Displaying publications 1 - 20 of 176 in total

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  1. Zulfikar MA, Mohammad AW
    Med J Malaysia, 2004 May;59 Suppl B:141-2.
    PMID: 15468858
    Hybrid organic-inorganic membranes were fabricated using sol-gel technique using PMMA and TEOS with 80/20 (w/w) ratio at various solvents. The thin membrane films were then characterized using DSC and TGA. From DSC analysis, the Tg value of the PMMA moieties in hybrids membranes was in the order H-15-Toluene < Pure PMMA < H-15-THF < H-15-DMF. Furthermore, from TGA analysis it was found that the hybrid membranes have higher thermal stability compared to pure PMMA, and the type of solvents used play an important role in their degradation behavior.
    Matched MeSH terms: Membranes, Artificial*
  2. Zaulkiflee ND, Ahmad AL, Che Lah NF, Shah Buddin MMH
    Environ Sci Pollut Res Int, 2022 Feb;29(9):12997-13023.
    PMID: 35048340 DOI: 10.1007/s11356-021-16658-5
    Emerging contaminants (ECs) originated from different agricultural, biological, chemical, and pharmaceutical sectors have been detected in our water sources for many years. Several technologies are employed to minimise EC content in the aqueous phase, including solvent extraction processes, but there is not a solution commonly accepted yet. One of the studied alternatives is based on separation processes of emulsion liquid membrane (ELM) that benefit low solvent inventory and energy needs. However, a better understanding of the process and factors influencing the operating conditions and the emulsion stability of the extraction/stripping process is crucial to enhancing ELM's performance. This article aims to describe the applications of this technique for the EC removal and to comprehensively review the ELM properties and characteristics, phase compositions, and process parameters.
    Matched MeSH terms: Membranes, Artificial*
  3. Zare-Zardini H, Amiri A, Shanbedi M, Taheri-Kafrani A, Kazi SN, Chew BT, et al.
    J Biomed Mater Res A, 2015 Sep;103(9):2959-65.
    PMID: 25690431 DOI: 10.1002/jbm.a.35425
    One of the novel applications of the nanostructures is the modification and development of membranes for hemocompatibility of hemodialysis. The toxicity and hemocompatibility of Ag nanoparticles and arginine-treated multiwalled carbon nanotubes (MWNT-Arg) and possibility of their application in membrane technology are investigated here. MWNT-Arg is prepared by amidation reactions, followed by characterization by FTIR spectroscopy, Raman spectroscopy, and thermogravimetric analysis. The results showed a good hemocompatibility and the hemolytic rates in the presence of both MWNT-Arg and Ag nanoparticles. The hemolytic rate of Ag nanoparticles was lower than that of MWNT-Arg. In vivo study revealed that Ag nanoparticle and MWNT-Arg decreased Hematocrit and mean number of red blood cells (RBC) statistically at concentration of 100 µg mL(-1) . The mean decrease of RBC and Hematocrit for Ag nanoparticles (18% for Hematocrit and 5.8 × 1,000,000/µL) was more than MWNT-Arg (20% for Hematocrit and 6 × 1000000/µL). In addition, MWNT-Arg and Ag nanoparticles had a direct influence on the White Blood Cell (WBC) drop. Regarding both nanostructures, although the number of WBC increased in initial concentration, it decreased significantly at the concentration of 100 µg mL(-1) . It is worth mentioning that the toxicity of Ag nanoparticle on WBC was higher than that of MWNT-Arg. Because of potent antimicrobial activity and relative hemocompatibility, MWNT-Arg could be considered as a new candidate for biomedical applications in the future especially for hemodialysis membranes.
    Matched MeSH terms: Membranes, Artificial
  4. Zaman SU, Saif-Ur-Rehman, Zaman MKU, Rafiq S, Arshad A, Khurram MS, et al.
    Artif Organs, 2021 Nov;45(11):1377-1390.
    PMID: 34152645 DOI: 10.1111/aor.14020
    In the current study, a phase inversion scheme was employed to fabricate hydroxyapatite (HA)/polysulfone (PSF)-based asymmetric membranes using a film applicator with water as a solvent and nonsolvent exchanging medium. Fourier Transform Infrared (FTIR) and X-ray diffraction (XRD) spectroscopic studies were conducted to confirm the bonding chemistry and purity of filler. The inherent thick nature of PSF generated sponge-like shape while the instantaneous demixing process produced finger-like pore networks in HA/PSF-based asymmetric membranes as exhibited by scanning electron microscope (SEM) micrographs. The FTIR spectra confirmed noncovalent weak attractions toward the polymer surface. The leaching ratio was evaluated to observe the dispersion behavior of HA filler in membrane composition. Hydrophilicity, pore profile, pure water permeation (PWP) flux, and molecular weight cutoff (MWCO) values of all formulated membranes were also calculated. Antifouling results revealed that HA modified PSF membranes exhibited 43% less adhesion of bovine serum albumin (BSA) together with >86% recovery of flux. Membrane composition showed 74% total resistance, out of which 60% was reversible resistance. Biocompatibility evaluation revealed that the modified membranes exhibited prothrombin time (PT), and thrombin time (TT) comparable with typical blood plasma, whereas proliferation of living cells over membrane surface proved its nontoxic behavior toward biomedical application. The urea and creatinine showed effective adsorption aptitude toward HA loaded PSF membranes.
    Matched MeSH terms: Membranes, Artificial*
  5. Zailani MZ, Ismail AF, Sheikh Abdul Kadir SH, Othman MH, Goh PS, Hasbullah H, et al.
    J Biomed Mater Res A, 2017 05;105(5):1510-1520.
    PMID: 28000366 DOI: 10.1002/jbm.a.35986
    In this study, poly (1,8-octanediol citrate) (POC) was used to modify polyethersulfone (PES)-based membrane to enhance its hemocompatibility. Different compositions of POC (0-3%) were added into the polyethersulfone (PES) dope solutions and polyvinylpyrrolidone (PVP) was used as pore forming agent. The hemocompatible POC modified PES membranes were fabricated through phase-inversion technique. The prepared membranes were characterized using attenuated total reflectance-Fourier transform infrared (ATR-FTIR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), Atomic-force microscopy (AFM), contact angle, Zeta-potential, membrane porosity and pore size and pure water flux (PWF) and BSA rejection. The hemocompatibility of the modified PES membranes was evaluated by human serum fibrinogen (FBG) protein adsorption, platelet adhesion, activated partial thromboplastin time (APTT) and prothrombin time (PT), and thrombin-antithrombin III (TAT), complement (C3a and C5a) activation and Ca2+ absorption on membrane. Results showed that by increasing POC concentration, FBG adsorption was reduced, less platelets adhesion, prolonged APTT and PT, lower TAT, C5a and C3a activation and absorb more Ca2+ ion. These results indicated that modification of PES with POC has rendered improved hemocompatibility properties for potential application in the field of blood purification, especially in hemodialysis. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1510-1520, 2017.
    Matched MeSH terms: Membranes, Artificial*
  6. Yuzir A, Chelliapan S, Sallis PJ
    Bioresour Technol, 2012 Apr;109:31-7.
    PMID: 22318083 DOI: 10.1016/j.biortech.2012.01.038
    The degradation of (RS)-MCPP was investigated in an anaerobic membrane bioreactor (AnMBR) using nitrate as an available electron acceptor under different COD/NO(3)(-)-N ratios. Results showed high soluble COD removal efficiency (80-93%) when the reactor was operated at high COD/NO(3)(-)-N ratios. However, the COD removal started to decline (average 15%) at high nitrate concentrations coinciding with a drop in nitrate removal efficiency to 37%, suggesting that the denitrification activity dropped and affected the AnMBR performance when nitrate was the predominant electron acceptor. Additionally, the removal efficiency of (RS)-MCPP increased from 2% to 47% with reducing COD/NO(3)(-)-N ratios, whilst the (RS)-MCPP specific utilisation rate (SUR) was inversely proportional to the COD/NO(3)(-)-N ratio, suggesting that a lower COD/NO(3)(-)-N ratios had a positive influence on the (RS)-MCPP SUR. Although nitrate had a major impact on methane production rates, the methane composition was stable (approximately 80%) for COD/NO(3)(-)-N ratios of 23 or more.
    Matched MeSH terms: Membranes, Artificial*
  7. Yuzir A, Chelliapan S, Sallis PJ
    Bioresour Technol, 2011 Oct;102(20):9456-61.
    PMID: 21862323 DOI: 10.1016/j.biortech.2011.07.083
    The effects of different hydraulic retention time (HRT) on (RS)-MCPP utilisation was investigated by decreasing the feed flow rate in an anaerobic membrane bioreactor (AnMBR). Results showed an average COD removal efficiency of 91.4%, 96.9% and 94.4% when the reactor was operated at HRT 3, 7 and 17 d, respectively. However, when the HRT was reduced to 1d, the COD removal efficiency declined to just only 60%, confirming the AnMBR is stable to a large transient hydraulic shock loads. The (RS)-MCPP removal efficiency fluctuated from 6% to 39% at HRT 3 d, however when it was increased to 7 and 17 d, the removal efficiency increased to an average of 60% and 74.5%. In addition, (RS)-MCPP specific utilisation rates (SUR) were dependent on the HRT and gradually improved from 18 to 43 μg mg VSS(-1) d(-1) as flow rate increased.
    Matched MeSH terms: Membranes, Artificial*
  8. Yuzir A, Abdullah N, Chelliapan S, Sallis P
    Bioresour Technol, 2013 Apr;133:158-65.
    PMID: 23422308 DOI: 10.1016/j.biortech.2013.01.086
    The effects of Mecoprop (RS)-MCPP were investigated in an anaerobic membrane bioreactor (AnMBr) fed with synthetic wastewater containing stepwise increases in Mecoprop concentration, 5-200 mg L(-1) over 240 days. Effects were observed in terms of soluble chemical oxygen demand (COD) removal efficiency, volatile fatty acid (VFA) production, and methane yield. Soluble COD removal efficiency was stable at Mecoprop concentrations below 200 (±3) mg L(-1), with an average of 98 (±0.7)% removal. However, at 200 (±3) mg L(-1) Mecoprop, the COD removal efficiency decreased gradually to 94 (±1.5)%. At 5 mg L(-1) Mecoprop, acetic and propionic acid concentrations increased by 60% and 160%, respectively. In contrast, when Mecoprop was increased to 200 (±3) mg L(-1), the formation and degradation of acetate was unaffected by the higher Mecoprop concentration, acetate remaining below 35 mg L(-1). Increases in the Mecoprop specific utilization rate were observed as Mecoprop was increased stepwise between 5 and 200 mg L(-1).
    Matched MeSH terms: Membranes, Artificial*
  9. Yogarathinam LT, Velswamy K, Gangasalam A, Ismail AF, Goh PS, Narayanan A, et al.
    J Environ Manage, 2022 Jan 01;301:113872.
    PMID: 34607142 DOI: 10.1016/j.jenvman.2021.113872
    Effluent originating from cheese production puts pressure onto environment due to its high organic load. Therefore, the main objective of this work was to compare the influence of different process variables (transmembrane pressure (TMP), Reynolds number and feed pH) on whey protein recovery from synthetic and industrial cheese whey using polyethersulfone (PES 30 kDa) membrane in dead-end and cross-flow modes. Analysis on the fouling mechanistic model indicates that cake layer formation is dominant as compared to other pore blocking phenomena evaluated. Among the input variables, pH of whey protein solution has the biggest influence towards membrane flux and protein rejection performances. At pH 4, electrostatic attraction experienced by whey protein molecules prompted a decline in flux. Cross-flow filtration system exhibited a whey rejection value of 0.97 with an average flux of 69.40 L/m2h and at an experimental condition of 250 kPa and 8 for TMP and pH, respectively. The dynamic behavior of whey effluent flux was modeled using machine learning (ML) tool convolutional neural networks (CNN) and recursive one-step prediction scheme was utilized. Linear and non-linear correlation indicated that CNN model (R2 - 0.99) correlated well with the dynamic flux experimental data. PES 30 kDa membrane displayed a total protein rejection coefficient of 0.96 with 55% of water recovery for the industrial cheese whey effluent. Overall, these filtration studies revealed that this dynamic whey flux data studies using the CNN modeling also has a wider scope as it can be applied in sensor tuning to monitor flux online by means of enhancing whey recovery efficiency.
    Matched MeSH terms: Membranes, Artificial
  10. Yogarathinam LT, Velswamy K, Gangasalam A, Ismail AF, Goh PS, Subramaniam MN, et al.
    Chemosphere, 2022 Jan;286(Pt 3):131822.
    PMID: 34416593 DOI: 10.1016/j.chemosphere.2021.131822
    In this study, fouling mechanism and modelling analysis of synthetic lignocellulose biomass and agricultural palm oil effluent was studied using polyethersulfone (PES) ultrafiltration (UF) 10 kDa membrane. The impact of process variables (transmembrane pressure (TMP), pH and concentration of feed solution) on lignocellulosic flux was analysed using pore blocking model. The feasible approaches on utilising deep learning artificial neural network (ANN) to predict smaller flux datasets are studied. Among the input variables, pH of lignin feed solution has significant control towards flux and lignin rejection coefficient for both lignin and lignocellulosic solution. Alteration in the structure of lignin at different pH conditions contributed in the improvement of lignin rejection coefficient to 0.98 at the feed pH of 9. A maximum steady state flux of 52.03 L/m2h was observed at the lower lignin concentration (0.25 g/L), TMP of 200 kPa and feed pH of 3. At high TMP and concentration, lignin rejection decreased due to enhancement of feed concentration on membrane surface. The mechanistic model exhibited that cake layer phenomena was dominant in both lignin and lignocellulosic solution. The proposed ANN model showed good correlation (R2-1.00) with experimental non-linear flux dynamic data of both lignin and synthetic lignocellulosic solution. In ANN analysis, activation function, algorithm and neuron effect have significant effect in design of accurate model for prediction of small flux datasets. Aerobically-treated palm oil mill filtration analysis also showed that cake layer phenomenon was dominant. A water recovery of 82 % was achieved even at low TMP under short durations.
    Matched MeSH terms: Membranes, Artificial
  11. Yogarathinam LT, Usman J, Othman MHD, Ismail AF, Goh PS, Gangasalam A, et al.
    J Hazard Mater, 2022 02 15;424(Pt A):127298.
    PMID: 34571470 DOI: 10.1016/j.jhazmat.2021.127298
    In this study, an economic silica based ceramic hollow fiber (HF) microporous membrane was fabricated from guinea cornhusk ash (GCHA). A silica interlayer was coated to form a defect free silica membrane which serves as a support for the formation of thin film composite (TFC) ceramic hollow fiber (HF) membrane for the removal of microplastics (MPs) from aqueous solutions. Polyacrylonitrile (PAN), polyvinyl-chloride (PVC), polyvinylpyrrolidone (PVP) and polymethyl methacrylate (PMMA) are the selected MPs The effects of amine monomer concentration (0.5 wt% and 1 wt%) on the formation of poly (piperazine-amide) layer via interfacial polymerization over the GCHA ceramic support were also investigated. The morphology analysis of TFC GCHA HF membranes revealed the formation of a poly (piperazine-amide) layer with narrow pore arrangement. The pore size of TFC GCHA membrane declined with the formation of poly (piperazine-amide) layer, as evidenced from porosimetry analysis. The increase of amine concentration reduced the porosity and water flux of TFC GCHA HF membranes. During MPs filtration, 1 wt% (piperazine) based TFC GCHA membrane showed a lower transmission percentage of PVP (2.7%) and other suspended MPs also displayed lower transmission. The impact of humic acid and sodium alginate on MPs filtration and seawater pretreatment were also analyzed.
    Matched MeSH terms: Membranes, Artificial*
  12. Xu FX, Ooi CW, Liu BL, Song CP, Chiu CY, Wang CY, et al.
    Int J Biol Macromol, 2021 Jun 30;181:508-520.
    PMID: 33775766 DOI: 10.1016/j.ijbiomac.2021.03.151
    This study aimed to develop a novel electrospun polyacrylonitrile (PAN) nanofiber membrane with the enhanced antibacterial property. The PAN nanofiber membrane was first subjected to alkaline hydrolysis treatment, and the treated membrane was subsequently grafted with chitosan (CS) to obtain a CS-modified nanofiber membrane (P-COOH-CS). The modified membrane was then coupled with different dye molecules to form P-COOH-CS-Dye membranes. Lastly, poly(hexamethylene biguanide) hydrochloride (PHMB) was immobilized on the modified membrane to produce P-COOH-CS-Dye-PHMB. Physical characterization studies were conducted on all the synthesized nanofiber membranes. The antibacterial efficacies of nanofiber membranes prepared under different synthesis conditions were evaluated systematically. Under the optimum synthesis conditions, P-COOH-CS-Dye-PHMB was highly effective in disinfecting a high concentration of Escherichia coli, with an antibacterial efficacy of approximately 100%. Additionally, the P-COOH-CS-Dye-PHMB exhibited an outstanding wash durability as its antibacterial efficacy was only reduced in the range of 5%-7% even after 5 repeated cycles of treatment. Overall, the experimental results of this study suggested that the P-COOH-CS-Dye-PHMB is a promising antibacterial nanofiber membrane that can be adopted in the food, pharmaceutical, and textile industries.
    Matched MeSH terms: Membranes, Artificial*
  13. Winie T, Arof AK
    Spectrochim Acta A Mol Biomol Spectrosc, 2006 Mar 1;63(3):677-84.
    PMID: 16157506
    Fourier transform infrared (FT-IR) spectroscopic studies have been undertaken to investigate the interactions among components in a system of hexanoyl chitosan-lithium trifluoromethanesulfonate (LiCF(3)SO(3))-diethyl carbonate (DEC)/ethylene carbonate (EC). LiCF(3)SO(3) interacts with the hexanoyl chitosan to form a hexanoyl chitosan-salt complex that results in the shifting of the N(COR)(2), CONHR and OCOR bands to lower wavenumbers. Interactions between EC and DEC with LiCF(3)SO(3) has been noted and discussed. Evidence of interaction between EC and DEC has been obtained experimentally. Studies on polymer-plasticizer spectra suggested that there is no interaction between the polymer host and plasticizers. Competition between plasticizer and polymer on associating with Li(+) ions was observed from the spectral data for gel polymer electrolytes. The obtained spectroscopic data has been correlated with the conductivity performance of hexanoyl chitosan-based polymer electrolytes.
    Matched MeSH terms: Membranes, Artificial
  14. Walter JK, Jin Z, Jornitz MW, Gorrschalk U
    Methods Biochem Anal, 2011;54:281-317.
    PMID: 21954783
    Matched MeSH terms: Membranes, Artificial*
  15. Ujang Z, Abdul Rashid AH, Suboh SK, Halim AS, Lim CK
    J Appl Biomater Funct Mater, 2014 Dec 30;12(3):155-62.
    PMID: 24700269 DOI: 10.5301/jabfm.5000190
    BACKGROUND: The physical and biological characteristics of oligochitosan (O-C) film, including its barrier and mechanical properties, in vitro cytotoxicity and in vivo biocompatibility, were studied to assess its potential use as a wound dressing.

    METHODS: Membrane films were prepared from water-soluble O-C solution blended with various concentrations of glycerol to modify the physical properties of the films. In vitro and in vivo biocompatibility evaluations were performed using primary human skin fibroblast cultures and subcutaneous implantation in a rat model, respectively.

    RESULTS: Addition of glycerol significantly influenced the barrier and mechanical properties of the films. Water absorption capacity was in the range of 80%-160%, whereas water vapor transmission rate varied from 1,180 to 1,618 g/m2 per day. Both properties increased with increasing glycerol concentration. Tensile strength decreased while elongation at break increased with the addition of glycerol. O-C films were found to be noncytotoxic to human fibroblast cultures and histological examination proved that films are biocompatible.

    CONCLUSION: These results indicate that the membrane film from O-C has potential application as a wound-dressing material.

    Matched MeSH terms: Membranes, Artificial*
  16. Ujang Z, Ng SS, Nagaoka H
    Water Sci Technol, 2005;51(10):335-42.
    PMID: 16104438
    Biofouling control is important for effective process of membrane bioreactor (MBR). In this study, phenomena of biofouling for immersed type extended aeration MBR with two different anti-fouling aeration intensities were studied through a laboratory set up. The objectives of this study were (a) to observe biofouling phenomena of MBR that operates under different anti-fouling bubbling intensity, and simultaneously monitors performance of the MBR in organic carbon and nutrients removal; (b) to compare effectiveness of detergent and detergent-enzyme cleaning solutions in recovering biofouled membranes that operated in the extended aeration MBR. For MBR, which operated under continuous anti-fouling aeration, deposition and accumulation of suspended biomass on membrane surface were prohibited. However, flux loss was inescapable that biofilm layer was the main problem. Membrane cleaning was successfully carried out with detergent-enzyme mixture solutions and its effectiveness was compared with result from cleaning with just detergent solution.
    Matched MeSH terms: Membranes, Artificial*
  17. Ujang Z, Au YL, Nagaoka H
    Water Sci Technol, 2002;46(9):109-15.
    PMID: 12448459
    This paper describes an investigation on the effect of microbial removal using IMF for high quality drinking water production. The comparison of IMF and IMF-PAC configuration was carried out in the study to highlight the importance of PAC in the system. The specific objective of this study was to study the effect of PAC adsorption in the IMF-PAC system particularly in removing microbial substances from contaminated raw water. A bench scale IMF-PAC configuration using a flat sheet microfiltration membrane was set up for experimental purposes. Experimentally, the result has shown high removal of microbial substances with the IMF-PAC system compared to IMF. The result of E. coli removal achieved was below the detectable level due to the microbial size, which is bigger than membrane pore size. The addition of PAC has shown a direct effect on total microbial removal. The adsorption of microbial onto PAC surfaces reduced the amount of smaller microbial present in permeate samples. As a conclusion, the configuration of IMF is a promising separation process in removing microbial substances, especially when the system is combined with PAC.
    Matched MeSH terms: Membranes, Artificial
  18. Ujang Z, Salim MR, Khor SL
    Water Sci Technol, 2002;46(9):193-200.
    PMID: 12448469
    A laboratory-scale membrane bioreactor (MBR) was fed with synthetic wastewater to investigate the possibility of simultaneous removal of organic, nitrogen and phosphorus by intermittent aeration. The MBR consists of two compartments using a microfiltration membrane with 0.2 microm pore size and a surface area of 0.35 m2. Hydraulic retention time was set at 24 hours and solid retention time 25 days. MLSS concentration in the reactor was in the range of 2,500-3,800 mg/L. The MLSS internal recycling ratio was maintained at 100% influent flow rate. Intermittent aeration was applied in this study to provide an aerobic-anaerobic cycle. Three stages of operations were conducted to investigate the effect of aeration and non-aeration on simultaneous organic and nutrient removal. In Stage 1, time cycles of aeration and non-aeration were set at 90/150 min and 150/90 min in the first and second compartment, the removal efficiency was 97%, 94% and 70% for COD, nitrogen and phosphorus respectively. In Stage 2, time cycles of aeration and non-aeration were set at 60/120 min and 120/60 min in the first and second compartment, the removal efficiency was 97%, 96% and 71% for COD, nitrogen and phosphorus respectively. In Stage 3, time cycles of aeration and non-aeration were set at 120/120 min and 120/120 min in compartment 1 and 2, the removal efficiency was 98%, 96% and 78% for COD, nitrogen and phosphorus respectively. Results show that longer non-aeration time in the second compartment provided better performances of biological phosphorus removal.
    Matched MeSH terms: Membranes, Artificial
  19. Teow YH, Zulkifli E, Wikramasinghe SR
    Water Sci Technol, 2023 Mar;87(5):1056-1071.
    PMID: 36919733 DOI: 10.2166/wst.2023.034
    This research aims to evaluate the performance of PolyCera® Titan membrane for different wastewater treatment. Membrane filtration of several cycles was conducted in understanding the fouling mechanism, fouling propensity, and defouling potential of the PolyCera® Titan which had not been studied by any other researcher before. The PolyCera® Titan membrane is effective for the treatment of textile industry wastewater, palm oil mill effluent (POME), leachate, and semiconductor-industry wastewater. Rejection of methylene blue (MB) and Congo red (CR) was in the range of 78.76-86.04% and 88.89-93.71%, respectively; 94.72-96.50% NaCl, 96.07-97.62% kaolin, and 97.26-97.73% glucose were rejected from synthetic leachate indicating the removal of TDS, TSS, and COD from the leachate, respectively. Standard blocking and complete model were the best models used to explain the PolyCera® Titan membrane fouling mechanism in all types of wastewater treatment processes with a high R2 value. Physical cleaning with the use of distilled water was able to recover the permeate flux with the flux recovery ratio (FRR) value in the range of 79.2-95.22% in the first cycle, 81.20-98.16% in the second cycle, and 86.09-95.96% in the third cycle.
    Matched MeSH terms: Membranes, Artificial
  20. Tan TJ, Wang D, Moraru CI
    J Dairy Sci, 2014;97(8):4759-71.
    PMID: 24881794 DOI: 10.3168/jds.2014-7957
    The main challenge in microfiltration (MF) is membrane fouling, which leads to a significant decline in permeate flux and a change in membrane selectivity over time. This work aims to elucidate the mechanisms of membrane fouling in cold MF of skim milk by identifying and quantifying the proteins and minerals involved in external and internal membrane fouling. Microfiltration was conducted using a 1.4-μm ceramic membrane, at a temperature of 6±1°C, cross-flow velocity of 6m/s, and transmembrane pressure of 159kPa, for 90min. Internal and external foulants were extracted from a ceramic membrane both after a brief contact between the membrane and skim milk, to evaluate instantaneous adsorption of foulants, and after MF. Four foulant streams were collected: weakly attached external foulants, weakly attached internal foulants, strongly attached external foulants, and strongly attached internal foulants. Liquid chromatography coupled with tandem mass spectrometry analysis showed that all major milk proteins were present in all foulant streams. Proteins did appear to be the major cause of membrane fouling. Proteomics analysis of the foulants indicated elevated levels of serum proteins as compared with milk in the foulant fractions collected from the adsorption study. Caseins were preferentially introduced into the fouling layer during MF, when transmembrane pressure was applied, as confirmed both by proteomics and mineral analyses. The knowledge generated in this study advances the understanding of fouling mechanisms in cold MF of skim milk and can be used to identify solutions for minimizing membrane fouling and increasing the efficiency of milk MF.
    Matched MeSH terms: Membranes, Artificial
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