Topology Optimization of Spacers for Maximizing Permeate Flux on Membrane Surface in Reverse Osmosis Channel

The objective of this study is to design spacers using fluid topology optimization in 2D crossflow Reverse Osmosis (RO) membrane channel to improve the performance of RO processes. This study is an initial attempt to apply topology optimization to designing spacers in RO membrane channel. The performance was evaluated by the quantity of permeate flux penetrating both upper and lower membrane surfaces. A coupled Navier-Stokes and Convection-Diffusion model was employed to calculate the permeate flux. To get reliable solutions, stabilization methods were employed with standard finite element method. The nine reference models which consist of the combination of circle, rectangular, triangle shape and zigzag, cavity, submerge configuration of spacers were simulated. Such models were compared with new model designed by topology optimization. The permeate flux at both membrane surfaces was determined as an objective function. In addition, permissible pressure drop along the channel and spacer volume were used as constraints. As a result of topology optimization as the permissible pressure drop changes in channel, characteristics of spacer design development was founded. Spacer design based on topology optimization was reconstructed to a simple one considering manufactuability and characteristics of development spacer design. When a simplified design was compared with previous 9 models, new design has a better performance in terms of permeate flux and wall concentration at membrane surface.

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Novel Spacer Design Using Topology Optimization in a Reverse Osmosis Channel

Journal of Fluids Engineering ◽

10.1115/1.4025680 ◽

2013 ◽

Vol 136 (2) ◽

Cited By ~ 4

Author(s):

Seungjae Oh ◽

Semyung Wang ◽

Minkyu Park ◽

Joon Ha Kim

Keyword(s):

Topology Optimization ◽

Reverse Osmosis ◽

Membrane Surface ◽

Navier Stokes ◽

Permeate Flux ◽

Membrane Channel ◽

Reference Models ◽

Membrane Surfaces ◽

Ro Membrane ◽

And Performance

The objective of this study is to design spacers using topology optimization in a two-dimensional (2D) crossflow reverse osmosis (RO) membrane channel in order to improve the performance of RO processes. This study is the first attempt to apply topology optimization to designing spacers in a RO membrane channel. The performance was evaluated based on the quantity of permeate flux penetrating both the upper and lower membrane surfaces. Here, Navier–Stokes and convection-diffusion equations were employed to calculate the permeate flux. The nine reference models, consisting of combinations of circle, rectangle, and triangle shapes and zig-zag, cavity, and submerged spacer configurations were then simulated using finite element method so that the performance of the model designed by topology optimization could be compared to the reference models. As a result of topology optimization with the allowable pressure drop changes in the channel, characteristics required of the spacer design were determined. The spacer design based on topology optimization was then simplified to consider manufacturability and performance. When the simplified design was compared to the reference models, the new design displayed a better performance in terms of permeate flux and wall concentration at the membrane surface.

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COMBINATION OF REVERSE OSMOSIS AND ELECTRODEIONIZATION FOR SIMULTANEOUS SUGAR RECOVERY AND SALTS REMOVAL FROM SUGARY WASTEWATER

REAKTOR ◽

10.14710/reaktor.11.2.91-97 ◽

2011 ◽

Vol 11 (2) ◽

pp. 91 ◽

Cited By ~ 2

Author(s):

I.N. Widiasa ◽

I Gede Wenten

Keyword(s):

Cation Exchange ◽

Reverse Osmosis ◽

Membrane Surface ◽

Type I ◽

Sugar Solution ◽

Sugar Recovery ◽

Permeate Flux ◽

Strong Base ◽

Ro Membrane ◽

Exchange Membrane

An integrated membrane system combining reverse osmosis (RO) and electrodeionization (EDI) is used for simultaneous sugar concentration and salts removal from a synthetic dilute sugar solution as a model of sugar-containing wastewater. The RO system uses a thin film composite RO membrane (Saehan CSM, RE1812-60). Meanwhile, the EDI stack has two diluted compartments, one concentrated compartment, one anode compartment, and one cathode compartment. Commercially available cation exchange membrane (MC-3470) and anion exchange membrane (MA-3475) are used as ionic selective barriers of the EDI stack. Both diluate and concentrate compartments are filled with mixed ion exchange resins (purolite strong acid cation exchange, C-100E and strong base type I anion resins, A-400). Two different operation modes, i.e. RO-EDI and EDI-RO, were assessed. The experimental results show that the observed sugar rejection of RO membrane is more than 99.9% and there is no sugar loss in the EDI stack. This indicates that the hybrid process allows almost total sugar recovery. In addition, significant reduction of salts content from the concentrated sugar solution is obtained. From permeate flux and permeate purity points of view, however, the EDI-RO configuration seems superior to the RO-EDI configuration. It should be emphasized that scale formation on the membrane surface of the concentrate compartment side has to be controlled.

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Removal of Monoethanolamine from Wastewater by Composite Reverse Osmosis Membrane

Jurnal Teknologi ◽

10.11113/jt.v68.3031 ◽

2014 ◽

Vol 68 (5) ◽

Author(s):

Azry Borhan ◽

Muhammad Muhibbudin Mat Johari

Keyword(s):

Reverse Osmosis ◽

Operating Parameter ◽

Operating Conditions ◽

Optimum Operating ◽

Transmembrane Pressure ◽

Processing Plant ◽

Permeate Flux ◽

Feed Concentration ◽

Desorption Process ◽

Ro Membrane

Monoethanolamine (MEA) has been vastly used for the removal of carbon dioxide (CO2) in natural gas processing plant. However, during the absorption-desorption process and maintenance activities, a small amount of amine get carries over and discharged into the effluent wastewater stream. Due to its high Chemical Oxygen Demand (COD) and require large volume of water for dilution, therefore treatment of MEA contaminated wastewater is a major concern in most amine sweetening plants. In this research, MEA wastewater generated from PETRONAS Fertilizer Kedah Sdn. Bhd (PFK) was treated via AFC99 tubular thin film composite polyamide Reverse Osmosis (RO) membrane. The effect of operating parameter (transmembrane pressure (TMP), feed concentration and pH) towards permeate flux and MEA rejection were studied to obtain the optimum operating conditions. Experimental results showed that AFC99 membrane is able to reject MEA up to 98% when operated at TMP of 20 bars, feed concentration of 300 ppm and pH of 4. This work shows that the RO membrane was feasible and desirable to be used for removal of MEA contaminants from wastewater. Besides, the treated water fulfills the watering standards.

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Silica scale formation and effect of sodium and aluminium ions -29Si NMR study

Environmental Science Water Research & Technology ◽

10.1039/c5ew00220f ◽

2016 ◽

Vol 2 (1) ◽

pp. 174-185 ◽

Cited By ~ 7

Author(s):

L. Lunevich ◽

P. Sanciolo ◽

A. Smallridge ◽

S. R. Gray

Keyword(s):

Reverse Osmosis ◽

Membrane Surface ◽

Scale Formation ◽

Significant Problem ◽

29Si Nmr ◽

High Recovery ◽

Desalination Plant ◽

Nmr Study ◽

Silica Scale ◽

Ro Membrane

Silica scale formation on reverse osmosis (RO) membrane surface is a significant problem for operation of high recovery RO desalination plant.

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Enhanced Fouling Resistance and Antimicrobial Property of Ultrafiltration Membranes Via Polyelectrolyte-Assisted Silver Phosphate Nanoparticle Immobilization

Membranes ◽

10.3390/membranes10100293 ◽

2020 ◽

Vol 10 (10) ◽

pp. 293

Author(s):

Kunal Olimattel ◽

Jared Church ◽

Woo Hyoung Lee ◽

Karin Y. Chumbimuni-Torres ◽

Lei Zhai ◽

...

Keyword(s):

Membrane Surface ◽

Antimicrobial Property ◽

Layer By Layer ◽

Permeate Flux ◽

Fouling Resistance ◽

Silver Phosphate ◽

Membrane Surfaces ◽

Polyallylamine Hydrochloride ◽

Assembly Technique ◽

Uf Membranes

Ultrafiltration (UF) is a low-pressure membrane that yields higher permeate flux and saves significant operating costs compared to high-pressure membranes; however, studies addressing the combined improvement of anti-organic and biofouling properties of UF membranes are lacking. This study investigated the fouling resistance and antimicrobial property of a UF membrane via silver phosphate nanoparticle (AgPNP) embedded polyelectrolyte (PE) functionalization. Negatively charged polyacrylic acid (PAA) and positively charged polyallylamine hydrochloride (PAH) were deposited on the membrane using a fluidic layer-by-layer assembly technique. AgPNPs were immobilized within the crosslinked “bilayers” (BL) of PAH/PAA. The effectiveness of AgPNP immobilization was confirmed by microprofile measurements on membrane surfaces using a solid contact Ag micro-ion-selective electrode. Upon stable and uniform BL formation on the membrane surface, the permeate flux was governed by a combined effect of PAH/PAA-derived hydrophilicity and surface/pore coverage by the BLs “tightening” of the membrane. When fouled by a model organic foulant (humic acid), the functionalized membrane exhibited a lower flux decline and a greater flux recovery due to the electrostatic repulsion imparted by PAA when compared to the unmodified membrane. The functionalization rendered antimicrobial property, as indicated by fewer attachments of bacteria that initiate the formation of biofilms leading to biofouling.

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An experimental study on the effect of spacer on concentration polarization in a long channel reverse osmosis membrane cell

Water Science & Technology ◽

10.2166/wst.2010.116 ◽

2010 ◽

Vol 61 (8) ◽

pp. 2035-2041 ◽

Cited By ~ 7

Author(s):

H. Mo ◽

H. Y. Ng

Keyword(s):

Membrane Fouling ◽

Concentration Polarization ◽

Permeate Flux ◽

Membrane Channel ◽

Organic Fouling ◽

Integral Effect ◽

Ro Membrane ◽

Long Channel ◽

Membrane Cell ◽

Extra Resistance

This study was to experimentally investigate the performance and organic fouling behaviour in a 1-m long RO membrane channel with or without spacer for desalting. It was found that local permeate flux distributed heterogeneously along the long membrane channel without a spacer inserted due to exponential growth of concentration polarization, which also resulted in decreasing salt rejection and increasing organic fouling along the membrane channel in the downstream direction. This heterogeneity could be lessened by inserting a spacer into the channel, which mitigated concentration polarization due to the enhanced turbulence caused by a spacer, especially at the downstream portion of the channel. However, in the upstream of the channel, inserting a spacer exerted an additional vertical resistance which might counteract the effect of concentration polarization mitigation by a spacer and caused a lower permeate flux. This suggests that it is necessary to consider the integral effect of spacer for designing an RO membrane module and an overall RO system in order to prevent extra resistance, reduce concentration polarization and membrane fouling.

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Improving performance of low pressure reverse osmosis systems by intermittent autoflushing

Jurnal Teknik Kimia Indonesia ◽

10.5614/jtki.2010.9.1.1 ◽

2018 ◽

Vol 9 (1) ◽

pp. 1

Author(s):

I N Widiasa ◽

N Sinaga ◽

D Ariyanti

Keyword(s):

Reverse Osmosis ◽

Membrane Surface ◽

Magnesium Silicate ◽

Operating Mode ◽

Low Pressure ◽

Calcium Sulphate ◽

Feed Water ◽

Low Grade ◽

Operating Pressure ◽

Permeate Flux

Improving performance of low pressure reverse osmosis systems by intermittent autoflushing Scaling formation on the membrane surface in the form of calcium carbonate, calcium sulphate, silica, and/or magnesium silicate is a main problem of the reverse osmosis (RO) application for upgrading low grade water. Scaling in RO system is generally controlled by softening the feed water, limiting the recovery and/or the addition of antiscalants which is impractical for household RO system. In this work, the feasibility of intermittent autoflushing to prevent scale formation in household RO systems was investigated. All experiments were carried out using commercially available RO membrane (CSM RE-1812LP) which operated for 6 hours under operating pressure 5 kg/cm2 and total recycle operating mode. Model solution of feed water contain CaCl2 and NaHCO3 were prepared to meet various LSI values in the range of 0 to 1.5. Duration and interval time of autoflush were in the range of 60 to 15 s and 5 to 60 min respectively. The results shown that the permeate flux of the system which operated using intermittent autoflushing relatively stable. It is emphasized that intermittent autoflushing may improve the performance of household reverse osmosis systems.Keywords: Autoflushing, scaling, physical cleaning, reverse osmosis Abstrak Pembentukan kerak (scaling) pada permukaan membran berupa kerak kalsium karbonat, kalsium sulfat, silika dan atau magnesium silikat merupakan permasalahan utama pada aplikasi sistem membran reverse osmosis (RO) pada proses pemurnian air. Scaling pada sistem RO umumnya dikontrol dengan melakukan pretreatment terhadap air umpan seperti softening, menambahkan zat antiscalant pada saat proses pemisahan serta membatasi tingkat recovery, dimana proses-proses tersebut tidak praktis apabila diaplikasikan pada sistem RO skala rumah tangga. Penelitian ini bertujuan untuk melihat kemungkinan metode intermittent autoflush dapat diaplikasikan untuk menghambat terjadinya scaling pada sistem RO skala rumah tangga. Penelitian ini dilakukan dengan menggunakan satu unit membran spiral wound jenis CSM RE-1812LP yang dioperasikan dengan tekanan operasi 5 kg/cm2 dan waktu operasi ± 6 jam. Larutan umpan sintesis dibuat dengan melarutkan CaCl2 dan NaHCO3 hingga nilai LSI mencapai kisaran 0-1,5. Durasi dan interval dari metode intermittent autoflush divariasikan pada kisaran 60-15 detik dan 5-60 menit. Hasil penelitian menunjukkan bahwa fluks permeat relatif stabil pada sistem RO yang menggunakan metode intermittent autoflush. Hal ini menandakan bahwa metode intermittent autoflush ini dimungkinkan untuk meningkatkan kinerja dari sistem RO skala rumah tangga.Kata Kunci: Autoflushing, scaling, physical cleaning, reverse osmosis

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Comparative Study on the Treatment of Biologically Treated Textile Effluent by Nanofiltration and Reverse Osmosis for Water Reuse

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.441.584 ◽

2012 ◽

Vol 441 ◽

pp. 584-588

Author(s):

San Chuan Yu ◽

Zhi Wen Chen ◽

Mei Hong Liu ◽

Jing Wei Zhao

Keyword(s):

Reverse Osmosis ◽

Water Reuse ◽

Cross Flow ◽

Water Shortage ◽

Nanofiltration Membrane ◽

Reverse Osmosis Membrane ◽

Permeate Flux ◽

Flux Decline ◽

Salinity Reduction ◽

Ro Membrane

In view of the water shortage, the increasingly severe regulations as well as the release thresholds, it is becoming increasingly necessary to reuse the textile effluents. This work concerned the treatment of textile plant effluent after conventional biological processing by membrane technology for water reuse. Desal5 DK nanofiltration (NF) membrane and BW30 reverse osmosis (RO) membrane were investigated in this study in terms of COD and color removal, salinity reduction as well as permeate flux through cross-flow permeation tests. The results showed that the Desal5 DK nanofiltration membrane exhibited higher stabilized water permeability and flux decline than the reverse osmosis membrane because of its higher porosity and tendency towards fouling. The BW30 reverse osmosis membrane reduced salinity to a great extent than the Desal5 DK nanofiltration membrane. While the nanofiltration membrane exhibited better COD removal efficiency compared to the RO membrane, possibly due to its sieving removal mechanism. The treated water with good enough quality could be recycled back into the process, thereby offering economical benefits by reducing the water consumption and wastewater treatment cost.

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Study on the Concentration of Acrylic Acid and Acetic Acid by Reverse Osmosis

Membranes ◽

10.3390/membranes10070142 ◽

2020 ◽

Vol 10 (7) ◽

pp. 142

Author(s):

Qian Liu ◽

Lixin Xie ◽

Hanxiao Du ◽

Shichang Xu ◽

Yawei Du

Keyword(s):

Acetic Acid ◽

Acrylic Acid ◽

Acid Solution ◽

Reverse Osmosis ◽

Membrane Surface ◽

Acid Resistance ◽

Operating Conditions ◽

Operating Pressure ◽

Permeate Flux ◽

Amide Bonds

In the production of acrylic acid, the concentration of acrylic acid solution from the adsorption tower was low, which would lead to significant energy consumption in the distillation process to purify acrylic acid, along with the production of a large amount of wastewater. Reverse osmosis (RO) was proposed to concentrate the acrylic acid aqueous solution taken from a specific tray in the absorption tower. The effects of operating conditions on the permeate flux and acid retention were studied with two commercial RO membranes (SWC5 and SWC6). When the operating pressure was 4 MPa and the temperature was 25 °C, the permeate fluxes of two membranes were about 20 L·m−2·h−1. The acrylic acid and acetic acid retentions were about 80% and 78%, respectively. After being immersed in the acid solutions for several months, the characteristics of the two membranes were tested to evaluate their acid resistance. After six months of exposure to the acid solution containing 2.5% acrylic acid and 2.5% acetic acid, the retentions of acrylic acid and acetic acid were decreased by 5.7% and 4.1% for SWC5 and 4.9% and 2.2% for SWC6, respectively. The changes of membrane surface morphology and chemical composition showed the hydrolysis of some amide bonds.

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Rapid novel test for the determination of biofouling potential on reverse osmosis membranes

Water Science & Technology ◽

10.2166/wst.2016.159 ◽

2016 ◽

Vol 73 (12) ◽

pp. 2978-2985 ◽

Cited By ~ 2

Author(s):

Cervinia V. Manalo ◽

Masaki Ohno ◽

Tetsuji Okuda ◽

Satoshi Nakai ◽

Wataru Nishijima

Keyword(s):

Reverse Osmosis ◽

Fluorescence Intensity ◽

Biofilm Formation ◽

Membrane Surface ◽

Cross Flow ◽

Direct Analysis ◽

Novel Method ◽

Ro Membrane ◽

Flow Experiments

Abstract A novel method was proposed to determine biofouling potential by direct analysis of a reverse osmosis (RO) membrane through fluorescence intensity analysis of biofilm formed on the membrane surface, thereby incorporating fouling tendencies of both feedwater and membrane. Evaluation of the biofouling potential on the RO membrane was done by accelerated biofilm formation through soaking of membranes in high biofouling potential waters obtained by adding microorganisms and glucose in test waters. The biofilm formed on the soaked membrane was quantified by fluorescence intensity microplate analysis. The soaking method's capability in detecting biofilm formation was confirmed when percentage coverage obtained through fluorescence microscopy and intensity values exhibited a linear correlation (R2 = 0.96). Continuous cross-flow experiments confirmed the ability and reliability of the soaking method in giving biofouling potential on RO membranes when a good correlation (R2 = 0.87) between intensity values of biofilms formed on the membrane during soaking and filtration conditions was obtained. Applicability of the test developed was shown when three commercially available polyamide (PA) RO membranes were assessed for biofouling potential. This new method can also be applied for the determination of biofouling potential in water with more than 3.6 mg L−1 easily degradable organic carbon.

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