono podstawowe problemy związane z usuwaniem skutków foulingu, towarzyszącego procesom filtracji membranowej techniką „cross flow”. Mechanizm powstawiania foulingu zależy od charakterystyki filtrowanej cieczy, charakterystyki membrany oraz warunków realizacji procesu filtracji i polega na akumulacji cząstek, koloidów, mikroorganizmów oraz soli na powierzchni i w porach membrany. Jego skutkiem jest zmniejszenie strumienia filtracji, a także pogorszenie charakterystyki retencyjnej membrany. Jednym z najskuteczniejszych, a zarazem kluczowych sposobów ograniczenia foulingu jest optymalne dobranie membrany i warunków procesu do charakterystyki filtrowanej cieczy. Nie rozwiązuje to jednak problemu w całości. Fouling może mieć charakter odwracalny lub nieodwracalny. W niektórych przypadkach, zależnych od rodzaju membran, fouling odwracalny może być usuwany poprzez płukanie zwrotne. W pozostałych niezbędne jest zastosowanie chemicznego oczyszczania membran. Jego efektywność zależy od sposobu działania reagenta myjącego, jego siły jonowej, stężenia oraz pH roztworu myjącego, a także temperatury, ciśnienia oraz czasu i szybkości przepływu cieczy myjącej. Wprowadzenie reagentów ma na celu rozluźnienie struktury i rozpuszczenie depozytu, utrzymanie foulanta w roztworze oraz zapobieganie ponownemu jego osadzeniu na powierzchni membrany. Usprawnienie oczyszczania można uzyskać poprzez poprawę warunków transportu masy produktów reakcji od membrany do roztworu. Najczęściej jest to kontrolowane przez prędkość przepływu kąpieli myjącej, jednakże należy brać także pod uwagę temperaturę i czas mycia, które wpływają na transport masy i szybkość reakcji chemicznych. Wymagane parametry procesu uzyskuje się dzięki zastosowaniu odpowiednio zaprojektowanej instalacji CIP. Mobilną pilotową instalację CIP opracowano w Instytucie Technologii Eksploatacji – PIB w Radomiu. Jest ona przeznaczona do opracowywania, weryfikacji i optymalizacji procedury CIP w odniesieniu do pilotowych i testowych instalacji membranowych.
Źródło:: Problemy Eksploatacji; 2016, 2; 183-196
1232-9312
Pojawia się w:: Problemy Eksploatacji
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Polylactide - carbon nanotubes nanocomposites as membranes for guided nerve regeneration (GNR)
Autorzy:: Stodolak-Zych, E.
Frączek-Szczypta, A.
Błażewicz, M.
Powiązania:: https://bibliotekanauki.pl/articles/285045.pdf
Data publikacji:: 2012
Wydawca:: Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:: nanocomposites
membranes
nerve regeneration
Opis:: New generation of membrane materials can play role in regeneration process in living organism e.g. creation of optimal conditions for regeneration of bone tissue (GBR/GTR technique) or defected peripheral nerve (GNR technique). However, biodegradable polymeric materials which are now widely used in GNR technique (PLA, PCL, collagen) does not have satisfactory mechanical properties such as strength (RM) or Young's modulus (E) because it is difficult to control their porosity [1,2]. Materials suitable for nerve regeneration should exhibit electrical properties which stimulate the regeneration [3]. The main idea of the guided nerve regeneration is utilisation of a membrane separating two tissues i.e. defected nerve tissue and connective tissue. Inside the defected nerve tissue surrounded by the membrane should be present factors influencing the regeneration process such as: ECM protein, nervotrofic factors. On the other hand, the membrane should act as a barrier for fibroblast cells inflowing into the defected area. The work presents results of investigations on porous nanocomposite materials basing on bioresorbable aliphatic polyesters i.e. poly-(L/DL)-lactide and carbon nanotubes (CNT). All materials i.e. nanocomposite foils and porous materials were prepared using synthetic co-polymer of L/DL-lactide with L/DL ratio of 80/20 from Purac®. The polymer had the FDA attestation confirming its biocompability. As the nanofillers, two types of CNTs produced by Nanostructured and Amorphous Materials (Inc. Huston, USA) were used: MWCNTs (multi-wall carbon nanotubes; diameter 10-30 nm and length 1-2 μm) and SWCNTs (single-wall carbon nanotubes; diameter 0.7-2 nm and length 15-30 μm). Nanocomposite membrane materials (PLDLA/0.5% wt. MWCNTs and PLDLA/0.5% wt. SWCNTs) were prepared using combined methods: phase inversion and freeze-drying. Porous microstructure of the nanocomposites was investigated using SEM/EDS. It was found, that the presence of the CNT influenced shape, size (5-50 μm) and distribution of pores in the material (total porosity of PLDLA/ MWCNTs was about ~65% and PLDLA/S WCNTs was about ~35%). The nanoadditives increased mechanical properties of the membrane materials. For example addtition of the SWCNTs increased the membrane strength (RM) form 16 to 24 MPa. Physicochemical properties of the materials surface were investigated by means of wettability and surface energy measurements. It was shown that dispersion part of surface free energy decreased when SWCNTs were used as additives (from 4.5 mm/mJ PLDLA membrane to 0.7 mm/mJ PLDLA/SWCNTs), while in the case of the MWCNTs addition dispersion part of surface energy increased from 4.5 mm/mJ to 6.9 mm/mJ. Such PLDLA-based materials modified with CNTs (MWCNTs, SWCNTs) may be an attractive support for adhering cells. SWCNTs were more suitable nanoad- ditives for PLDLA-matrix membranes than MWCNTs, because such membranes were stronger, hydrophilic and much more bioactive.
Źródło:: Engineering of Biomaterials; 2012, 15, no. 116-117 spec. iss.; 139-140
1429-7248
Pojawia się w:: Engineering of Biomaterials
Dostawca treści:: Biblioteka Nauki

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