Ultrafiltration Mixed Matrix Membranes Research Articles

Preparation of TA-O-MoS2/PES mixed matrix ultrafiltration membrane for rare earth wastewater treatment

The trade-off between permeability and selectivity, along with the issue of membrane fouling, has constrained the widespread application of ultrafiltration (UF) membranes in recycling rare earth wastewater. Here, we present the incorporation of tannic acid (TA) modified molybdenum disulfide oxide (O-MoS2) as a functional enhancer to fabricate polyethersulfone (PES) based mixed matrix membranes through a nonsolvent induced phase separation (NIPS) approach. Compared to the unmodified PES membrane, the integration of TA-O-MoS2 significantly improves the hydrophilicity, porosity in the mixed matrix membrane. By altering the concentration of TA-O-MoS2, the TA-O-MoS2/PES UF membrane achieves enhanced hydrophilicity and charge properties, resulting in a remarkable improvement in separation performance. Specifically, the optimized membrane M2 (TA-O-MoS2 addition of 0.1 wt%) exhibits a water flux of 140.98 Lm−2h−1bar−1 and a PEG 20000 rejection rate of 91.00 %, representing increases of 180 % and 120 % over the control PES membrane, respectively. Notably, membrane M2 effectively retains 91.31 % of macromolecular organic compounds in rare earth wastewater, while permitting nearly complete passage of inorganic salts, for instance CaCl2 (3.26 %) and MgSO4 (4.84 %). Moreover, the TA-O-MoS2/PES membrane demonstrates robust antifouling properties and exceptional durability, indicating its significant potential for efficient treatment and resource recovery in rare earth wastewater.

Polysulfone (Psf) Mixed Matrix Membrane incorporating Titanium Dioxide (TiO2)/Polyethylene Glycol (PEG) for the removal of copper

The global increasing contamination of water resources with toxic metals such as copper (Cu), poses severe threats to human health and aqueous ecosystems. Therefore, the ultrafiltration mixed matrix membranes (UF MMMs) possess an applicable approach for the removal of copper ions. This novel fabricated technology can be applied in various wastewater treatment systems for the removal of heavy metals, especially copper. MMMs were fabricated by blending polysulfone (Psf) with additives into the dope solution via the phase inversion method by incorporating titanium dioxide (TiO2) and polyethylene glycol (PEG) in Psf MMMs. Seven Psf MMMs samples labelled M0 to M6, each with its own formulation, were prepared and tested for density, porosity, and degree of Cu retention. MMMs were further characterized via Fourier transform infrared spectroscopy (FTIR), which revealed the range of the IR spectrum of Psf polymer membrane from 1319 cm-1 to 1600 cm-1, 1650 cm-1 to 3400 cm-1 for PEG, and 800 cm-1 to 3600 cm-1 for TiO2 NPs. As for the scanning electron microscopy (SEM), M6 (Psf/TiO2/PEG 6000) was found to be the most dense and highest porous morphology asymmetric Psf MMM. The retained percentage of Cu and flux for M6 attained the highest value of 80.3% and 136.99 L/m2 .h respectively, whereas for the neat Psf membrane, M0 exhibited the lowest retained percentage of Cu and flux, about 25.8% and 61.64 L/m2.h. The inclusion of pore former and additives has shown an improvement of 54.5% in the copper rejection. Moreover, M6 displayed the highest antifouling properties compared to other Psf MMMSs. This study proves that PEG and TiO2 additives have significant potential to improve membrane performance due to the highest percentage of Cu retained on the surface of the membrane as adsorptive separation on Psf MMMs.

Enhanced permeability and antifouling properties of carboxylated polysulfone/quaternized polyimide blend ultrafiltration membrane

AbstractThe intricate interplay between chemical composition and the incorporation of functional fillers plays a pivotal role in shaping the structural attributes and separation efficacy of mixed matrix ultrafiltration membranes. In this work, we report the utilization of a novel organic filler of hydrophilic modified polyimide particles (PI‐SO3) for the first time in the preparation of mixed matrix ultrafiltration membranes. A series of ultrafiltration membranes were fabricated using polysulfone as the matrix material and PI‐SO3 as the additive. The addition of PI‐SO3 to the mixed matrix membrane effectively enhanced both water flux and antifouling ability. The ultrafiltration membrane with 0.2% particle content exhibited the highest pure water flux at 535.5 L h−1 m−2, owing to the synergistic regulation of pore structures and surface hydrophilicity. The ultrafiltration membrane with 0.5% PI‐SO3 particles demonstrated the highest flux recovery rate at 76.8%, attributed to the superior hydrophilicity displayed by the added particles within the ultrafiltration membrane. The increased particles content correlated with improved hydrophilicity on the membrane surface, resulting in enhanced antifouling performance. The hydrophilic modified particles effectively regulated pore structures, surface hydrophilicity, and surface charge, ultimately enhancing the performance of mixed matrix ultrafiltration membranes for wastewater purification. Therefore, the use of modified polyimide particles as fillers introduces an innovative method to economically enhance ultrafiltration membranes, providing a potential solution to mitigate the economic costs associated with trade‐off effects during the modification process.

Heavy metals remediation using MOF5@GO composite incorporated mixed matrix ultrafiltration membrane

A polysulfone-based mixed matrix membrane (MMM) was prepared by incorporation of MOF5@GO composite in the polymer matrix. The prepared membrane was characterized by permeability, scanning electron microscopy, Fourier transform infrared spectroscopy, zeta potential, X-ray photoelectron spectroscopy, atomic force microscope, molecular weight cut-off and average pore radius. MMM exhibits enhanced permeability, pore size, surface roughness and molecular weight cut-off compared to polysulfone membrane. Pure water permeability of M−0.5 enhanced from 37.9 to 59.5 L/m2h.bar, which corroborated an increase in molecular weight cut-off from 46.9 to 74.1 kDa and pore radius from 66.9 to 75.4 Å as MOF5@GO composite was incorporated in polysulfone polymer matrix. At neutral pH, the optimized MMM (M−0.5) shows –22.7 mV zeta potential facilitating the adsorption of heavy metals. The M−0.5 membrane exhibits 95–99 % rejection of Pb, Cu, Zn and Cd at 2 bar pressure with enhanced permeate flux (∼116 L/m2h) compared to the polysulfone membrane. M−0.5 membrane shows better antifouling properties than the polysulfone membrane. Among the heavy metals studied, lead and copper showed the maximum rejection. The MMM shows 99 % rejection of lead and copper and breakthrough time of 12 and 9 h, respectively for a small membrane area (0.0012 m2). Thus, the prepared low-pressure driven mixed matrix ultrafiltration membrane was suitable and competent for heavy metal rejection. A modified convection-adsorption model based on the first principle was used to predict the long-term filtration performance of the membrane. The same model was used to generate the performance curve for scaling up the process.

The role of membrane filtration in wastewater treatment

AbstractWater is vital for the sustainable growth of human communities. Due to the greatest population and significant economic development, demands on water and purification have significantly risen. Classical wastewater treatment procedures have made some progress over the years in purifying effluents for disposal, but they fall lacking in the way they deeply control emerging harmful substances. The potential to reuse treated wastewater for home, agricultural, and industrial needs depends on breakthroughs in purifying technologies. One of the most recent breakthroughs to be implemented effectively in reducing contaminants to desirable levels is membrane technology. Nanofiltration, microfiltration, reverse osmosis, ultrafiltration, and membrane bioreactors are examples of widely utilized membrane processes depending on features such as size or charge. Over traditional treatment, membrane technology offers various benefits. This review article discusses a number of membrane‐related topics, including membrane categorizing, application in various fields, benefits, and drawbacks. Furthermore, offers an outlook of the filtering membranes that will be used in the future. Smart membranes have gained interest because of their tunable permeability and selectivity characteristics. Technological advancements in the media that are utilized in activated growth membrane bioreactors. Modified interfacial polymerization approaches have been investigated in addition to adsorptive ultrafiltration mixed matrix membranes to enhance the performance of the polyamide thin‐film composite and thin‐film nanocomposite membranes.

Mesoporous Mg–Al–Ti composite oxide incorporated mixed matrix ultrafiltration membrane with superior multi-heavy metal removal capacity, anti-fouling & anti-microbial property

Mesoporous Mg–Al–Ti ternary composite oxide nano-adsorbents have demonstrated an exceptional performance to remove multiple heavy metals (As, Pb, Cd, Cr). Incorporation of these nanoparticles (NPs) in polysulfone membrane created a multifunctional mixed matrix membrane (MMM) with heavy metal adsorption capacity (both cationic and anionic species), enhanced hydrophilicity, anti-fouling property, and anti-microbial activity. The best heavy metal removal performance was shown by the membrane incorporated with 0.8 wt% NPs. Hydrophilicity improvement was studied through the decrease in water contact angle from 71° to 57° and surface probing using atomic force microscopy (AFM). With a maximum As(III) adsorption capacity of 256.6 mg/g, the membrane had a breakthrough volume of 25L and could provide safe drinking water for 19 h from a real Arsenic (As) contaminated groundwater sample with a flux of 48 l/m2-h. Beyond that, >90 % removal of Cd, Pb & Cr was also observed with maximum adsorption capacity of 652.9 mg/g, 332.5 mg/g, and 89.4 mg/g respectively. 92.5 % flux recovery after filtering a 1000 ppm bovine serum albumin showed the anti-fouling property. Successful inhibition of both gram-positive and gram-negative bacterial growth, and >99.99 % removal of colony forming units (CFU/ml) in the filtration process confirmed the anti-microbial resistance. With its multifunctionality, these membranes hold great potential for practical water treatment applications.

Morphological effects of sphericalSiO2and hexagonal mesoporousMCM‐41 nanoparticles in polyacrylonitrile mixed matrix membranes on the biofouling mitigation in short‐term filtration

AbstractIn this study, the morphology of the nanostructures is evaluated on the surface characterization and performance of the polyacrylonitrile (PAN) ultrafiltration mixed matrix membranes (MMM). To this end, silica nanoparticles (NPs) such as spherical (SiO2) and hexagonal mesoporous (MCM‐41) with high hydrophilicity were incorporated at 0.5, 1, and 2 wt%. Attenuated total reflectance‐Fourier transform infrared analysis illustrated the placement of NP on the surface of the MMM. Atomic force microscopy studies also showed that SiO2NP added to PAN exhibited a smoother surface than MCM‐41 NP. Field‐emission scanning electron microscope analysis of the MMM identified that all membranes are composed of a finger‐like porous structure. Contact angle measurements indicate that the morphology of the NPs has no significant effect on MMM hydrophilicity. Moreover, the performance of the MMM was evaluated, and regardless of NP morphology, the MMM showed better permeate flux with increased loading. A higher pure water flux was observed in the PAN‐MCM41‐1% membrane (237 L/m2 h), possibly because of inherent porosity and high hydrophilicity of MCM‐41 compared to SiO2NP. Further, the PAN‐SiO2‐1% membrane exhibited superior antifouling properties due to a lower surface roughness. The present studies reveal that the morphology of the NP greatly influence on the structure, permeation, and antifouling properties of PAN membranes.

Effect of Thermally Reduced Graphene on the Characteristics and Performance of Polysulfone Mixed Matrix Ultrafiltration Membranes

Ultrafiltration (UF) polymeric membranes are widely used in water treatment and support desalination and gas separation membranes. In this article, we enhance the performance of Polysulfone (PSF) mixed matrix membranes (MMMs) by dispersing different concentrations of thermally reduced graphene (TRG) nanofillers. The UF PSF-TRG MMMs were fabricated via the phase inversion process, and the impact of TRG loading on the characteristics of the membrane, including hydrophilicity, porosity, roughness, and morphology, were analyzed using a contact angle measurement, atomic force microscopy (AFM), scanning electron microscopy (SEM), and dynamic mechanical analysis. Incorporating TRG into the PSF matrix led to favorable effects in the instantaneous de-mixing during phase inversion, increasing the porosity and hydrophilicity of MMMs and improving the mechanical properties of the membranes. Moreover, membrane performance was examined to remove dispersed oil from oil–water emulsion and support air-dehumidification membranes. MMM performance in terms of flux and oil rejection was superior to the control PSF membrane. Incorporating 0.25% TRG into PSF resulted in a 70% water flux increase and higher oil rejection compared to the control PSF membrane. As a support for air-dehumidification membranes, the MMM also demonstrated enhanced humidity reduction and an over 20% increase in water vapor permeance over the control PSF membrane. These results indicate that the PSF-TRG MMMs are an excellent candidate for reliable oil–water separation and as a support for air-dehumidification membranes.

Efficiency of Fabricated Adsorptive Polysulfone Mixed Matrix Membrane for Acetic Acid Separation.

The ultrafiltration mixed matrix membrane (UF MMMs) process represents an applicable approach for the removal of diluted acetic acid at low concentrations, owing to the low pressures applied. The addition of efficient additives represents an approach to further improve membrane porosity and, subsequently, enhance acetic acid removal. This work demonstrates the incorporation of titanium dioxide (TiO2) and polyethylene glycol (PEG) as additives into polysulfone (PSf) polymer via the non-solvent-induced phase-inversion (NIPS) method to improve the performance of PSf MMMs performance. Eight PSf MMMs samples designated as M0 to M7, each with independent formulations, were prepared and investigated for their respective density, porosity, and degree of AA retention. Morphology analysis through scanning electron microscopy elucidated sample M7 (PSf/TiO2/PEG 6000) to have the highest density and porosity among all samples with concomitant highest AA retention at approximately 92.2%. The application of the concentration polarization method further supported this finding by the higher concentration of AA solute present on the surface of the membrane compared to that of AA feed for sample M7. Overall, this study successfully demonstrates the significance of TiO2 and PEG as high MW additives in improving PSf MMM performance.

Highly efficient ultrafiltration membrane performance of PES@microcrystalline cellulose extracted from waste fruits for the removal of BrO3− from drinking water samples

New mixed-matrix ultrafiltration membranes (MMMs) made of polyethersulfone (PES) and microcrystalline cellulose (MCC) were created utilizing a nonsolvent induced phase separation (NIPS) approach for the remediation of bromate (BrO3−) from aqueous medium. The influence of MCC integrated on the contact angle, porosity, water flux, and BrO3− adsorption performance was also examined. The addition of MCC, up to 5 wt%, resulted in a significant decline in the contact angle from 60.1° of neat PES to 43.1°, indicating an increase in membrane hydrophilicity. Moreover, MCC incorporation at 1, 3, and 5 wt% concentrations led to an enhancement in the water flux to 169, 178, and 180 L m−2 h−1, respectively, indicating the improved membrane permeability. MCC-integrated PES membranes exhibited enhanced antifouling properties, as demonstrated by the achieved high flux recovery ratio (99%) of the 5% MCC-containing membrane. Furthermore, all MCC-integrated PES membranes exhibited superior performance in the removal of bromate ions (BrO3−), with rejection rates of 60.8%, 80.2%, and 92% for 1%, 3%, and 5% MCC, respectively, which was much greater than that of the virgin PES membrane.

Preparation and Characterization of PVDF-TiO2 Mixed-Matrix Membrane with PVP and PEG as Pore-Forming Agents for BSA Rejection.

Polymeric membranes offer straightforward modification methods that make industry scaling affordable and easy; however, these materials are hydrophobic, prone to fouling, and vulnerable to extreme operating conditions. Various attempts were made in this study to fix the challenges in using polymeric membranes and create mixed-matrix membrane (MMMs) with improved properties and hydrophilicity by adding titanium dioxide (TiO2) and pore-forming agents to hydrophobic polyvinylidene fluoride (PVDF). The PVDF mixed-matrix ultrafiltration membranes in this study were made using the non-solvent phase inversion approach which is a simple and effective method for increasing the hydrophilic nature of membranes. Polyvinylpyrrolidone (PVP) and polyethylene glycol (PEG) as pore-forming chemicals were created. Pure water flux, BSA flux, and BSA rejection were calculated to evaluate the mixed-matrix membrane's efficiency. Bovine serum albumin (BSA) solution was employed in this study to examine the protein rejection ability. Increases in hydrophilicity, viscosity, and flux in pure water and BSA solution were achieved using PVP and PEG additives. The PVDF membrane's hydrophilicity was raised with the addition of TiO2, showing an increased contact angle to 71°. The results show that the PVDF-PVP-TiO2 membrane achieved its optimum water flux of 97 L/(m2h) while the PVDF-PEG-TiO2 membrane rejected BSA at a rate greater than 97%. The findings demonstrate that use of a support or additive improved filtration performance compared to a pristine polymeric membrane by increasing its hydrophilicity.

Preparation of a CAB-GO/PES Mixed Matrix Ultrafiltration Membrane and Its Antifouling Performance.

Serious membrane fouling has limited the development of ultrafiltration membrane technology for water purification. Synthesis of an ultrafiltration membrane with prominent anti-fouling ability is of vital importance. In this study, CAB-GO composite nanosheets were prepared by grafting graphene oxide (GO) with a zwitterionic material cocamidopropyl betaine (CAB) with strong antifouling properties. Anti-fouling CAB-GO/PES mixed matrix ultrafiltration membrane (CGM) was prepared by the phase inversion method with polyethersulfone (PES). Due to its electrostatic interaction, the interlayer distance between CAB-GO nanosheets was increased, and the dispersibility of GO was improved to large extent, thereby effectively avoiding the phenomenon of GO agglomeration in organic solvents. Based on the improvement of the surface porosity and surface hydrophilicity of the CAB-GO/PES mixed matrix membrane, the pure water flux of CGM-1.0 can reach 461 L/(m2·h), which was 2.5 times higher than that of the original PES membrane, and the rejection rates toward BSA and HA were above 96%. Moreover, when the content of CAB-GO was 0.1 wt%, the prepared CAB-GO/PES membrane exhibited very high BSA (99.1%) and HA (98.1%) rejection during long-term operation, indicating excellent anti-fouling ability.

Construction of Ag@ZIF-8/PVDF mixed-matrix ultrafiltration membranes with high separation performance for dye from high-salinity wastewater by microemulsion coupling with blending

In order to improve the separation performance and anti-fouling property of polyvinylidene fluoride (PVDF) ultrafiltration membranes, PVDF mixed matrix membranes (MMMs) were obtained by mixing PVDF with Ag@ZIF-8 using a simple one-pot microemulsion strategy. First, both Ag and ZIF-8 were generated in one micelle of the microemulsion during the formation of composites. After in-situ polymerization of microemulsion， the latex containing Ag@ZIF-8 was blended with PVDF by phase-inversion method to construct the MMMs. The small-sized Ag particles were closely distributed on the surface of ZIF-8 after the formation of ZIF-8 in micelles. The subtle interaction forces between the two facilitated the distribution of the composite in the PVDF matrix. In addition, the hydrophilic component in the latex improves the pore structure, the permeation and anti-fouling performance of the PVDF matrix compared to neat PVDF and the MMM with ZIF-8 added. Mixed-matrix ultrafiltration membranes with 0.3 wt% of microemulsion containing Ag@ZIF-8 exhibited good permeation (Jw = 222 L m−2 h−1) and flux recovery rate (FRR = 82%). The well-distributed Ag@ZIF-8 in PVDF polymeric matrix strengthened the dye retention of MMMs from high-salinity wastewater, due to the interaction between Ag@ZIF-8 and dye molecules. This mixed-matrix ultrafiltration membrane also showed optimum dye rejection (97.3%) and low salt rejection (0.2%). The MMMs combined with Ag@ZIF-8 in this work are promising for the removal of dye contaminants for high-salinity wastewater, so as to achieve the goal of advanced treatment for high-salinity wastewater.

Probing the separation efficiency of sulfur-doped graphitic carbon nitride (g-C3N4)/polysulfone low-pressure ultrafiltration mixed matrix membranes

Probing the separation efficiency of sulfur-doped graphitic carbon nitride (g-C3N4)/polysulfone low-pressure ultrafiltration mixed matrix membranes

PVDF/MOFs mixed matrix ultrafiltration membrane for efficient water treatment.

Polyvinylidene fluoride (PVDF), with excellent mechanical strength, thermal stability and chemical corrosion resistance, has become an excellent material for separation membranes fabrication. However, the high hydrophobicity of PVDF membrane surface normally leads a decreased water permeability and serious membrane pollution, which ultimately result in low operational efficiency, short lifespan of membrane, high operation cost and other problems. Metal-organic frameworks (MOFs), have been widely applied for membrane modification due to its large specific surface area, large porosity and adjustable pore size. Currently, numerous MOFs have been synthesized and used to adjust the membrane separation properties. In this study, MIL-53(Al) were blended with PVDF casting solution to prepare ultrafiltration (UF) membrane through a phase separation technique. The optimal separation performance was achieved by varying the concentration of MIL-53(Al). The surface properties and microstructures of the as-prepared membranes with different MIL-53(Al) loading revealed that the incorporation of MIL-53(Al) enhanced the membrane hydrophilicity and increased the porosity and average pore size of the membrane. The optimal membrane decorated with 5 wt% MIL-53(Al) possessed a pure water permeability up to 43.60 L m−2 h−1 bar−1, while maintaining higher rejections towards BSA (82.09%). Meanwhile, the prepared MIL-53(Al)/LiCl@PVDF membranes exhibited an excellent antifouling performance.

Efficient Recovery of Lignin and Hemicelluloses from Kraft Black Liquor

Black liquor (BL) from kraft pulping industries contains a large fraction of lignin and hemicelluloses and their efficient separation can open up new possibilities for integrated biorefineries. In this work, lignin and hemicelluloses were separated from BL and concentrated BL (obtained by ultrafiltration), by precipitation using acidification and antisolvent precipitation method, respectively. For lignin precipitation, different organic acids, namely acetic, lactic and citric acid, were used and the yield and purity of the extracted lignin were compared with the lignin precipitated using inorganic acids, namely sulphuric and phosphoric acid. Among the organic acids, the highest yield of lignin (57.2%) was obtained by lactic acid, but the extract also contained the highest levels of inorganic impurities (9.2%). The extract obtained from acetic acid contained lower inorganic impurities and the lignin yield was 48.1%. The hemicellulose was extracted from BL liquor that was concentrated using the ZnObased PES mixed matrix ultrafiltration membrane, which was started by first separating lignin (at pH 3.5, 4 and 4.5) from it. The supernatants from the lignin precipitation process were used as a source of hemicellulose and this was precipitated by using acetone as an antisolvent. The highest hemicellulose yield (54.4%) was obtained from the supernatant with the lowest lignin content and highest acetone to supernatant ratio.
 Keywords: acidification, antisolvent precipitation, hemicelluloses, kraft black liquor, lignin

Recent Progress of Adsorptive Ultrafiltration Membranes in Water Treatment—A Mini Review

Adsorptive ultrafiltration mixed matrix membranes (MMMs) are a new strategy, developed in recent years, to remove harmful cations and small-molecule organics from wastewater and drinking water, which achieve ultrafiltration and adsorption functions in one unit and are considered to be among the promising technologies that have exhibited efficiency and competence in water reuse. This mini review concerns the research progress of adsorptive ultrafiltration MMMs for removing heavy metal ions and small-molecule organics. We firstly introduce the types and classifications of adsorptive ultrafiltration MMMs (their classifications can be established based on the type of the adsorbent used). Furthermore, we discuss the removal mechanism of adsorptive ultrafiltration MMMs, as well as summarizing the main fabrication techniques for adsorptive ultrafiltration membranes. In addition, we identified some of the issues and challenges of the practical application for adsorptive ultrafiltration.

A novel temperature-responsive mixed matrix ultrafiltration membrane based on boron nitride nanomaterial

A novel mixed matrix membrane was prepared by blending polysulfone with two-dimensional boron nitride followed by its hydroxyl functionalization. Prepared nanocomposite membranes were characterized for the surface morphology, surface roughness, zeta potential and hydrophilicity. Uniform dispersion of boron nitride nanoparticles in polysulfone matrix and consequent changes in membrane properties were confirmed by scanning electron microscope images, atomic force microscope images, zeta potential, contact angle analysis, and X-Ray photoelectron spectroscopy. Differential scanning calorimetry (DSC) technique was used to determine the glass transition temperature (Tg) of the modified membrane and the results revealed the presence of BN in the membrane matrix. The highest water flux of 329.52 Liters per sqm per hour (LMH) was obtained in case of PS/BN (1%) as compared to 151.87 LMH of virgin membrane and Albumin rejection also increased by nanocomposites membranes up to certain concentration of Boron nitride. A unique behavior of temperature responsiveness of nanocomposite membrane was observed, where a steep increment in permeate flux by 205% at higher temperature was noted as compared to the virgin Polysulfone membrane where only 103% increase was recorded for the same temperature range. Moreover, the water uptake capacity of nanocomposite membranes were measured to understand the changes with nanomaterial incorporation. The membrane showed a good promise for high-temperature separation applications.

Book Review: Advanced and Hybrid Membranes for Wastewater Treatment

The interesting part of this recent published book is that it offers better understanding on the mechanism of wastewater treatment for membrane technologies, current information about technologies and limitation of wastewater treatment, recent discovered solutions from experts for wastewater treatment and information on weaknesses and solution to membrane technologies. There are 10 chapters in which wrote by the membrane expertise covering the recent progress and development of the various membrane technologies towards water and wastewater treatment. In chapter 1, overview of wastewater treatment including conventional treatment such as ion-exchange, coagulation-flocculation and adsorption has been discussed. At the end of the chapter, membrane technology and its advantages has been introduced. Chapter 2 discussed the conventional technology stated in Chapter 1 in detail. In the chapter, the advantages and disadvantages of the conventional technologies has also been stated. Example of the advantages are including depending on pH and slow process. Chapter 3 provide an insight in the recent advanced separation technology for wastewater treatment such as hybrid adsorption-separation application that can be achieved by membrane technology and membrane distillation application. Meanwhile, Chapter 4 addressed in detail the recent progress of adsorptive ultrafiltration mixed matrix membrane for heavy metals removal such as zinc, nickel and chromium. In chapter 5, photocatalytic membrane has been introduced in the chapter with the brief mechanism on the photocatalytic activity has also been explained. Chapter 6 focussed on the membrane distillation for wastewater treatment. In the chapter, various membrane distillation type has been stated with example of recent works such as direct contact membrane distillation (DCMD), air gap membrane distillation (AGMD), vapour membrane distillation (VMD) and sweeping gas membrane distillation (SGMD). In Chapter 7, integrated forward osmosis processes have been described such as FO-MD, FO-RO or both. Chapter 8 introduced ceramic membrane technology to the readers in the book with new alternative material in production of low-cost ceramic membrane. In Chapter 9, recent works on metal organic framework (MOF) including MOF membrane for wastewater separation has been explained. In the last Chapter 10, some potential solution to overcome weaknesses of advanced membranes technologies for wastewater treatment are also discussed. Future recommendation for these technologies is also discussed at the end of the book. This book focused on the collection of recent progress related to advanced membrane technologies towards water and wastewater treatment, for example forward osmosis and membrane distillation. This book has been written by membrane experts from Malaysia and India, providing an insight of recent progress on advanced membrane technologies. This book will be the vital references for the researchers, students, membrane technologist, membrane manufacturer and academicians. Some improvement can be made by adding several interesting topics such as incorporation of waste inorganic materials into polymeric membranes and commercial ceramic membrane that made up from alumina and titania. In addition, some integrated technologies combining two advanced membrane technologies such as integrated forward osmosis and membrane distillation can be interesting if discussed.

Azido-group functionalized graphene oxide/polysulfone mixed matrix ultrafiltration membrane with enhanced interfacial compatibility for efficient water and wastewater treatment

• Oxygen-containing azido functionalized GO were synthesized via facile EMR-FD method. • Novel MMMs were synthesized by incorporating azido functionalized GO nanosheets. • Oxygen-containing AGO enhanced interaction with polymer to achieve high compatibility. • AGO/PSF membranes displayed high permeability and good antibacterial performance. Bio-fouling of membranes caused by microorganisms seriously limited the development of membrane technology in practical applications. Design and synthesis of antifouling and antibacterial membranes with high quality are of paramount importance. In this study, we report a facile and safe method of extended Mitsunobu reaction (EMR)-freeze drying (FD) method to achieve oxygen-containing azido functionalized GO (AGO) nanosheets and synthesize novel azido-group functionalized graphene/polysulfone mixed matrix ultrafiltration membranes with enhanced permselective, antifouling and antibacterial property. Unlike reported thermochemical or chemical reactions to modify GO nanosheets, GO nanosheets were functionalized at low temperature which effectively prevented the decomposition of structural frame of pristine GO materials and the self-stacking phenomenon. Because of strong interactions between oxygen-containing AGO nanosheets and polymer matrices, high dispersity and interfacial compatibility were obtained in polysulfone membranes, resulting in sharp decrease of interfacial defects. Different kinds of techniques include SEM, ATR-FTIR, XPS, XRD, TEM and EDX were used to investigate the structure and morphology of AGO nanosheets and blended membranes, and cross-flow filtration experiments, anti-fouling and antibacterial test were applied to predict the behavior of hybrid membranes. High performance AGO/PSF mixed matrix membranes with excellent anti-fouling ability were successfully synthesized, which exhibited pure water flux as large as 245.1 L m −2 h −1 with satisfactory rejection of 95.8% for BSA. Moreover, the prepared membranes displayed good antibacterial activity against E. coli and S. aureus in long-term duration.