Soymilk concentration by ultrafiltration: effects of pore size and transmembrane pressure on filtration performance

This paper presents an experimental investigation of the cross-flow microfiltration process applied to the clarifying of ac¸ai (Euterpe oleracea Mart.) juice. Ac¸ai juice is a complex fluid, similar to a suspension of particles (fibers and cellulose) mixed in water, which contains ions of iron, zinc, maganese and pigments, as anthocyanins. In this study, a commercial membrane of α-alumina (Al2O3) in the form of a tube with 1.2μm of average pore size was utilized to investigate the clarifying of juice. This pore size of the ceramic structure was utilized in an attempt to reduce the polarization phenomenon and improve the permeate flux without utilizing the usual enzymatic treatment made in the microfiltration processes. The rheological behaviour of the suspension was investigated in a cone/plate rheometer (model, DVIII-Ultra) and a cylindrical rheometer (model, DVIII+), both by Brookfield/USA, as the shear stress (τ) in function of shear rate (γ) was fitted and analyzed with the power-law and Herschel-Bulkley’s models. All the mixtures showed flow behaviour index values (n) near to one, characterizing Newtonian fluids (pseudo-plastic). The particle size distribution (PSD) of the samples of suspension and permeate were analyzed by APS100 (ultrasound spectroscopy) by Matec/USA. The analysis of the suspension showed the presence of particles of size equal 0.16micra, while the permeate did not present particles. The experiments were performed in a turbulent range higher than 2400 until 57500 and with variation to values of transmembrane pressure from 1 to 4bar; the usual and direct correlation between transmembrane flux and transmembrane pressure was not observed in the experiments and a new correlation to the dimensionless of TMP (trans-membrane pressure) and Reynolds (Re) was presented.

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Preparation and filtration performance of the circular weft-knitted seamless weft-insertion fabric materials

Journal of Industrial Textiles ◽

10.1177/1528083719855320 ◽

2019 ◽

pp. 152808371985532 ◽

Cited By ~ 1

Author(s):

Fei Tian ◽

Gaoming Jiang ◽

Zhe Gao

Keyword(s):

Pore Size ◽

Production Efficiency ◽

Filtration Efficiency ◽

High Porosity ◽

Filtration Performance ◽

Air Particulate ◽

Forming Technology ◽

New Type ◽

High Production ◽

Fabric Materials

Air particulate matter pollution has become a severe environment concern calling for filtration materials with great filtration performance. As the development of seamless forming technology, knitted filtration materials gradually show great potential. This study aimed to develop a novel kind of knitted seamless structure for filtration materials of filter bags with high production efficiency and excellent filtration performance. A new type of the circular weft-knitted seamless weft-insertion fabric (CKSW) filtration materials were developed on the modified circular knitting machine. This CKSW filtration materials consisting of the ground yarns, connection yarns and weft-insertion yarns, polyester full drawn yarns, and polyester draw texturing yarns with different yarn configurations were employed to realize series of CKSW samples. The polytetrafluoroethylene filaments with tourmaline particles were used to verify whether the static electric material produced an adsorption filtration effect on the CKSW filtration materials or not. After pretreatment, the filtration performance of the CKSW filtration materials was evaluated by analyzing its pore size, porosity, and filtration efficiency. Ultimately, the CKSW filtration materials with ground yarns and weft insertion yarns of draw texturing yarn and the connection yarns of full drawn yarn exhibited the most excellent filtration performance. The CKSW filtration materials show a high porosity of 87.14%, the pore size of 67.55 µm, and good filtration efficiency of 91.57% with the particles size of ≥ 5.0 µm. The successful fabrication of such knitted filtration materials may provide ideas for the development of filtration materials with new architecture mainly used as filter bags for baghouse.

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Preparation of Fine Porous Ultrafiltration Membranes from Polyacrylonitrile

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.869.437 ◽

2020 ◽

Vol 869 ◽

pp. 437-442

Author(s):

Alexey A. Yushkin ◽

Alexey V. Balynin ◽

Mikhail E. Efimov ◽

Galina Karpacheva ◽

Alexey V. Volkov

Keyword(s):

Pore Size ◽

Polymer Concentration ◽

Volatile Component ◽

Membrane Preparation ◽

Solubility Parameters ◽

Precipitation Method ◽

Hansen Solubility Parameters ◽

Casting Solution ◽

Filtration Performance ◽

Hansen Solubility

PAN membranes were prepared from mixture of good and weak solvents by two different methods. Immersion precipitation method with and without volatile component evaporation used for membrane preparation. From analysis of Hansen solubility parameters DMSO chosen as good solvent and acetone chosen as weak solvent. The effect of volatile weak solvent investigated on pore size and filtration performance. By evaporation of acetone, it was possible to increase polymer concentration on casting solution and obtain smaller pore size in comparison to membrane prepared from DMSO. Membranes prepared from DMSO/acetone without solvent evaporation had even lower pore size and higher filtration performances. It was shown, that presence of acetone creates more pronounced effect on pore size than increase of polymer concentration. As a result membranes with pore size 3.7 nm obtained from Acetone/DMSO mixture with composition 50:50 and polymer concentration 50 % by immersion precipitation Resulted membranes have permeance 23 kg/m2·h·bar and retention of Lysozime 99 %.

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Study on drainage layer strategy for improving performance of glass fibrous coalescing filter

10.22541/au.160574585.52889476/v1 ◽

2020 ◽

Author(s):

chengwei xu ◽

chenglong xiao ◽

Yan yu ◽

xiaodong si

Keyword(s):

Pressure Drop ◽

Pore Size ◽

High Efficiency ◽

Size Difference ◽

Drainage Layer ◽

Filtration Performance ◽

Fibrous Filters ◽

Drainage Layers ◽

Commercial Glass ◽

Positive Effect

The drainage layer strategy is a common method for improving filtration performance of coalescing filter. In this study, using the commercial glass fibrous filters, the influence of sub-high efficiency drainage layers on high efficiency coalescing filters were investigated experimentally. The efficiency of coalescing filter slight increases, whereas the total wet pressure drop reduces 0.32 kPa after assembling drainage layer. In addition, the influence of pore size, thickness and wettability on performance were evaluated. While the pore size of drainage layer decrease, the wet pressure drop reduces and quality factor increase. Likewise, the thickness of drainage layer also has positive effect on filtration performance. By contrast, the wettability has a weak affect on the filtration performance. As different coalescing filter with the same drainage layer, the improvement in the filtration performance increase with the decrease of pore size difference between the coalescing and drainage layers.

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Investigation on the spatial filtration performance in spiral-wound membranes – Influence and length-dependent adjustment of the transmembrane pressure

Journal of Membrane Science ◽

10.1016/j.memsci.2019.117311 ◽

2019 ◽

Vol 591 ◽

pp. 117311 ◽

Cited By ~ 5

Author(s):

Martin Hartinger ◽

Simon Schiffer ◽

Hans-Jürgen Heidebrecht ◽

Joseph Dumpler ◽

Ulrich Kulozik

Keyword(s):

Transmembrane Pressure ◽

Filtration Performance ◽

Spatial Filtration ◽

Spiral Wound

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Mechanistic Model of Coaxial Microfiltration for Semi-Synthetic Metalworking Fluid Microemulsions

Journal of Manufacturing Science and Engineering ◽

10.1115/1.1763187 ◽

2004 ◽

Vol 126 (3) ◽

pp. 435-444 ◽

Cited By ~ 10

Author(s):

Fu Zhao ◽

Marcy Urbance ◽

Steven J. Skerlos

Keyword(s):

Pore Size ◽

Surface Film ◽

Mechanistic Model ◽

Membrane Surface ◽

Confocal Scanning Laser Microscopy ◽

Transmembrane Pressure ◽

Model Parameters ◽

Membrane Pore ◽

Metalworking Fluid ◽

Flux Decline

This paper discusses the development of a mechanistic model that describes the rate of flow reduction (i.e., flux decline) for a semi-synthetic metalworking fluid (MWF) during the application of microfiltration for extended MWF reuse and recycling. For the transport of unused semi-synthetic MWF through microfiltration membranes ranging in pore size from 0.2 to 5.0 micrometers, Environmental Scanning Electron Microscopy (ESEM) and Confocal Scanning Laser Microscopy (CSLM) are used to identify three interdependent and sequential mechanisms of flux decline: pore constriction, pore blockage, and surface film retardation. These mechanisms are modeled together mathematically as a four-parameter model that quantitatively describes flux decline versus time for semi-synthetic MWF as a function of membrane pore size and transmembrane pressure. The four parameters of the model are the rate constants for pore constriction and pore blocking, the steady-state effective internal pore constriction, and the specific surface film resistance. Independent experimental observations confirmed both the existence of the three stages of flux decline, and the physical interpretation of the model parameters across the pore size range of polycarbonate membranes investigated. It was also found that the mechanistic model fit experimental flux data over time with low error and that the magnitudes and trends of the model parameters closely fit direct microscopic observations and expected behavior of fouled membrane surfaces. Consequently, the mechanistic model enables quantitative modeling of microscopic phenomena at the membrane surface using only macroscale flux observations. This will enable a better understanding of the relationship between MWF formulation and membrane transport in novel MWF recycling applications.

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Effect of Temperature on the Structure and Filtration Performance of Polypropylene Melt-Blown Nonwovens

Autex Research Journal ◽

10.2478/aut-2019-0067 ◽

2020 ◽

Vol 0 (0) ◽

Cited By ~ 2

Author(s):

Si Cheng ◽

Alam S. M. Muhaiminul ◽

Zhonghua Yue ◽

Yan Wang ◽

Yuanxiang Xiao ◽

...

Keyword(s):

Pressure Drop ◽

Pore Size ◽

Fiber Diameter ◽

Temperature Treatment ◽

Filtration Efficiency ◽

Effect Of Temperature ◽

Filtration Performance ◽

Different Temperatures ◽

Polypropylene Melt ◽

Filtration Properties

AbstractBy applying the simultaneous corona-temperature treatment, the effect of electret temperature on the structure and filtration properties of melt-blown nonwovens was investigated. Fiber diameter, pore size, thickness, areal weight, porosity, crystallinity, filtration efficiency, and pressure drop were evaluated. The results demonstrated that some changes occurred in the structure of electret fabrics after treatment under different temperatures. In the range of 20°C~105°C, the filtration efficiency of melt-blown nonwovens has a relationship with the change in crystallinity, and the pressure drop increased because of the change in areal weight and porosity. This work may provide a reference for further improving filtration efficiency of melt-blown nonwovens.

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Efficient Reduction of Pathogenic and Spoilage Microorganisms from Apple Cider by Combining Microfiltration with UV Treatment

Journal of Food Protection ◽

10.4315/0362-028x.jfp-14-452 ◽

2015 ◽

Vol 78 (4) ◽

pp. 716-722 ◽

Cited By ~ 14

Author(s):

DONGJUN ZHAO ◽

JESSIE USAGA BARRIENTOS ◽

QING WANG ◽

SARAH M. MARKLAND ◽

JOHN J. CHUREY ◽

...

Keyword(s):

Pore Size ◽

Ceramic Membranes ◽

Transmembrane Pressure ◽

Uv Treatment ◽

Apple Cider ◽

E Coli ◽

Log Reduction ◽

Off Flavors ◽

Uv Dose ◽

Thermal Pasteurization

Thermal pasteurization can achieve the U.S. Food and Drug Administration–required 5-log reduction of pathogenic Escherichia coli O157:H7 and Cryptosporidium parvum in apple juice and cider, but it can also negatively affect the nutritional and organoleptic properties of the treated products. In addition, thermal pasteurization is only marginally effective against the acidophilic, thermophilic, and spore-forming bacteria Alicyclobacillus spp., which is known to cause off-flavors in juice products. In this study, the efficiency of a combined microfiltration (MF) and UV process as a nonthermal treatment for the reduction of pathogenic and nonpathogenic E. coli, C. parvum, and Alicyclobacillus acidoterrestris from apple cider was investigated. MF was used to physically remove suspended solids and microorganisms from apple cider, thus enhancing the effectiveness of UV and allowing a lower UV dose to be used. MF, with ceramic membranes (pore sizes, 0.8 and 1.4 μm), was performed at a temperature of 10°C and a transmembrane pressure of 155 kPa. The subsequent UV treatment was conducted using at a low UV dose of 1.75 mJ/cm2. The combined MF and UV achieved more than a 5-log reduction of E. coli, C. parvum, and A. acidoterrestris. MF with the 0.8-μm pore size performed better than the 1.4-μm pore size on removal of E. coli and A. acidoterrestris. The developed nonthermal hurdle treatment has the potential to significantly reduce pathogens, as well as spores, yeasts, molds, and protozoa in apple cider, and thus help juice processors improve the safety and quality of their products.

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Effect of Pre-Heating Prior to Low Temperature 0.1 µm-Microfiltration of Milk on Casein–Whey Protein Fractionation

Foods ◽

10.3390/foods10051090 ◽

2021 ◽

Vol 10 (5) ◽

pp. 1090

Author(s):

Simon Schiffer ◽

Bello Teslim Adekunle ◽

Andreas Matyssek ◽

Martin Hartinger ◽

Ulrich Kulozik

Keyword(s):

Low Temperature ◽

Pore Size ◽

Whey Protein ◽

Protein Fraction ◽

Skim Milk ◽

Casein Micelle ◽

Protein Fractionation ◽

Filtration Performance ◽

Micellar Casein ◽

Filtration Step

During skim milk microfiltration (nominal pore size of 0.1 µm) at 10 °C, the whey protein purity in the permeate is reduced by an enhanced serum casein permeation, primarily of β-casein. To decrease casein permeation, the possibility of a pre-heating step under pasteurization conditions before the filtration step was investigated, so as to shift the equilibrium from soluble serum casein monomers to impermeable micellar casein. Immediately after the pre-heating step, low temperature microfiltration at 10 °C was conducted before the casein monomers could diffuse into the serum. The hypothesis was that the dissociation of β-casein into the serum as a result of a decreasing temperature takes more time than the duration of the microfiltration process. It was found that pre-heating reduced the β-casein permeation during microfiltration without significantly affecting the flux and whey protein permeation, compared with a microfiltration at 10 °C without the pre-heating step. Furthermore, the addition of calcium (5 and 10 mM) not only reduced the casein permeation and thus increased the permeate purity, defined as a high whey protein-to-casein (g L−1/g L−1) ratio, but also decreased the filtration performance, possibly due to the structural alteration of the deposited casein micelle layer, rendering the deposit more compact and more retentive. Therefore, the possible combination of the addition of calcium and pre-heating prior to microfiltration was also investigated in order to evidence the potential increase of whey protein (WP) purity in the permeate in the case of Ca2+ addition prior to microfiltration. This study shows that pre-heating very close to low temperature microfiltration results in an increased purity of the whey protein fraction obtained in the permeate.

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