The present work deals with the fabrication of novel poly(vinylidene fluoride) (PVDF)/Multi-wall Carbon Nanotubes (MWCNT)/Polypyrrole (PPy) ultrafiltration membrane by phase inversion technique for the removal of crude oil from refinery wastewater. In situ polymerization of pyrrole with different concentrations of MWCNT ranging from 0.025 wt.% to 0.3 wt.% in PVDF prepared solutions. Measurement of permeability, porosity, contact angle, tensile strength, zeta potential, rejection studies and morphological characterization by scanning electron microscopy (SEM) were conducted. The results showed that membrane with (0.05% MWCNT) concentration had the highest permeability flux (850 LMH/bar), about 17 folds improvement of permeability compared to pristine PVDF membrane. Moreover, membrane rejection of crude oil reached about 99.9%. The excellent performance of this nanocomposite membrane suggests that novel PVDF modification with polypyrrole had a considerable effect on permeability with high potential for use in the treatment of oily wastewater in the refinery industry.

Polyvinylidene fluoride (PVDF) membranes have become a favored choice for membrane filtration because of their outstanding mechanical characteristics, chemical resistance, thermal stability, and ease of handling. Nevertheless, the hydrophobic nature of PVDF membranes can result in fouling, which diminishes their efficiency over time. This study explores the impact of ZnO-Nanoclay on the properties and performance of mixed matrix membranes made from polyvinylidene fluoride (PVDF) at different loading percentages (0, 1, and 3 wt%). The ZnO-Nanoclay nanoparticles were synthesized using environmentally friendly methods, characterized, and blended into PVDF matrices via a solution-casting technique, resulting in a series of membranes. The synthesized nanoparticles were analyzed using Scanning Electron Microscopy (SEM) and X-ray diffraction (XRD). The resulting mixed-matrix membranes underwent comprehensive analyses to assess their structure and surface properties, employing SEM, XRD, Atomic Force Microscopy (AFM), and contact-angle measurements. Furthermore, tensile, antibacterial, and barrier properties were evaluated. Integrating ZnO-Nanoclay into PVDF membranes greatly improves antifouling properties, achieving inhibition rates of 99.92% at a clay-loading percentage of 3 wt% and increasing water-flux rates by 16% compared to pure PVDF membranes at 1 wt%. In addition, ZnO-Nanoclay nanoparticles significantly boost the mechanical properties of PVDF membranes, enhancing maximum strength by 500% at 3 wt% loading. This study examines the interplay between the structure, properties, and performance of mixed-matrix membranes by comparing different PVDF membranes that were mixed with different nanoclay composites, providing significant insights into improving these membranes through the incorporation of nanoclay composites to enhance their overall properties and effectiveness.

Polyethersulfone (PES) membranes are essential in separation processes; however, their inherent hydrophobicity can limit their effectiveness in water-intensive applications. This study aims to enhance PES membranes by modifying them with a NiFe₂O₄–nanoclay composite nanoparticle to improve both their hydrophilicity and photocatalytic potential as a photocatalytic membrane. The nanoparticles were synthesized using the sol–gel auto-combustion method and incorporated into PES membranes through mixed-matrix embedding (1 wt% and 3 wt%) and surface coating. X-ray diffraction confirmed the cubic spinel structure of the composite nanoparticles, which followed the second order kinetic reaction during the photodegradation–adsorption of crystal violet. The mixed-matrix membranes displayed a remarkable 170% increase in water flux and a 25% improvement in mechanical strength, accompanied by a slight decrease in contact angle at 1 wt% of nanoparticle loading. In contrast, the surface-coated membranes demonstrated a significant reduction in contact angle to 18°, indicating a highly hydrophilic surface and increased roughness. All membranes achieved high dye removal rates of 98–99%, but only the coated membrane system exhibited approximately 50% photocatalytic degradation, following mixed kinetics. These results highlight the critical importance of surface modification in advancing PES membranes, as it significantly reduces fouling and enhances water–material interaction qualities essential for future filtration and photocatalytic applications. Exploring hybrid strategies that combine both embedding and coating approaches may yield even greater synergies in membrane functionality.

Oily water treatment is a critical environmental challenge owing to the increasing demand for clean water and water pollution mitigation. Among the various treatment methods, membrane filtration stands out because of its numerous advantages, such as high separation efficiency, consistent water quality, versatility, and scalability. However, conventional treatment methods face notable limitations, such as non-uniform pore sizes, fouling problems, and severe environmental concerns owing to the use of toxic solvents in traditional phase inversion processes. Recent advancements in 3D printing technology offer promising solutions to address these drawbacks. This review investigates the potential of 3D-printed membranes as superior alternatives to conventional oil/water separation methods by comprehensively exploring their related aspects. This review begins by classifying 3D printing methods and examining their applications in 3D-printed water treatment membranes for oil/water separation. The key areas covered include membrane properties and characterization, membrane material selection, membrane fabrication and modification, and membrane design. This review also addresses the sustainability aspects of 3D-printed membranes for oil/water separation, highlighting the use of highly stable, renewable, and green materials, as well as the potential for material reuse and recycling. The challenges associated with the adoption of 3D printing for membrane production were addressed, focusing on material and process limitations, safety and environmental issues, and industrial scalability of the technology. Finally, this review outlines the prospects and future directions of research and innovation in 3D-printed membranes for oil/water separation, providing a comprehensive roadmap for advancing this emerging technology. Graphical Abstract

The growing demand for efficient, sustainable water treatment technologies has driven the development of thin-film nanocomposite (TFN) membranes, which offer improved selectivity and permeability. In this research, high-performance TFN membranes were produced by embedding amine-functionalized zirconium-based metal–organic framework (UiO-66-NH ₂ ) nanoparticles into a polyamide active layer created via interfacial polymerization of trimesoyl chloride (TMC) and trans -1,4-diaminocyclohexane (CHDA). A polyethersulfone (PES) ultrafiltration membrane provided a durable and compatible support. Comprehensive characterization with SEM, AFM, XRD, and FTIR confirmed successful nanoparticle integration and uniform membrane structure. At an optimal UiO-66-NH ₂ content of 0.05 wt%, the membrane showed enhanced performance, with notably reduced surface roughness and increased permeability. Water flux increased from 8.65 to 305.4 LMH, while dye flux rose from 8.6 to 225 LMH, all maintaining a dye rejection rate of 97.5% at 10 bar pressure. At a higher nanoparticle load (0.1 wt%), agglomeration led to decreased permeability, though selectivity remained high. These findings highlight the importance of balancing nanoparticle dispersion and loading for optimal membrane performance. Incorporating UiO-66-NH ₂ into the polyamide enhances hydrophilicity and flux without compromising the structural stability needed for long-term use. This study demonstrates the potential of MOF-based TFN membranes for advanced dye wastewater treatment, textile effluent management, and other separation processes in the chemical and pharmaceutical industries. The scalable fabrication method and compatibility with standard membrane systems make this approach highly practical for industry, especially in regions facing water shortages and strict effluent regulations.