Prevention of Membrane Fouling Using Electric Pulse in Dead End Microfiltration of Titanium Suspensions

2012 ◽  
Author(s):  
Abdul Latif Ahmad ◽  
Suzylawati Ismail
Keyword(s):  
Ionic Strength ◽  
Pulse Duration ◽  
Applied Voltage ◽  
Membrane Fouling ◽  
Electric Pulse ◽  
Membrane Surface ◽  
Pulse Interval ◽  
Electric Pulses ◽  
Average Percentage ◽  
Dead End

Denyutan elektrik merupakan salah satu kaedah yang berkesan untuk menyingkirkan bahan–bahan endapan pada permukaan membran polimerik dan mampu mencegah permukaan daripada tersumbat. Hasil–hasil dapatan uji kaji pencegahan permukaan membran dari tersumbat menggunakan denyutan elektrik bagi proses penurasan mikroampaian titanium dibentangkan. Kesan beberapa pembolehubah proses seperti selang masa antara denyutan elektrik, jangkamasa sesuatu denyutan elektrik, pH larutan, kekuatan ionik bagi elektrolit dan kekuatan voltan sesuatu denyutan elektrik telah dikaji dari segi prestasi dan keberkesanannya dalam mencegah membran dari tersumbat. Didapati bahawa fluks meningkat secara ketara dengan adanya pergerakan elekroforetik butiran bahan endapan menjauhi permukaan membran dan berlakunya proses elektroosmosis di dalam bahan endapan itu sendiri. Keputusan–keputusan telah dianalisis dari segi purata fluks, purata kepekatan bahan endapan, peratus purata perolehan semula bahan endapan dan peratus perolehan semula air. Didapati bahawa sifat fizikal dan kimia larutan (pH dan kekuatan ionik elektrolit) memberi kesan yang besar ke atas kaedah pencegahan permukaan membran dari tersumbat. Ampaian titanium pada pH 8 dan dengan kekuatan ionik elektrolit 0.01M memberi prestasi terbaik dalam pembersihan permukaan membran. Selang masa antara dua denyutan yang singkat dan jangkamasa 10 saat sesuatu denyutan dengan kekutan voltan 100V merupakan keadaan optimum bagi denyutan elektrik untuk menyingkirkan bahan–bahan endapan dari permukaan membran menggunakan denyutan elektrik. Kata kunci: pemisahan membran; penurasan mikro; membran tersumbat; denyutan elektrik;titanium dioksida. Electric pulse in an effective means of removing particulate materials from polymeric membrane and preventing the membrane fouling. The experimental results for dead end microfiltration of titanium suspension to prevent membrane fouling using electric pulses are presented. The effect of processing variables such as the pulse interval, pulse duration, pH of the solution, ionic strength of the electrolyte and the strength of the applied voltage for dead end microfiltration of titanium suspensions were studied on the performance and effectiveness of this prevention of membrane fouling. The flux was significantly increased by both electrophoretic motion of particles away from the membrane surface and electroosmosis occurring in the filtercake. The results were analyzed for its average flux, average cake concentration, average percentage recovery of cake and average percentage recovery of water. It is found that the physical and chemical properties of the solution (pH and ionic strength of the electrolyte) have a great effect on this membrane fouling prevention method. Titanium suspension at pH 8 and ionic strength of 0.01M electrolyte strength gave the best membrane cleaning performance. Shorter pulse interval with 10 seconds pulse duration with 100V applied voltage were the optimum conditions to remove the filtercake from the membrane surface. Key words: membrane separation; microfiltration; membrane fouling; electric pulses; titanium dioxide

scholarly journals Membrane cleaning using electric pulse in dead end ultrafiltration of proteinaceous solution

2017 ◽  
Vol 18 (2) ◽  
Author(s):  
A.L. Ahmad' ◽  
And I.A. Azid
Keyword(s):  
Ionic Strength ◽  
Pulse Duration ◽  
Filter Cake ◽  
Polymeric Membrane ◽  
Pulse Interval ◽  
Water Recovery ◽  
Membrane Cleaning ◽  
Electric Pulses ◽  
Average Percentage ◽  
Dead End

Dead end ultrafiltration of Bovine Serum Albumine (BSA) using a polymeric membrane has been studied. Membrane fouling for such fine biological product due to the formation of filter cake and adsorption of the proteinaceous solution is the major bottleneck for such separation process. The application of electric pulses has shown an effective means in cleaning the membrane and reducing the fouling rate for dead-end ultrafiltration of BSA. The flux is significantly increased by both electrophoretic motion of solutes away from the membrane surface and electro-osmosis occurring in the filter cake. An automated experimental rig equipped with data acquisition system has been developed to test the effectiveness and performance of such membrane cleaning. The improvement of flux becomes more pronounced with increasing electric field strength. The effects of other processing variables such as pulse interval, pulse duration, ionic strength of the electrolyte, pH of the solution and solution concentration were studied on this membrane cleaning technique. Data are analysed for its average flux, average cake concentration, average percentage of cake and water recovery for every cleaning condition. It is found out that the chemical and physical properties of the solution (pH and ionic strength of the electrolyte) have a great effect on this membrane cleaning method. Protein solution at pH 8 and 0.0 lM ionic strength of the electrolyte gave the best membrane cleaning performance. Shorter pulse interval and with relatively 10 seconds pulse duration are the optimum conditions on application of pulse to remove the filter cake from the membrane.

Nanofiltration performance of lead solutions: effects of solution pH and ionic strength

2010 ◽  
Vol 10 (2) ◽  
pp. 193-200 ◽  
Author(s):  
Wuthikorn Saikaew ◽  
Supatpong Mattaraj ◽  
Ratana Jiraratananon
Keyword(s):  
Ionic Strength ◽  
Membrane Surface ◽  
Aromatic Polyamide ◽  
Solution Chemistry ◽  
Lead Ion ◽  
Solution Ph ◽  
Dead End ◽  
Flux Decline ◽  
Charged Membrane ◽  
Double Layer Thickness

Nanofiltration performance (i.e. rejection and flux decline) of lead solutions was investigated using a dead-end test cell at room temperature. An aromatic polyamide NF-90 membrane was chosen to determine the impacts of solution chemistry. The experimental results revealed that solution flux decline was dependent on solution pH, ionic strength, and type of lead solutions. Solution flux conducted with different types of lead solutions (i.e. PbCl2 and Pb(NO3)2) decreased with increased solution pH. Solutions having high pH exhibited greater flux decline than those having low solution pH, while lead ion rejections were relatively high. Increased ionic strengths resulted in a greater flux decline, while lead ion rejections decreased with decreasing solution pH and increasing ionic strengths. Such results were related to low solution pH, suggesting an increase in fixed charge of proton (H+), decreasing electrical double layer thickness within membrane, thus allowing increased lead concentration passing through the membrane surface. Solution flux and rejection decreased further at higher ionic strengths, which caused a reduced negatively charged membrane, and thus decreased rejections. It was also found that lead ion for PbCl2 solution exhibited higher rejections than that of Pb(NO3)2 solution.

scholarly journals Ozone Chemically Enhanced Backwash for Ceramic Membrane Fouling Control in Cyanobacteria-Laden Water

Membranes ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 213
Author(s):  
Stéphane Venne ◽  
Onita D. Basu ◽  
Benoit Barbeau
Keyword(s):  
Surface Water ◽  
Surface Waters ◽  
Membrane Fouling ◽  
Ceramic Membrane ◽  
Membrane Surface ◽  
Operating Costs ◽  
Fouling Control ◽  
Dead End ◽  
Cake Layer ◽  
Flow Experiments

Membrane fouling in surface waters impacted by cyanobacteria is currently poorly controlled and results in high operating costs. A chemically enhanced backwash (CEB) is one possible strategy to mitigate cyanobacteria fouling. This research investigates the potential of using an ozone CEB to control the fouling caused by Microcystis aeruginosa in filtered surface water on a ceramic ultrafiltration membrane. Batch ozonation tests and dead-end, continuous flow experiments were conducted with ozone doses between 0 and 19 mg O3/mg carbon. In all tests, the ozone was shown to react more rapidly with the filtered surface water foulants than with cyanobacteria. In addition, the ozone CEB demonstrated an improved mitigation of irreversible fouling over 2 cycles versus a single CEB cycle; indicating that the ozone CEB functioned better as the cake layer developed. Ozone likely weakens the compressible cake layer formed by cyanobacteria on the membrane surface during filtration, which then becomes more hydraulically reversible. In fact, the ozone CEB reduced the fouling resistance by 35% more than the hydraulic backwash when the cake was more compressed.

Development of an Integrated Moving Bed Biofilm Reactor-Membrane Bioreactor for Wastewater Treatment

2013 ◽  
Vol 361-363 ◽  
pp. 611-614 ◽  
Author(s):  
Liang Duan ◽  
Yong Hui Song ◽  
Wei Jiang ◽  
Slawomir W. Hermanowicz
Keyword(s):  
Membrane Fouling ◽  
Membrane Surface ◽  
Biofilm Reactor ◽  
Moving Bed Biofilm Reactor ◽  
Filling Fraction ◽  
Moving Bed ◽  
Operating Modes ◽  
Dead End ◽  
The Media ◽  
Reactor Operating

Development of a MBBR-MBR has been investigated combining a moving bed biofilm reactor with a submerged membrane biomass separation reactor. Treatment efficiencies were found to be high with the production of a consistent high-quality effluent, irrespective of media fill ratio of MBBR or membrane reactor operating modes. There had some obvious fouling in MBR, MBBR and IFAS 3000, while no fouling were detected in IFAS 1500. The great difference indicated the media filling fraction have an important role and effect on membrane fouling. Traditional MBR and IFAS 3000 have more non-flocculating microorganisms in most time due to the mixed liquor suspended solids (MLSS) concentration. There had almost the same MLSS on media surface, independent of the volume of media and the MLSS concentration in each tank. The MBBR had more biomass enriched on membrane surface due to the dead end system.

Integration of ceramic membrane and compressed air-assisted solvent extraction (CASX) for metal recovery

2010 ◽  
Vol 62 (6) ◽  
pp. 1274-1280 ◽  
Author(s):  
Chi-Wang Li ◽  
Chun-Hao Chiu ◽  
Yu-Cheng Lee ◽  
Chia-Hao Chang ◽  
Yu-Hsun Lee ◽  
...  
Keyword(s):  
Solvent Extraction ◽  
Removal Efficiency ◽  
Membrane Fouling ◽  
Water Solubility ◽  
Ceramic Membrane ◽  
Metal Removal ◽  
Membrane Surface ◽  
Extraction Process ◽  
Compressed Air ◽  
Dead End

In our previous publications, compressed air-assisted solvent extraction process (CASX) was developed and proved to be kinetically efficient process for metal removal. In the current study, CASX with a ceramic MF membrane integrated for separation of spent solvent was employed to remove and recover metal from wastewater. MF was operated either in crossflow mode or dead-end with intermittent flushing mode. Under crossflow mode, three distinct stages of flux vs. TMP (trans-membrane pressure) relationship were observed. In the first stage, flux increases with increasing TMP which is followed by the stage of stable flux with increasing TMP. After reaching a threshold TMP which is dependent of crossflow velocity, flux increases again with increasing TMP. At the last stage, solvent was pushed through membrane pores as indicated by increasing permeate COD. In dead-end with intermittent flushing mode, an intermittent flushing flow (2 min after a 10-min or a 30-min dead-end filtration) was incorporated to reduce membrane fouling by flush out MSAB accumulated on membrane surface. Effects of solvent concentration and composition were also investigated. Solvent concentrations ranging from 0.1 to 1% (w/w) have no adverse effect in terms of membrane fouling. However, solvent composition, i.e. D2EHPA/kerosene ratio, shows impact on membrane fouling. The type of metal extractants employed in CASX has significant impact on both membrane fouling and the quality of filtrate due to the differences in their viscosity and water solubility. Separation of MSAB was the limiting process controlling metal removal efficiency, and the removal efficiency of Cd(II) and Cr(VI) followed the same trend as that for COD.

Application of Bdellovibrio bacteriovorus for reducing fouling of membranes used for wastewater treatment

2018 ◽  
Vol 43 (3) ◽  
pp. 296-305 ◽  
Author(s):  
Melek Özkan ◽  
Hilal Yılmaz ◽  
Merve Akay Çelik ◽  
Çişel Şengezer ◽  
Elif Erhan ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Membrane Fouling ◽  
Membrane Surface ◽  
Hybridization Technique ◽  
Fish Analysis ◽  
Bdellovibrio Bacteriovorus ◽  
Steady State Condition ◽  
Dead End ◽  
Pure Cultures

Abstract Background: Membrane bioreactor (MBR) systems used for wastewater treatment (WWT) processes are regarded as clean technologies. Degradation capacity of the predator bacterium, Bdellovibrio bacteriovorus, was used as a cleaning strategy for reducing membrane fouling. Method: Wastewater with different sludge age and hydraulic retention time were filtered through Poly(ether)sulphone (PES) membranes using dead end reactor. Change in filtration performance after cleaning of membrane surface by B. bacteriovorus was measured by comparison of flux values. Bacterial community of the sludge was determined by 16SrRNA sequence analysis. Community profile of membrane surface was analyzed by fluorescent in situ hybridization technique. Results: After cleaning of MP005 and UP150 membranes with predator bacteria, 4.8 L/m2·h and 2.04 L/m2·h increase in stable flux at steady state condition was obtained as compared to the control, respectively. Aeromonas, Proteus, and Alcaligenes species were found to be dominant members of the sludge. Bdellovibrio bacteriovorus lysed pure cultures of the isolated sludge bacteria successfully. FISH analysis of the membrane surface showed that Alfa-proteobacteria are the most numerous bacteria among the biofilm community on the membrane surface. Conclusion: Results suggested that cleaning of MBR membranes with B. bacteriovorus has a potential to be used as a biological cleaning method.

scholarly journals Membrane fouling remediation in ultrafiltration of latex contaminated wastewater

2015 ◽  
Vol 51 (3) ◽  
pp. 256-269 ◽  
Author(s):  
Amira Abdelrasoul ◽  
Huu Doan ◽  
Ali Lohi
Keyword(s):  
Ionic Strength ◽  
Zeta Potential ◽  
Membrane Fouling ◽  
Membrane Surface ◽  
Cross Flow ◽  
Flow Mode ◽  
High Concentration ◽  
Alkyl Benzene Sulfonate ◽  
Latex Particles ◽  
Constant Flow Rate

The current study aimed to remediate membrane fouling by latex effluent by altering membrane surface charge or ionic strength of the effluent. Hydrophilic polysulfone and Ultrafilic flat membranes, with molecular weight cutoff (MWCO) of 60,000 and 100,000, respectively, and hydrophobic polyvinylidene difluoride membrane (PVDF; MWCO 100,000) were used under a constant flow rate and in cross-flow mode for ultrafiltration of latex effluent. The effect of linear alkyl benzene sulfonate (LAS) on the ionic strength of the effluent and the zeta potential of latex particles was investigated. LAS was also used to improve the anti-fouling properties of the membrane surface. The ionic strength of latex effluent was increased by raising its pH from 7 to 12, resulting in an increase of the zeta potential negativity of the latex particles from −26.61 to −42.66 mV. LAS was found to be an ineffective pretreatment for limiting the fouling propensity of latex effluent using hydrophilic membranes even at high concentration and long treatment times. It was concluded that LAS-treated membrane surface is much more favorable than pH changed feed pretreatment. The total mass of fouling decreased by 44.00 and 29.60%, when PVDF membrane surface was treated with LAS at a concentration of 1 × 10−4 g/L, and latex effluent at pH 11 was used, respectively.

Coagulation/flocculation/ultrafiltration for natural organic matter removal in drinking water production

2004 ◽  
Vol 4 (5-6) ◽  
pp. 215-222 ◽  
Author(s):  
A.R. Costa ◽  
M.N. de Pinho
Keyword(s):  
Drinking Water ◽  
Organic Matter ◽  
Natural Organic Matter ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Membrane Surface ◽  
Water Production ◽  
Cellulose Acetate Membranes ◽  
Wide Range ◽  
Drinking Water Production

Membrane fouling by natural organic matter (NOM), namely by humic substances (HS), is a major problem in water treatment for drinking water production using membrane processes. Membrane fouling is dependent on membrane morphology like pore size and on water characteristics namely NOM nature. This work addresses the evaluation of the efficiency of ultrafiltration (UF) and Coagulation/Flocculation/UF performance in terms of permeation fluxes and HS removal, of the water from Tagus River (Valada). The operation of coagulation with chitosan was evaluated as a pretreatment for minimization of membrane fouling. UF experiments were carried out in flat cells of 13.2×10−4 m2 of membrane surface area and at transmembrane pressures from 1 to 4 bar. Five cellulose acetate membranes were laboratory made to cover a wide range of molecular weight cut-off (MWCO): 2,300, 11,000, 28,000, 60,000 and 75,000 Da. Severe fouling is observed for the membranes with the highest cut-off. In the permeation experiments of raw water, coagulation prior to membrane filtration led to a significant improvement of the permeation performance of the membranes with the highest MWCO due to the particles and colloidal matter removal.

scholarly journals Potential Pitfalls in Membrane Fouling Evaluation: Merits of Data Representation as Resistance Instead of Flux Decline in Membrane Filtration

Membranes ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 460
Author(s):  
Bastiaan Blankert ◽  
Bart Van der Bruggen ◽  
Amy E. Childress ◽  
Noreddine Ghaffour ◽  
Johannes S. Vrouwenvelder
Keyword(s):  
Membrane Fouling ◽  
Membrane Filtration ◽  
Data Representation ◽  
Strong Impact ◽  
Experimental Conditions ◽  
Permeable Membrane ◽  
Dead End ◽  
Flux Decline ◽  
The Difference ◽  
Filtration Flux

The manner in which membrane-fouling experiments are conducted and how fouling performance data are represented have a strong impact on both how the data are interpreted and on the conclusions that may be drawn. We provide a couple of examples to prove that it is possible to obtain misleading conclusions from commonly used representations of fouling data. Although the illustrative example revolves around dead-end ultrafiltration, the underlying principles are applicable to a wider range of membrane processes. When choosing the experimental conditions and how to represent fouling data, there are three main factors that should be considered: (I) the foulant mass is principally related to the filtered volume; (II) the filtration flux can exacerbate fouling effects (e.g., concentration polarization and cake compression); and (III) the practice of normalization, as in dividing by an initial value, disregards the difference in driving force and divides the fouling effect by different numbers. Thus, a bias may occur that favors the experimental condition with the lower filtration flux and the less-permeable membrane. It is recommended to: (I) avoid relative fouling performance indicators, such as relative flux decline (J/J0); (II) use resistance vs. specific volume; and (III) use flux-controlled experiments for fouling performance evaluation.

scholarly journals Engineered Nanoparticles with Decoupled Photocatalysis and Wettability for Membrane-Based Desalination and Separation of Oil-Saline Water Mixtures

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1397
Author(s):  
Bishwash Shrestha ◽  
Mohammadamin Ezazi ◽  
Gibum Kwon
Keyword(s):  
Membrane Fouling ◽  
Municipal Wastewater ◽  
Uv Light ◽  
Saline Water ◽  
Membrane Surface ◽  
Sio2 Nanoparticles ◽  
Engineered Nanoparticles ◽  
Water Mixture ◽  
Organic Substances ◽  
Suspended Substances

Membrane-based separation technologies are the cornerstone of remediating unconventional water sources, including brackish and industrial or municipal wastewater, as they are relatively energy-efficient and versatile. However, membrane fouling by dissolved and suspended substances in the feed stream remains a primary challenge that currently prevents these membranes from being used in real practices. Thus, we directly address this challenge by applying a superhydrophilic and oleophobic coating to a commercial membrane surface which can be utilized to separate and desalinate an oil and saline water mixture, in addition to photocatalytically degrading the organic substances. We fabricated the photocatalytic membrane by coating a commercial membrane with an ultraviolet (UV) light-curable adhesive. Then, we sprayed it with a mixture of photocatalytic nitrogen-doped titania (N-TiO2) and perfluoro silane-grafted silica (F-SiO2) nanoparticles. The membrane was placed under a UV light, which resulted in a chemically heterogeneous surface with intercalating high and low surface energy regions (i.e., N-TiO2 and F-SiO2, respectively) that were securely bound to the commercial membrane surface. We demonstrated that the coated membrane could be utilized for continuous separation and desalination of an oil–saline water mixture and for simultaneous photocatalytic degradation of the organic substances adsorbed on the membrane surface upon visible light irradiation.

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