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Though the forward osmosis (FO) process has been primarily accepted for desalination and wastewater treatment, it still faces significant challenges of (i) low water flux and high reverse solute flux and (ii) membrane fouling. In the present study, a new thin film composite (TFC) FO membrane was prepared by interfacial polymerization of chitosan biopolymer and trimesoyl chloride (TMC) as a separation layer and porous CuBTC MOF embedded polyethersulfone (PES) as the support layer to increase transport and antifouling properties. When compared to the bare membrane (J w : 26 LMH, J s : 0.12 GMH) and similar literature reported membranes, the optimized FO membrane with 0.5 wt % CuBTC (Cu@FO-0.5) exhibits higher water flux (J w : 58 LMH) with low reverse salt flux (J s : 0.57 GMH). This improvement is due to the additional pathways for water transportation due to CuBTC MOF. The modified membrane also had a reduced structural parameter (S), a lower reverse salt flux, and increased water wettability. Various physical and chemical membrane cleaning agents were studied to eliminate organic (algae) and inorganic (clay) foulants added to synthetic feed wastewater. The selected cleaning agents were later studied in series and in combinations for both foulants. Chemical cleaning showed higher water flux recovery than physical cleaning and obtained similar results for water collected from natural sources (river, reservoir, and pond). The findings suggest that Cu@FO-0.5 FO membranes integrated with reverse osmosis could be an effective technology in treating drinking water and wastewater sources. [Display omitted] • CuBTC-MOF based thin film composite membrane was prepared. • The forward osmosis membrane showed high water flux and solute rejection. • The CuBTC in FO membrane provided addition pathways for water transportation. • The FO membrane showed resistance to organic and inorganic foulants. [ABSTRACT FROM AUTHOR]

Biodegradable film-based packaging is a current concern to replace packaging that depends on petroleum. This is because petroleum-based packaging is very unfriendly to the environment. The bioresource-based biodegradable film has the disadvantage that its mechanical properties are still low, that it requires two or three bioresource materials to be used as polymer hybrids. As a film hybrid polymer that has superior properties such as flexibility, strength, heat resistance, and environmental resistance, it can be applied to various packaging materials and can be developed for various purposes. In this review, the authors review biomass sources as a matrix, as a filler in hybrid polymer-based packaging, the properties of the biodegradable file, and the development for the future. In addition to the raw materials as matrices and fillers, the synthesis method is also described. The properties of biodegradable hybrid polymer film include physicochemical, mechanical, and thermal. This review also summarizes the emerging aspects of bioresources for the development of sustainable and biodegradable hybrid polymer film friendly to the environment. [ABSTRACT FROM AUTHOR]

Applications of ultra-low-pressure filtration systems are increasing as they offer enhanced sustainability due to lower energy input, almost no use of chemicals, and minimum operational expenditure. In many cases, they operate as a decentralized system using a gravity-driven membrane (GDM) filtration process. These applications are relatively new; hence, the fundamental knowledge of the process is still limited. In this study, we investigated the phenomenon of polymeric membrane compaction under an ultra-low-pressure system. The compaction phenomenon is well-recognized in the traditional pressure-driven system operating at high transmembrane pressures (ΔPs > 200 kPa), but it is less documented in ultra-low-pressure systems (ΔP < 10 kPa). A simple GDM filtration setup operated under a constant-pressure system was employed to investigate the compaction phenomena in a polymeric hollow fiber membrane for clean water filtration. Firstly, a short-term pressure stepping test was performed to investigate the occurrence of instantaneous compaction in the ΔP range of 1–10 kPa. The slow compaction was later investigated. Finally, the compaction dynamic was assessed under alternating high and low ΔP and relaxation in between the filtrations. The findings demonstrated the prominence of membrane compaction, as shown by the decreasing trend in clean water permeability at higher ΔPs (i.e., 3240 and 2401 L m−2 h−1 bar−1 at ΔPs of 1 and 10 kPa, respectively). We also found that the intrinsic permeability of the applied polymeric membrane was significantly higher than the apparent one (4351 vs. 2401 L m−2 h−1 bar−1), demonstrating >50% loss due to compaction. The compaction was mainly instantaneous, which occurred when the ΔP was changed, whereas only minor changes in permeability occurred over time when operating at a constant ΔP. The compaction was highly reversible and could be restored (i.e., decompaction) through relaxation by temporarily stopping the filtration. A small fraction of irreversible compaction could be detected by operating alternating filtrations under ΔPs of 1 and 10 kPa. The overall findings are essential to support emerging GDM filtration applications, in which membrane compaction has been ignored and confounded with membrane fouling. The role of compaction is more prominent for high-flux GDM filtration systems treating less-fouling-prone feed (i.e., rainwater, river water) and involving membrane cleaning (i.e., relaxation) in which both reversible and irreversible compaction occurred simultaneously. [ABSTRACT FROM AUTHOR]

Ultra-low-pressure membrane (ULPM) filtration has emerged as a promising decentralized water and wastewater treatment method. It has been proven effective in long-term filtration under stable flux without requiring physical or chemical cleaning, despite operating at considerably lower flux. The use of ultra-low pressure, often simply by hydrostatic force (often called gravity-driven membrane (GDM) filtration), makes it fall into the uncharted territory of common pressure-driven membrane filtration. The applied polymeric membrane is sensitive to compaction, wetting, and fouling. This paper reviews recent studies on membrane compaction, wetting, and fouling. The scope of this review includes studies on those phenomena in the ULPM and how they affect the overall performance of the system. The performance of GDM systems for water and wastewater treatment is also evaluated. Finally, perspectives on the future research direction of ULPM filtration are also detailed. [ABSTRACT FROM AUTHOR]

The feasibility of ribbed-PVC–silica mixed matrix membranes (MMM) in a membrane bioreactor (MBR) application was investigated. Three operational aspects were evaluated: inclusion of vibration, use of relaxation (cycle time), and optimization of the cleaning procedure. Results show that the specific ribs on the membranes give a 52% higher surface area compared to the corresponding flat membranes, offering two main benefits: i.e. a higher clean water permeability (increased by 70%) and an increased critical flux (increased by 30%) for activated sludge filtration. Applying vibration increased the critical fluxes about 30–50%. In aeration mode, a filtration time of 8 min and a relaxation time of 1 min are found to keep both reversible and residual fouling minimal. Despite these advantages, the increase of the critical flux and the filtration performance (i.e. fouling resistance) are not completely in proportion with the increase of the surface area. Furthermore, a lower cleaning efficiency for the ribbed membrane was found. These results indicate that the ribs on the membrane of the current system are still not optimized to additionally work to promote local shear near the membrane surface and as turbulence promoter in the vibration mode. [ABSTRACT FROM AUTHOR]

In porous mixed matrix membrane formation, identifying the effect of filler/additive loading is essential to enhance the membrane surface properties, especially pore size, porosity, and hydrophilicity. However, there is a limited investigation on the direct correlation between filler loading and specific membrane properties (i.e., is filler loading affecting pore size more prominently than porosity and hydrophilicity or vice versa), leading to extensive laboratory experiments. Hence, this work aims to quantify the correlation of filler loading on pore size, porosity, and hydrophilicity. Porous membranes with different hydrophilic and hydrophobic silica loadings (0–3 wt%) with different polymer concentrations (12–15 wt%) were prepared, and their impact on the pore size, porosity, and contact angle was studied using response surface methodology. The analysis of variance results revealed a significant correlation between hydrophobic silica loading and pore size and porosity, with p-value of 0.03 for the former and 0.01 for the latter, respectively. Moreover, according to analysis, hydrophobic silica loading was identified as a significant factor affecting porosity. Conversely, the hydrophilic silica loading exhibited significant correlations, with p-values of 0.0045, 0.0267, and 0.0001 for pore size, porosity, and contact angle, respectively, thus concluding that loading of hydrophilic silica is crucial in determining contact angle and porosity. The confirmatory test validated that the developed models are reliable, with a maximum deviation of 10.7% for pore size, 7.5% for porosity, and 8.5% for contact angle. These statistical correlations offer valuable insights into membrane formation, surpassing the qualitative approaches typically reported. [ABSTRACT FROM AUTHOR]

The synergistic magnetic interaction between biofunctionalized magnetic nanoparticles and a hybrid membrane is exploited to develop a nano-inspired, magnetic-responsive enzyme membrane (micro) reactor. The novelty of the process lies in the use of superparamagnetic nanoparticles both as enzyme carrier to form bionanocomposites and as nanofiller to form organic–inorganic (O/I) hybrid membrane to render both reversibly magnetizable. This reversible magnetic force facilitates dispersion of the enzymatically active magnetic nanoparticles (bionanocomposites) over the membrane surface, allows retention of the enzyme by a large pore, i.e., high-flux membrane and renders enzyme recovery after use is very easy. The feasibility and versatility of the concept is demonstrated through 2 case studies, i.e., a pectin/polygalacturonase and an arabinoxylan/xylanase system, for membrane fouling prevention through in-situ enzymatic membrane cleaning. This robust multidisciplinary approach resulted in a 75% reduction in filtration resistance, thus realizing significant energy savings and high reactor productivity. The advantages of the novel approach include: (i) absence of need for neither functionalized nor retentive membrane surfaces, (ii) no leakage of nanosized, high surface area immobilized enzymes through microporous membranes, (iii) full recovery and re-usability of the enzymes, (iv) possibility to apply enzyme cocktails to achieve optimal conversions and (v) use of the membrane beyond the enzyme life cycle. [ABSTRACT FROM AUTHOR]

• A novel membrane-based bubble generator (MBG) is proposed. • The MBG system could suck air at the rates of up to 5.46 L/min. • The oxygen dissolution efficiency was up to 1.48 kgO 2 /kWh. • The energy efficiency of the MBG system was comparable with commercial oxygenators. Dissolved oxygen is one of the leading indicators of aquatic quality. This study explored a membrane-based bubble generator (MBG) for oxygen dissolution in water. It is achieved by creating negative pressures to suck the air through a thin, porous film and forming bubbles in liquid water. Both airflow and liquid flow rates played essential roles in forming the bubbles. The highest oxygen dissolution energy efficiency of 1.48 kgO 2 /kWh was achieved under free-flowing air at corresponding air and liquid velocities of 4.87 L/min and 2.46 m/s, respectively. The obtained oxygen dissolution energy efficiencies were comparable with established commercial oxygenators. The results revealed a promising application of porous membranes in MBG as a potential energy-efficient oxygen dissolution technology. [Display omitted] [ABSTRACT FROM AUTHOR]

Wetland water is an alternative water resource around wetland areas. However, it is typically saline due to seawater intrusion and contains high natural organic matter (NOM) that is challenging to treat. This study evaluated the stability of interlayer-free mesoporous silica matrix membranes employing a dual acid–base catalyzed sol–gel process for treatment of saline wetland water. The silica sols were prepared under a low silanol concentration, dip-coated in 4 layers, and calcined using the rapid thermal processing method. The membrane performance was initially evaluated through pervaporation under various temperatures (25–60 °C) using various feeds. Next, the long-term stability (up to 400 h) of wetland saline water desalination was evaluated. Results show that the water flux increased at higher temperatures up to 6.9 and 6.5 kg·m−2·h−1 at the highest temperature of 60 °C for the seawater and the wetland saline water feeds, respectively. The long-term stability demonstrated a stable performance without flux and rejection decline up to 170 h operation, beyond which slow declines in water flux and rejection were observed due to fouling by NOM and membrane wetting. The overall findings suggest that an interlayer-free mesoporous silica membrane offers excellent performance and high salt rejection (80–99%) for wetland saline water treatments. [ABSTRACT FROM AUTHOR]

Tapioca processing industries are very popular in the rural community to produce a variety of foods as the end products. Due to their small scales and scattered locations, they require robust modular systems to operate at low capacity with minimum supervision. This study explores the application of a novel sequencing batch-integrated fixed-film activated sludge membrane (SB-IFASM) process to treat tapioca processing wastewater for reuse purposes. The SB-IFASM employed a gravity-driven system and utilizes biofilm to enhance biodegradation without requiring membrane cleaning. The SB-IFASM utilizes the biofilm as a secondary biodegradation stage to enhance the permeate quality applicable for reuse. A lab-scale SB-IFASM was developed, preliminarily assessed, and used to treat synthetic tapioca processing industry wastewater. The results of short-term filtration tests showed the significant impact of hydrostatic pressure on membrane compaction and instant cake layer formation. Increasing the pressure from 2.2 to 10 kPa lowered the permeability of clean water and activated sludge from 720 to 425 and from 110 to 50 L/m2·h bar, respectively. The unsteady-state operation of the SB-IFASM showed the prominent role of the bio-cake in removing the organics reaching the permeate quality suitable for reuse. High COD removals of 63–98% demonstrated the prominence contribution of the biofilm in enhancing biological performance and ultimate COD removals of >93% make it very attractive for application in small-scale tapioca processing industries. However, the biological ecosystem was unstable, as shown by foaming that deteriorated permeability and was detrimental to the organic removal. Further developments are still required, particularly to address the biological stability and low permeability. [ABSTRACT FROM AUTHOR]

The rise in energy consumption is largely driven by the growth of population. The supply of energy to meet that demand can be fulfilled by slowly introducing energy from renewable resources. The fluctuating nature of the renewable energy production (i.e., affected by weather such as wind, sun light, etc.), necessitates the increasing demand in developing electricity storage systems. Reliable energy storage system will also play immense roles to support activities related to the internet of things. In the past decades, metal-air batteries have attracted great attention and interest for their high theoretical capacity, environmental friendliness, and their low cost. However, one of the main challenges faced in metal-air batteries is the slow rate of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) that affects the charging and the discharging performance. Various types of nanostructure manganese oxide with high specific surface area and excellent catalytic properties have been synthesized and studied. This review provides a discussion of the recent developments of the nanostructure manganese oxide and their performance in oxygen reduction and oxygen evolution reactions in alkaline media. It includes the experimental work in the nanostructure of manganese oxide, but also the fundamental understanding of ORR and OER. A brief discussion on electrocatalyst kinetics including the measurement and criteria for the ORR and the OER is also included. Finally, recently reported nanostructure manganese oxide catalysts are also discussed. [ABSTRACT FROM AUTHOR]

Membrane technology is one of reliable options for treatment of oil/water emulsion. It is highly attractive because of its effectiveness in separating fine oil droplets of <2 µm sizes, which is highly challenging for other processes. However, the progress for its widespread implementations is still highly restricted by membrane fouling. Most of the earlier studies have demonstrated the promise of achieving more sustained filtration via membrane material developments. This study addresses issues beyond membrane development by assessing the impact of membrane material (blend of polysulfone, PSF and polyethylene glycol, PEG), operational pressure, and crude oil concentration on the filtration performance of oil/water emulsion. The filtration data were then used to project the pumping energy for a full-scale system. Results show that fouling resistant membrane offered high oil/water emulsion permeability, which translated into a low energy consumption. The oil/water emulsion permeability was improved by three-fold from 45 ± 0 to 139 ± 1 L/(m2 h bar) for PSF/PEG-0 membrane in comparison to the most optimum one of PSF/PEG-60. It corresponded to an energy saving of up to ~66%. The pumping energy could further be reduced from 27.0 to 7.6 Wh/m3 by operation under ultra-low pressure from 0.2 to 0.05 bar. Sustainable permeability could be achieved when treating 1000 ppm oil/water emulsion, but severe membrane fouling was observed when treating emulsion containing crude oils of >3000 ppm to a point of no flux. [ABSTRACT FROM AUTHOR]

Membrane filtration exhibits excellent separation performance for water and wastewater treatment but is still limited by the membrane fouling. This study presents a novel membrane rotating biological contactor (MRBC) that combines a conventional rotating biological contactor (RBC) with membrane filtration. MRBC combines conventional RBC with the membrane filtration placed in between two adjacent rotating disks to offer inherent control over membrane fouling. The disks rotations provide some degree of foulant removal, maintain membrane permeability, and potentially save a substantial amount of energy. The biological and hydraulic performance of MRBC was compared with a series of RBC and external membrane filtration (RBC + ME) where the membrane is treated as a post-treatment unit. Results show that the MRBC enhances not only the biological performance but also offers advantages for inherent membrane fouling control through the rotation of the disk. Membrane fouling control primarily originates from the enhanced shear rate from higher disk rotation and minimum membrane-to-disk gap. The hydraulic performance is 92.4% higher than literature, which further enhanced at smaller membrane-to-disk gaps and higher disk rotations. The highest steady-state permeability of 297 L/(m2.h.bar) and 288 L/(m2.h.bar) results at 40 rpm disk rotational speed and 0.5 cm membrane-to-disk gap, respectively. A projected full-scale MRBC consumes 0.18 kWh/m3 permeate, one-fourth of the energy for the referenced MBR system thanks to the active role of disks rotation for membrane fouling control which eliminates the need of extensive aeration like in the traditional MBRs. MRBC offers a promising alternative for traditional wastewater treatment as a low energy foot-print process, which is in line with the requirements of sustainable development and promotes the development of cleaner production. Image 1 • The proof of concept of membrane rotating biological contactor (MRBC) is reported. • It utilizes the disk rotations to dissolve oxygen and to control membrane fouling. • High rotation speeds and small gaps offer high permeability of up to 297 L/(m2.h.bar). • The energy consumption of the MRBC is merely 0.18 kWh/m3. [ABSTRACT FROM AUTHOR]

This study employed response surface methodology to optimize the preparation of biocomposites based on whey protein isolate, glycerol, and nanocrystalline cellulose from pineapple crown leaf. The effects of different concentrations of nanocrystalline cellulose as a filler and glycerol as a plasticizer on the thickness, the tensile strength, and the elongation at break on the resulting biocomposite films were investigated. The central composite design was used to determine the optimum preparation conditions for biocomposite films with optimum properties. The regression of a second-order polynomial model resulted in an optimum composition consisting of 4% glycerol and 3.5% nanocrystalline cellulose concentrations, which showed a desirability of 92.7%. The prediction of the regression model was validated by characterizing the biocomposite film prepared based on the optimum composition, at which the thickness, tensile strength, and elongation at break of the biocomposite film were 0.13 mm, 7.16 MPa, and 39.10%, respectively. This optimum composition can be obtained in range concentrations of glycerol (4–8%) and nanocrystalline cellulose (3–7%). Scanning electron microscope images showed that nanocrystalline cellulose dispersed well in the pure whey protein isolate, and the films had a relatively smooth surface. In comparison, a rough and uneven surface results in more porous biocomposite films. Fourier transform infrared spectroscopy revealed that nanocrystalline cellulose and glycerol showed good compatibility with WPI film by forming hydrogen bonds. The addition of nanocrystalline cellulose as a filler also decreased the transparency, solubility, and water vapor permeability and increased the crystallinity index of the resulting biocomposite film. [ABSTRACT FROM AUTHOR]

The discharge of improperly treated oil/water emulsion by industries imposes detrimental effects on human health and the environment. The membrane process is a promising technology for oil/water emulsion treatment. However, it faces the challenge of being maintaining due to membrane fouling. It occurs as a result of the strong interaction between the hydrophobic oil droplets and the hydrophobic membrane surface. This issue has attracted research interest in developing the membrane material that possesses high hydraulic and fouling resistance performances. This research explores the vapor-induced phase separation (VIPS) method for the fabrication of a hydrophilic polysulfone (PSF) membrane with the presence of polyethylene glycol (PEG) as the additive for the treatment of oil/water emulsion. Results show that the slow nonsolvent intake in VIPS greatly influences the resulting membrane structure that allows the higher retention of the additive within the membrane matrix. By extending the exposure time of the cast film under humid air, both surface chemistry and morphology of the resulting membrane can be enhanced. By extending the exposure time from 0 to 60 s, the water contact angle decreases from 70.28 ± 0.61° to 57.72 ± 0.61°, and the clean water permeability increases from 328.70 ± 8.27 to 501.89 ± 8.92 (L·m−2·h−1·bar−1). Moreover, the oil rejection also improves from 85.06 ± 1.6 to 98.48 ± 1.2%. The membrane structure was transformed from a porous top layer with a finger-like macrovoid sub-structure to a relatively thick top layer with a sponge-like macrovoid-free sub-structure. Overall results demonstrate the potential of the VIPS process to enhance both surface chemistry and morphology of the PSF membrane. [ABSTRACT FROM AUTHOR]

Standalone membrane distillation (MD) and forward osmosis (FO) have been considered as promising technologies for produced water treatment. However, standalone MD is still vulnerable to membrane-wetting and scaling problems, while the standalone FO is energy-intensive, since it requires the recovery of the draw solution (DS). Thus, the idea of coupling FO and MD is proposed as a promising combination in which the MD facilitate DS recovery for FO—and FO acts as pretreatment to enhance fouling and wetting-resistance of the MD. This study was therefore conducted to investigate the effect of DS temperature on the dynamic of water flux of a hybrid FO–MD. First, the effect of the DS temperature on the standalone FO and MD was evaluated. Later, the flux dynamics of both units were evaluated when the FO and DS recovery (via MD) was run simultaneously. Results show that an increase in the temperature difference (from 20 to 60 °C) resulted in an increase of the FO and MD fluxes from 11.17 ± 3.85 to 30.17 ± 5.51 L m−2 h−1, and from 0.5 ± 0.75 to 16.08 L m−2 h−1, respectively. For the hybrid FO–MD, either MD or FO could act as the limiting process that dictates the equilibrium flux. Both the concentration and the temperature of DS affected the flux dynamic. When the FO flux was higher than MD flux, DS was diluted, and its temperature decreased; both then lowered the FO flux until reaching an equilibrium (equal FO and MD flux). When FO flux was lower than MD flux, the DS was concentrated which increased the FO flux until reaching the equilibrium. The overall results suggest the importance of temperature and concentration of solutes in the DS in affecting the water flux dynamic hybrid process. [ABSTRACT FROM AUTHOR]

Integrated fixed-film activated sludge (IFAS) process is considered as one of the leading-edge processes that provides a sustainable solution for wastewater treatment. IFAS was introduced as an advancement of the moving bed biofilm reactor by integrating the attached and the suspended growth systems. IFAS offers advantages over the conventional activated sludge process such as reduced footprint, enhanced nutrient removal, complete nitrification, longer solids retention time and better removal of anthropogenic composites. IFAS has been recognized as an attractive option as stated from the results of many pilot and full scales studies. Generally, IFAS achieves >90% removals for combined chemical oxygen demand and ammonia, improves sludge settling properties and enhances operational stability. Recently developed IFAS reactors incorporate frameworks for either methane production, energy generation through algae, or microbial fuel cells. This review details the recent development in IFAS with the focus on the pilot and full-scale applications. The microbial community analyses of IFAS biofilm and floc are underlined along with the special emphasis on organics and nitrogen removals, as well as the future research perspectives. Image 1 • Recent progress of integrated fixed-film activated sludge (IFAS) process is reviewed. • IFAS process is an effective upgrade of existing conventional activated sludge system. • IFAS process can be retrofitted to improve nitrification in partial nitritation anammox. • IFAS process can incorporate energy generation through algae and microbial fuel cells. • IFAS process offers low sludge production, low energy foot-print and cost saving. [ABSTRACT FROM AUTHOR]

Membrane fouling is seen as the main culprit that hinders the widespread of membrane application in liquid-based filtration. Therefore, fouling management is key for the successful implementation of membrane processes, and it is done across all magnitudes. For optimum operation, membrane developments and surface modifications have largely been reported, including membrane surface patterning. Membrane surface patterning involves structural modification of the membrane surface to induce secondary flow due to eddies, which mitigate foulant agglomeration and increase the effective surface area for improved permeance and antifouling properties. This paper reviews surface patterning approaches used for fouling mitigation in water and wastewater treatments. The focus is given on the pattern formation methods and their effect on overall process performances. [ABSTRACT FROM AUTHOR]

Membrane distillation (MD) is an attractive technology for desalination, mainly because its performance that is almost independent of feed solute concentration as opposed to the reverse osmosis process. However, its widespread application is still limited by the low water flux, low wetting resistance and high scaling vulnerability. This study focuses on addressing those limitations by developing a novel corrugated polyvinylidene difluoride (PVDF) membrane via an improved imprinting technique for MD. Corrugations on the membrane surface are designed to offer an effective surface area and at the same time act as a turbulence promoter to induce hydrodynamic by reducing temperature polarization. Results show that imprinting of spacer could help to induce surface corrugation. Pore defect could be minimized by employing a dual layer membrane. In short term run experiment, the corrugated membrane shows a flux of 23.1 Lm−2h−1 and a salt rejection of >99%, higher than the referenced flat membrane (flux of 18.0 Lm−2h−1 and similar rejection). The flux advantage can be ascribed by the larger effective surface area of the membrane coupled with larger pore size. The flux advantage could be maintained in the long-term operation of 50 h at a value of 8.6 Lm−2h−1. However, the flux performance slightly deteriorates over time mainly due to wetting and scaling. An attempt to overcome this limitation should be a focus of the future study, especially by exploring the role of cross-flow velocity in combination with the corrugated surface in inducing local mixing and enhancing system performance. [ABSTRACT FROM AUTHOR]

This study aims to determine the effect of variations in the percentage of Ketapang fruit (KF) bio briquette on calorific value and burning rate. This research is experimental in a physics laboratory with a literature review carried out in three stages, namely the preparation stage, the bio briquette manufacturing stage, and the bio briquette testing stage. The main ingredient used in the manufacture of bio briquettes is Ketapang fruit. The adhesive materials used were tapioca flour and sago flour with percentages of 10%, 12.5% and 15%. The results showed that the calorific value of the following bio briquettes using the tapioca predicate included 5,139.45 Cal, 5,540.97 Cal, 5,922.42 Cal, and those using the sago predicate including 2,409.12 Cal, 3,653.83 Cal, 3,894.74 cal. The highest calorific value was in bio briquettes with tapioca adhesive type in the sample at 85%:15%. The burning rate of bio briquettes using tapioca glue included 1.98 gr/minute, 1.76 gr/minute, 1.62 gr/minute and those using sago glue included 2.62 gr/minute, 2.50 gr/minute, 2.31 gr/minute. The lowest burning rate value was in bio briquettes with the type of sago glue in the sample at 85%:15%. Based on the test results, it is known that the lower the percentage of keta pang fruit in the bio briquettes, the lower the burning rate, and the resulting calorific value increases. [ABSTRACT FROM AUTHOR]

River water can be used as a source of drinking water. However, it is vital to consider the existence of natural organic matter (NOM) and its possible influence on water quality (low turbidity, high color). The level of NOM in river water significantly impacts the ecosystem's health and the water's quality, and needs to be removed. A membrane-based approach is attractive for treating NOM successfully, but is still hindered by the membrane fouling problem. This study aims to develop polyvinylidene fluoride (PVDF)-based membranes customized for NOM removal from river water. The anti-fouling property was imposed by a coating of tannic acid (TA) and Fe3+ on the pre-prepared PVDF membrane. The results show that the TA–Fe coatings were effective, as demonstrated by the FTIR spectra, SEM, and EDS data. The coatings made the membrane more hydrophilic, with smaller pore size and lower clean water permeability. Such properties offer enhanced NOM rejections (up to 100%) and remarkably higher fouling recovery (up to 23%), desirable for maintaining a long-term filtration performance. [ABSTRACT FROM AUTHOR]

Highlights • High performance MMMs comprising of Bio-MOF-1 and PSf matrix were synthesized. • Bio-MOF-1 crystals showed well defined rectangular-like shapes and smooth surfaces. • MMMs exhibited good dispersion and interaction of the filler in the polymer matrix. • MMMs were tested for CO 2 separation from single and mixed gas (CO 2 /CH 4 and CO 2 /N 2). • MMMs showed remarkably higher selectivity of CO 2 coupled with improved permeability. Abstract This paper reports the development of high performance mixed matrix membranes (MMMs) comprising of bio metal-organic framework (Bio-MOF-1) and polysulfone (PSf) polymer matrix. For the very first time, a Bio-MOF was used as filler in MMMs. Bio-MOF-1 crystals showed well defined rectangular-like shapes (nano-bars) with lengths of ∼0.5–4.0 µm and widths of ∼0.05–0.20 µm and smooth surfaces. SEM images of membranes demonstrate good dispersion and interaction of the filler in the polymer matrix, even at high loadings. The gas transport properties of MMMs with Bio-MOF-1 loading up to 30 wt% were investigated, and the results showed such MMMs had a CO 2 permeability of 16.57 Barrer and ideal selectivity of 42.6 and 45.6 for CO 2 /CH 4 and CO 2 /N 2 respectively. This corresponds to an increase in 168% and 58% for CO 2 permeability and ideal selectivity respectively in comparison to pristine polymer membranes. Analysis of solubility-diffusivity in the MMMs revealed that the presence of adeninate amino and pyrimidine Lewis basic sites that decorate the pores and have relatively narrow pore dimensions in Bio-MOF-1 can greatly enhance the adsorption of the CO 2 molecules. All synthesized MMMs were tested at different condition of CO 2 feed concentration, various operating temperatures and their activation energies were also calculated. Finally, the comparison with relevant literature showed that even without any functionalization of Bio-MOF-1, it showed higher selectivity than amine functionalized MOFs and quite comparable permeability. [ABSTRACT FROM AUTHOR]

Highlights • Biodiesel processes using realistic composition of waste cooking oil are designed. • Reaction yield and free fatty acids contents are the most sensitive parameters. • Combined approach of process flowsheets, design of experiments, and Monte Carlo simulations are developed. • More selective membrane and better separation process is required for future work. • Catalytic membrane reactor process is more robust and more profitable. Abstract Since the use of virgin oil as feedstock to biodiesel production leads to competition between food and energy sources, waste cooking oil (WCO) has been proposed as an alternative. However, due to its high concentration of free fatty acids (FFA), its use in the conventional process that uses alkali catalyst has been limited. Catalytic membrane reactor (CMR) process is proposed to overcome these issues as well as to intensify the process. The objectives of this study are to perform techno-economic analysis and to compare the CMR and conventional processes to produce biodiesel and high purity glycerol. Unlike previous reports that applied simplified feed composition, this study employs realistic component mixtures during the process development to better reflect practical situations and anticipate potential technical challenges. The results show that the CMR process is economically more attractive. Reaction yield and FFA content are the most sensitive parameters in the conventional and in the CMR process, respectively. Sensitivity analysis are performed via a combined approach of design of experiments on the process simulation flowsheets and Monte Carlo simulations. The results show that the CMR process is more robust and more profitable by at least 50% in all scenarios than the conventional one. Due to its importance, more selective membrane toward biodiesel and better separation techniques for separating biodiesel and FFA still need to be developed to improve the economics of the process. [ABSTRACT FROM AUTHOR]

One of the common techniques for treating water and water from waste effluent is membrane filtration. Polymer is the main material that is most extensively employed as a substance for membranes. Because of its outstanding strength and resistance to chemicals, Polyethersulfone, also known as PES, is a common polymer used in the production of membranes. Unfortunately, its hydrophobicity makes it easy to foul when applied to water treatment processes. This study introduced a chitosan additive isolated from golden snail shell waste as an additive for PES-based membrane fabrication via blending at 0 wt%, 1 wt%, 3 wt%, 5 wt%, and 7 wt%. After preparation, the resultant membranes were analyzed and tested for their ability to filter a humic acid solution at a concentration of 50 mg L -1 . According to the findings, the chitosan additive has the potential to change the characteristics of the membrane as well as its filtration performance. It increased the pure water flux from 110 181 L m-2 h -1 (no chitosan loading) to 181 L m-2 h -1 (for five wt% loadings). The membrane characterization results supported this increase in pure water flux, which showed that adding chitosan additives improved the porosity, size of pores, and hydrophilicity. The addition of this additive also has a good effect on the anti-fouling property by increasing the fouling recovery ratio (FRR). The FRRs for the modified membranes were 79% to 82%, which were higher than the neat PES membrane with an FRR of merely 60%. [ABSTRACT FROM AUTHOR]

Membrane distillation (MD) performance in seawater desalination can be improved by enhancing the material properties (hydrophobicity, porosity) and process parameters (feed flow rate, temperature). In this study, the effects of hydrophobic silica loading on the properties and MD performance of a polyvinylidene difluoride‐based membrane in seawater desalination were investigated, and a sensitivity analysis (temperature gradient, feed flow rate, salinity) was performed. Incorporation of hydrophobic silica improved the hydrophobicity of the membrane. Higher filler loading increased the number of surface pores while maintaining their size. This resulted in improved flux compared with the neat membrane while maintaining high salt rejection. The optimized membrane was 73 % more efficient than the neat membrane. [ABSTRACT FROM AUTHOR]

This study develops bio-nano composite gelatin-based edible film (NEF) by combining nanogelatin, cellulose nanocrystal (CNC), and nanopropolis (NP) fillers to improve the resulting film characteristics. The NEF was characterized in terms of thickness, swelling, pH, water content, solubility, vapor and oxygen permeability, mechanical properties, heat resistance, morphology, transparency, and color. The results showed that the thickness and swelling increased significantly, whilst the pH did not significantly differ in each treatment. The water content and the water solubility also showed no significant changes with loadings of both fillers. At the same time, vapor and oxygen permeability decreased with addition of the fillers but were not significantly affected by the loading amounts. The heat resistance properties increased with the filler addition. Tensile strength and Young's modulus increased for the films loaded with >3% CNC. The elongation at break showed a significant difference together with transparency and color change. The greater the CNC concentration and NP loading were, the darker the resulting transparency and the color of the NEF. Overall results show a considerable improvement in the properties of the resulting NEFs with the incorporation of CNC and NP fillers. [ABSTRACT FROM AUTHOR]

Membrane-based processes are a promising technology in water and wastewater treatments, to supply clean and secure water. However, during membrane filtration, biofouling phenomena severely hamper the performance, leading to permanent detrimental impacts. Moreover, regular chemical cleaning is ineffective in the long-run for overcoming biofouling, because it weakens the membrane structure. Therefore, the development of a membrane material with superior anti-biofouling performance is seen as an attractive option. Hydrophilic-anti-bacterial precursor polyethylene glycol-silver nanoparticles (PEG-AgNPs) were synthesized in this study, using a sol-gel method, to mitigate biofouling on the polyethersulfone (PES) membrane surface. The functionalization of the PEG-AgNP hybrid material on a PES membrane was achieved through a simple blending technique. The PES/PEG-AgNP membrane was manufactured via the non-solvent induced phase separation method. The anti-biofouling performance was experimentally measured as the flux recovery ratio (FRR) of the prepared membrane, before and after incubation in E. coli culture for 48 h. Nanomaterial characterization confirmed that the PEG-AgNPs had hydrophilic-anti-bacterial properties. The substantial improvements in membrane performance after adding PEG-AgNPs were evaluated in terms of the water flux and FRR after the membranes experienced biofouling. The results showed that the PEG-AgNPs significantly increased the water flux of the PES membrane, from 2.87 L·m−2·h−1 to 172.84 L·m−2·h−1. The anti-biofouling performance of the PES pristine membrane used as a benchmark showed only 1% FRR, due to severe biofouling. In contrast, the incorporation of PEG-AgNPs in the PES membrane decreased live bacteria by 98%. It enhanced the FRR of anti-biofouling up to 79%, higher than the PES/PEG and PES/Ag membranes. [ABSTRACT FROM AUTHOR]

It is necessary to sustain energy from an external reservoir or employ advanced technologies to enhance oil recovery. A greater volume of oil may be recovered by employing nanofluid flooding. In this study, we investigated oil extraction in a two-phase incompressible fluid in a two-dimensional rectangular porous homogenous area filled with oil and having no capillary pressure. The governing equations that were derived from Darcy's law and the mass conservation law were solved using the finite element method. Compared to earlier research, a more efficient numerical model is proposed here. The proposed model allows for the cost-effective study of heating-based inlet fluid in enhanced oil recovery (EOR) and uses the empirical correlations of the nanofluid thermophysical properties on the relative permeability equations of the nanofluid and oil, so it is more accurate than other models to determine the higher recovery factor of one nanoparticle compared to other nanoparticles. Next, the effect of nanoparticle volume fraction on flooding was evaluated. EOR via nanofluid flooding processes and the effect of the intake temperatures (300 and 350 K) were also simulated by comparing three nanoparticles: SiO 2 , Al 2 O 3 , and CuO . The results show that adding nanoparticles (<5 v%) to a base fluid enhanced the oil recovery by more than 20%. Increasing the inlet temperature enhanced the oil recovery due to changes in viscosity and density of oil. Increasing the relative permeability of nanofluid while simultaneously reducing the relative permeability of oil due to the presence of nanoparticles was the primary reason for EOR. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the feasibility study in the production of sieve shaker for teaching particle size to students with visual impairment. The sieve shaker is important as a tool for understanding the definition of particles and their sizes, while this equipment has been well developed for engineering purposes. Different from other sieve shakers that are expensive, the present sieve shaker is just for educational goals only (especially for being used in developing countries), making the design of this equipment simpler, user friendlier, and more portable. The feasibility study was done from the engineering and economic perspectives. Engineering analysis was performed based on a simple mass balance analysis, adding it to the calculation of scale-up production from commercially available apparatuses. Economic evaluation was carried out using a number of economic parameters, including gross profit margin, payback period, and net profit value, in which all calculations were done under ideal and nonideal conditions (labor conditions, sales and raw materials, utilities, and external conditions and environmental uncertainties (competition, taxes and subsidiaries)) in 20 years (y) of project. All prices, utilizing components, and specifications for the apparatuses used in the scale-up production were taken based on the available online shopping web. The results of the engineering confirmed that the project was potentially conducted, even in small-scale industries because all processing steps could be carried out using simple equipment that is commercially available in the market. Economic evaluation results showed positive values for all economic parameters with a few exceptions. This research was complemented by some basic theories to support the definition of sieve shaker. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel MOF, BIT-72, was synthesized and modified by plasma of N 2 and O 2. • MMM were fabricated with BIT-72 and plasma modified BIT-72. • CO 2 /CH 4 and CO 2 /N 2 selectivity of 30.96 and 56.28 was achieved respectively with BIT-72 MMM. • CO 2 /CH 4 and CO 2 /N 2 selectivity was enhanced to 43.07 and 72.64 respectively with N 2 -BIT-72 MMM. • CO 2 /CH 4 and CO 2 /N 2 selectivity was enhanced to 37.28 and 66.21 respectively with O 2 -BIT-72 MMM. Gas separation membranes are a key development in eradication of harmful greenhouse gases such as carbon dioxide (CO 2). Different strategies have been utilized to enhance membrane performance and to overcome their drawbacks. In this study a unique approach has been utilized to enhance membrane performance. Initially mixed matrix membranes (MMM) were fabricated with a novel metal-organic framework (MOF), namely BIT-72 incorporated in Pebax®1657 matrix. At 30% loading of BIT-72, CO 2 /CH 4 and CO 2 /N 2 selectivities of 30.96 and 56.28 were achieved respectively with CO 2 permeability of 139 Barrer. To further enhance the performance of the MMM, BIT-72 was treated with plasma of N 2 or O 2 gases to prepare MMMs with same polymer (N 2 -BIT-72 MMM and O 2 -BIT-72 MMM, respectively). As a result, CO 2 /CH 4 and CO 2 /N 2 selectivity was enhanced to 43.07 and 72.64 respectively for N 2 plasma treated BIT-72 MMM (CO 2 permeability 146 Barrer) and for O 2 plasma treated BIT-72 MMM (CO 2 permeability 145 Barrer) CO 2 /CH 4 and CO 2 /N 2 selectivity was increased to 37.28 and 66.21 respectively. Plasma modified BIT-72 MMM showed promising results for further applications. [ABSTRACT FROM AUTHOR]

• Preparation of highly selective alkanolamines based deep eutectic solvents for CO 2 capture. • High CO 2 selectivity and permeability achieved due to strong hydrogen bonding and lower molar volume. • DES based supported liquid membranes cross the Robeson's upper bound reflecting their effectiveness. Amine based solvents are being used extensively for CO 2 capture for the last several decades owing to their relatively high CO 2 affinity. They are considered as standard solvents for CO 2 separation but still, face limitations of high energy requirement, high volatility, high vapor pressure and toxicity. To overcome these limitations, for the first time in this study, amine based deep eutectic solvents (DES) are incorporated into membranes for CO 2 capture. Three different alkanolamines; monoethanolamine, (MEA), diethanolamine (DEA), triethanolamine (TEA) were selected as HBDs and choline chloride as HBA. The synthesis of the DESs was confirmed by FTIR characterization as well as physicochemical properties of the resulting liquid mixture. Subsequently, the synthesized DESs were impregnated into the porous support to prepare supported liquid membranes (SLMs). The SLMs showed excellent selectivity of CO 2 up to 70.47 and 78.86 for CO 2 /CH 4 and CO 2 /N 2 respectively. This high selectivity of CO 2 over CH 4 and N 2 can be attributed to the chemisorption of CO 2 with DES and high basicity of DES. The effect of operating temperature, the HBA: HBD mole ratio, and CO 2 concentration on membrane performance was also investigated. The results of amine DESs were compared with the competing ionic liquids based membranes, and the significant high gas separation was attributed to the low viscosity and the high CO 2 solubility in amines that makes them an appropriate alternative to the conventional ILs. [ABSTRACT FROM AUTHOR]

The increasing rate of oil and gas production has contributed to a release of oil/water emulsion or mixtures to the environment, becoming a pressing issue. At the same time, pollution of the toxic cigarette butt has also become a growing concern. This study explored utilization of cigarette butt waste as a source of cellulose acetate-based (CA) polymer to develop a phase inverted membrane for treatment of oil/water emulsion and compare it with commercial polyvinylidene difluoride (PVDF) and polysulfone (PSF). Results show that the CA-based membrane from waste cigarette butt offers an eco-friendly material without compromising the separation efficiency, with a pore size range suitable for oil/water emulsion filtration with the rejection of >94.0%. The CA membrane poses good structural property similar to the established PVDF and PSF membranes with equally asymmetric morphology. It also poses hydrophilicity properties with a contact angle of 74.5°, lower than both PVDF and PSF membranes. The pore size of CA demonstrates that the CA is within the microfiltration range with a mean flow pore size of 0.17 µm. The developed CA membrane shows a promising oil/water emulsion permeability of 180 L m−2 h−1 bar−1 after five filtration cycles. However, it still suffers a high degree of irreversible fouling (>90.0%), suggesting potential future improvements in terms of membrane fouling management. Overall, this study demonstrates a sustainable approach to addressing oil/water emulsion pollution treated CA membrane from cigarette butt waste. [ABSTRACT FROM AUTHOR]

The type and properties of the filtration solution affect the formation and thickness of the cake layer on the membrane surface. This study aims to identify the effect of the acidity of Sodium Alginate (SA) solution on the filtration profile and cake layer formation on the Polyethersulfone/Aerosol OT (PES/A-OT) membrane surface. The filtration process was carried out using a single hollow fiber module by the pressure-driven outside system with the feed flowing from the membrane's outer wall and clean water collected on the inside of the hollow fiber membrane. The pH solution was tested at neutral, acid, and bases, and the filtration performance of the membrane was evaluated based on water flux recovery ratio (FRR) and cake formation on the membrane surface. The results showed that SA solution with neutral pH produced the best FRR (up to 87.3%) and the thinnest cake layer formation. [ABSTRACT FROM AUTHOR]

This study focuses on the effect of modified silica fillers by [EMIN][Tf2N] via physical adsorption on the CO2 separation performance of a mixed matrix membrane (MMM). The IL-modified silica was successfully synthesized as the presence of fluorine element was observed in both Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectrometer (XPS) analyses. The prepared MMMs with different loadings of the IL-modified silica were then compared with an unmodified silica counterpart and neat membrane. The morphology of IL-modified MMMs was observed to have insignificant changes, while polymer chains of were found to be slightly more flexible compared to their counterpart. At 2 bar of operating pressure, a significant increase in performance was observed with the incorporation of 3 wt% Sil-IL fillers compared to that of pure polycarbonate (PC). The permeability increased from 353 to 1151 Barrer while the CO2/CH4 selectivity increased from 20 to 76. The aforementioned increment also exceeded the Robeson upper bound. This indicates that the incorporation of fillers surface-modified with ionic liquid in an organic membrane is worth exploring for CO2 separation. [ABSTRACT FROM AUTHOR]

Wastewater containing oil/water emulsion has a serious ecological impact and threatens human health. The impact worsens as its volume increases. Oil/water emulsion needs to be treated before it is discharged or reused again for processing. A membrane-based process is considered attractive in effectively treating oil/water emulsion, but progress has been dampened by the membrane fouling issue. The objective of this study is to develop polyvinylidene fluoride (PVDF) membranes customized for oil/water emulsion separation by incorporating assembly of tannic acid (TA) and polyvinylpyrrolidone (PVP) in the polymer matrix. The results show that the assembly of TA/PVP complexation was achieved as observed from the change in colour during the phase inversion and as also proven from the characterization analyses. Incorporation of the TA/PVP assembly leads to enhanced surface hydrophilicity by lowering the contact angle from 82° to 47°. In situ assembly of the TA/PVP complex also leads to enhanced clean water permeability by a factor of four as a result of enhanced mean flow pore size from 0.2 to 0.9 µm. Owing to enhanced surface chemistry and structural advantages, the optimum hydrophilic PVDF/TA/PVP membrane poses permeability of 540.18 L/(m2 h bar) for oil/water emulsion filtration, three times higher than the pristine PVDF membrane used as the reference. [ABSTRACT FROM AUTHOR]

Membrane-based technology is an attractive option for the treatment of oily wastewater because of its high oil removal efficiency, small footprint and operational simplicity. However, filtration performance is highly restricted by membrane fouling, especially when treating oil/water emulsion as a result of strong interaction between oil droplets and the hydrophobic property of the membrane. This study explores the fabrication of polyvinylidene fluoride (PVDF)-based membrane via the vapour induced phase separation (VIPS) method while incorporating polyvinyl pyrrolidone (PVP) as a hydrophilic additive to encounter membrane fouling issues and improve membrane filterability. The resulting membranes were characterized and tested for oil/water emulsion filtration to evaluate their hydraulic, rejection and anti-fouling properties. Results show that the changes in membrane morphology and structure from typical macrovoids with finger-like substructure to cellular structure and larger membrane pore size were observed by the prolonged exposure time from 0 to 30 min through the VIPS method. The enhanced clean water permeability is attributed to the addition of PVP–LiCl in the dope solution that enlarges the mean flow pore size from 0.210 ± 0.1 to 7.709 ± 3.5 µm. The best performing membrane was the VIPS membrane with an exposure time of 5 min (M-5), showing oil/water emulsion permeability of 187 Lm−2 h−1 bar−1 and oil rejection of 91.3% as well as an elevation of 84% of clean water permeability compared to pristine PVDF developed using a typical non-solvent induced phase separation (NIPS) method. Despite the relatively high total fouling, M-5 was able to maintain its high permeability by water flushing as a simple operation for membrane fouling control. The performance was achieved thanks to combination of the large mean flow pore size and hydrophilic property from residual PVP in the membarne matrix. Overall, the results demonstrate the potential of the optimum VIPS method in the presence of PVP and LiCl additives for oil/water emulsion treatment. [ABSTRACT FROM AUTHOR]