Oil Rejection Research Articles

Ecofriendly hydrophilic modification of microfiltration membranes using pyrogallol/ε-polylysine

Microfiltration (MF) membranes need to be hydrophilized to enhance their fouling resistance and applicability. Previous modification strategies are somewhat ineffective and rely on harmful synthetic chemicals. Here, we propose a versatile and ecofriendly strategy to hydrophilize MF membranes via simple coating with the natural compounds, pyrogallol (PG) and ε-polylysine (EPL). The PG/EPL aqueous coating solution produced crosslinked macromolecular PG/EPL complexes via the auto-oxidation of PG and its subsequent reactions with numerous EPL amines. The PG/EPL complexes were densely coated on MF membranes via collective hydrophobic interactions between their abundant PG moieties and membrane surfaces, achieving the excellent hydrodynamic and pH stabilities of the PG/EPL coating. The PG/EPL coating also significantly and uniformly improved the hydrophilicity of the poly(vinylidene fluoride) (PVDF) membrane with no distinct deformation of the membrane pore structure. Hence, the PG/EPL-coated PVDF membrane exhibited remarkably higher organic fouling resistance and water permeance (∼22% enhancement) than its pristine control. Furthermore, the PG/EPL-coated PVDF membrane demonstrated dramatic improvements in oil–water separation (∼27% higher oil rejection) and oil antifouling performance compared with its pristine counterpart. The PG/EPL coating was further extended to hydrophilize other polytetrafluoroethylene and polyethylene MF membranes. The proposed coating strategy provides a versatile and ecofriendly platform for hydrophilizing various membranes.

Novel in-situ zwitterionization of carbon quantum dots on membrane surface for oil/water separation

Industrial growth led to an increase in the release of hazardous oily wastewater that seriously threatens human health and the ecosystem. Developing polymeric membranes for treating such wastewater has garnered significant attention, yet their fouling resistance remains a challenge. In this study, an anti-fouling zwitterionic cellulose acetate (CA) membrane, called ZQDs-g-CA, was fabricated by grafting carbon quantum dots (CQDs) on the surface of the CA membrane, followed by zwitterionization of CQDs (Zwitterionic carbon quantum dots, ZQDs). The grafting of ZQDs increased the hydrophilicity and oleophobicity of the membrane due to the hydrophilic functional groups present in the nanomaterial. The surface roughness was increased, allowing a greater surface area for contact between water molecules and the membrane. The modified CA membrane demonstrated excellent water flux (602.2 ± 30.2 L m−1 h−1 bar−1 (LMHB)) and oil/water emulsion separation performance, with a permeation flux of 426.1 ± 9.6 LMHB and oil rejection of 99.4 %. Additionally, the anti-fouling tests demonstrated remarkable performance with more than 96 % flux recovery ratio (FRR), 30.35 % reversible fouling ratio (Rr), and 3.05 % irreversible fouling ratio (Rir). The results showed that the in-situ ZQDs on the CA membrane exceeded the 96 % rejection rate for different oil/water emulsions. ZQDs were successfully applied on the CA membrane, which would provide a reference for the application of ZQDs-g-CA in oil/water separation.

Degumming and bleaching process troubleshooting in a palm oil refining process using fuzzy expert system with thematic analysis

AbstractDegumming and bleaching are critical steps in the palm oil refining process, as they are the precursors to the qualities of refined, bleached, and deodorized palm oil. In practice, plant operators often face oil rejections in these processes and solve the problem by trial and error. Hence, a fuzzy expert system is developed to troubleshoot the degumming and bleaching process, for identifying failures and suggesting actions. However, developing the knowledge base and inference engine in the fuzzy expert system for troubleshooting the degumming and bleaching process is challenging because the data in the actual palm oil refining process are poorly documented and must be obtained from various sources, including field observation, document analysis, and interviews, and need to be analyzed using thematic analysis. The results from the thematic analysis were represented as input and output variables of the fuzzy expert system. The developed fuzzy expert system is tested and validated against different data sets and industrial data to identify faults and suggest necessary actions. To evaluate the robustness of the troubleshooting system, the membership functions of the fuzzy expert system are adjusted based on the distributed control system (DCS). The results show that the troubleshooting system can effectively diagnose potential faults and provide necessary actions and can serve as a useful guidance for failures in the degumming and bleaching process.

Enrichment of Nutmeg Essential Oil from Oil-in-Water Emulsions with PAN-Based Membranes.

This study used polyacrylonitrile (PAN) and heat-treated polyacrylonitrile (H-PAN) membranes to enrich nutmeg essential oils, which have more complex compositions compared with common oils. The oil rejection rate of the H-PAN membrane was higher than that of the PAN membrane for different oil concentrations of nutmeg essential oil-in-water emulsions. After heat treatment, the H-PAN membrane showed a smaller pore size, narrower pore size distribution, a rougher surface, higher hydrophilicity, and higher oleophobicity. According to the GC-MS results, the similarities of the essential oils enriched by the PAN and H-PAN membranes to those obtained by steam distillation (SD) were 0.988 and 0.990, respectively. In addition, these two membranes also exhibited higher essential oil rejection for Bupleuri Radix, Magnolia Officinalis Cortex, Caryophylli Flos, and Cinnamomi Cortex essential oil-in-water emulsions. This work could provide a reference for membrane technology for the non-destructive separation of oil with complex components from oil-in-water emulsions.

Simple surface modification of PVDF membrane via a quaternization of NM88B for efficient oil/water separation

Developing a stable MOF-modified membrane for efficient treatment of oily wastewater remains a challenge. In this study, NH2-MIL-88B(Fe) (NM88B) was deposited on the commercial polyvinylidene fluoride (PVDF) membranes, and grafted with perfluorohexane-1-sulfonic acid potassium salt (PFHx) to achieve quaternization modification. This reaction proceeds in an environmentally friendly manner due to the absence of any catalyst. The introduction of fluorine atoms through grafting PFHx resulted in the modified PVDF membrane (NPF) demonstrating remarkable underwater superoleophobic property with an underwater oil contact angle at ∼180°. In separation of various oil-water emulsions, the NPF membrane afforded a high permeation flux (up to 2043 L·m−2·h−1) and rejection rate (∼99 %). The oil rejection of NPF membrane was >99 % after 10 filtration cycles of n-hexadecane-water emulsion, and the pure water flux of the recovered membrane was kept at 82.65 % of the original flux, indicating a very good reusability and stability. Filtration of mixed dye/oil-water emulsions showed that the NPF membrane remove 99 % of both oil and dye from the mixture. This work provides a simple and stable modification of PVDF membrane, exhibiting remarkable underwater superoleophobicity and hydrophilicity, thereby harboring substantial prospects in the treatment of oily wastewater.

Integrated membrane process for pretreating and desolventizing hexane-soybean oil miscella – A pilot plant study

The study aimed to develop a membrane desolventizing technology for solvent recovery in vegetable oil extraction. Pretreatment of crude miscella is a prerequisite for an organic solvent nanofiltration (OSN) based desolventizing process. Solvent-resistant ultrafiltration (SRUF) membrane employed in micelle-enhanced ultrafiltration (MEUF) of hexane-crude soybean oil miscella displayed high phospholipids (PL) rejection (98.5 %) and productivity (∼28 L/m2/h), accompanied with a moderate oil rejection (∼22 %). The PL-rich retentate fraction was alkali-treated to recover the oil in the stream (8.8 %). This complementary pretreatment approach met the quality requirements and maximized the yield of treated oil (>98 %) while reducing the chemicals in the process. A subsequent two-stage desolventizing of MEUF-treated miscella with solvent-resistant nanofiltration (SRNF) membrane reduced the oil-in-permeate to 1.37 %, achieving the set recycling criteria (<2 %). The results obtained from the pilot scale study (batch size 40 kg of crude miscella) revealed that the MEUF met the pretreatment requirements, and the subsequent OSN process recovered ∼63 % of hexane through a non-thermal route for recycling in the extraction process. The pilot-scale evaluation demonstrated the technical feasibility of the proposed membrane desolventizing process employing indigenous spiral-wound SRUF and SRNF membrane modules.

Antifouling macrocyclic-engineered PVDF membrane for the low-pressure separation of surfactant-stabilized oily wastewater

Fouling is a common phenomenon which affects the long-term efficacy of membranes in the practical treatment of oily wastewater. It often results in a dramatic decline in flux, and a consequent increase in maintenance and operational cost. To address this, various substrates have been incorporated during membrane fabrication to enhance the fouling resistance, and improve the separation efficiency. Herein, we report the fabrication of a novel symmetrical ball-copper phthalocyanine incorporated PVDF membrane (CuPc@PVDF) for the effective separation of surfactant-stabilized oil-in-water emulsions. The symmetrical ball-Cu phthalocyanine with four non-peripheral substituents synthesized ab-initio and characterized using UV–vis, FT-IR, 1H NMR, and MALDI-TOF spectroscopies was added to the casting solution during membrane fabrication resulting in the formation of highly hydrophilic and anti-fouling CuPc@PVDF membrane. In contrast to the PVDF membrane, having a water contact angle of 82.3° ± 0.7°, the CuPc@PVDF membrane demonstrated high hydrophilicity with a contact angle of 55.5° ± 0.5°, and pure water permeance up to 768 LMH at 3 bar. It further achieved 99.9 % rejection of oil with size in the range of 50–450 nm at 1 bar, and demonstrated high stability and excellent anti-fouling property during 10 cycles of continuous demulsification, with a flux recovery ratio (FRR) of 98.5 %, and extremely low irreversible flux of 1.5 %. Similarly, the CuPc@PVDF membrane exhibited high resistance to accelerated organic fouling, maintaining a steady flux and an FRR of 93.0 % during 1 hour of continuous operation with 10 ppm sodium alginate and Ca2+ ions. This study reports a novel strategy to enhance the fouling resistance of demulsification membranes, and could be further explored in the design of next generation of advanced membranes for the purification of oily wastewater.

Mussel-inspired fabrication of fouling-resistant PPSU-based nanocomposite membrane using polydopamine and tannic acid-functionalized CeO2 nanoparticles towards effective oil-water emulsions separation

Surface modification of membranes using hydrophilic nanoparticles has proved promising to improve the surface wettability and antifouling properties of the membranes that are otherwise prone to the attachment of oil droplets. Nonetheless, the strong adhesion of nanoparticles onto the membrane surface and their long-term performance pose problems for their widespread application. To address these issues, a novel organic-inorganic hybrid coating was constructed onto surfaces of polyphenylsulfone (PPSU) ultrafiltration membrane via simultaneous deposition of mussel-inspired polydopamine (PDA) followed by immobilization of tannic-acid functionalized cerium oxide (CeO2) nanoparticles. These prepared membranes were characterized by FTIR, XPS, FESEM, EDX, pore size, water contact angle (WCA), underwater oil contact angle (UOCA), and separation performance. The effects of functionalization and nanoparticle concentration on membrane properties were investigated. SEM and EDX results showed that functionalized nanoparticles (up to optimum concentration: 0.05 wt%) were uniformly distributed onto the membrane surface, which exhibited increase in permeate flux (∼375 %), UOCA (∼36 %), Fouling resistance ratio (FRR ∼ 300 %) with a decrease in irreversible fouling (∼94 %) and WCA (∼80 %) and high oil rejection of > 99 % compared to pristine PPSU membrane. Long-term operation (for six cycles) indicates that the optimum membrane possessed high efficiency and durability for oil-in-water emulsion separation due to superb antifouling properties and strong binding of the functionalized nanoparticles onto the membrane surface.

Heterogeneous wettability membrane for efficient demulsification and separation of oil-in-water emulsions

Single super-wetting membranes have been used to treat oily wastewater, but most membranes lack demulsification ability and often exhibit poor separation performance. Herein, we fabricate a desert beetle-like heterogeneous wettability membrane with a superhydrophilic fiber substrate and weakly hydrophilic discontinuous protrusions for demulsification and separation of oil-in-water emulsions. The unbalanced force formed by the difference in hydrophilicity between the substrate and protrusions promotes the demulsification of the emulsion. Additionally, the protrusions capture and gather dispersed oil droplets due to Laplace pressure, forming a layered oil slick. This synergistic effect overcomes the limitation of traditional size-sieving mechanism, enhances the separation performance, and avoids membrane fouling. The heterogeneous wettability membrane demonstrates a 99.8 % gravity-driven oil rejection for various oil-in-water emulsions with a permeability of 2600 L·m−2·h−1. It can also achieve effective separation of high viscosity crude oil emulsions without contamination. Furthermore, molecular dynamic simulations reveal that the heterogeneous wettability structure of the membrane surface promotes the demulsification and separation of emulsified oil droplets. And the presence of two hydration layers is found to be the main reason for the great antifouling property of the membrane. This study provides valuable insights for the design of separation membranes for oil-in-water emulsions and the advancement of separation technology.

Antifouling performance enhancement of PES membranes using hydrophilic nanoparticles of poly(dopamine-acrylate) for oil/water separation

Polydopamine-acrylate (P(A-D)x) nanoparticles were blended with polyethersulfone (PES) to fabricate a high-performance hybrid ultrafiltration (UF) membrane for the separation of water from oily wastewater. In tris-alkaline buffer solution at room temperature, P(A-D)x nanoparticles were synthesized by intramolecular Michael addition of dopamine with acrylic acid (AA) monomers. Hybrid PES membranes were prepared using P(A-D)x at 0.05–0.4 wt% and characterized using various assays including Field emission scanning electron microscopy (FESEM), Thermogravimetric analysis (TGA), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), and water contact angle (WCA). The membranes showed a significant increase in hydrophilicity, water permeability, and oil rejection (R). The primary and secondary pure water fluxes of the membrane with 0.2 wt% P(A-D)0.25 were 45% and 110.78% higher than those of neat PES membrane, respectively. For 3300 ppm oil feed solution, water flux during water/oil separation increased by 107%, while the oil rejection (R) remained at 99.08%. The surface of membrane was markedly hydrophilic, with a WCA about 40°, much lower than that of the neat PES membrane (80.67°). UF hybrid membranes also showed a remarkable reduction in oil adhesion on the membrane surface as well as superior antifouling performance for membranes containing 0.2 wt% P(A-D)0.25, flux recovery ratio (FRR) = 84.88 ± 3.27%, reversible fouling (Rr) = 51.12 ± 1.09%, and irreversible fouling (Rir) = 15.12 ± 3.27%. In addition, the pure water flux was 446% higher than that of the unmodified membrane after five cycles (900 minutes).

Pre-treatment of hydrolysable nuclear organic liquids prior to their waste management: Solid impregnation of vegetable oil on surfactant-grafted clay particles

In the context of advancing nuclear waste management techniques, this study delves into the novel use of surfactant-grafted clay particles for pre-treating hydrolysable nuclear organic liquids. Our research explores the potential of modified clay materials in immobilizing vegetable oil, a surrogate for complex nuclear waste. We investigate the adsorption capabilities of various clays, including metakaolin, diatomaceous earth and sepiolite, when grafted with cetyltrimethylammonium bromide (CTAB) as cationic surfactant, or decyl glucoside (DG) as non-ionic surfactant. This study employs characterization techniques to assess the physicochemical transformations in clays post surfactant-grafting. Grafting was initially highlighted by TGA, where the breakdown of surfactants can be observed. This is also evidenced by measurements of the ζ-potential, which demonstrate a reduction in surface charge upon the addition of the cationic surfactant, excepted for sepiolite for which the surface charge did not change. Additionally, Washburn measurements indicate that the grafting process converts hydrophilic particles into hydrophobic ones. The oil absorption tests indicated that the CTAB-grafted sepiolite demonstrated superior characteristics, notably exhibiting no oil rejection. Consequently, this specifically synthesized powder was utilized in a two-step process consisting in pre-impregnation of oil up to 20 %v of vegetable oil prior to its immobilization within a geopolymer matrix. Furthermore, the outcomes of the leaching tests revealed that the vegetable oil remained effectively confined within the immobilization matrix, ensuring its retention. The research contributes to the goal of enhancing hydrolysable nuclear waste management practices, ensuring long-term sustainability and environmental safety.

Robust Synthesis of Hydrophobic Biosorbent for Effective Oil/Organic Solvent Cleanup

AbstractDifferent carbon‐based sorbents are widely used for the refinement of industrial as well as domestic effluent because of their availability, low cost, and excellent hydrophobicity. In this article, the activated biosorbent (ABs) material was prepared and applied to develop a membrane (ABs@Membrane) and sponge (ABs@Sponge) for effective oil and organic solvent cleanup from water mixtures. The one‐pot process was adopted to prepare ABs material by the simple carbonization of naturally available cotton and biowaste chitosan with sulphuric acid. The fabricated ABs@Membrane and ABs@Sponge showed excellent hydrophobicity with excellent water contact angle, i. e., 138.06° and 135.58°, respectively. Moreover, the synthesized ABs@Sponge showed excellent oil/organic solvent absorption capacity in the presence of water, i. e., 40 gm of machine oil and 62 gm of chloroform. Whereas the synthesized ABs@Membrane material showed excellent oil‐water separation efficiency (&gt;90 %) and water flux (219.29 Lm−2 h−1) with a good oil rejection ratio (&gt;91 %). The synthesized ABs@Membrane and ABs@Sponge material showed excellent recyclability performance up to 5th no of consecutive cycles. The straightforward synthesis and fabrication of ABs@Membrane and ABs@Sponge materials with excellent oil rejection ratio and oil/organic solvent separation performance open a new window in the effluent water treatment application.

High performance and antifouling zeolite@polyethersulfone/cellulose acetate asymmetric membrane for efficient separation of oily wastewater

Microfiltration membranes have emerged as a promising alternative for oily wastewater treatment due to their high efficiency, low cost, and ease of operation. In this study, polyethersulfone (PES), cellulose acetate (CA), and 4A zeolite were blended to fabricate asymmetric membranes by the phase inversion technique and examined in oily wastewater treatment. Kerosene was chosen as a model polluting oil. The fabricated pure PES membrane (P), PES membranes incorporating 4A zeolite (ZP), PES membrane blended with CA (PC), and PES/CA blended membranes with 4A zeolite (ZPC) were characterized using field emission scanning electron microscopy, atomic force microscopy, Fourier-transform infrared spectroscopy, porosity, and contact angle to study the structure properties of these membranes. The performance of membranes was examined by water permeation, oil permeation flux, oil rejection, flux recovery ratio, and relative flux reduction. The ZPC membranes showed the highest performance in comparison with other prepared membranes. Incorporating 4A zeolite nanoparticles with 0.5 wt% into the PES/CA blended membrane significantly enhanced the microfiltration performance and decreased the contact angle of the P membrane from 70° to 29.8°. The effect of operation parameters such as transmembrane pressure (1–4 bar), feed temperature (25–50 ºC), and concentration of oil feed solution (250–1000 mg/L) on the permeation flux and oil rejection was studied on the PES/CA blended membrane containing 0.5 wt% 4A zeolite (0.5%ZPC). The 0.5%ZPC membrane showed improved porosity of 87.7% and it gave the highest value of pure water flux of 91.1 L/m2.h, oil permeation flux of 75.55 L/m2.h, maximum oil rejection of 98.8%, flux recovery ratio of 97.7%, and relative flux reduction of 21.8%. The permeation flux given by the 0.5%ZPC membrane was improved by about 8 times that of the P membrane. Re-usability studies verified the durability of the blended membranes and their performance in oily wastewater treatment.

Fast fabricating superhydrophilic PVDF membrane via proanthocyanidins crosslinking at room temperature

Mussels in nature can adhere to the surface of hydrophobic substances by secreting adhesive substances, which has attracted wide attention by coating method for membrane modification. However, complicated processing procedures remain major problems. Here, we proposed a simple, mild and fast surface coating method. Proanthocyanidins (PC) react with 3-aminopropyl triethoxysilane (KH550) under the accelerated action of the oxidant ammonium persulfate (APS) at room temperature to form a polyphenol network. The hydrophilic network coating was constructed on PVDF membrane by surface co-deposition method for 1 h, which could effectively separate different emulsions. The water permeability of modified membrane was 18,271 L∙m−2∙h−1∙bar−1. The permeability for separating isooctane-in-water emulsion arrived at 14,223 L∙m−2∙h−1∙bar−1 and the oil rejection rate was 99.6 %. After ten cycles, the separation flux was 10,836 L∙m−2∙h−1∙bar−1 with the rejection rate of 98.8 %. Modified membranes were soaked in acid and alkali salt solutions of different pH values for 30 days, and maintained good underwater oleophobic performance (>156°). The developed membrane showed excellent separation performance, oleophobic property and acid-base stability. The proposed membrane modification strategy was prospective for efficient separation of oily wastewater.

Potential Nanoparticles to Integrate with Ceramic Membranes for Treating Industrial Wastewater: A Review

Due to human indifference and reckless oily wastewater production from industry, environmental or ecological pollution has become a challenge for our planet. Oily industrial wastewater mostly released by oil fields, refineries, cars, palm oil sectors, and many others is one of the biggest dangers. Oil and water can be virtually completely separated using membrane-based technologies. However, these technologies still face challenges in upholding efficiency over extended periods due to membrane fouling induced by oil droplets mixing with the membranes. Therefore, to overcome these challenges, the creation of polymeric, ceramic, and metallic-based membrane materials with enhanced performance is the focus of research in this field. In this review, various published approaches applied for treating industrial wastewater by using Ceramic Membranes integrated with nanoparticles were focused initially. Then, a modified experimental procedure from the literature for wastewater treatment process by using ceramic membranes is discussed. The majority of studies indicate nearly total oil rejection and increased outputs. Silicon carbide (SiC), Titanium dioxide (TiO2), Aluminum Oxide (Al2O3), Iron Oxide (Fe2O3) Powdered Activated Carbon (PAC), Zirconium dioxide (ZrO2), Alumina powder (Al), Silica (SiO2), Graphene Oxide (GO), and Silver (Ag) are identified potential nanoparticles to mix with ceramic membranes for wastewater treatment application.

Novel activated biochar-enhanced superhydrophilic nanofibrous membrane for superior oil-in-water emulsion separation

In this research, a high-performance Polyamide 6/Polyvinyl Alcohol/Activated biochar (PA6/PVA/AB) composite nanofibrous membrane was developed for effective separation of oil-in-water emulsions. The membrane was produced by blend electrospinning of Polyamide 6 (PA6), Polyvinyl Alcohol (PVA), and Activated biochar (AB) derived from peanut shell biomass. Glutaraldehyde (GA) cross-linking was applied to enhance stability in aqueous environments to prevent PVA swelling. The resulting nanofibrous membrane exhibited a cost-effective design with a superhydrophilic/underwater superoleophobic surface (WCA of 0° and UWOCA of 164°), a porous structure (93% porosity), and robust mechanical properties (Tensile strength: 7.73 MPa, Young modulus: 45 MPa). Optimization of the membrane composition, with 5%wt. PVA and 2%wt. AB relative to the total polymer weight in the electrospinning solution, yielded a superhydrophilic membrane capable of withstanding 2 bar pressure. Pure water flux measurements in the pressure range of 0.5–2 bar demonstrated a high permeability of 1727.5 LMH/bar and a pure water flux of 3455 LMH. The PA6/PVA/AB composite membrane exhibited exceptional performance in separating non-surfactant (NS) and surfactant-stabilized (SS) toluene-in-water emulsions (separation flux: 2006 LMH, oil rejection: 99.52%). Furthermore, it demonstrated high efficiency in the separation of SS oil-in-water emulsions of different types of oil (separation flux >1800 LMH, oil rejection >98%). The membrane's durability and chemical stability were confirmed through 15 cycles of oil-in-water emulsion separation, showcasing anti-fouling properties and reusability (separation flux >833, Oil rejection >97%). Considering its superior performance in oil-in-water emulsion separation and robust reusability, the developed nanofibrous membrane holds significant promise for practical applications.

The influences of Keggin-type H3PW12O40 nanostructure on Polyurethane microfiltration membrane to reinforce screening organic pollutants from wastewater

Manifestly, unceasing growth industrialization has caused to produce the non-segregated phases, engendering complexity in wastewater remediation. Therefore, we endeavored to construct the electrospun Polyurethane (PU)-based Microfiltration (MF) membrane that the Keggin-type H3PW12O40 (KHPW) nanostructure embedded in it by simplified strategy; after that, the PU/KHPWx (x= 0.5, 1, 1.5, and 2 %wt) nanocomposite membranes executed to purify the emulsifier-stabilized Walnut oil (EWO). Fortunately, perfect wettability, controlled porosity, and high negative charge boosted the values of Permeated Water Flux (PWF) and Oil Rejection Efficiency (ORE), which equaled 2150 L.m−2.h−1 and 100 % for the 1400 mg.L-1 of EWO by the PU/KHPW2 membrane, respectively; after that, the fouling resistance parameter (i.e., the Flux Recovery Ratio (FRR)) improved to 62.18 % in pH = 9. Notably, the MB Removal Efficiency (MRE) surveyed to render the light-driven catalytic activities of KHPW, and the Taguchi method optimized the values of operational parameters. Hence, the MRE astonishingly elevated to 79.3 % by PU/KHPW2 at the ameliorated conditions under UV-light irradiation, conferring the self-cleaning merits to the PU/KHPWx samples. After reviewing previously published articles, these authentic observations about the multifunctional capabilities of PU/KHPW2 elucidated insights towards robust screening water pollutants, which discreetly could utilize it in the pre-treatment units of MF.

Water Treatment Performance of PAN/HPMC/Gr Nano Composites

This study investigates polyacrylonitrile:hydroxypropyl methylcellulose )PAN:HPMC( and PAN:HPMC: graphene (Gr) composite nanofibers prepared using the electrospinning technique. Electrospinning is a simple and versatile technique that relies on the electrostatic repulsion between surface charges to continuously draw nanofibers from a viscoelastic fluid. Membrane technology is vital in removing contaminants due to its easy handling and high efficiency. The results demonstrated that the Gr was successfully incorporated into the PAN:HPMC nanofiber membranes, as confirmed by scanning electron microscopy, Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) measurements. The Gr content has a significant impact on the diameter, porosity, and pore size. The PAN:HPMC:0.02Gr electrospun nanofiber membranes achieved excellent oil rejection (72.47%) and good permeability flux (750 LMH); this might be a result of how well the functional groups of the equally distributed Gr within the PAN:HPMC nanofibers interacted with oil. It was noticed that oil rejection dropped a lot as the Gr content went up. This is likely because the pores got wider and some of the Gr stacked or agglomerated across the nanofibers.

Revolutionizing water treatment: Enhanced flux and selectivity in polyethersulfone mixed matrix membrane through magnetic CuO-functionalized Fe3O4 nanoparticles for synthetic oily produced water remediation

In this research, we present a novel CuO@Fe3O4/PES nanocomposite membrane designed to address the complex challenge of separating oil from synthetic oily produced water. This exceptional membrane demonstrates remarkable separation capabilities, achieving an impressive oil rejection rate of 97.5 % and an exceptionally high permeate flux of 0.095 L/m2·h, surpassing traditional pure PES membranes. Our dedicated efforts to optimize membrane efficiency involved a thorough exploration of critical parameters. The peak performance was unequivocally achieved with a solution dosage of 60 mL, a solution concentration of 60 mg·L−1, and a pump pressure of 1.5 bar, ensuring comprehensive optimization. Moreover, contact angle measurements revealed significantly improved hydrophilicity of the CuO@Fe3O4/PES membrane compared to the PES blank membrane. Additionally, SEM, XRD, and FTIR analyses provided valuable insights into the composition, morphology, and properties of the membrane. The outstanding performance of the membrane is attributed to the incorporation of CuO@Fe3O4 nanoparticles, which enhance surface area, permeability, mechanical strength, and catalytic emulsion decomposition. This innovative approach holds great promise for applications in treating oily produced water across diverse industries.

PPS/TA-PEI/β-FeOOH membranes with powerful photo-Fenton self-cleaning capability for efficient oil–water emulsion separation

Polyphenylene sulfide (PPS) microporous membranes have garnered extensive research enthusiasm concerning their outstanding permeation performance and separation accuracy in treating oily wastewater. Nevertheless, the inherent hydrophobic chemical structure, along with the noticeable concentration polarization effect, predisposes them to severe membrane contamination during the separation process. Accordingly, it is desirable to design a PPS self-cleaning membrane with superior anti-fouling capability, fast transport, and remarkable flux recovery. This study marks the first combination of PPS membrane materials with the photo-Fenton process. In detail, the polyphenol (tannic acid, TA)-polycation (polyethyleneimine, PEI)-metal ion (Fe3+) double cross-linking coatings were first assembled on the PPS substrate surface. Subsequently, β-FeOOH photocatalysts were synthesized through in-situ mineralization to further strengthen the hydrophilicity of the membranes. The obtained PPS/TA-PEI/β-FeOOH composite membrane achieved exceptional separation of diverse oil-in-water (O/W) emulsions. The PPS/TA-PEI/β-FeOOH membranes exhibited in-air superhydrophilic and under-water superoleophobicity, exhibiting under-water oil contact angles greater than 151° for diverse oil agents. The fabricated composite membranes displayed high permeability (a flux of the petroleum ether-in-water (P/W) emulsion reached 3400.5 L m−2h−1 bar−1 driven by a pressure of 0.05 MPa) along with ideal oil rejection (98.6 %). Significantly, the PPS/TA-PEI/β-FeOOH membrane possessed powerful photo-Fenton self-cleaning capability, and its flux recoveries of the contaminated membrane exceeded 90.3 % for varied O/W emulsions after being cleaned by visible light for 10 min. We believe that our research presents a novel approach for the exploitation of PPS-based photo-Fenton self-cleaning membranes, which also exhibit great applicative potential in oily wastewater treatment.