Separation and Purification Technology 188 (2017) 9097

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Separation and Purification Technology

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Deep purification of seawater using a novel zeolite 3A incorporatedpolyether-block-amide composite membrane

http://dx.doi.org/10.1016/j.seppur.2017.07.0171383-5866/ 2017 Elsevier B.V. All rights reserved.

Corresponding author.E-mail addresses: filiz.ugur@kocaeli.edu.tr, filiz.ugurr@gmail.com (F.U. Nigiz).

Filiz Ugur Nigiz a,, Sevil Veli b, Nilufer Durmaz Hilmioglu aaKocaeli University, Chemical Engineering Department, Kocaeli 41380, TurkeybKocaeli University, Environmental Engineering Department, Kocaeli 41380, Turkey

a r t i c l e i n f o a b s t r a c t

Article history:Received 11 May 2017Received in revised form 7 July 2017Accepted 7 July 2017Available online 8 July 2017

Keywords:Water purificationHydrophilic-hydrophobic membranePolyether block amideDesalination

In this study, a novel hydrophilic-hydrophobic composite membrane was prepared and used in a perva-porative desalination of NaCl-water solution and seawater. For this purpose, polyether block amide(PEBA) was selected as membrane matrix. Zeolite 3A was incorporated to PEBA polymer for facilitatingthe water permeation through the membrane. The surface morphologies of the pristine and compositemembranes were examined by scanning electron microscopy. Thermogravimetric analyses of the pristineand composite membranes were performed by adjusting the zeolite 3A concentration in the PEBA poly-mer. The effect of the zeolite addition on membranes surface hydrophilicity was analyzed using contactangle measurement. Firstly, influences of zeolite content, feed temperature and NaCl concentration onpervaporative desalination performances were performed in the pervaporation of NaCl-water solution.All membranes exhibited excellent performance, and the salt rejection of >99.5% and flux of>2.07 kg m2 h1 were achieved. Secondly, seawater desalination was performed. Effect of zeolite addi-tion at a given temperature was also investigated. The better salt rejection was obtained as 99.81%accompanied with a very good flux of 4.57 kg m2 h1 in pervaporative seawater desalination at 40 Cusing 20 wt.% zeolite 3A incorporated membrane.

2017 Elsevier B.V. All rights reserved.

1. Introduction

The water scarcity in the world is growing at a fearful ratebecause of the increasing human population. In addition that, theglobal warming and climate change effects threaten the existingfresh water source. Today, 97% of the worlds water (seawater,brackish groundwater, ocean, i.e.) is classified as saline water indifferent concentration.

Freshwater supplying from saline water by removing ions, min-erals, heavy metals, bacteria, dissolved salts, and other impuritiesis called as Desalination. The water is called as a freshwater ifthe total dissolved solid (TDS) in the water is less than 1000 mg/L. The limited TDS value for freshwater can be changed dependingon the purpose of the water consumption [1]. Desalinated watercan be used for industrial purposes, irrigation, and most impor-tantly potable drinking water. In the current state, desalination isestimated as an expensive technology for freshwater supplying[2,3]. However, it is predicted that the water crisis will force togovernments to improve their own desalination technology in aclose future. Especially for the countries that are located near the

coast, desalination will become a potential water supplyingprocess.

Desalination technology has already been using in the MiddleEast, Africa, Europe, China, Singapore and the USA with differentfreshwater capacities. There are several desalination methodsand types which preferred depending on the concentration of thesaline water to be separated and the countrys energy politics. Basi-cally, desalination methods are classified into two main categoriesas thermal separation and membrane separation. Thermal separa-tion techniques such as multi-effect and multistage flash distilla-tion are based on the phase separation phenomena whereby theseawater is heated and then condensed to produce freshwaterusing thermal energy. Thermal desalination plants have mostlybeen built in the country located in the Middle East due to theextensive petroleum reserves. Membrane separation process is fre-quently constructed in the country that has a limited energysource. Reverse osmosis (RO), forward osmosis (FO), electrodialy-sis, and nanofiltration are commercialized membrane processes[46]. RO is a pressure driven process in which the membrane actsas a barrier. Because of the separation character of RO method, thesize of the intermolecular void in the membrane and the differ-ences in component diffusivities play a key role on water purifica-tion. Although the purity of the permeate water changes based on

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F.U. Nigiz et al. / Separation and Purification Technology 188 (2017) 9097 91

the membranes material, most of RO membranes are able to retaindissolved ions. Hence, it is handled to obtain greater than 99% ofion rejections using RO technology [79].

Membrane distillation (MD) is a relatively new method inwhich mostly hydrophobic membranes are used [1013]. Separa-tion phenomenon in MD depends on vapor pressure differencebetween the upstream and downstream sides of the membrane.The membrane acts as a separator in MD and the water-membrane interaction is very low due to its hydrophobic nature.

Pervaporation (PV) offers new opportunities for alternativewater desalination technology. In this process, almost all impuri-ties in water -from nano-scale to micro scale- are retained on thefeed side and the freshwater preferentially permeates through adense membrane [1416]. By enabling the rejection of almost allimpurities in seawater, greater than 99% of salt rejection resultshave been achieved using PV. Compared to other desalination pro-cesses, pervaporation has some advantages. In PV, the separationfactor is relatively higher than that of RO under the same operatingconditions [17]. Many of minerals, metal elements, and ions havesmaller diameters than that of the membrane with micro-poresized; consequently, the trace amount of undesired hazardouscompounds can be non-selectively permeated in the othermembrane-based desalination technology. In PV very sensitiveseparation occurs thanks to the dense and non-porous membraneusage.

While very high pressure is needed for desalination in RO, per-vaporation is carried out at the atmospheric pressure on the feedside and the vacuum on the downstream side. Differently fromthe thermal desalination techniques where a great heat energy isneeded for entire water evaporation, the vacuum is used in perva-poration to evaporate the permeate stream at low temperatures[17].

In fact, pervaporation is a long-known process for dehydrationof alcohols and organic solvents [1820], removal of volatileorganic compounds from industrial discharge [21,22], and separa-tion of organic-organic mixture selectively [23,24]

The driving force in PV is the chemical potential gradient gener-ated from a pressure difference across the membrane. The perfor-mance of PV is directly related to the difference in the partialpressures of the components. Separation behavior in PV is basicallyexplained using solution-diffusion law. When the feed solutioncontact with the membrane, the target compound (water fordesalination) preferentially dissolves on the membranes surface,permeates through the membrane, and evaporates to the down-stream side. It is needed to investigate the feasibility of PV to pro-duce large quantities of water. In the literature, there are severalsuccessful pervaporative desalination studies by using differenttypes of membranes. Pristine polymeric membranes, inorganicparticle loaded polymeric membranes, hybrid membranes includ-ing more than one polymer, and inorganic membranes have beenused. The most parts of these studies depend on a hydrophilic per-vaporation membrane usage in order to increase the water flux. Ina study performed by Xie et al. [25], polyvinyl alcohol/maleic anhy-dride/silica (PVA/MA/Si) hybrid membrane was prepared and usedfor the pervaporation of a NaCl-water solution. Influence of thetemperature, salinity of the water, and permeate pressure ondesalination performance were analyzed. They reported a flux of11.7 kg/m2 h and rejection factor up to 99.9%. In another studyreported by Xie et al. (2011), the same membrane was used andthe effect of membrane thickness was investigated. The water fluxand rejection factor were found as 6.93 kg/m2 h and 99.5% respec-tively [26]. Chaudhri et al. (2015) prepared a PVA-coated polysul-fone membrane to be used for pervaporation with a differentrange of NaCl incorporated model solution. They pointed out thatthe final conductivity of the permeate water was 20 ls/cm andthe flux was 7.4 L/m2 h at 344 K [27]. Inorganic membrane desali-

nation via pervaporation was carried out by Cho et al. (2011). Theyprepared very thin NaA zeolite membrane and used for real seawa-ter desalination. The highest rejection was obtained as 99.9% witha reasonable flux of 1.9 kg/m2 h [28]. Drobek and co-workers alsoprepared two different inorganic membranes of silicalite-1 andZSM-5 [29]. They investigated the performance of pervaporationat different temperature with varying concentration of the NaCl-water solution. The highest salt rejections were reported as 99%and 96% for ZSM-5 and silicalite-1 membranes respectively [29].Khajavi and co-workers synthesized a hydroxy sodalite membraneand they achieved 99.99% of salt rejection [30]. Additionally,almost the all impurities retained in the feed side, and the finalconcentration of ions in the permeate side reduced below a levelof 0.02 ppm [30]. Feng et al. (2017) reported a graphene oxide(GO) incorporated polyimide membrane and found a high rejectionof 99.9% with 36.1 kg m2 h1 [31]. Xu et al. (2016) prepared a GOloaded polydopamine membrane to desalinate NaCl-water solu-tion. The better flux of 48 kg m2 h was found with a rejectiongreater than 99.7% [32]. In another study performed by Fenget al. (2016), graphene oxide framework modified with 1, 4-phenylene diisocyanate (PDI) was synthesized and 99.9% rejectionwas achieved with a high water flux (11.4 kg m2 h1) [33].Hamouda et al. [34] reported a pervaporative desalination studywhere the less-hydrophilic polyether-block-amide membraneswere used. They only investigated the effect of temperature andNaCl concentration on flux and found very low flux of 3.67 g/m2.h at 28.7 C due to the hydrophobic nature of PEBA.

In this study, it is aimed to produce a novel zeolite 3A loadedPEBA membrane for pervaporative seawater desalination. Themain novelty of this study is converting a hydrophobic matrix(PEBA) to a hydrophilic membrane by incorporating a water selec-tive zeolite (zeolite 3A). By this means, the water selectivity andpassage through the membrane is aimed to increase. Even thoughmany researchers were fabricated hydrophilic mixed matrix mem-brane, the most of them used hydrophilic filler into hydrophilicpolymer matrix. Because of the high water uptake capacity ofhydrophilic polymers, they can be exhibit unstable desalinationperformance with relatively short lifetime. Therefore, using ahydrophobic matrix can be a key solution to reinforce the mem-brane durability. Incorporating a hydrophilic zeolite intohydrophobic matrix contributes to enhancing water flux and saltrejection. For these purposes, zeolite 3A was incorporated intoPEBA matrix. This is the first study of using hydrophilic zeolite3A loaded PEBA membrane based on the authors knowledge.

Zeolite 3A is a crystalline potassium aluminosilicate, which isderivated from the sodium form zeolite 4A. AlO2 group in the zeo-lite exhibits a negative charge and it is compensated with thepotassium (K+) ion in its frameworks [35]. Zeolite 3A is an appro-priate zeolite for water treatment process because of the molecularsieving effect and hydrogen bonding capability of the water withinthe zeolite cages. The molecules which have kinetic diametersgreater than 0.3 nm are retained and the water is allowed to passthrough the cages of zeolite 3A. To take these advantages of thezeolite, different amounts of zeolite 3A was incorporated to PEBAmatrix. Regarding the 3A incorporation, it was expected to increasewater flux coupled with higher salt rejection.

2. Materials and methods

2.1. Materials

Polyether-block-amide (Pebax 2533) which is a block copoly-mer contain 80 wt.% poly(ethylene oxide) and 20 wt.% polyamidewas kindly obtained from the distributor of the Arkema, Turkey.Zeolite 3A powder, acetic acid, and sodium chloride were

Table 1Seawater chemical compositions.

Analysis Marmara seawater

Conductivity (ls/cm) 43,700Sodium (mg/L) 13,015Magnesium (mg/L) 1411Cloride (mg/L) 25,580Potassium (mg/L)

F.U. Nigiz et al. / Separation and Purification Technology 188 (2017) 9097 93

determined with a constant NaCl concentration (3 wt.%). Followingthe optimum zeolite determination, influences of the temperature(40, 50, 60 C) and NaCl concentration (1, 2, 3, 5, 10 wt.%) on theperformance were investigated.

Secondly, membrane performance for Marmara Seawaterdesalination was investigated. Effect of zeolite 3A concentration(in the range of 050 wt.%) on desalination performance of seawa-ter at 40 C was performed.

The performance of the desalination was evaluated in terms ofthe water flux (J) and salt rejection factor (R). With an hourly inter-val, permeated fresh water was weighted and analyzed using con-ductivity method.

J Wp=A t 1

R Cf Cp=Cf 100 2

where Wp represents the total permeate weight of the permeatedsample, A is the effective area of the flat sheet membrane and t isthe operation time. Cf and Cp are conductances of the feed and per-meate stream respectively.

Fig. 2. Surface micrographs of pristine (a), 10 wt.% zeolite 3A lo

3. Results and discussion

3.1. Membrane characterization

The morphological analysis of the pristine and mixed matrixmembrane were observed using SEM analysis. The SEM results ofthe membranes appeared in Fig. 2.

Fig. 2a represents the smooth and non-defected dense structureof the pristine PEBAmembrane. It is clearly indicated in Fig. 2b thatthe zeolite was homogeneously dispersed within the polymer.However, when the zeolite amount was increased, local zeoliteaggregations were observed as seen in Fig. 2c. Although theagglomeration tendency of excess amount zeolite, any contact-free region (between the polymer and zeolite) was not seen(Fig. 2df). Therefore, it is predicted that any non-selective ion pas-sage may not be occurred resulting the excess amount of zeoliteloading. However, the total permeation is expected to change byincreasing amount.

The zeolite presence in PEBA matrix was analyzed using FTIRanalysis. The FTIR spectra of the pristine and 20 wt.% zeolite 3Aincorporated membranes are given in Fig. 3.

aded (b) and 50 wt.% zeolite 3A loaded membrane (c)(f).

Fig. 3. FTIR spectra of the pristine and zeolite incorporated PEBA membrane.

Fig. 4. TGA curves and contact angle of the pristine and zeolite 3A/PEBA membrane.

Fig. 5. Effect of zeolite concentration on NaCl rejection and flux.

94 F.U. Nigiz et al. / Separation and Purification Technology 188 (2017) 9097

The peak at 3312 cm is corresponding to the characteristic NAHgroups in pristine PEBA. The peaks in the region of 29232852 cm

are attributed to the asymmetric and symmetric stretching of theCAHbond. The intense of the CAHbonds reduced after zeolite addi-tion. Characteristic peaks of zeolite reveal between the band of1019 cm and 957 cm. The peak at 1019 cm is corresponding tothe SiAOASi stretching of the zeolite within PEBA. The peak at3407 cm1 indicates the SiAOH and SiAOHAAl bonding in the zeo-lite incorporated membrane and confirms the presence of zeolite.

Fig. 4 shows the thermal analysis and contact angle measure-ments of the pristine and zeolite 3A loaded membranes. Althoughthere is not a significant difference between the first decomposi-tion temperatures of the pristine and 20 wt.% membrane, the resid-ual weight of the composite membrane is higher. Meanwhile, thethermal durability of the zeolite loaded membrane is expected tobe relatively higher compared to pristine one during the pervapo-ration experiments. However, an early decomposition is observedat low temperature with the excess zeolite loaded membrane(50 wt.%). Fig. 4 also shows the increasing contact angle values ofthe membrane surfaces by zeolite addition. Meanwhile, thehydrophilicity of the membrane enhanced with zeolite addition.This observation was very important to fulfill the main purposeof the study. The hydrophilicity of the hydrophobic membranewas improved by zeolite and it could be lead to enhance bothwater flux and salt retention.

3.2. Membrane performance of NaCl-water solution

Fig. 5 indicates the influence of zeolite loading on pervaporativedesalination performance at a constant temperature (40 C) with aconstant NaCl concentration (3 wt.%). It is clear from the figure thatall membranes showed excellent NaCl rejection results (>99.5)with reasonable flux results (>2 kg m2 h1). With increasing zeo-lite amount, salt rejection firstly increased up to 99.63%, and thengradually decreased. The better rejection was observed using20 wt.% zeolite 3A loaded composite membrane. Same as the rejec-tion, the flux value enhanced from 2.07 kg m2 h1 to 3.1 kg m2 -h1 with an improvement of 49.7% when the zeolite additionincreased from 0 wt.% to 20 wt.%. Similar increment-decrementrelationship depending on the amount of filler in the membranewas also reported in the literature [25,26].

This was due to the hydrophilic feature of the zeolite 3A. Theincreasing hydrophilicity of the membrane caused a higherwater-membrane interaction, consequently, water permeation rate

increased in a given operation period. Flux increment also attribu-ted to appropriate cage structure of zeolite 3A, which only hasenough size to allow water permeation. Although flux valuesdecreased after 20 wt.% of zeolite loading, the decline was notremarkable to change the overall performance of desalination. This

Fig. 7. Effect of temperature on rejection and flux.

F.U. Nigiz et al. / Separation and Purification Technology 188 (2017) 9097 95

slight decrement could be explained by agglomeration tendency ofzeolite which was also observed in SEM micrographs. The excessamount of zeolite 3A would restrict the free volume of the polymerand the vacant spaces of the zeolite, therefore caused a reverseeffect on flux.

Fig. 6 indicates the NaCl concentration effect on flux and rejec-tion at constant temperature (40 C) using 20 wt.% zeolite 3Aloaded membrane.

As seen in Fig. 6, NaCl rejection did not affect from the concen-tration variations. The NaCl rejection increased from 99.6 to99.64%. The decrease in flux was also very small at the low NaClconcentration (between 1 wt.% and 3 wt.%). Flux decreased from3.33 kg m2 h1 to 3.1 kg m2 h1 when the NaCl concentrationincreased from 1 wt.% to 3 wt.%. However, when the NaCl concen-tration increased from 3 wt.% to 10 wt.%, flux values remarkablydecreased from 3.1 kg m2 h1 to 1.98 kg m2 h1. This differencewas attributed to the change in driving force in which maintainedby the partial vapor pressure of the water. NaCl was a non-volatilemolecule, therefore the total vapor pressure of the feed mixturedecreased by NaCl addition. At the low temperature, this relationcould be negligible, but could not be underestimated at the hightemperature. The similar rejection-flux behavior was also obtainedby Xie et al. [25], Drobek et al. [29] and Swenson et al. [38]. It wasalso reported in the literature that the thermodynamical activity ofthe water decreases with the salt addition [39]. In addition that,the excessive amount of NaCl on the surface of the membranewould cause a concentration polarization and flux affected nega-tively. Another reason of the flux decrement could be related tothe free volume of the polymer. The free volumes might be filledwith non-volatile salt residuals; therefore the flux permeationrestricted during the experiments.

Fig. 7 shows the influence of the feed temperature on the per-formance of pervaporation experiments with a constant NaCl con-centration (3 wt.%). Despite to the effect of NaCl on performance,temperature changed the performance superiorly.

As it is indicated in Fig. 7, when the temperature increasedfrom 40 C to 60 C, flux enhanced from 3.1 kg m2 h1 to4.33 kg m2 h1. Increasing flux with temperature is a prevalentobservation for pervaporative separation studies [3942]. Thereare many of known reasons to increase the permeation rate of thecomponent through the membrane. Firstly, temperature increasesthe partial vapor pressure of the solvent in feed solution exponen-tially, and the pressure gradient across the membrane increases.Diffusivity of the component through the membrane and solubilityof the component within the membrane are also increased withtemperature, thus the flux enhances as expected. Based on the freevolume theory of polymers, feed temperature directly affects the

Fig. 6. Effect of NaCl concentration on rejection and flux.

segmental chainmovement andpermeation rates of solventswithinthe membrane [43]. Arrhenius equation is helpful for better under-standing the relationship between the flux and temperature [44].

It is also observed in Fig. 7 that the increasing temperatureadversely affected the NaCl rejection. Salt rejection resultsdecreased from 99.65% to 99.16% when the temperature increasedfrom 40 C to 60 C. This result directly related to the factors whichpositively affected the water permeation. In particular, increasingfree volume of the polymer would allow for the non-selective ionpassage and the rejection decreased. The similar observation wasalso obtained by Chaudrhi et al. [27].

The trade-off phenomenon between the flux and rejection is afrequent observation in the literature studies related to membraneseparation process, especially in pervaporation where themembrane-solvent interaction is remarkable.

3.3. Membrane performance of seawater

Salt rejection through a dense membrane depends on the size ofthe hydrated ions. In the present study, an appropriate zeolite wasused which allowed the only water permeation [28]. Therefore, theions having larger molecule diameter than the cage size of thezeolite or restricted free volume of the polymer were retainedin the feed side, and excellent salt rejections were achieved(99.67>) with all membranes (Fig. 8). As shown in Fig. 8, whenthe zeolite ratio in polymer matrix was increased from 0 to20 wt.%, salt rejection enhanced from 99.67% to 99.81% when the

Fig. 8. Seawater desalination results of the pristine and composite membranes.

Table 2Comparison of the experimental results of permeate water with related standards.

Analysis Marmaraseawater

WHO drinkingwater standard

Europe/Turkishdrinking waterstandard

Turkish irrigationwater standard

Concentration of thepermeate (Pristine PEBA)

Concentration of thepermeate (PEBA-zeolite 3A)

Conductivity (ls/cm) 43,700 2500 116 73Sodium (mg/L) 13,015 200 200 75.8 3.5Magnesium (mg/L) 1411 2.1 0.5Cloride (mg/L) 25,580 250 250 2 0Potassium (mg/L)

F.U. Nigiz et al. / Separation and Purification Technology 188 (2017) 9097 97

The better salt rejection was obtained as 99.81% accompaniedwith a very good flux of 4.57 kg m2 h1 in pervaporative sea-water desalination experiments using 20 wt.% zeolite 3A incor-porated membrane at 40 C. The flux of pristine membrane forseawater desalination was found as 3.33 at the same conditions,and 37% flux improvement was achieved.

The 20 wt.% 3A zeolite incorporated membranes showed astable rejection results and preserved 99.9% of its rejection per-formance during 40 h experiments period for seawater desali-nation. Regarding the flux increment and salt rejectionenhancement, 20 wt.% zeolite incorporated PEBA membranecould be consider more feasible than pristine PEBA for pervapo-rative desalination.

Additionally, ICP-MS analysis of purified water confirmed thatthe zeolite 3A loaded PEBA membrane was a proper candidatefor being a high-performance dense membrane to obtain potablepure water from the saline water.

Acknowledgements

The authors would like to thank Hayim Pinhas Group (Distrib-utor of Arkema in Turkey) for kindly supplying of the Pebax2533. The study was financially funded by the Scientific ResearchCenter of Kocaeli University (2017/009).

References

[1] L.F. Greenlee, D.F. Lawler, B.D. Freeman, B. Marrot, P. Moulin, P. Ce, Reverseosmosis desalination: water sources, technology, and todays challenges,Water Res. 43 (9) (2009) 23172348.

[2] K.P. Lee, T.C. Arnot, D. Mattia, A review of reverse osmosis membrane materialsfor desalinationdevelopment to date and future potential, J. Memb. Sci. 370(12) (2011) 122.

[3] C. Fritzmann, J. Lwenberg, T. Wintgens, T. Melin, State-of-the-art of reverseosmosis desalination, Desalination 216 (2007) 176.

[4] Y. Cai, W. Shen, S. Leng Loo, W.B. Krantz, R. Wang, A.G. Fane, X. Hu, Towardstemperature driven forward osmosis desalination using Semi-IPN hydrogels asreversible draw agents, Water Res. 47 (2013) 37733781.

[5] R.V. Linares, Z. Li, S. Sarp, Sz.S. Bucs, G. Amy, J.S. Vrouwenvelder, Forwardosmosis niches in seawater desalination and wastewater reuse, Water Res. 66(2014) 122139.

[6] G. Kang, Y. Cao, Development of antifouling reverse osmosis membranes forwater treatment: a review, Water Res. 46 (3) (2011) 584600.

[7] D. Li, H. Wang, Recent developments in reverse osmosis desalinationmembranes, J. Mater. Chem. 20 (2010) 45514566.

[8] B. Penate, L. Garca-rodrguez, Current trends and future prospects in thedesign of seawater reverse osmosis desalination technology, Desalination 284(2012) 18.

[9] T. Suzuki, R. Tanaka, M. Tahara, Y. Isamu, M. Niinae, L. Lin, J. Wang, J. Luh, O.Coronell, Relationship between performance deterioration of a polyamidereverse osmosis membrane used in a seawater desalination plant and changesin its physicochemical properties, Water Res. 100 (2016) 326336.

[10] Y.D. Kim, K. Thu, K. Choon, G.L. Amy, N. Ghaffour, A novel integrated thermal-/membrane-based solar energy-driven hybrid desalination system: conceptdescription and simulation results, Water Res. 100 (2016) 719.

[11] M. Bhadra, S. Roy, S. Mitra, Enhanced desalination using carboxylated carbonnanotube immobilized membranes, Sep. Purif. Technol. 120 (2013) 373377.

[12] S. Roy, M. Bhadra, S. Mitra, Enhanced desalination via functionalized carbonnanotube immobilized membrane in direct contact membrane distillation,Sep. Purif. Technol. 136 (2014) 5865.

[13] S. Bano, A. Mahmood, S.J. Kim, K. Lee, Chlorine resistant binary complexedNaAlg/PVA composite membrane for nanofiltration, Sep. Purif. Technol. 137(2014) 2127.

[14] M.C. Duke, S. Mee, J.C. Diniz da Costa, Performance of porous inorganicmembranes in non-osmotic desalination, Water Res. 41 (2007) 39984004.

[15] A. Subramani, J.G. Jacangelo, Emerging desalination technologies for watertreatment: a critical review, Water Res. 75 (2015) 164187.

[16] Z. Xie, M. Hoang, D. Ng, C. Doherty, A. Hill, S. Gray, Effect of heat treatment onpervaporation separation of aqueous salt solution using hybrid PVA/MA/TEOSmembrane, Sep. Purif. Technol. 127 (2014) 1017.

[17] A. Gao, Desalination of High-salinity Water by Membranes, Master Thesis,University of Waterloo, Canada, 2016.

[18] A. Basile, A. Figoli, M. Khayet, Pervaporation, Vapour Permeation andMembrane Distillation, Principles and Applications, First ed. WoodheadPublishing, 2015.

[19] H.E.A. Brschke, State-of-art of pervaporation processes in the chemicalindustry, in: S.P. Nunes, K.-V. Peinemann (Eds.), Membrane Technology: in theChemical Industry, Wiley-VCH Verlag GmbH, Weinheim, 2001.

[20] Y.K. Ong, G.M. Shi, N.L. Lea, Y.P. Tang, J. Zuo, S.P. Nunes, T. Chung, Recentmembrane development for pervaporation processes, Prog. Polym. Sci. 57(2016) 131.

[21] L. Aouinti, D. Roizard, M. Belbachir, PVCactivated carbon based matrices: apromising combination for pervaporation membranes useful for aromaticalkane separations, Sep. Purif. Technol. 147 (2015) 5161.

[22] H. Zhou, Y. Su, Y. Wan, Phase separation of an acetonebutanolethanol (ABE)water mixture in the permeate during pervaporation of a dilute ABE solution,Sep. Purif. Technol. 132 (2014) 354361.

[23] S.B. Kuila, S.K. Ray, Separation of benzene cyclohexane mixtures by filledblend membranes of carboxymethyl cellulose and sodium alginate, Sep. Purif.Technol. 123 (2014) 4552.

[24] G. Genduso, H. Farrokhzad, Y. Latr, S. Darvishmanesh, P. Luis, B. Van derBruggen, Polyvinylidene fluoride dense membrane for the pervaporation ofmethyl acetatemethanol mixtures, J. Membr. Sci. 482 (2015) 128136.

[25] Z. Xie, D. Ng, M. Hoang, T. Duong, S. Gray, Separation of aqueous salt solutionby pervaporation through hybrid organic inorganic membrane: effect ofoperating conditions, Desalination 273 (1) (2011) 220225.

[26] Z. Xie, M. Hoang, T. Duong, D. Ng, B. Dao, S. Gray, Sol gel derived poly (vinylalcohol)/ maleic acid/silica hybrid membrane for desalination bypervaporation, J. Memb. Sci. 383 (12) (2011) 96103.

[27] S.G. Chaudhri, B.H. Rajai, P.S. Singh, Preparation of ultra-thin poly (vinylalcohol) membranes supported on polysulfone hollow fiber and theirapplication for production of pure water from seawater, Desalination 367(2015) 272284.

[28] C.H. Cho, K.Y. Oh, S.K. Kim, J.G. Yeo, P. Sharma, Pervaporative seawaterdesalination using NaA zeolite membrane: mechanisms of high water flux andhigh salt rejection, J. Memb. Sci. 371 (12) (2011) 226238.

[29] M. Drobek, C. Yacou, J. Motuzas, A. Julbe, L. Ding, J.C.D. da Costa, Long termpervaporation desalination of tubular MFI zeolite membranes, J. Membr. Sci.416 (2012) 816823.

[30] S. Khajavi, J.C. Jansen, F. Kapteijn, Production of ultra pure water bydesalination of seawater using a hydroxy sodalite membrane, J. Memb. Sci.356 (12) (2010) 5257.

[31] B. Feng, K. Xu, A. Huang, Synthesis of graphene oxide/polyimide mixed matrixmembranes for desalination, RSC Adv. 7 (2016) 22112217.

[32] K. Xu, B. Feng, C. Zhou, A. Huang, Synthesis of highly stable graphene oxidemembranes on polydopamine functionalized supports for seawaterdesalination, Chem. Eng. Sci. 146 (2016) 159165.

[33] B. Feng, K. Xu, A. Huang, Covalent synthesis of three-dimensional grapheneoxide framework (GOF) membrane for seawater desalination, Desalination394 (2016) 123130.

[34] S.B. Hamouda, A. Boubakri, Q.T. Nguyen, A.M. Ben Amor, PEBAX membranesfor water desalination by pervaporation process, High Perform. Polym. 23 (2)(2011) 25.

[35] M.L. Restrepo, M.A. Mosquera, Accurate correlation, thermochemistry, andstructural interpretation of equilibrium adsorption isotherms of water vaporin zeolite 3A by means of a generalized statistical thermodynamic adsorptionmodel, Fluid Phase Equilib. 283 (2009) 7388.

[36] F. Ugur, H. Dogan, N. Durmaz, Pervaporation of ethanol/water mixtures usingclinoptilolite and 4A fi lled sodium alginate membranes, Desalination 300(2012) 2431.

[37] F.U. Nigiz, N.D. Hilmioglu, Pervaporation of ethanol/water mixtures by zeolitefilled sodium alginate membrane, Desalination Water Treat. 51 (2013) 637643.

[38] P. Swenson, B. Tanchuk, A. Gupta, W. An, S.M. Kuznicki, Pervaporativedesalination of water using natural zeolite membranes, Desalination 285(2012) 6872.

[39] Q. Wang, N. Li, B. Bolto, M. Hoang, Z. Xie, Desalination by pervaporation: areview, Desalination 387 (2016) 4660.

[40] D. Sun, B. Li, Z. Xu, Pervaporation of ethanol/water mixture by organophilicnano-silica filled PDMS composite membranes, Desalination 322 (2013) 159166.

[41] Y. Fu, C. Lai, J. Chen, C. Liu, S. Huang, Hydrophobic composite membranes forseparating of water alcohol mixture by pervaporation at high temperature,Chem. Eng. Sci. 111 (2014) 203210.

[42] Q. Wang, Y. Lu, N. Li, Preparation, characterization and performance ofsulfonated poly (styrene-ethylene/butylene-styrene) block copolymermembranes for water desalination by pervaporation, Desalination 390(2016) 3346.

[43] A. Mafi, A. Raisi, M. Hatam, A. Aroujalian, A comparative study on the freevolume theories for diffusivity through polymeric membrane in pervaporationprocess, J. Appl. Polym. Sci. 40581 (2014) 112.

[44] H.G. Premakshi, K. Ramesh, M.Y. Kariduraganavar, Modification of crosslinkedchitosan membrane using NaY zeolite for pervaporation separation of water isopropanol mixtures, Chem. Eng. Res. Des. 94 (2014) 3243.

[45] URL-1. (visiting date: 24.03.2017)[46] URL-2.

(visiting date: 24.03.2017)[47] URL-3.

(visiting date: 24.03.2017)

http://refhub.elsevier.com/S1383-5866(17)31511-3/h0005http://refhub.elsevier.com/S1383-5866(17)31511-3/h0005http://refhub.elsevier.com/S1383-5866(17)31511-3/h0005http://refhub.elsevier.com/S1383-5866(17)31511-3/h0010http://refhub.elsevier.com/S1383-5866(17)31511-3/h0010http://refhub.elsevier.com/S1383-5866(17)31511-3/h0010http://refhub.elsevier.com/S1383-5866(17)31511-3/h0015http://refhub.elsevier.com/S1383-5866(17)31511-3/h0015http://refhub.elsevier.com/S1383-5866(17)31511-3/h0020http://refhub.elsevier.com/S1383-5866(17)31511-3/h0020http://refhub.elsevier.com/S1383-5866(17)31511-3/h0020http://refhub.elsevier.com/S1383-5866(17)31511-3/h0025http://refhub.elsevier.com/S1383-5866(17)31511-3/h0025http://refhub.elsevier.com/S1383-5866(17)31511-3/h0025http://refhub.elsevier.com/S1383-5866(17)31511-3/h0030http://refhub.elsevier.com/S1383-5866(17)31511-3/h0030http://refhub.elsevier.com/S1383-5866(17)31511-3/h0035http://refhub.elsevier.com/S1383-5866(17)31511-3/h0035http://refhub.elsevier.com/S1383-5866(17)31511-3/h0040http://refhub.elsevier.com/S1383-5866(17)31511-3/h0040http://refhub.elsevier.com/S1383-5866(17)31511-3/h0040http://refhub.elsevier.com/S1383-5866(17)31511-3/h0045http://refhub.elsevier.com/S1383-5866(17)31511-3/h0045http://refhub.elsevier.com/S1383-5866(17)31511-3/h0045http://refhub.elsevier.com/S1383-5866(17)31511-3/h0045http://refhub.elsevier.com/S1383-5866(17)31511-3/h0050http://refhub.elsevier.com/S1383-5866(17)31511-3/h0050http://refhub.elsevier.com/S1383-5866(17)31511-3/h0050http://refhub.elsevier.com/S1383-5866(17)31511-3/h0055http://refhub.elsevier.com/S1383-5866(17)31511-3/h0055http://refhub.elsevier.com/S1383-5866(17)31511-3/h0060http://refhub.elsevier.com/S1383-5866(17)31511-3/h0060http://refhub.elsevier.com/S1383-5866(17)31511-3/h0060http://refhub.elsevier.com/S1383-5866(17)31511-3/h0065http://refhub.elsevier.com/S1383-5866(17)31511-3/h0065http://refhub.elsevier.com/S1383-5866(17)31511-3/h0065http://refhub.elsevier.com/S1383-5866(17)31511-3/h0070http://refhub.elsevier.com/S1383-5866(17)31511-3/h0070http://refhub.elsevier.com/S1383-5866(17)31511-3/h0075http://refhub.elsevier.com/S1383-5866(17)31511-3/h0075http://refhub.elsevier.com/S1383-5866(17)31511-3/h0080http://refhub.elsevier.com/S1383-5866(17)31511-3/h0080http://refhub.elsevier.com/S1383-5866(17)31511-3/h0080http://refhub.elsevier.com/S1383-5866(17)31511-3/h0100http://refhub.elsevier.com/S1383-5866(17)31511-3/h0100http://refhub.elsevier.com/S1383-5866(17)31511-3/h0100http://refhub.elsevier.com/S1383-5866(17)31511-3/h0105http://refhub.elsevier.com/S1383-5866(17)31511-3/h0105http://refhub.elsevier.com/S1383-5866(17)31511-3/h0105http://refhub.elsevier.com/S1383-5866(17)31511-3/h0110http://refhub.elsevier.com/S1383-5866(17)31511-3/h0110http://refhub.elsevier.com/S1383-5866(17)31511-3/h0110http://refhub.elsevier.com/S1383-5866(17)31511-3/h0115http://refhub.elsevier.com/S1383-5866(17)31511-3/h0115http://refhub.elsevier.com/S1383-5866(17)31511-3/h0115http://refhub.elsevier.com/S1383-5866(17)31511-3/h0120http://refhub.elsevier.com/S1383-5866(17)31511-3/h0120http://refhub.elsevier.com/S1383-5866(17)31511-3/h0120http://refhub.elsevier.com/S1383-5866(17)31511-3/h0125http://refhub.elsevier.com/S1383-5866(17)31511-3/h0125http://refhub.elsevier.com/S1383-5866(17)31511-3/h0125http://refhub.elsevier.com/S1383-5866(17)31511-3/h0130http://refhub.elsevier.com/S1383-5866(17)31511-3/h0130http://refhub.elsevier.com/S1383-5866(17)31511-3/h0130http://refhub.elsevier.com/S1383-5866(17)31511-3/h0135http://refhub.elsevier.com/S1383-5866(17)31511-3/h0135http://refhub.elsevier.com/S1383-5866(17)31511-3/h0135http://refhub.elsevier.com/S1383-5866(17)31511-3/h0135http://refhub.elsevier.com/S1383-5866(17)31511-3/h0140http://refhub.elsevier.com/S1383-5866(17)31511-3/h0140http://refhub.elsevier.com/S1383-5866(17)31511-3/h0140http://refhub.elsevier.com/S1383-5866(17)31511-3/h0145http://refhub.elsevier.com/S1383-5866(17)31511-3/h0145http://refhub.elsevier.com/S1383-5866(17)31511-3/h0145http://refhub.elsevier.com/S1383-5866(17)31511-3/h0150http://refhub.elsevier.com/S1383-5866(17)31511-3/h0150http://refhub.elsevier.com/S1383-5866(17)31511-3/h0150http://refhub.elsevier.com/S1383-5866(17)31511-3/h0155http://refhub.elsevier.com/S1383-5866(17)31511-3/h0155http://refhub.elsevier.com/S1383-5866(17)31511-3/h0160http://refhub.elsevier.com/S1383-5866(17)31511-3/h0160http://refhub.elsevier.com/S1383-5866(17)31511-3/h0160http://refhub.elsevier.com/S1383-5866(17)31511-3/h0165http://refhub.elsevier.com/S1383-5866(17)31511-3/h0165http://refhub.elsevier.com/S1383-5866(17)31511-3/h0165http://refhub.elsevier.com/S1383-5866(17)31511-3/h0175http://refhub.elsevier.com/S1383-5866(17)31511-3/h0175http://refhub.elsevier.com/S1383-5866(17)31511-3/h0175http://refhub.elsevier.com/S1383-5866(17)31511-3/h0175http://refhub.elsevier.com/S1383-5866(17)31511-3/h0180http://refhub.elsevier.com/S1383-5866(17)31511-3/h0180http://refhub.elsevier.com/S1383-5866(17)31511-3/h0180http://refhub.elsevier.com/S1383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Deep purification of seawater using a novel zeolite 3A incorporated polyether-block-amide composite membrane1 Introduction2 Materials and methods2.1 Materials2.2 Membrane preparation2.3 Membrane characterization2.4 Seawater sample characterization2.5 Permeate analysis2.6 Pervaporative desalination of the NaCl-water solution and seawater

3 Results and discussion3.1 Membrane characterization3.2 Membrane performance of NaCl-water solution3.3 Membrane performance of seawater

4 ConclusionsAcknowledgementsReferences