Pub Date : 2019-10-01DOI: 10.22079/JMSR.2019.96835.1225
Shabnam Azami, M. Amirinejad
In this study, the effect of ultrasound irradiation on the flux recovery and fouling mitigation for the membranes made of the polysulfone by the phase inversion method were investigated. Two ultrasound irradiation regimes, including inside and outside the module, were chosen for this study. The experiments were conducted to investigate the effect of ultrasound irradiation on the membrane structure and cleaning. The ultrasound was irradiated in the frequency of 20 kHz and at the intensity of 25.5-127.4 W/cm2. When the membranes were irradiated directly out of the module, they may be damaged and the large holes were formed due to remaining in direct acoustic cavitation area. The flux recovery for the whey ultrafiltration process was increased with the increase of the irradiation time and the ultrasound intensity. The released energy which is the result of the cavitation threshold of bubbles indirectly may clean the foulant. During 60 min ultrasound irradiation, the flux recoveries were between 83-91% for membranes. At the probe distance of 1 cm from the module and after 20 min, the destruction or cracks in the membrane may be happened. The FE-SEM showed that the adjacent holes were connected and the crack was formed. The results for using the ultrasound for cleaning the fouled membranes showed that in the long distances, a large number of cavitation bubbles collapses before they reach to the membrane and in short distance, due to higher energy density, the produced acoustic and turbulence stream are increased and the membrane may be damaged.
{"title":"Effect of Ultrasonication on Membrane Structure and Flux Recovery for Whey Ultrafiltration","authors":"Shabnam Azami, M. Amirinejad","doi":"10.22079/JMSR.2019.96835.1225","DOIUrl":"https://doi.org/10.22079/JMSR.2019.96835.1225","url":null,"abstract":"In this study, the effect of ultrasound irradiation on the flux recovery and fouling mitigation for the membranes made of the polysulfone by the phase inversion method were investigated. Two ultrasound irradiation regimes, including inside and outside the module, were chosen for this study. The experiments were conducted to investigate the effect of ultrasound irradiation on the membrane structure and cleaning. The ultrasound was irradiated in the frequency of 20 kHz and at the intensity of 25.5-127.4 W/cm2. When the membranes were irradiated directly out of the module, they may be damaged and the large holes were formed due to remaining in direct acoustic cavitation area. The flux recovery for the whey ultrafiltration process was increased with the increase of the irradiation time and the ultrasound intensity. The released energy which is the result of the cavitation threshold of bubbles indirectly may clean the foulant. During 60 min ultrasound irradiation, the flux recoveries were between 83-91% for membranes. At the probe distance of 1 cm from the module and after 20 min, the destruction or cracks in the membrane may be happened. The FE-SEM showed that the adjacent holes were connected and the crack was formed. The results for using the ultrasound for cleaning the fouled membranes showed that in the long distances, a large number of cavitation bubbles collapses before they reach to the membrane and in short distance, due to higher energy density, the produced acoustic and turbulence stream are increased and the membrane may be damaged.","PeriodicalId":16427,"journal":{"name":"Journal of Membrane Science and Research","volume":"5 1","pages":"261-267"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46890197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-10-01DOI: 10.22079/JMSR.2019.100177.1239
N. Ghasem
Absorption of CO2 from a gas mixture containing CO2 and nitrogen by water-based CNT nanofluids in gas–liquid hollow fiber membrane contactor was modeled and solved using COMSOL Multiphysics 5.4. The model assumed partial wetting of the membrane, along with diffusion in the axial and radial directions. In addition, Brownian motion and grazing effects were both considered in the model. The main contribution to the mass transfer resistance for the case of external diffusion-controlled adsorption is the stagnant liquid layer around the particles, despite the layer being very thin. Accordingly, the nanofluid flows in the lumen tube side of the hollow fiber membrane was modeled as a solid-free zone and dense solid phase. The simulations were performed using 7% wetting of the membrane thickness. The results showed a significant increase in CO2 absorption with increasing concentration of carbon nanotubes (CNT). At a fixed inlet gas flow rate (20 L/h), increasing the CNT concentration from 0.1 wt.% to 0.25 wt.% increased the CO2 removal from around 20% to 45%. Comparison of the model predictions with experimental data available in the literature confirmed the validity of the developed model.
{"title":"Modeling and Simulation of CO2 Absorption Enhancement in Hollow-Fiber Membrane Contactors using CNT–Water-Based Nanofluids","authors":"N. Ghasem","doi":"10.22079/JMSR.2019.100177.1239","DOIUrl":"https://doi.org/10.22079/JMSR.2019.100177.1239","url":null,"abstract":"Absorption of CO2 from a gas mixture containing CO2 and nitrogen by water-based CNT nanofluids in gas–liquid hollow fiber membrane contactor was modeled and solved using COMSOL Multiphysics 5.4. The model assumed partial wetting of the membrane, along with diffusion in the axial and radial directions. In addition, Brownian motion and grazing effects were both considered in the model. The main contribution to the mass transfer resistance for the case of external diffusion-controlled adsorption is the stagnant liquid layer around the particles, despite the layer being very thin. Accordingly, the nanofluid flows in the lumen tube side of the hollow fiber membrane was modeled as a solid-free zone and dense solid phase. The simulations were performed using 7% wetting of the membrane thickness. The results showed a significant increase in CO2 absorption with increasing concentration of carbon nanotubes (CNT). At a fixed inlet gas flow rate (20 L/h), increasing the CNT concentration from 0.1 wt.% to 0.25 wt.% increased the CO2 removal from around 20% to 45%. Comparison of the model predictions with experimental data available in the literature confirmed the validity of the developed model.","PeriodicalId":16427,"journal":{"name":"Journal of Membrane Science and Research","volume":"5 1","pages":"295-302"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41538807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-10-01DOI: 10.22079/JMSR.2019.101683.1242
Ravikumar Gogar, G. Vaseghi, G. Lipscomb
Spacers are used in spiral wound and plate and frame membrane modules to create flow channels between adjacent membrane layers and mix fluid within the flow channel. Flow through the spacer has a significant beneficial impact on mixing and resulting mass transfer rates but is accompanied by an undesirable increase in pressure drop. Computational Fluid Dynamics (CFD) is a common tool used to evaluate the effect of spacer design on fluid flow. While numerous theoretical studies are reported in the literature, confirmation of simulation results through experimental velocity field measurements is limited. Comparisons of CFD simulations with experimental velocity measurements using Particle Image Velocimetry (PIV) for traditional symmetric diamond and asymmetric spacer designs and a novel static mixing spacer design are presented. The results include comparisons of the two velocity components in planes parallel to the flow channel walls for the diamond and asymmetric spacer as well as the first reported comparisons of all three velocity components for the static mixing spacer. The results indicate good agreement between theory and experiment and help validate the use of CFD for spacer design.
{"title":"Comparisons of Experimental and Simulated Velocity Fields in Membrane Module Spacers","authors":"Ravikumar Gogar, G. Vaseghi, G. Lipscomb","doi":"10.22079/JMSR.2019.101683.1242","DOIUrl":"https://doi.org/10.22079/JMSR.2019.101683.1242","url":null,"abstract":"Spacers are used in spiral wound and plate and frame membrane modules to create flow channels between adjacent membrane layers and mix fluid within the flow channel. Flow through the spacer has a significant beneficial impact on mixing and resulting mass transfer rates but is accompanied by an undesirable increase in pressure drop. Computational Fluid Dynamics (CFD) is a common tool used to evaluate the effect of spacer design on fluid flow. While numerous theoretical studies are reported in the literature, confirmation of simulation results through experimental velocity field measurements is limited. Comparisons of CFD simulations with experimental velocity measurements using Particle Image Velocimetry (PIV) for traditional symmetric diamond and asymmetric spacer designs and a novel static mixing spacer design are presented. The results include comparisons of the two velocity components in planes parallel to the flow channel walls for the diamond and asymmetric spacer as well as the first reported comparisons of all three velocity components for the static mixing spacer. The results indicate good agreement between theory and experiment and help validate the use of CFD for spacer design.","PeriodicalId":16427,"journal":{"name":"Journal of Membrane Science and Research","volume":"5 1","pages":"283-294"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43380272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-10-01DOI: 10.22079/JMSR.2019.98343.1235
M. Daramola, O. Sadare, O. Oluwasina, S. Iyuke
In this study, polymer composite membranes comprising carbon nanotube (CNT), polysulfone (PSF) and polyvinyl alcohol (PVA) were synthesized via the phase inversion method and used to remove phenol from the phenol-containing wastewater. The fabricated membranes were reinforced with the functionalized carbon nanotubes (fCNTs) and coated with PVA to enhance their mechanical strength and anti-fouling property, respectively. Performance of the membranes was evaluated for the treatment of the synthetic phenol-containing wastewater using a dead-end filtration cell operated at different feed pressures in the range of 1-8 bar. The non-coated membrane with 5% fCNTs displayed the highest flux of 70.21 L.m2.h-1, followed by the PVA coated membrane loaded with 5% fCNTs displaying flux of 59.63 L.m2.h-1. The results showed that the non-coated PSF membrane loaded with 5% CNTs displayed the highest permeability of 28.24 L.m-2.h-1.bar-1 at transmembrane pressure (TMP) of 1 bar. Pure PSF with 0% loaded fCNTs showed the lowest permeability of 0.68 L.m-2.h-1.bar-1 at TMP of 1 bar. Analysis of the constituents of the wastewater using a pre-calibrated Gas chromatography-Mass chromatography (GC-MS) reveal that the membrane reinforced with fCNTs (1% CNT loading) and coated with PVA displayed the highest phenol rejection of 65%. It is noteworthy to mention that all the membranes showed 100% selectivity to the hydrocarbons (petrol and kerosene) contained in the wastewater. The results of this study could be a platform to develop cost-effective membrane materials for treatment of the refinery wastewater at low pressure for low energy consumption.
{"title":"Synthesis and Application of Functionalized Carbon Nanotube Infused Polymer Membrane (fCNT/PSF/PVA) for Treatment of Phenol-Containing Wastewater","authors":"M. Daramola, O. Sadare, O. Oluwasina, S. Iyuke","doi":"10.22079/JMSR.2019.98343.1235","DOIUrl":"https://doi.org/10.22079/JMSR.2019.98343.1235","url":null,"abstract":"In this study, polymer composite membranes comprising carbon nanotube (CNT), polysulfone (PSF) and polyvinyl alcohol (PVA) were synthesized via the phase inversion method and used to remove phenol from the phenol-containing wastewater. The fabricated membranes were reinforced with the functionalized carbon nanotubes (fCNTs) and coated with PVA to enhance their mechanical strength and anti-fouling property, respectively. Performance of the membranes was evaluated for the treatment of the synthetic phenol-containing wastewater using a dead-end filtration cell operated at different feed pressures in the range of 1-8 bar. The non-coated membrane with 5% fCNTs displayed the highest flux of 70.21 L.m2.h-1, followed by the PVA coated membrane loaded with 5% fCNTs displaying flux of 59.63 L.m2.h-1. The results showed that the non-coated PSF membrane loaded with 5% CNTs displayed the highest permeability of 28.24 L.m-2.h-1.bar-1 at transmembrane pressure (TMP) of 1 bar. Pure PSF with 0% loaded fCNTs showed the lowest permeability of 0.68 L.m-2.h-1.bar-1 at TMP of 1 bar. Analysis of the constituents of the wastewater using a pre-calibrated Gas chromatography-Mass chromatography (GC-MS) reveal that the membrane reinforced with fCNTs (1% CNT loading) and coated with PVA displayed the highest phenol rejection of 65%. It is noteworthy to mention that all the membranes showed 100% selectivity to the hydrocarbons (petrol and kerosene) contained in the wastewater. The results of this study could be a platform to develop cost-effective membrane materials for treatment of the refinery wastewater at low pressure for low energy consumption.","PeriodicalId":16427,"journal":{"name":"Journal of Membrane Science and Research","volume":"5 1","pages":"310-316"},"PeriodicalIF":0.0,"publicationDate":"2019-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45463475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-28DOI: 10.22079/JMSR.2019.110424.1269
A. S. Figueiredo, A. R. García, M. Minhalma, L. Ilharco, M. D. Pinho
Integral asymmetric cellulose acetate (CA) membranes were casted by phase-inversion with formamide varying content - 22, 30 and 34% - as pore promoter. These membranes, CA-22, CA-30 and CA-34, were analyzed by infrared spectroscopy in attenuated total reflection mode (ATR-FTIR) to investigate the porous membrane matrix influence on the polymer/water/solute interactions and the selective ultrafiltration of salts. The membranes covered a wide range of hydraulic permeabilities, from 3.5 to 81.0 kg.m-2.h-1.bar-1, and of molecular weight cut-offs, from 4.17 to 31.43 kDa. The experimental apparent rejection coefficients of neutral solutes of increasing molecular weight are related to their intrinsic rejection coefficients through the film model. The surface average pore radius, estimated by an iterative algorithm, ranges from 2.1 to 4.5 nm. The tighter membrane, CA-22, displays experimental apparent rejection coefficients to the Na2SO4, CaSO4, MgSO4 of 50% or higher values and this is in contrast with the lower values, between 14 and 18%, to the NaCl, CaCl2 and MgCl2 salts. The ATR-FTIR evidences that in the membranes with larger pores, CA-30 and CA-34, the water molecules are organized with a liquid-water-like structure, in which most molecules are hydrogen bonded to four or to two others; nevertheless, a fraction of water molecules is strongly bonded to the CA carbonyl groups. For the CA-22 membrane, there are more free carbonyl groups and a larger fraction of free water, both able to interact with solutes, such as the hydrated sulphate ions. Therefore, this ultrafiltration membrane has the capability of differentiating anionic species.
{"title":"The ultrafiltration performance of cellulose acetate asymmetric membranes: a new perspective on the correlation with the infrared spectra","authors":"A. S. Figueiredo, A. R. García, M. Minhalma, L. Ilharco, M. D. Pinho","doi":"10.22079/JMSR.2019.110424.1269","DOIUrl":"https://doi.org/10.22079/JMSR.2019.110424.1269","url":null,"abstract":"Integral asymmetric cellulose acetate (CA) membranes were casted by phase-inversion with formamide varying content - 22, 30 and 34% - as pore promoter. These membranes, CA-22, CA-30 and CA-34, were analyzed by infrared spectroscopy in attenuated total reflection mode (ATR-FTIR) to investigate the porous membrane matrix influence on the polymer/water/solute interactions and the selective ultrafiltration of salts. The membranes covered a wide range of hydraulic permeabilities, from 3.5 to 81.0 kg.m-2.h-1.bar-1, and of molecular weight cut-offs, from 4.17 to 31.43 kDa. The experimental apparent rejection coefficients of neutral solutes of increasing molecular weight are related to their intrinsic rejection coefficients through the film model. The surface average pore radius, estimated by an iterative algorithm, ranges from 2.1 to 4.5 nm. The tighter membrane, CA-22, displays experimental apparent rejection coefficients to the Na2SO4, CaSO4, MgSO4 of 50% or higher values and this is in contrast with the lower values, between 14 and 18%, to the NaCl, CaCl2 and MgCl2 salts. The ATR-FTIR evidences that in the membranes with larger pores, CA-30 and CA-34, the water molecules are organized with a liquid-water-like structure, in which most molecules are hydrogen bonded to four or to two others; nevertheless, a fraction of water molecules is strongly bonded to the CA carbonyl groups. For the CA-22 membrane, there are more free carbonyl groups and a larger fraction of free water, both able to interact with solutes, such as the hydrated sulphate ions. Therefore, this ultrafiltration membrane has the capability of differentiating anionic species.","PeriodicalId":16427,"journal":{"name":"Journal of Membrane Science and Research","volume":"6 1","pages":"70-80"},"PeriodicalIF":0.0,"publicationDate":"2019-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46412103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-01DOI: 10.22079/JMSR.2018.88804.1199
S. Karunanithi, E. Poonguzhali, A. Kapoor, P. Delfino, S. Prabhakar
Separation of formic, acetic, and propionic acids from the aqueous stream using membrane solvent extraction has been studied using three different membrane contactors made of polysulfone (PS), polyethersulfone (PES), and polyvinylidene fluoride (PVDF) using two different solvents; including ethyl acetate (EA) and diisopropyl ether (DIPE). The efciency of the membrane and extractants were obtained by partitioning coefcient comparison. The overall mass transfer coefcient was determined by resistance in series model. The results indicated signifcant difference amongst the performance of the membranes for the same system, even though one usually would expect the membrane only to play a role in facilitating high interfacial mass transfer contact area. The observable results of high distribution coefcient were obtained for the propionic acid with the PVDF membrane and EA as an extractant, on the other hand, the formic acid with PVDF and EA as extractants obtained a better mass transfer coefcient of 9×10-6 m/s.
{"title":"Separation of Carboxylic Acids from Aqueous Solutions using Hollow Fiber Membrane Contactors","authors":"S. Karunanithi, E. Poonguzhali, A. Kapoor, P. Delfino, S. Prabhakar","doi":"10.22079/JMSR.2018.88804.1199","DOIUrl":"https://doi.org/10.22079/JMSR.2018.88804.1199","url":null,"abstract":"Separation of formic, acetic, and propionic acids from the aqueous stream using membrane solvent extraction has been studied using three different membrane contactors made of polysulfone (PS), polyethersulfone (PES), and polyvinylidene fluoride (PVDF) using two different solvents; including ethyl acetate (EA) and diisopropyl ether (DIPE). The efciency of the membrane and extractants were obtained by partitioning coefcient comparison. The overall mass transfer coefcient was determined by resistance in series model. The results indicated signifcant difference amongst the performance of the membranes for the same system, even though one usually would expect the membrane only to play a role in facilitating high interfacial mass transfer contact area. The observable results of high distribution coefcient were obtained for the propionic acid with the PVDF membrane and EA as an extractant, on the other hand, the formic acid with PVDF and EA as extractants obtained a better mass transfer coefcient of 9×10-6 m/s.","PeriodicalId":16427,"journal":{"name":"Journal of Membrane Science and Research","volume":"5 1","pages":"233-239"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42691828","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-01DOI: 10.22079/JMSR.2018.90181.1204
M. F. Labastida, A. Yaroshchuk
This communication demonstrates the relevance of membrane sealing in a test cell to its performance. Membranes need to be sealed, and therefore a more or less significant (depending on the test cell design) peripheral part of the membrane is supported directly by the cell body (instead of a permeate spacer). Although it may seem that there should be no filtration through the membrane when it is supported by an impermeable surface, this communication demonstrates that this is not generally true due to filtration along the membrane porous support. To confirm this, experiments were performed with a cross-flow test cell (GE SEPA™ CF II), blocking the membrane hydraulically from beneath in order to simulate the effect of having the membrane supported by an impermeable surface. The results show that the trans-membrane volume flux obtained in all cases is only slightly affected by the membrane blocking. In view of this, in the cell design, care should be taken to reduce such peripheral parts of the membrane to a minimum because it may be technically very difficult to have there the same conditions of concentration polarization as over the membrane part supported by the permeate spacer
{"title":"Influence of membrane sealing in pressure-driven test cells on their performance","authors":"M. F. Labastida, A. Yaroshchuk","doi":"10.22079/JMSR.2018.90181.1204","DOIUrl":"https://doi.org/10.22079/JMSR.2018.90181.1204","url":null,"abstract":"This communication demonstrates the relevance of membrane sealing in a test cell to its performance. Membranes need to be sealed, and therefore a more or less significant (depending on the test cell design) peripheral part of the membrane is supported directly by the cell body (instead of a permeate spacer). Although it may seem that there should be no filtration through the membrane when it is supported by an impermeable surface, this communication demonstrates that this is not generally true due to filtration along the membrane porous support. To confirm this, experiments were performed with a cross-flow test cell (GE SEPA™ CF II), blocking the membrane hydraulically from beneath in order to simulate the effect of having the membrane supported by an impermeable surface. The results show that the trans-membrane volume flux obtained in all cases is only slightly affected by the membrane blocking. In view of this, in the cell design, care should be taken to reduce such peripheral parts of the membrane to a minimum because it may be technically very difficult to have there the same conditions of concentration polarization as over the membrane part supported by the permeate spacer","PeriodicalId":16427,"journal":{"name":"Journal of Membrane Science and Research","volume":"5 1","pages":"240-243"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47635899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-01DOI: 10.22079/JMSR.2018.80046.1173
B. Mbuli, Mphilisi M. Mahlambi, C. Ngila, R. Moutloali
This paper reports on the synthesis and characterisation of polysulfone (PSf) ultrafltration (UF) membranes modifed with carbon coated alumina Ni-doped titanium dioxide (CCA/Ni-TiO2) nanoparticles. The syntheses of the membranes was carried out using the phase inversion process. The permeate flux of the membrane modifed with 0.25% CCA/Ni-TiO2 nanoparticles (213.5±6.40 L.m-2.h-1) was found to be higher than that of the unmodifed membrane (130.95±4.50 L.m-2.h-1) at 13.8 bar. The membrane modifed with 0.50% CCA/NiTiO2 nanoparticles had the lowest permeate flux at 105.18±4.52 L.m-2.h-1. The improved water permeability was brought about by the hydrophilicity resulting from introduction of the hydroxyl groups of the nanoparticles. At 13.8 bar, the NaCl salt rejection properties of the mixed matrix membranes were relatively higher (31.38±1.23%) for the 0.25% PSf/CCA/Ni-TiO2 membranes compared to that of the unmodifed PSf membrane (12.76±1.10%). Similar observations were made for the Cr3+ heavy metal rejection, which ranged between 56.27±2.54% and 60.48±2.52% for the modifed membranes. These results have demonstrated the role the electrostatic effects of the nanoparticles play in the rejection mechanism of the modifed membranes when compared to the unmodifed membranes. Unmodifed membranes were found to reject 28.32±1.65% of Cr3+ heavy metals at the same pressure. Over a period of 180 minutes, the membranes were found to be more photocatalytically active towards bromophenol blue, and a maximum photodegradation efciency of 81% was achieved compared to only 50.5% for methyl orange. The photo-degradation process for both dyes followed a pseudo-frst-order reaction rate.
{"title":"Polysulfone Ultrafiltration Membranes Modified with Carbon-Coated Alumina Supported NiTiO2 Nanoparticles for Water Treatment: Synthesis, Characterization and Application","authors":"B. Mbuli, Mphilisi M. Mahlambi, C. Ngila, R. Moutloali","doi":"10.22079/JMSR.2018.80046.1173","DOIUrl":"https://doi.org/10.22079/JMSR.2018.80046.1173","url":null,"abstract":"This paper reports on the synthesis and characterisation of polysulfone (PSf) ultrafltration (UF) membranes modifed with carbon coated alumina Ni-doped titanium dioxide (CCA/Ni-TiO2) nanoparticles. The syntheses of the membranes was carried out using the phase inversion process. The permeate flux of the membrane modifed with 0.25% CCA/Ni-TiO2 nanoparticles (213.5±6.40 L.m-2.h-1) was found to be higher than that of the unmodifed membrane (130.95±4.50 L.m-2.h-1) at 13.8 bar. The membrane modifed with 0.50% CCA/NiTiO2 nanoparticles had the lowest permeate flux at 105.18±4.52 L.m-2.h-1. The improved water permeability was brought about by the hydrophilicity resulting from introduction of the hydroxyl groups of the nanoparticles. At 13.8 bar, the NaCl salt rejection properties of the mixed matrix membranes were relatively higher (31.38±1.23%) for the 0.25% PSf/CCA/Ni-TiO2 membranes compared to that of the unmodifed PSf membrane (12.76±1.10%). Similar observations were made for the Cr3+ heavy metal rejection, which ranged between 56.27±2.54% and 60.48±2.52% for the modifed membranes. These results have demonstrated the role the electrostatic effects of the nanoparticles play in the rejection mechanism of the modifed membranes when compared to the unmodifed membranes. Unmodifed membranes were found to reject 28.32±1.65% of Cr3+ heavy metals at the same pressure. Over a period of 180 minutes, the membranes were found to be more photocatalytically active towards bromophenol blue, and a maximum photodegradation efciency of 81% was achieved compared to only 50.5% for methyl orange. The photo-degradation process for both dyes followed a pseudo-frst-order reaction rate.","PeriodicalId":16427,"journal":{"name":"Journal of Membrane Science and Research","volume":"5 1","pages":"222-232"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45156233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-04-01DOI: 10.22079/JMSR.2019.102138.1245
S. Gaeta
{"title":"Enrico Drioli: A Professor with a Vision and an Inspirational Leader","authors":"S. Gaeta","doi":"10.22079/JMSR.2019.102138.1245","DOIUrl":"https://doi.org/10.22079/JMSR.2019.102138.1245","url":null,"abstract":"","PeriodicalId":16427,"journal":{"name":"Journal of Membrane Science and Research","volume":"5 1","pages":"90-91"},"PeriodicalIF":0.0,"publicationDate":"2019-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47919065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-04-01DOI: 10.22079/JMSR.2018.93621.1214
P. Argurio, A. Tagarelli, R. Molinari
Liquid Membrane (LM) based processes, as Supported Liquid Membranes (SLMs), have been proposed, for over 30 years, as effective methods for the selective separation of inorganic/organic species from different water streams. The industrial use of SLMs has been limited mainly by their insufcient stability. To investigate on the main cause of system destabilization and the optimal conditions for mass transport, a good reference system is the traditional SLM. To this aim the recovery of neodymium (Nd) from acidic media by a traditional SLM has been studied, giving particular attention to permeation and stability. The results clearly evidenced that system stability was strongly influenced by the solubilization of the carrier in the aqueous phases. The consideration and the experimental results reported in this work give useful information to shift the next research step versus the development of a 2nd generation of SwLM able to give satisfactory system performance in view of industrial application, such as Nd as well as rare earth elements or salt recovery from aqueous media.
{"title":"A Study on Neodymium Recovery from Aqueous Solutions for Designing a New Generation of Sandwich Liquid Membrane","authors":"P. Argurio, A. Tagarelli, R. Molinari","doi":"10.22079/JMSR.2018.93621.1214","DOIUrl":"https://doi.org/10.22079/JMSR.2018.93621.1214","url":null,"abstract":"Liquid Membrane (LM) based processes, as Supported Liquid Membranes (SLMs), have been proposed, for over 30 years, as effective methods for the selective separation of inorganic/organic species from different water streams. The industrial use of SLMs has been limited mainly by their insufcient stability. To investigate on the main cause of system destabilization and the optimal conditions for mass transport, a good reference system is the traditional SLM. To this aim the recovery of neodymium (Nd) from acidic media by a traditional SLM has been studied, giving particular attention to permeation and stability. The results clearly evidenced that system stability was strongly influenced by the solubilization of the carrier in the aqueous phases. The consideration and the experimental results reported in this work give useful information to shift the next research step versus the development of a 2nd generation of SwLM able to give satisfactory system performance in view of industrial application, such as Nd as well as rare earth elements or salt recovery from aqueous media.","PeriodicalId":16427,"journal":{"name":"Journal of Membrane Science and Research","volume":"5 1","pages":"147-156"},"PeriodicalIF":0.0,"publicationDate":"2019-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44345874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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