Decontaminating liquid-containing Cs-137 by natural Pumice stone.

Radionuclides, emanating as consequential by-products of nuclear operations, are recognized as a potent source of environmentally deleterious contamination. In light of these concerns, the present investigation has employed unmodified natural pumice within a batch process to effectuate the removal of Cs-137 radionuclides from real liquid radioactive wastes (RLRWs). The discernment of optimal adsorption parameters encompassed a pH level of 5, a pumice dosage of 3.33 g/L, a mixing duration of 5 min, a mixing speed of 100 revolutions per minute, all maintained at room temperature. The attainment of a peak removal efficiency of 91.75% for Cs-137 substantiates the efficacy of the chosen conditions. Moreover, the determination of regression coefficients (R2) arising from the application of Freundlich and Langmuir isotherm analyses yielded values of 0.91 and 0.96, respectively, thus validating the appropriateness of both models in depicting the adsorption mechanism. Evidently, the pseudo-second-order kinetic model exhibited a high correlation coefficient of 0.99, attesting to its aptitude in characterizing the adsorption dynamics. A thermodynamic appraisal of the process indicated an endothermic nature, offering insights into the fundamental energetics governing the interaction. Consequently, the adsorption phenomenon unfolded predominantly on monolayer, heterogeneous surfaces, with chemical interactions taking precedence on the active pumice sites.

Permeation Flux Prediction of Vacuum Membrane Distillation Using Hybrid Machine Learning Techniques.

Vacuum membrane distillation (VMD) has attracted increasing interest for various applications besides seawater desalination. Experimental testing of membrane technologies such as VMD on a pilot or large scale can be laborious and costly. Machine learning techniques can be a valuable tool for predicting membrane performance on such scales. In this work, a novel hybrid model was developed based on incorporating a spotted hyena optimizer (SHO) with support vector machine (SVR) to predict the flux pressure in VMD. The SVR-SHO hybrid model was validated with experimental data and benchmarked against other machine learning tools such as artificial neural networks (ANNs), classical SVR, and multiple linear regression (MLR). The results show that the SVR-SHO predicted flux pressure with high accuracy with a correlation coefficient (R) of 0.94. However, other models showed a lower prediction accuracy than SVR-SHO with R-values ranging from 0.801 to 0.902. Global sensitivity analysis was applied to interpret the obtained result, revealing that feed temperature was the most influential operating parameter on flux, with a relative importance score of 52.71 compared to 17.69, 17.16, and 14.44 for feed flowrate, vacuum pressure intensity, and feed concentration, respectively.

Novel partially cross-linked nanoparticles graft co-polymer as pore former for polyethersulfone membranes for dyes removal.

A newly developed water-soluble polymeric nano-additive termed "partially cross-linked nanoparticles graft copolymer (PCLNPG)" has been successfully synthesized and harnessed as a pore former for modifying a polyethersulfone ultrafiltration membrane for dyes removal. The PCLNPG content was varied in the PES polymeric matrix aiming to scrutinize its impact on membrane surface characteristics, morphological structure, and overall performance. Proposed interaction mechanism between methylene blue (MB), methyle orange (MO), and malachite green (MG) dyes with PES membrane was presented as well. Hydrophilicity and porosity of the novel membrane increased by 18 and 17 %, respectively, when manufactured with a 3 Wt. % PCLNPG, according to the findings. Besides this, the disclosed increased porosity, rather than the hydrophilic properties of the water-soluble PCLNPG, was the principal cause of the diminished contact angle. Meanwhile, raising the PCLNPG content in the prepared membrane made worthy shifts in its structure. A sponge-like region was materialized near the bottom surface as well. The membrane's pure water flux (PWF) synthesized with 3 Wt.% PCLNPG recorded 628 LMH, which is estimated 3.95 fold the pristine membrane. MG, MB, and MO dyes were rejected by 90.6, 96.3, and 97.87 %, respectively. These findings showed that the performance characteristics of the PES/PCLNPG membrane make it a potentially advantageous option to treat the textile wastewater.

Experimental Investigation of a Plate-Frame Water Gap Membrane Distillation System for Seawater Desalination.

This study presented a detailed investigation into the performance of a plate-frame water gap membrane distillation (WGMD) system for the desalination of untreated real seawater. One approach to improving the performance of WGMD is through the proper selection of cooling plate material, which plays a vital role in enhancing the gap vapor condensation process. Hence, the influence of different cooling plate materials was examined and discussed. Furthermore, two different hydrophobic micro-porous polymeric membranes of similar mean pore sizes were utilized in the study. The influence of key operating parameters, including the feed water temperature and flow rate, was examined against the system vapor flux and gained output ratio (GOR). In addition, the used membranes were characterized by means of different techniques in terms of surface morphology, liquid entry pressure, water contact angle, pore size distribution, and porosity. Findings revealed that, at all conditions, the PTFE membrane exhibits superior vapor flux and energy efficiency (GOR), with 9.36% to 14.36% higher flux at a 0.6 to 1.2 L/min feed flow rate when compared to the PVDF membrane. The copper plate, which has the highest thermal conductivity, attained the highest vapor flux, while the acrylic plate, which has an extra-low thermal conductivity, recorded the lowest vapor flux. The increasing order of GOR values for different cooling plates is acrylic < HDPE < copper < aluminum < brass < stainless steel. Results also indicated that increasing the feed temperature increases the vapor flux almost exponentially to a maximum flux value of 30.36 kg/m2hr. The system GOR also improves in a decreasing pattern to a maximum value of 0.4049. Moreover, a long-term test showed that the PTFE membrane, which exhibits superior hydrophobicity, registered better salt rejection stability. The use of copper as a cooling plate material for better system performance is recommended, while cooling plate materials with very low thermal conductivities, such as a low thermally conducting polymer, are discouraged.

Effect of MAX Phase Ti3ALC2 on the Ultrafiltration Membrane Properties and Performance.

Membrane fouling remains a major obstacle to ultrafiltration. Due to their effectiveness and minimal energy demand, membranes have been extensively employed in water treatment. To improve the antifouling property of the PVDF membrane, a composite ultrafiltration membrane was created employing the in-situ embedment approach throughout the phase inversion process and utilizing a new 2D material, MAX phase Ti3ALC2. The membranes were described using FTIR (Fourier transform infrared spectroscopy), EDS (energy dispersive spectroscopy), CA (water contact angle), and porosity measurements. Additionally, atomic force microscopy (AFM), field emission scanning electron microscopy (FESEM), and energy dispersive spectroscopy (EDS) were employed. Standard flux and rejection tests were applied to study the produced membranes' performance. Adding Ti3ALC2 reduced composite membranes' surface roughness and hydrophobicity compared to the pristine membrane. Porosity and membrane pore size increased with the addition up to 0.3% w/v, which decreased as the additive percentage increased. The mixed matric membrane with 0.7% w/v of Ti3ALC2 (M7) had the lowest CA. The alteration in the membranes' properties reflected well on their performance. The membrane with the highest porosity (0.1% w/v of Ti3ALC2, M1) achieved the highest pure water and protein solution fluxes of 182.5 and 148.7. The most hydrophilic membrane (M7) recorded the highest protein rejection and flux recovery ratio of 90.6, which was much higher than that of the pristine membrane, 26.2. MAX phase Ti3ALC2 is a potential material for antifouling membrane modification because of its protein permeability, improved water permeability, and outstanding antifouling characteristics.

Forward Osmosis Membrane: Review of Fabrication, Modification, Challenges and Potential.

Forward osmosis (FO) is a low-energy treatment process driven by osmosis to induce the separation of water from dissolved solutes/foulants through the membrane in hydraulic pressure absence while retaining all of these materials on the other side. All these advantages make it an alternative process to reduce the disadvantages of traditional desalination processes. However, several critical fundamentals still require more attention for understanding them, most notably the synthesis of novel membranes that offer a support layer with high flux and an active layer with high water permeability and solute rejection from both solutions at the same time, and a novel draw solution which provides low solute flux, high water flux, and easy regeneration. This work reviews the fundamentals controlling the FO process performance such as the role of the active layer and substrate and advances in the modification of FO membranes utilizing nanomaterials. Then, other aspects that affect the performance of FO are further summarized, including types of draw solutions and the role of operating conditions. Finally, challenges associated with the FO process, such as concentration polarization (CP), membrane fouling, and reverse solute diffusion (RSD) were analyzed by defining their causes and how to mitigate them. Moreover, factors affecting the energy consumption of the FO system were discussed and compared with reverse osmosis (RO). This review will provide in-depth details about FO technology, the issues it faces, and potential solutions to those issues to help the scientific researcher facilitate a full understanding of FO technology.

Incorporation of graphene oxide nanosheets into polyethersulfone membranes to improve their separation performance and antifouling characteristics for Congo red removal.

Due to worldwide shortage of water sources and, on the other hand, producing a huge amount of contaminated industrial wastewater, there is an urgent need to provide proper treatment processes such as fast-growing membrane ones. In this study, some nanocomposite nanofilter membranes, as a promising solution for this goal, were fabricated by incorporation of graphene oxide (GO) nanosheets into polyethersulfone (PES) membrane matrix and polyvinylpyrrolidone (PVP) via the method of non-solvent-induced phase separation (NIPS) to dedicate them higher separation performance and a higher antifouling tendency. The produced GO nanosheets and the prepared membranes' structure were evaluated by field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), and atomic force microscopy (AFM) analysis. Then, the separation performance and antifouling characteristics of the prepared pristine and nanocomposite membranes were evaluated at 3 bar, 27°C, and Congo red (CR) dye concentrations of 50, 100, and 200 ppm. The observations revealed that the incorporation of GO nanosheets into the polymer matrix of PES-PVP increases the permeation flux, rejection of CR, and flux recovery ratio (FRR) to the maximum values of 276.4 L/m2 .h, 99.5%, and 92.4%, respectively, at 0.4 wt.% loading of GO nanosheets as an optimum filler loading. PRACTITIONER POINTS: Graphene oxide nanosheets were prepared and uniformly incorporated in the polyethersulfone porous membrane. The nanocomposite membranes revealed higher separation performance, that is, permeation flux and dye rejection as 282.5 L/m2 .h and 99.5% at 0.4 wt.% loading of GO nanosheets. Flux recovery ratio of the nanocomposite membrane, as their antifouling character, also increased as 92.4%, as the GO nanosheets were incorporated by 0.4 wt.%.

Enhanced Antifouling in Flat-Sheet Polyphenylsulfone Membranes Incorporating Graphene Oxide-Tungsten Oxide for Ultrafiltration Applications.

In this study tungsten oxide and graphene oxide (GO-WO2.89) were successfully combined using the ultra-sonication method and embedded with polyphenylsulfone (PPSU) to prepare novel low-fouling membranes for ultrafiltration applications. The properties of the modified membranes and performance were investigated using Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), contact angle (CA), water permeation flux, and bovine serum albumin (BSA) rejection. It was found that the modified PPSU membrane fabricated from 0.1 wt.% of GO-WO2.89 possessed the best characteristics, with a 40.82° contact angle and 92.94% porosity. The permeation flux of the best membrane was the highest. The pure water permeation flux of the best membrane showcased 636.01 L·m-2·h-1 with 82.86% BSA rejection. Moreover, the membranes (MR-2 and MR-P2) manifested a higher flux recovery ratio (FRR %) of 92.66 and 87.06%, respectively, and were less prone to BSA solution fouling. The antibacterial performance of the GO-WO2.89 composite was very positive with three different concentrations, observed via the bacteria count method. These results significantly overtake those observed by neat PPSU membranes and offer a promising potential of GO-WO2.89 on activity membrane performance.

Polydimethylsiloxane (PDMS) Membrane for Separation of Soluble Toluene by Pervaporation Process.

A commercial polydimethylsiloxane (PDMS) membrane was employed to separate the soluble toluene compounds (C7H8) from an aqueous solution via the pervaporation (PV) process. The performance and the efficacy of the PDMS PV membrane were evaluated through the estimation of the permeation flux and separation factor under various operating parameters. The response surface method (RSM) built in the Minitab-18 software was used for the design of the experiment in this study, and the responses of the permeation flux and the separation factor were analyzed and optimized based on the operating conditions. A nonlinear regression analysis was applied to the experimental output and input, and as a result, a quadratic equation model with parameters interactions was obtained as mathematical expressions to predict the permeation flux and separation factor. At the optimal conditions of temperature 30 °C, initial toluene concentration 500 ppm, and feed flowrate 3.5 L/min, the toluene permeation flux and separation factor were 125.855 g/m2·h and 1080, respectively. The feed concentration was the most impactful and significant in the improvement of the permeation flux and separation factor of the PDMS membrane.

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

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.

Modeling and simulation of pervaporation (PV) separation for alcohol dehydration.

The separation performance of commercial crosslinked poly (vinyl alcohol) (PVA) membranes (i.e., the new commercial membrane PERVAP™ 4100 H F and standard membrane PERVAP™ 4100) used for the dehydration of two alcohol-water systems (i.e., ethanol-water and isopropanol-water mixtures, with an azeotropic point) were studied based on pervaporation process (PV) experimental data and mathematical modeling. Pervaporation process experiments proved that these two membranes have excellent applicability for the dehydration of alcohol. A semi-empirical solution-diffusion transport model was developed to describe the mass transport in the PVA membranes, which showed a good agreement with the experimental values. The universal quasi-chemical (UNIQUAC) model was utilized to predict the activity coefficient of nonideal alcohol-water systems in PVA membranes. In addition to the UNIQUAC model, the transport of alcohol-water across the commercial polymeric membrane was modeled using the conventional driving force model. The PV process experimental data with the mathematical model were used to develop the diffusivity correlations for water and alcohol (i.e., ethanol and isopropanol) through the PVA membranes. It was found that for swollen membranes (PVA), the developed correlations of water and alcohol diffusivity were strongly influenced by the feed water activity and feed temperature. Based on the mass transport model and developed diffusivity correlations, the permeation flux of water and alcohol through the PVA membranes was predicted, and the results showed a good agreement between the experimental data and the predictive model. The mean relative errors estimated for the permeate mass fluxes of water were 8.4%, and 3.8%, and for the permeate mass fluxes of ethanol were 18%, and 13.6% for the PERVAP™ 4100 and 4100 H F, respectively, as well as for the IPA-water-PVA system are as follows: 5% and 2.8% for the permeate mass fluxes of water and 14.4%, and 12.6% for the permeate mass fluxes of IPA for the PERVAP™ 4100 and 4100 H F, respectively.

Recent progress and future directions of membranes green polymers for oily wastewater treatment.

The preparation, modification and application of green polymers such as poly-lactic acid (PLA), chitosan (CS), and cellulose acetate (CA) for oily wastewater treatment is summed up in this review. Due to the low environmental pollution, good chemical resistivity, high hydrophobicity, and good capacity for water-oil emulsion separation of the presented polymers, it then highlights the various membrane production methods and their role in producing effective membranes, with a focus on recent advances in improving membrane properties through the addition of various Nano materials. As a result, the hydrophilic/hydrophobic properties that are critical in the oil separation mechanism are highlighted. Finally, it looks at the predictions and challenges in oil/water separation and recovery. These ideas are discussed with a focus on modern production methods and oil separation proficiency.

Modification of polyethersulfone membranes by Polyethyleneimine (PEI) grafted Silica nanoparticles and their application for textile wastewater treatment.

In the current work, a novel nanocomposite membrane for wastewater treatment applications has been synthesized. A hydrophilic nature nanoadditive comprised grafting polyethylenimine (PEI) molecules onto the surfaces of silica nanoparticles (SiO2 NPs) was synthesized then entrapped within a polyethersulfone polymeric matrix at disparate ratios via the classical phase inversion technique. A series of experimental tools were employed to probe the influence of SiO2-PEI on the surface topography and morphological changes, hydrophilicity, porosity, surface chemistry as well as permeation and dyes retention characteristics of the new nanocomposite. Upon increasing the nanoadditives content (up to 0.7 wt. % SiO2- PEI), clear cross-sectional changes were depicted along with a noticeable decline in the water contact angle by 29.7%. Performance evaluation measurements against synthetic dye solutions were disclosed explicit enhancement in both; retention and permeation characteristics of the nanocomposite membranes. Besides, prolonged permeation test has maintained high flux stability against real textile wastewater; implying better resistance and self-cleaning characteristics have been achieved.

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.

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.

Modification of Polyethersulfone Ultrafiltration Membrane Using Poly(terephthalic acid-co-glycerol-g-maleic anhydride) as Novel Pore Former.

In this research, poly terephthalic acid-co-glycerol-g-maleic anhydride (PTGM) graft co-polymer was used as novel water-soluble pore formers for polyethersulfone (PES) membrane modification. The modified PES membranes were characterized to monitor the effect of PTGM content on their pure water flux, hydrophilicity, porosity, morphological structure, composition, and performance. PTGM and PES/PTGM membranes were characterized by field emission scanning electron microscopy (FESEM), Fourier-transform infrared spectroscopy (FTIR), and contact angle (CA). The results revealed that the porosity and hydrophilicity of the fabricated membrane formed using a 5 wt.% PTGM ratio exhibited an enhancement of 20% and 18%, respectively. Similarly, upon raising the PTGM ratio in the casting solution, a more porous with longer finger-like structure was observed. However, at optimum PTGM content (i.e., 5%), apparent enhancements in the water flux, bovine serum albumin (BSA), and sodium alginate (SA) retention were noticed by values of 203 L/m2.h (LMH), 94, and 96%, respectively. These results illustrated that the observed separation and permeation trend of the PES/PTGM membrane may be a suitable option for applications of wastewater treatment. The experimental results suggest the promising potential of PTGM as a pore former on the membrane properties and performance.

Ethanol Separation from an Ethanol-Water Solution Using Vacuum Membrane Distillation.

The vacuum membrane distillation (VMD) process was applied to separate ethanol from a simulated ethanol-water solution using a commercial polytetrafluoroethylene (PTFE) membrane. The presence of ethanol in the ethanol-water solution with a 2 wt.% ethanol concentration at a temperature above 40 °C during the MD process may result in membrane failure due to an increase in the chance of the PTFE membrane wetting at high temperatures. Therefore, the operating temperature in this study was not higher than 35 °C, with an initial ethanol concentration up to 10 wt.%. This work focuses on optimizing the VMD operating parameters using the Taguchi technique based on an analysis of variance (ANOVA). It was found that the feed temperature was the most-affected parameter, leading to a significant increase in the permeation flux of the PTFE membrane. Our results also showed that the permeate flux was reported at about 24.145 kg/m2·h, with a separation factor of 8.6 of the permeate under the operating conditions of 2 wt.%, 30 °C, 60 mm Hg(abs), and 0.6 L/min feed (concentration, temperature, permeate vacuum pressure, and flow rate, respectively). The initial feed concentration, vacuum pressure, and feed flow rate have a lower impact on the permeation flux.

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.

Optimization of MCM-41 Mesoporous Material Mixed Matrix Polyethersulfone Membrane for Dye Removal.

The aim of this work is the optimization of the operating conditions under which MCM-41-mesoporous material can be incorporated into polyethersulfone (PES)/MCM-41 membranes for nanofiltration (NF) applications. MCM-41 mesoporous material mixed matrix PES membranes have the potential to reduce membrane fouling by organic dye molecules. Process optimization and modeling aim to reduce wasted energy while maintaining high flow during the operation to handle the energy efficiency problems membranes often have. An optimization technique was applied to obtain optimum values for some key parameters in the process to produce a certain amount of flux above the desired values. Response surface methodology (RSM) and analysis of variance (ANOVA) were used as mathematical and statistical analyses to improve the performance of the process on a larger scale. This work investigated the influence of the operating parameters, such as the feed pH values (3-11), MCM-41 content (0-1 wt.%), and the feed dye concentration (10-100 ppm) for each of the two studied dyes, acid black 210 (AB-210) and rose bengal (RB), and their interactions on the PES membrane permeability. The results showed that the PES membrane had the best performance at 64.25 (L·m-2·h-1·bar-1) and 63.16 (L·m-2·h-1·bar-1) for the AB-210 and RB dyes, respectively. An MCM-41 content of nearly 0.8 wt.% in the casting solution, feed dye concentration of 10 ppm for the studied dyes, and feed pH of 3 for the RB dye was found to be the optimal parameters for eliciting the response. The pH had no significant influence on the response for the AB-210 dye, while the pH shows some minor effects on response with the RB dye, and the Pareto chart of the standardized effects on the permeation flux of both dyes using statistically significant at the 5% significance level support these results.

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.