Fabrication of gum arabic-graphene (GGA) modified polyphenylsulfone (PPSU) mixed matrix membranes: A systematic evaluation study for ultrafiltration (UF) applications

In the current work, a Gum, Arabic-modified Graphene (GGA), has been synthesized via a facile green method and employed for the first time as an additive for enhancement of the PPSU ultrafiltration membrane properties. A series of PPSU membranes containing very low (0–0.25) wt.% GGA were prepared, and their chemical structure and morphology were comprehensively investigated through atomic force microscopy (AFM), Fourier transforms infrared spectroscopy (FTIR), X-ray diffraction (XRD), and field emission scanning electron microscopy (FESEM). Besides, thermogravimetric analysis (TGA) was harnessed to measure thermal characteristics, while surface hydrophilicity was determined by the contact angle. The PPSU-GGA membrane performance was assessed through volumetric flux, solute flux, and retention of sodium alginate solution as an organic polysaccharide model. Results demonstrated that GGA structure had been successfully synthesized as confirmed XRD patterns. Besides, all membranes prepared using low GGA content could impart enhanced hydrophilic nature and permeation characteristics compared to pristine PPSU membranes. Moreover, greater thermal stability, surface roughness, and a noticeable decline in the mean pore size of the membrane were obtained

Separation of Soluble Benzene from an Aqueous Solution by Pervaporation Using a Commercial Polydimethylsiloxane Membrane

A developed polydimethylsiloxane (PDMS) membrane was used to separate soluble benzene compounds (C6H6) from an aqueous solution via a pervaporation (PV) process. This membrane was characterized by scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy, contact angle (CA), and energy-dispersive spectroscopy (EDS). To evaluate the performance of the membrane, the separation factor and permeation flux were estimated in various operating conditions, including the feed temperature, initial benzene concentration, and feed flow rate. The experiments to maximize the separation factor and permeation flux were designed using the response surface method (RSM) that is built into Minitab 18. A quadratic model (nonlinear regression equation) was suggested to obtain mathematical expressions to predict the benzene permeation flux and the separation factor according to the effect of the parameters’ interaction. The optimization of the PV was performed using an RSM that was based on the analysis of variance (ANOVA). The optimal values of the benzene permeation flux and separation factor were 6.7 g/m2·h and 39.8, respectively, at the optimal conditions of temperature (30 °C), initial concentration of benzene (1000 ppm), and feed flow rate (3.5 L/min). It was found that the feed concentration was the most influential parameter, leading to a significant increase in the permeation flux and separation factor of the PDMS membrane

Attapulgite as an eco-friendly adsorbent in the treatment of real radioactive wastewater

Operators cannot ignore the radiation hazards arising from nuclear weapons. In this study, batch adsorption experiments were investigated to remove the radioactive isotope Cs-137 from the real radioactive wastewater. The attapulgite natural clay mineral was characterized and adopted as an adsorbent in a batch adsorption system. Equilibrium was reached after 2 h with a Cs-137 removal efficiency of 97% for attapulgite. The kinetics of Cs-137 adsorption on the attapulgite clay surface were evaluated. The pseudo-second-order kinetic model produced an excellent fit with the experimental kinetic data. HIGHLIGHTS Very cheap attapulgite clay was used in a batch adsorption system.; Iraqi attapulgite natural clay proved as an efficient adsorbent for the removal of Cs-137.; Natural clay was modified and manufactured from a locally available material.; The real samples of radioactive wastewater containing 137Cs have been treated.

Removal of 4-Nitrophenol from Aqueous Solution by Using Polyphenylsulfone-Based Blend Membranes: Characterization and Performance

Among many contaminants in wastewater, organic phenol compounds presented a major concern to endanger the water resources safety. In the present study, blend nanofiltration (NF) membranes comprising polyphenylsulfone (PPSU) and polyethersulfone (PES) were prepared via the non-induced phase separation and their performance was examined against 4-Nitrophenol (4-NP). The PES ratio in the dope solution was varied from 6 to 9 wt.% to probe the impact of PES on the retention and permeation characteristics of the final membranes. A series of experimental tools were employed to estimate the characteristics of the membranes, including surface and cross-section, hydrophilicity, pore size and pore size distribution. Performance evaluation of the NF membranes was conducted considering two operational variables; pH and initial feed solution. About 99% removal of 4-NP along with 6.2 L/m2·h·bar was achieved at the optimum operating conditions as revealed by optimization and mathematical modelling

Fabrication and Characterization of Polyphenylsulfone/Titanium Oxide Nanocomposite Membranes for Oily Wastewater Treatment

Polyphenylsulfone (PPSU) membranes are critical for numerous applications, including water treatment, oil separation, energy production, electronic manufacturing, and biomedicine because of their low cost; regulated crystallinity; and chemical, thermal, and mechanical stability. Numerous studies have shown that altering the surface characteristics of PPSU membranes affects their stability and functionality. Nanocomposite membranes of PPSU (P0), PPSU-1%TiO2 (P1), and PPSU-2% TiO2 (P2) were prepared using the phase inversion method. Scanning electron microscopy and thermal analysis were performed to determine the contact angle and mechanical integrity of the proposed membranes. The results showed that the membranes contained channels of different diameters extending between 1.8 μm and 10.3 μm, which made them useful in removing oil. Thermal measurements showed that all of the PPSU membranes were stable at a temperature of not less than 240 °C, and had good mechanical properties, including tensile strength of 7.92 MPa and elongation of 0.217%. These properties enabled them to function in a harsh thermal environment. The experimental results of oil and water separation and BSA solution fouling on membrane P2 showed a 92.95% rejection rate and a flux recovery ratio of 82.56%, respectively, compared to P0 and P1

Novel MXene-Modified Polyphenyl Sulfone Membranes for Functional Nanofiltration of Heavy Metals-Containing Wastewater

Funding Information: This research was funded by the Ministry of Higher Education, Malaysia under the HICoE with the grant number R.J090301.7851.4J433 and by the Universiti Teknologi Malaysia under Hi-Tech(F4) Research Grant with the grant number Q.J130000.4609.00Q14. Publisher Copyright: © 2023 by the authors.In this work, MXene as a hydrophilic 2D nanosheet has been suggested to tailor the polyphenylsulfone (PPSU) flat sheet membrane characteristics via bulk modification. The amount of MXene varied in the PPSU casting solution from 0–1.5 wt.%, while a series of characterization tools have been employed to detect the surface characteristics changes. This included atomic force microscopy (AFM), scanning electron microscopy (SEM), contact angle, pore size and porosity, and Fourier-transform infrared spectroscopy (FTIR). Results disclosed that the MXene content could significantly influence some of the membranes’ surface characteristics while no effect was seen on others. The optimal MXene content was found to be 0.6 wt.%, as revealed by the experimental work. The roughness parameters of the 0.6 wt.% nanocomposite membrane were notably enhanced, while greater hydrophilicity has been imparted compared to the nascent PPSU membrane. This witnessed enhancement in the surface characteristics of the nanocomposite was indeed reflected in their performance. A triple enhancement in the pure water flux was witnessed without compromising the retention of the membranes against the Cu2+, Cd2+ and Pd2+ feed. In parallel, high, and comparable separation rates (>92%) were achieved by all membranes regardless of the MXene content. In addition, promising antifouling features were observed with the nanocomposite membranes, disclosing that these nanocomposite membranes could offer a promising potential to treat heavy metals-containing wastewater for various applications.Peer reviewe

Fuel Cell Types, Properties of Membrane, and Operating Conditions: A Review

Fuel cells have lately received growing attention since they allow the use of non-precious metals as catalysts, which reduce the cost per kilowatt of power in fuel cell devices to some extent. Until recent years, the major barrier in the development of fuel cells was the obtainability of highly conductive anion exchange membranes (AEMs). On the other hand, improvements show that newly enhanced anion exchange membranes have already reached high conductivity levels, leading to the suitable presentation of the cell. Currently, an increasing number of studies have described the performance results of fuel cells. Much of the literature reporting cell performance is founded on hydrogen‒anion exchange membrane fuel cells (AEMFCs), though a growing number of studies have also reported utilizing fuels other than hydrogen—such as alcohols, non-alcohol C-based fuels, and N-based fuels. This article reviews the types, performance, utilized membranes, and operational conditions of anion exchange membranes for fuel cells

Evaluation of different methods to ameliorate the performance of PV/T systems using hybrid nanofluids and PCM in a spiral tube with different cross sections

This study proposes a novel design for a serpentine tube to develop an efficient photovoltaic-thermal (PV/T) system. For this purpose, three different hybrid nanofluids and two types of PCM were numerically investigated in a novel serpentine tube with different cross-sectional shapes (rectangular, circular, and triangular). The electrical, thermal, and exergy efficiencies of the PV/T system are evaluated to ascertain the feasibility of the proposed configuration and working fluid. The results showed that using PCM composite and a rectangular cross-section increased thermal and electrical efficiency by 31.1 % and 5.4 %, respectively, compared to the state without PCM and the circular cross-section.For a more comprehensive assessment, the effect of three hybrid nanofluids with a volume concentration of 1.5 % is studied to determine which nanofluid improves heat transfer. Fe3O4-MWCNT demonstrates the most effective nanofluid for cooling down the PV cell temperature. It is used with a volume concentration of up to 4.5 % to investigate how increasing the concentration of hybrid nanofluid can affect important parameters such as cell temperature, fluid outlet temperature, electrical, and thermal efficiency.Moreover, using Fe3O4-MWCNT (4.5 %) along with PCM and PCM composite increases the exergy efficiency by 13.3 % and 16.2 %

Classification of Nanomaterials and the Effect of Graphene Oxide (GO) and Recently Developed Nanoparticles on the Ultrafiltration Membrane and Their Applications: A Review

The emergence of mixed matrix membranes (MMMs) or nanocomposite membranes embedded with inorganic nanoparticles (NPs) has opened up a possibility for developing different polymeric membranes with improved physicochemical properties, mechanical properties and performance for resolving environmental and energy-effective water purification. This paper presents an overview of the effects of different hydrophilic nanomaterials, including mineral nanomaterials (e.g., silicon dioxide (SiO2) and zeolite), metals oxide (e.g., copper oxide (CuO), zirconium dioxide (ZrO2), zinc oxide (ZnO), antimony tin oxide (ATO), iron (III) oxide (Fe2O3) and tungsten oxide (WOX)), two-dimensional transition (e.g., MXene), metal–organic framework (MOFs), covalent organic frameworks (COFs) and carbon-based nanomaterials (such as carbon nanotubes and graphene oxide (GO)). The influence of these nanoparticles on the surface and structural changes in the membrane is thoroughly discussed, in addition to the performance efficiency and antifouling resistance of the developed membranes. Recently, GO has shown a considerable capacity in wastewater treatment. This is due to its nanometer-sized holes, ultrathin layer and light and sturdy nature. Therefore, we discuss the effect of the addition of hydrophilic GO in neat form or hyper with other nanoparticles on the properties of different polymeric membranes. A hybrid composite of various NPs has a distinctive style and high-quality products can be designed to allow membrane technology to grow and develop. Hybrid composite NPs could be used on a large scale in the future due to their superior mechanical qualities. A summary and future prospects are offered based on the current discoveries in the field of mixed matrix membranes. This review presents the current progress of mixed matrix membranes, the challenges that affect membrane performance and recent applications for wastewater treatment systems

A review on development and modification strategies of MOFs Z-scheme heterojunction for photocatalytic wastewater treatment, water splitting, and DFT calculations

Increasing water pollution and decreasing energy reserves have emerged as growing concerns for the environment. These pollution are due to the dangerous effects of numerous pollutants on humans and aquatic organisms, such as hydrocarbons, biphenyls, pesticides, dyes, pharmaceuticals, and metal ions. On the other hand, the need for a clean environment, finding alternatives to fossil and renewable fuels is very important. Hydrogen (H2) is regarded as a viable and promising substitute for fossil fuels, and a range of methodologies have been devised to generate this particular source of energy. Metal-organic frameworks (MOFs) are a new generation of nanoporous coordination polymers whose crystal structure is composed of the juxtaposition of organic and inorganic constituent units. Due to their flexible nature, regular structure, and high surface area, these materials have attracted much attention for removing various pollutants from water and wastewater, and water splitting. MOFs Z-scheme heterojunctions have been identified as an economical and eco-friendly method for eliminating pollutants from wastewater systems, and producing H2. Their low-cost synthesis and unique properties increase their application in various energy and environment fields. The heterojunctions possess diverse properties, such as exceptional surface area, making them ideal for degradation and separation. The development and formulation of Z-scheme heterojunctions photocatalytic systems using MOFs, which possess stable and potent redox capability, have emerged as a successful approach for addressing environmental pollution and energy shortages in recent times. Through the utilization of the benefits offered by MOFs Z-scheme heterojunctions photocatalysts, such as efficient separation and migration of charge carriers, extensive spectrum of light absorption, among other advantages, notable enhancements can be attained. This review encompasses the synthesis techniques, structure, and properties of MOFs Z-scheme heterojunctions, and their extensive use in treating various wastewaters, including dyes, pharmaceuticals, and heavy metals, and water splitting. Also, it provides an overview of the mechanisms, pathways, and various theoretical and practical aspects for MOFs Z-scheme heterojunctions. Finally, it thoroughly assesses existing challenges and suggests further research on the promising applications of MOFs Z-scheme in industrial-scale wastewater treatment