Removal of Copper (II) from Wastewater Using Modified Carbon Nanotubes

In the present work, carbon nanotubes were prepared by Chemical Vapor Deposition (CVD) method, acetylene gas was used as a carbon source. In CVD system, a catalytic growth of CNTs is carried out by decomposition of acetylene (C2H2 ) at a temperature of 750 0C for one hour ,argon is used as an oxidation protection gas. The carbon nanotubes produced are purified to remove impurities such as metal catalyst and then functionalized by treating with HNO3. Scanning Electron Microscopy (SEM), FT-IR spectra and BET for Surface Area measurement technique were used for characterization of CNTs. CNTs with about 30 nm in diameter and with length of several microns were obtained. The effects of initial concentration of metal (ppm), pH, carbon nanotube (CNT) dosage (mg) and contact time (min) on the adsorption of Cu+2 ion were studied. The results show that the pH of aqueous solution is one of the major parameters that control the adsorption of ion at the solid-water interfaces. Maximum removal percentage of Cu+2 species is achieved at pH 8, CNT dosage of 50 mg/L and initial concentration of 50 mg/L and it is 98.39%. The constants of Langmuir and Freundlich models are obtained from fitting the adsorption equilibrium data. The correlation coefficients of Langmuir and Freundlich models are 0.75 and 1, respectively, indicating that the Freundlich model is more appropriate to describe the adsorption characteristics of Cu+2 onto CNTs

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

Sodium Dodecyl Sulfate-Modified Fe 2

Studying the removal of rhodamine B (RB) dye by using zeolite 13X molecular sieves supported by Fe2O3 nanoparticles (denoted as Fe2O3-13X) is the main objective of this study. Fe2O3-13X was synthesized and modified by the addition of sodium dodecyl sulfate (SDS). The prepared Fe2O3-13X was characterized by XRD, TEM, SEM, and zeta potential. The effects of the solution pH, SDS amount, contact time, initial dye concentration, and adsorbent dosage on the removal efficiency of RB were studied. A maximum removal efficiency of 99.3% was achieved. The adsorption equilibrium data of RB were fitted using the Freundlich model, yielding the maximum adsorption capacity of 89.3 mg/g. The findings revealed that the RB adsorption onto Fe2O3-13X modified with SDS (Fe2O3-13X-Ms) was described by a pseudo-second-order kinetic equation. The results reported in this paper indicate that a high RB removal percentage was attained by adding SDS to Fe2O3-13X

Green Synthesis of Fe3O4 Nanoparticles and Its Applications in Wastewater Treatment

In this paper, the extract of Citrus aurantium (CA) was used as a green approach for the preparation of Fe3O4 nanoparticles. The green Fe3O4 (Fe3O4/CA) was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy analysis (EDX), Fourier-transform infrared (FTIR) spectroscopy, Brunauer–Emmett–Teller (BET) surface area measurement, and vibrating sample magnetometry (VSM). The synthesized Fe3O4/CA was used to remove methylene blue (MB) dye from an aqueous solution. A four-factor central composite design (CCD), combined with response surface modeling (RSM), was used to maximize the MB dye removal. The four independent variables, which were initial dye concentration (10–50 mg/L), solution pH (3–9), adsorbent dose (ranging from 200–1000 mg/L), and contact time (30–90 min), were used as inputs to the model of the perecentage dye removal. The results yielded by an analysis of variance (ANOVA) confirmed the high significance of the regression model. The predicted values of the MB dye removal were in agreement with the corresponding experimental values. Optimized conditions for the maximum MB dye removal (93.14%) by Fe3O4/CA were the initial dye concentration (10.02 mg/L), pH (8.98), adsorbent mass (997.99 mg/L), and contact time (43.71 min). The validity of the quadratic model was examined, and good agreement was found between the experimental and predicted values. Our findings demonstrated that green Fe3O4NPs is a good adsorbent for MB removal

Green Synthesis of Fe₃O₄ Nanoparticles and Its Applications in Wastewater Treatment

In this paper, the extract of Citrus aurantium (CA) was used as a green approach for the preparation of Fe3O4 nanoparticles. The green Fe3O4 (Fe3O4/CA) was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy analysis (EDX), Fourier-transform infrared (FTIR) spectroscopy, Brunauer–Emmett–Teller (BET) surface area measurement, and vibrating sample magnetometry (VSM). The synthesized Fe3O4/CA was used to remove methylene blue (MB) dye from an aqueous solution. A four-factor central composite design (CCD), combined with response surface modeling (RSM), was used to maximize the MB dye removal. The four independent variables, which were initial dye concentration (10–50 mg/L), solution pH (3–9), adsorbent dose (ranging from 200–1000 mg/L), and contact time (30–90 min), were used as inputs to the model of the perecentage dye removal. The results yielded by an analysis of variance (ANOVA) confirmed the high significance of the regression model. The predicted values of the MB dye removal were in agreement with the corresponding experimental values. Optimized conditions for the maximum MB dye removal (93.14%) by Fe3O4/CA were the initial dye concentration (10.02 mg/L), pH (8.98), adsorbent mass (997.99 mg/L), and contact time (43.71 min). The validity of the quadratic model was examined, and good agreement was found between the experimental and predicted values. Our findings demonstrated that green Fe3O4NPs is a good adsorbent for MB removal

Optimum operating parameters for PES nanocomposite membranes for mebeverine hydrochloride removal

This study aims to optimize operating parameters of the effect of embedded silica nanoparticles (SiO2 NPs) and modified silica NPs with polyethylenimine (PEI) (SiO2-g-PEI NPs) into polyethersulfone (PES) to fabricate a mixed matrix membranes (MMMs) for pharmaceutical wastewater treatment. The performance of modified MMMs was compared in the separation of Mebeverine hydrochloride (MBV) from aqueous pharmaceutical wastewater. In order to produce a particular quantity of flux and rejection above desired levels, an optimization technique was used to find the best values for various important process parameters. To enhance the effectiveness on a bigger scale, response surface methodology (RSM) and analysis of variance (ANOVA) were utilized as mathematical and statistical approaches. This study examined the effects of operational parameters on the PES-NPs membranes permeate flux and MBV rejection for each sample. These parameters included SiO2/or SiO2-g-PEI NPs content (0.7–1 wt %), solution feed pH values (4-10), and MBV concentration (10–100 ppm). A mathematical model to calculate the permeate flux and rejection (%) was established. The results showed that the SiO2 MMMs had the best performance of 38.27 LMH permeate flux and 81.26% of MBV rejection, while the permeate flux and MBV rejection % for SiO2-g-PEI MMMs were 104.11LMH and 99.00%. The SiO2 wt % of 0.8447%, MBV concentration of 98.18 ppm, and pH of 4 were the optimal parameters for the SiO2 MMMs, while the optimal parameters for SiO2-g-PEI MMMs were SiO2-g-PEI wt. % of 0.93%, MBV concentration of 22.7 ppm, and pH of 4.79 for eliciting the optimum response

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

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

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