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Background/Objectives: Membrane distillation (MD) is a thermally driven water separation process which has lately attracted the attention from the academics and industries due to its lower energy requirement relative to pressure driven process. The aim of this paper is to study the performance of self-fabricate hollow fiber membrane in reactive blue dye removal by membrane distillation technique. Methods/Statistical Analysis: In this work, the potential use of polyvinylidene fluoride (PVDF) for reactive blue dye removal was study by direct contact membrane distillation (DCMD). The membranes were produced by phase inversion spinning method with 1-methyl-2-pyrrolidone (NMP) solvent and ethylene glycol (EG) additive. The membranes were characterized in term of membrane morphology, porosity, liquid entry pressure and hydrophobicity. Findings: Relative to the pristine membrane, PVDF membrane with additive was discovered to be possessed enhanced membrane characteristics, i.e. higher liquid entry pressure and larger pore size. In terms of membrane stability, the experimental results demonstrated that the PVDF membranes with EG as additive were able to generate consistent flux, while maintaining a superior rejection rate of reactive blue dye. Application/Improvements: The result in this work shown that PVDF membrane with EG as additive possesses a superior permeate flux performance and rejection rate which suggested that this membrane possesses the prospect to be applied in the industrial textile wastewater treatment.

In this work, the efficiency of crude palm oil (CPO) deacidification using solvent extraction integrated with membrane technology is studied. Different solvents including ethanol, hexane and methanol were selected to extract the palmitic acid from model fatty system in the model fatty system to solvent ratio of 1:2. Experimental results showed that ethanol was the best solvent to extract palmitic acid from the model fatty system, recording about 65.5% fatty acid reduction in the model fatty system. Three commercial solvent resistant nanofiltration (SRNF) membranes (SolSep NF010206, NF030306, and NF030705) were then selected to examine their respective performance in recovering ethanol from palmitic acid-rich ethanol solvent. The results revealed that the combination of solvent extraction and membrane technology is remarkable simple and waste-free approach to overcome major drawbacks of conventional refinery operation.

The membrane technology is still considered a costly method to produce potable water. In view of this, RO membrane with enhanced water permeability without trade-off in salt rejection is desirable as it could further reduce the cost for water desalination. In this study, thin film nanocomposite (TFN) membranes containing 0.05 or 0.10 w/v% hydrophilic nanofillers in polyamide layer were synthesized via interfacial polymerization of piperazine and trimesoyl chloride monomers. The resultant TFN membranes were characterized and compared with a control thin film composite (TFC) membrane. Results from the filtration experiments showed that TFN membranes exhibited higher water permeability, salt rejection and fouling resistance compared to that of the TFC membrane. Excessive amount of nanofillers incorporated in the membrane PA layer however negatively affected the cross-linking in the polymer matrix, thus deteriorating the membrane salt rejection. TFN membrane containing 0.05 w/v% of nanofillers showed better performances than the TFC membrane, recording a pure water flux of 11.2 L/m2∙h, and salt rejection of 95.4%, 97.3% and 97.5% against NaCl, Na2SO4 and MgSO4, respectively.

In this study, nanoporous titanate (NT) nanoparticle synthesized by the solvothermal method was used to modify polyamide layer of thin film composite membranes with the aim of improving membrane resistances against organic and inorganic fouling. Thin film nanocomposite membranes (NMs) were synthesized by adding mNTs (modified nanoparticles) into polyamide selective layer followed by characterization using different analytical instruments. The results of XPS and XRD confirmed the presence of mNTs in the polyamide layer of NMs, while FESEM, AFM, zeta potential and contact angle measurement further supported the changes in physical and chemical properties of the membrane surface upon mNTs incorporation. Results of fouling showed that NM1 (the membrane incorporated with 0.01 w/v% mNTs) always demonstrated lower degree of flux decline compared to the control membrane when membranes were tested with organic, inorganic and multicomponent synthesized water, brackish water or seawater. Besides showing greater antifouling resistance, the NM also displayed significantly higher water flux compared to the control M membrane. The findings of this work confirmed the positive impact of mNTs in improving the properties of NM with respect to fouling mitigation and flux improvement.

Bisphenol A (BPA) is one of the recalcitrant contaminants that are detected in drinking water sources, as the conventional water treatment plant is incapable of removing it completely. This study was conducted to explore the performance of ultrafiltration (UF) membrane system for the BPA removal in which BPA was spiked in water sample collected from a treatment plant. The effects of process conditions that may influence the removal and flux performance of the membrane including operating pressure, feed pH and BPA concentration, and backwash cleaning were investigated. The results showed that an applied pressure of 1 bar was the optimum pressure for achieving good balance of BPA removal (95 %) and water flux (109 L m−2 h−1) compared to operating pressure of 0.5 and 1.5 bar. The variation of feed pH showed significant impact on BPA elimination with the highest rejection (90 %) achieved at pH 7 while the lowest removal (20 %) at pH 10. BPA concentration had no significant impact on BPA removal as high removal rate (>95 %) was observed regardless of feed concentration (between 10 and 100 μg L−1). The normalized flux showed decreasing trend with filtration cycle due to increased membrane resistance of BPA adsorption onto the membrane. The membrane cleaning via backwash was able to recover 90 % BPA removal even after three consecutive cycles of filtration. This indicated the promising performance of UF membrane system for industrial water treatment.

A synthesized dyeing solution consisted of reactive dye, salts, and polyvinyl alcohol was prepared and treated by two different types of commercial nanofiltration (NF) membranes, i.e. NF90 and NF270 under various process conditions. These NF membranes were evaluated for permeate flux, salt, and color rejection as well as fouling propensity for a certain period of operation. Results revealed that NF90 suffered significant flux decline compared to NF270 after four operation cycles of treatment process, indicating its high sensitivity to foulant attachment. With respect to color removal, it is found that NF270 demonstrated greater stability in maintaining its separation efficiency (between 94 and 98% rejection) regardless of the feed properties and number of operation cycles. Though the salt rejection of NF270 was not as high as NF90, its consistent separation performance throughout the study period proved its reliability in long run. Recommended chemical cleaning process was also conducted in an ef...

The influence of air bubble flow rate (ABFR), hydraulic retention time (HRT), mixed liquor suspended solid (MLSS) concentration, and pH on the performances of modified polyvinylidene fluoride (PVDF) was investigated in submerged membrane ultrafiltration (SMUF).The refinery wastewater process was conducted using an experimental set-up consisted of an SMUF reservoir, a circulation pump, and an aerator. For SMUF, operated at vacuum pressure, deposition and accumulation of suspended solids on membrane surface were prohibited with continuous aeration. The process performance was measured in terms of the membrane water flux and chemical oxygen demand (COD) removal efficiency. The air bubbles flow rate was controlled at 1.2–3.0 mL/min while HRT was manipulated in the range of 120–300 min. MLSS and pH solution were controlled at 4.5 g/L and 6.5, respectively. Results from response surface methodology (RSM) have demonstrated the improvement in water flux and COD removal, achieving 145.7 L/m2 h and 90.8%, respectively. By using pH at 6.50, the optimized conditions achieved for refinery wastewater treatment were 2.25 mL/min, 276.93 min, 4.50 g/L for ABFR, HRT and MLSS concentration, respectively.

Since the breakthrough discovery made by Cadotte and his co-workers in the 1970s, thin-film composite (TFC) membrane prepared using interfacial polymerization (IP) technique has experienced significant progress in composite membrane development and emerged as one of the most advanced technologies in water and wastewater purification processes. Nowadays, the most promising technology to desalinate seawater is reverse osmosis (RO), which is driven by a pressure gradient across a semi-permeable membrane. This technology has drawn great attention mainly due to its relatively low energy usage during operation as well as easy of operation and maintenance compared to other conventional technologies such as thermal desalination. On the basis of the brief introduction on TFC membrane, this paper will highlight the recent developments of RO TFC membrane and its challenges in seawater desalination process with respect to fouling problem, boron rejection and chlorine attack. Future directions in SWRO membrane research are also discussed to further expand research and development related to seawater desalination process.

The major breakthrough in the preparation of thin film composite (TFC) membrane via interfacial polymerization technique has resulted in tremendous achievements in producing a membrane with a right combination of flux and salt rejection, and generating huge interest in industrial sectors. Over the past decade, there have been intensive and continuous efforts in the development of TFC membrane, both from the industry and academia with the interests to further improve the membrane productivity and selectivity as well as its tolerance against chlorine, solvent, fouling, etc. On basis of a brief introduction of the development history of TFC membranes, this paper reviews the recent research progress of the TFC membrane science and technology, particularly in the fields of water-related separation processes. Reviewing the research progress is imperative and necessary in order to provide an insight for the future development and perhaps open a door to extend the applications to other more challenging areas.

Carboxylated polysulfone (CPS), poly (1,4-phenylene ether ethersulfone) (PPEES), membranes were prepared and used for the separation of NaCl and CaCl2, in efficient way with less energy consumption. In this work, nanofiltration and reverse osmosis membranes were employed to the salt rejection behavior of the different salt solutions. The influence of applied pressure (1-12 bar), on the membrane performance was assessed. In CM series of membranes, CM1 showed maximum of 97% water uptake and 36% water swelling, whereas, CM4 showed 75% water uptake and 28% water swelling. In RCM series, RCM1 showed 85% water uptake and 32% water swelling whereas, in RCM4 it was 68% for water uptake and 20% for water swelling. Conclusively reverse osmosis membranes gave better rejection whereas nanofiltration membrane showed enhanced flux. CM1 showed 58% of rejection with 12 L/(m 2 h) flux and RCM1 showed 55% of rejection with 15 L/(m 2 h) flux for 0.1 wt.% NaCl solution. Whereas, in 0.1 wt.% CaCl2 solution, membrane CM1 showed 78% of rejection with 12 L/(m 2 h) flux and RCM1 showed 63% rejection with flux of 9 L/(m 2 h).

In this study, polysulfone (PSF) hollow fiber membranes with enhanced performance for humic acid removal were prepared from a dope solution containing PSF/DMAc/PVP/TiO2. The main reason for adding titanium oxide during dope solution preparation was to enhance the antifouling properties of membranes prepared. In the spinning process, air gap distance was varied in order to produce different properties of the hollow fiber membranes. Characterizations were conducted to determine membrane properties such as pure water flux, molecular weight cut off (MWCO), humic acid (HA) rejection and resistance to fouling tendency. The results indicated that the pure water flux and MWCO of membranes increased with an increase in air gap distance while HA retention decreased significantly with increasing air gap. Due to this, it is found that the PSF/TiO2 membrane spun at zero air gap was the best amongst the membranes produced and demonstrated > 90% HA rejection. Analytical results from FESEM and AFM also provided supporting evidence to the experimental results obtained. Based on the anti-fouling performance investigation, it was found that membranes with the addition of TiO2 were excellent in mitigating fouling particularly in reducing the fouling resistances due to concentration polarization, cake layer formation and absorption.

Polyethersulfone (PES)/poly (ether ether ketone) (SPEEK) blends nanofiltration membrane at different SPEEK contents were prepared using a simple dry-jet wet spinning technique. The SPEEK polymer with fixed sulfonation degree was used for membrane preparation and characterized using FTIR and nuclear magnetic resonance (NMR) spectrometer. The morphological and electrical properties of the blends membrane were deduced based on the combination of irreversible thermodynamic model, steric-hindrance pore model (SHP) and Teorell-Meyer-Sievers model (TMS). The modeling results have been analyzed and discussed. The effect of SPEEK content on the blend properties was further studied in detail by FTIR, DSC and TGA and the results were discussed.

This paper reviews the application of polymeric nanofiltration membranes (NF) in the specific waste stream in the textile industry, which typically generates large volumes of wastewater containing complex contaminants from its daily operation. It is necessary that as much of this waste as possible is recycled instead of being disposed of in landfill sites. Most of the conventional technologies seem unable to provide sufficient treatment for the effluents. Therefore, it is generally accepted that NF membranes offer solutions for the problem. Of these NF membranes, the thin-film composite nanofiltration (TFC-NF) membrane is the most widely used by researchers in their studies. The effects of the manufacturing conditions of TFC-NF are discussed to provide valuable information for those who are going to choose NF membranes in textile wastewater treatment. The preliminary performances of commercial NF membranes have been examined in terms of dye rejection, salt rejection, permeate flux and COD rejection. Some of the commercial membranes achieved maximum separation of dye and salts while some achieved higher flux. This is because of the large variability of the parameters of textile wastewater and the NF membranes chosen. Due to the scarcity of published papers covering the transport model that is specifically suitable for textile coloured wastewater, a brief review of transport models of NF membranes with the presence of the dyes and salts is given. Membrane fouling mechanisms and methods to control fouling are also reviewed. Future directions in NF membrane research are also discussed to further expand research and development related to textile wastewater treatment.

Polyethersulphone (PES) membranes blended with silicon dioxide (SiO2) nanoparticles were prepared via a dry-jet wet spinning technique for the removal of bisphenol A (BPA) by adsorption mechanism. The morphology of SiO2 nanoparticles was analysed using a transmission electron microscopy and particle size distribution was also analysed. The prepared membranes were characterized by several techniques including field emission scanning electron microscopy, Fourier transform infrared spectroscopy and water contact angle. The adsorption mechanism of membrane towards BPA was evaluated by batch experiments and kinetic model. The influence of natural organic matter (NOM) in feed water on membrane BPA removal was also studied by filtration experiments. Results showed that BPA adsorption capacity as high as 53 µg/g could be achieved by the PES membrane incorporated with 2 wt% SiO2 in which the adsorption mechanism was in accordance with the pseudo-second-order kinetic model. The intraparticles diffusion model suggested that the rate limiting factor of membrane adsorption mechanism is governed by the diffusion of BPA into the membrane pores. The presence of 10 ppm NOM has reported to negatively reduce BPA removal by 24%, as it tended to compete with BPA for membrane adsorption. This work has demonstrated that PES-SiO2 membrane has the potential to eliminate trace amount of BPA from water source containing NOM.

In this research, novel ultrafiltration nanocomposite membranes were prepared by incorporating self-synthesized nanoporous titanium dioxide (NTiO2) nanoparticles into polysulfone. The surface of the nanoparticle was treated with a silane-based modifier to improve its distribution in the host polymer. Atomic-force microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller, transmission electron microscopy, energy-dispersive x-ray spectroscopy, porosity and contact angle tests were conducted to characterize the properties of the particles as well as the fabricated nanocomposite membranes. The effects of the nanoparticle incorporation were evaluated by conducting ultrafiltration experiments. It was reported that the membrane pure water flux was increased with increasing NTiO2 loading owing to the high porosity of the nanoparticles embedded and/or formation of enlarged pores upon addition of them. The antifouling capacity of the membranes was also tested by ultrafiltration of bovine serum albumin fouling solution. It was found that both water flux and antifouling capacity tended to reach desired level if the NTiO2 added was at optimized loading.

The present work reviews the current fabrication methods of the functionally graded polymeric material (FGPM) and introduces a novel fabrication method that is versatile in applications as compared to those of existing used methods. For the first time electrophoresis was used to control the distribution of the tetracycline hydrochloride (TC) in a film made of polylactic acid (PLA), aiming to induce antimicrobial effect on the film prepared. The elemental analysis on the film surface showed that by employing electrophoresis force, higher amount of TC was detected near the top surface of the film. Results also showed that the FGPM samples with higher percentage of the TC on the film surface were highly effective to minimize the growth of Escherichia coli. These findings are useful and important to improve dispersion quality of the particles in the composite material and further enhance its antibacterial property.

The introduction of inorganic nanoparticles in polymeric dope solution for the fabrication process of membrane can potentially enhance the separation performances of membrane without negatively affecting its permeability. In this study, hollow fiber mixed matrix membranes were prepared by incorporating polyethersulfone (PES) membranes with silicon dioxide (SiO2) nanoparticles at different concentration. Prior to separation tests, the prepared membranes were characterized by SEM, EDX, DSC, water contact angle, and FTIR-ATR in order to study the impact of silica nanoparticles on the properties of the membranes. Bisphenol A (BPA) was selected as the subject compound of this study because it is one of the emerging pollutants that have been frequently detected in the water treatment plant (WTP). BPA was spike into the pre-treated water sample taken from the WTP and was used as the feed solution to evaluate the membrane performance in terms of water flux and removal rate. The addition of SiO2 was reported to improve the hydrophilicity of membrane and induce greater micro-voids formation in the membrane structures, leading to increased water flux during BPA filtration process. The presence of more silanol (Si-OH) and siloxane (Si-O-Si) bonding groups resulted from increased SiO2 contents in membrane has improved membrane adsorption rate and further increased BPA removal.

This review focuses on the development of polyamide (PA) thin film nanocomposite (TFN) membranes for various aqueous media-based separation processes such as nanofiltration, reverse osmosis and forward osmosis since the concept of TFN was introduced in year 2007. Although the total number of published TFN articles falls far short of the articles of the well-known thin film composite (TFC) membranes, its growth rate is significant, particularly since 2012. Generally, by incorporating an appropriate amount of nanofiller into a thin selective PA layer of a composite membrane, one could produce TFN membranes with enhanced separation characteristics as compared to the conventional TFC membrane. For certain cases, the resulting TFN membranes demonstrate not only excellent antifouling resistance and/or greater antibacterial effect, but also possibly overcome the trade-off effect between water permeability and solute selectivity. Furthermore, this review attempts to give the readers insights into the difficulties of incorporating inorganic nanomaterials into the organic PA layer whose thickness usually falls in a range of several-hundred nanometers. It is also intended to show new possible approaches to overcome these challenges in TFN membrane fabrication.

This review provides a comprehensive survey on the characterization methods used to study the properties and performances of thin film composite nanofiltration (NF) membranes in water separation processes. In general, the intrinsic properties of NF membranes are characterized with respect to chemical properties and physical properties using various analytical instruments. For instance, FTIR spectroscope, zeta potential analyzer, XPS, XRD, and NMR spectroscope are some of the widely used instruments to evaluate the membrane chemical properties while SEM, FESEM, TEM, AFM, contact angle goniometer, and positron annihilation spectroscopy are those that have been commonly employed to study the membrane structural properties. With respect to permeability and selectivity, NF membranes are generally characterized through filtration experiments using appropriate feed properties under specific testing conditions. Furthermore, this review also covers the characterization techniques used to study the resistance of NF...

In the present study, the self-synthesized thin film nanocomposite (TFN) membrane incorporated with hydrophilic functionalized titanate nanotubes (TNTs) has been fabricated and tested for forward osmosis (FO) desalination. The ATR-FTIR results showed that NH 2 -TNT S were successfully modified by AATPS and while TEM and XRD revealed the tubular morphology and crystal structure of NH 2 -TNTs nanotubes, respectively. The presence of the chemical bondings between NH 2 -TNTs and polyamide (PA) selective top layer of TFN is corroborated with the FTIR results. The existence of NH 2 -TNTs in PA top layer was further confirmed by XPS analysis on the control and TFN membranes. The effect of NH 2 -TNTs on the PA layer was investigated and discussed in terms of surface morphology and separation performance. The morphology of the PA layer was investigated through FESEM and AFM micrographs and the outgrowth of the “leaf-like” structure was observed following the increase in NH 2 -TNTs content. Compared to the thin film composite (TFC) control membrane, the TFN membrane embedded with 0.05 wt% NH 2 -TNTs (designated as TFN0.05) exhibited two times improvement in water flux without sacrificing salt rejection.

Facile blending approach utilizing amphiphilic copolymers has received enormous attention from researchers owing to their unique self-organizing behaviour that can improve membrane structure and separation properties. This paper discusses the effect of the amount of acrylonitrile (AN) monomer added during polyacrylonitrile-g-polyvinyl alcohol (PAN-g-PVA) copolymer synthesis and its relationship to the properties and performance of PAN-based ultrafiltration (UF) hollow fiber membrane. The hollow fiber membranes were characterized using atomic force microscope, scanning electron microscope, X-ray photoelectron spectroscope and contact angle goniometer, in addition to performance evaluation with respect to protein rejection and antifouling resistance. As for the UF experiments, the membrane incorporated with copolymer of highest monomer composition achieved the highest pure water flux (178.76 L/m2.hr) coupled with good rejection of bovine serum albumin (BSA) and albumin from chicken egg (at least 83 %) when tested at 1 bar. The promising results are mainly due to the changes in the membrane morphological properties, surface roughness, surface chemical composition and hydrophilicity upon the addition of the copolymer. In terms of anti-fouling performance, generally, blend membrane prepared from copolymer of lowest amount of monomer produced good flux recovery for all proteins (74 %, 67 % and 62 % during BSA, albumin from chicken egg and trypsin) filtration due to the enrichment of PVA on membrane surface and its low surface roughness. The experimental results offer an important insight into the relationship between amount of monomer added during graft copolymer synthesis and membrane properties and performance, providing valuable information for high performance UF membrane for fouling mitigation especially in the area involving proteinaceous solution.

Sulfonated poly (ether ether ketone) (SPEEK)/Cloisite 15A® nanocomposite membranes were prepared via solution intercalation method. For better dispersion of nanoclay in the polymer matrix, the solution intercalation method was modified and a compatibilizer was introduced. The state of nanoclay dispersion was determined by FESEM. The effect of the solution formulation preparation method and compatibilizer on the performance properties such as proton conductivity and methanol permeability of all membranes was studied. FESEM analysis confirmed that SPEEK/Cloisite 15A® nanocomposite membrane prepared via modified solution intercalation method and in the presence of compatibilizer was the best membrane in terms of its morphological structure. Due to its well nanoclay distribution in polymer matrix, this kind of membrane exhibited the highest selectivity owing to its high proton conductivity and low methanol permeability. SPEEK/Cloisite 15A® with compatibilizer prepared via modified solution intercalation method was found to be the best membrane.

In this study, polyphenylsulfone (PPSU) which is a third member of the polysulfone (PSF) family, with even better properties than PSF and polyethersulfone (PES) was used to prepare flat sheet solvent resistant nanofiltration (SRNF) membranes. The SRNF membranes were prepared from different PPSU concentrations (i.e. 17, 21 and 25 wt%) via phase inversion method. The performance of membranes was then evaluated by measuring the methanol flux and rejection against dyes of different molecular weight (MW) dissolved in methanol. The study revealed that the membrane with the lowest polymer concentration produced the highest pure methanol flux and required the longest time to achieve steady-state owing to its porous structure. Results also showed that the flux of the membranes tended to decrease with filtration time due to the membrane compaction. With respect to the membrane separation performance, it was found that the membrane dye rejection increased while permeate flux decreased with increasing the MW of dye components from 269 to 1470 g/mol, irrespective of the polymer concentration. Furthermore, the membrane MWCO was found to change with polymer concentration in which an increase in polymer concentration led to a lower membrane MWCO.

Membrane distillation (MD) is one of the recent rising membrane separation techniques adopted in the desalination and wastewater treatment. Unlike other pressure-driven separation processes such as reverse osmosis and nanofiltration, MD is a thermal-driven process which involves vapor pressure difference across the feed and permeates solutions. As such, MD requires low energy consumption. Hydrophobic polymeric materials such as polyvinylidene fluoride (PVDF) are frequently used in direct contact membrane distillation (DCMD) due to low surface energy and promising thermal resistance. In this study, the DCMD hollow fiber membranes were separately prepared with PVDF and PVDF blended with lithium chloride (LiCl) through dry/wet phase inversion method. Subsequently, the membranes were used in a DCMD process to remove sodium chloride (NaCl) under different feed inlet temperatures to examine the effect of LiCl additives on the neat membrane. The result showed that by adding LiCl into the neat membrane solution, the finger-like structure was change to a sponge-like structure with microvoids. Furthermore, the performance of the LiCl additive membrane in term of permeate flux was found to be 20% higher compared to that of the neat membrane. Other results of the membrane characteristics were also discussed.

Polyvinylidene fluoride (PVDF) hollow fiber ultrafiltration (UF) membranes consisted of TiO2 and different molecular weight (Mw) of polyvinylpyrrolidone (PVP) (i.e. 10, 24, 40 and 360 kDa) were prepared to treat synthesized oily wastewater. The membrane performances were characterized in terms of pure water flux, permeate flux and oil rejection while the membrane morphological properties were studied using SEM and AFM. PVDF-TiO2 composite membrane prepared from PVP40k was found as the optimum membrane due to its high flux and high rejection during filtration process, recording 45 L/m2.h and 80% respectively, when tested using 250 ppm oily solution under submerged condition. The experimental results demonstrated that with increasing Mw of PVP, PVDF-TiO2 membrane had higher protein rejection, smaller porosity and smoother surface layer. With increasing oil concentration from 250 to 1000 ppm, the permeate flux of the PVDF-PVP40k was obviously decreased while the oil rejection was gradually increased due to the additional selective layer formed on the membrane surface. Based on the findings, the PVDF-TiO2 membrane with PVP40k can be considered as a potential membrane for oily wastewater industry due to the high permeate flux and oil rejection.

The objectives of this study are to study the effect of hydrophobicity degree of polyvinylidene fluoride (PVDF) hollow fiber membranes blended with different types of additives i.e. ethylene glycol (EG) and polyvinylpyrrolidone (PVP) on textile wastewater application. The degree of hydrophobicity of each membrane was analyzed using contact angle goniometer. The membrane morphology and gas permeability were characterized prior to filtration experiment. Both membranes were tested using direct contact membrane distillation (DCMD) system and their performances were evaluated with respect to water flux and dye removal. This study revealed that the membrane with higher contact angle has greater stability in terms of flux and dye rejection compared to the membrane with low hydrophobic property. This is mainly due to the low surface energy obtained by the highly hydrophobic membrane that prevented the liquids from both sides to penetrate through membrane pores.

Palm oil mill effluent (POME) is the largest pollutant discharged into the rivers of Malaysia. An efficient treatment system is highly desirable in palm oil mills in order to control the effluent discharged to any water bodies. In this study, composite ultrafiltration (UF) membranes were successufully prepared by incorporating polysulfone (PSF)/polyphenylsulfone (PPSU) blend membranes with inorganic TiO2 nanoparticles in the range of 0–4 wt%. Prior to POME treatment process, the properties of the resulting membranes were first characterized with respect to pure water flux, BSA rejection, hydrophilicity and structural morphologies. Of the membranes tested, it is found that membrane without TiO2 incorporation demonstrated the highest pure water flux, i.e. 82.81 L/m2h with BSA rejection of 98% when tested at 2 bar. The decreasing water flux with increasing TiO2 loading in the membrane is mainly due to the high viscosity of the dope solution which delayed the phase inversion process and resulted in reduced surface pore size. For the POME treatment process, the results showed that UF membrane could effectively treat the wastewater by removing up to 87% BOD3, 90% COD and almost complete elimination of turbidity.

One of the big challenges in developing a good asymmetric membrane is macrovoid formation that leads to reduction of rejection value. The most common method to reduce or suppress macrovoid formation is by addition of controlled solvent to the coagulation bath. Therefore, the effect of difference coagulants based on dissolved KCl (monovalent) and dissolved Na2SO4(divalent) with different concentration onto asymmetric Polysulfone (PSf) ultrafiltration membrane was investigated in this work. The PSf ultrafiltration membranes were prepared by using phase inversion method using these two immerse aqueous solutions. The performances of membranes were evaluated via pure water flux (distilled water) and solute rejection (humic acid). Results on the cross section revealed that the structure of membrane show a straight pattern of bigger finger-like pore structure from top to bottom layer tend to reduce with at the same time the diameter of finger-like pore structure also increased, as salt medium of coagulant increases. These obviously shown by permeation values for both salt mediums were higher compared to without salt coagulant. This reduction of finger-like structure at bottom layer occurred along together with the formation of sponge shape structure. The growth of thick sponge shape is strongly influence by kinetic phase inversion of salt coagulant that also creates resistance to permeation mechanism. However the intense salt coagulant medium can cause the bigger sponge structure that will slightly reduce rejection and increase the permeation. This was proved by the rejection of KCl medium started to increase at 1-3% but slightly reduced at 4%. Based on the result analysis demonstrated that the ideal membrane with highest rejection and good permeation values was membrane immersed into 1% Na2SO4 coagulation medium.

The present study focuses on the effect of poly (acrylonitrile) (PAN)-g-poly (vinyl alcohol) (PVA) amphiphilic copolymer as an additive on fabrication of PAN-based UF hollow fiber membrane. The PAN-based hollow fiber membranes with different copolymer composition in dope solution were prepared via dry-wet phase inversion process. Compared to PAN-based membrane, membranes incorporated with PAN-g-PVA copolymer displayed good morphology and better hydrophilicity. It is found that pure water flux of the membrane incorporated with amphiphilic copolymer was 5 times higher than that of control membrane, recording 244.97 L/m2.hr when tested at 1 bar. Results also showed that the UF membranes incorporated with amphiphilic copolymer were able to retain efficiently bovine serum albumin (BSA) (66 kDa) and possessed better anti-fouling performance.

In the current study, the impact of self-synthesized nanoporous titanium oxide (NT) on the morphology, performance and fouling of a polyamide (PA) thin-film composite (TFC) membrane was investigated when the membrane was applied for engineering osmosis (EO). The nanoporous structure and the spindle-like shape of NT were revealed through transmission electron microscopy (TEM), while the AATPS modification of NT was verified by attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. The results of x-ray photoelectron spectroscopy (XPS) and x-ray diffraction (XRD) confirmed the presence of modified NT (mNT) in the PA dense active layer of the TFC membrane. The outgrowth of the 'leaf-like' structure, upon mNT loading, at the surface of the PA layer was observed by field-emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM). The TFC membrane prepared with 0.05 wt% mNT loading in the organic phase showed the water flux of 26.4 l m(-2) h(-1) when tested in the forward osmosis (FO) mode using 0.5M and 10 mM NaCl solution as the draw and feed solution, respectively. Moreover, the TFC-mNT membrane also demonstrated an intensified antifouling property against organic foulant during FO application and it was possible to retrieve the initial water flux almost completely with a simple water-rinsing process.

The improvement of membrane performances in terms of separation and permeation is a constant research problem. In this study, polyethersulfone (PES) hollow fiber nanocomposite membranes were fabricated with titania nanotubes (TNT) synthesized via hydrothermal method used as inorganic filler to improve separation and membrane permeation. The membranes were prepared using dry/wet phase inversion process. The concentration of PES was fixed at 18% and TNT was added at concentration of 0.1% wt. The membranes were characterized in terms of pure water permeation rate (PWP), proteins (BSA) rejection, porosity and water contact angle. The results showed that addition of TNT improves the water flux and rejection rate as well as increasing hydrophilicity of the membrane. The flux of membrane is improved more than 20% while the rejection has been improved from 79% to 96%. The addition of TNT into the membrane matrix has shown that photocatalytic property can be introduced to a normal membrane.

Membrane distillation is one of the recently interest rising membrane separation processes used for the separation of seawater and saline wastewater, and etc. Membrane distillation has the advantage of adopting the low grade waste energy and/or renewable energy such as solar and geothermal energy due to the nature of thermal driven process and low temperature range. Computational Fluid Dynamics (CFD) is a numerical simulation tool that is able to perform the calculation in order to investigate and simulate the performance of the processes that involve fluid, heat and mass transfer. In this study, a direct contact membrane distillation (DCMD) experiment will be studied using hollow fiber membrane module. A three dimensional (3D) CFD simulation will be examined for its viability in the investigation of the DCMD. Furthermore, various CFD multiphase models will be studied for its suitability in predicting heat and mass behavior within the membrane.