Filtration using membranes

Filtration Using Membrane-Thermotolerant Escherichia coli Agar (mTEC)... 

R02021 Method 1106.1 Enterococci in Water by Membrane Filtration Using Membrane-Enterococcus-Esculin Iron Agar (mE-EIA)... 

Another reported application of backshock is in filtration using membranes called microsieves, which are very thin and smooth membranes with uniform pores made by silicon micromachining [54]. The thinness (ca. 1.2 p,m) and high porosity of... 

Clarifying fining lees tangential micro filtration, using membranes with pore diameters from 0.2 to 0.8 p.m, was compared with a rotary vacuum filter (Serrano, 1994). The flow rates were lower (50-100 1/h/m instead of 350-500 1/h/m ) but clarification was better, both in terms of much lower turbidity as well as the elimination of microorganisms. Wine losses were also lower ... 

Filtration using membrane filters with a pore size of 0.45 xm is the most common sample pretreatment procedure for ion chromatography. For biologically active samples, the use of sterile filters with a pore size of 0.2 j,m is strongly advisable. Filters are made either from PTFE, polyvinyldienedifluoride (PVDF), or similar material. Cellulose filters are generally unsuitable. Filter materials differ in pore size, porosity, filtration speed, compatibility with acids, abuse, and organic solvents, as well as in their adsorption properties and blank values. 

That part of inorganic carbon in water that cannot be removed by specific phase separation, for example by centrifugation at 40000m-s- for 15min or by membrane filtration using membranes with pores of 0.2 im to 0.45 im diameter. 

Anotlier standard metliod is to use a (high-speed) centrifuge to sediment tire colloids, replace tire supernatant and redisperse tire particles. Provided tire particles are well stabilized in tire solvent, tliis allows for a rigorous purification. Larger objects, such as particle aggregates, can be fractionated off because tliey settle first. A tliird metliod is (ultra)filtration, whereby larger impurities can be retained, particularly using membrane filters witli accurately defined pore sizes. 

PVDF-based microporous filters are in use at wineries, dairies, and electrocoating plants, as well as in water purification, biochemistry, and medical devices. Recently developed nanoselective filtration using PVDF membranes is 10 times more effective than conventional ultrafiltration (UF) for removing vimses from protein products of human or animal cell fermentations (218). PVDF protein-sequencing membranes are suitable for electroblotting procedures in protein research, or for analyzing the phosphoamino content in proteins under acidic and basic conditions or in solvents (219). 

Emerging Membrane Control Technologies The recent improvements in membrane technology have spawned several potentially commercial membrane filtration uses. 

Denyer S.P. Ward K.H. (1983) A rapid method for the detection of bacterial contaminants in intravenous fluids using membrane filtration and eprfluorescent microscopy. JParenfa/ Sci Technol, 37, 156-158. 

Rather than use ion exchange, water can be deionized using membrane processes. Both nano-filtration and reverse... 

Lamminen MO, Walker HW, Weavers LK (2006) Cleaning of particle-fouled membranes during cross-flow filtration using an embedded ultrasonic transducer system. J Membrane Sci 283 225-232... 

Akaya G, Erhan E, Keskinler B, Algur OF (2002) Removal of phenol from wastewater using membrane-immobilized enzymes Part II. Cross-flow filtration. J Membr Sci 206 61-68... 

Purify the modified protein from reaction by-products by dialysis using a membrane with a low molecular weight cutoff or gel filtration using desalting resin and a buffer consisting of 50mM sodium phosphate, 0.15M NaCl, lOmM EDTA, pH 7.2. 

Membrane filtration using a polyaramide membrane [56] showed a retention of more than 99.8%. Application of this catalyst in a continuously operated membrane reactor showed conversion for more than 150 h. The ee dropped from 80% in the beginning (non-bonded analogue 97%) to about 20% after 150 h. The average ee for the first 80 h was 50%. 

Back-pulse Filtration using GORE-TEX Membrane Filter Cloths... 

The soluble ions of iron and aluminium are usually reduced to a minimum by adjusting the electrolyte pH. For the removal of solid iron hydroxide and aluminium hydroxide Bayer decided to use a new pre-coat-free brine purification technology -back-pulse filtration using GORE-TEX membrane filter cloths. 

In cases where a dilute solution containing small quantities of solids which tend to blind the filter cloth is to be filtered, cross-flow filtration is extensively used. This is the normal mode of operation for ultrafiltration using membranes, a topic which is discussed in Chapter 8. 

Protein removed by filtration using Centricon-10 membrane. 

NMR analysis, the PHA was extracted from freeze-dried cells. For this purpose, 1.0 g freeze-dried cells were stirred in 200 mL of chloroform for 24 hours at 30°C. The extract was filtered to remove cells debris, and the chloroform was concentrated to a volume of about 15 ruL using rotary evaporator. The concentrated solution was then added drop-wise to 150 luL of rapidly stirred methanol to precipitate the dissolved PHA.The precipitated PHA was then recovered by filtration using a 0.45 pm PTFE membrane and dried overnight at room temperature. The purified PHA was dissolved in deuterated chlorofonn (CDCl ) and subjected to H and NMR analyses. 

Membrane Filtration Using a Simultaneous Detection Technique (MI Medium)... 

Combining these techniques, they carried out cultivations for 250-350 h, and were able to repeatedly use the same cartridge (four times at least) without measurable deterioration in filtration efficiency. However, when perfusion rate and cell concentration in the bioreactor increased, fouling eventually occurred. Van Reis et al. [92] provided backpressure on the filtrate line to control filtrate rates and so to avoid too high initial filtration rates, which can cause rapid fouling. De la Broise et al. [99] compared the filter performance using membranes of different pore sizes (2 and 10 pm). In both cases partial retention of the produced IgM was observed and membranes had to be changed every 5 days, the... 

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