Polyethersulfone Nanofiltration Membrane Research Articles

Techno-economic analysis of arsenic (III) removal using spiral wound polyethersulfone nanofiltration membrane at pilot scale

In this work, the influence of initial solution pH on membrane performance was carried out for arsenic (III) removal using spiral wound polyethersulfone (HFN300) Nanofiltration membrane at pilot scale. The rejection percentage was found to increase from 49 % to 96 % while increasing initial solution pH from 4 to 10. Speciation of arsenic, solute-membrane affinity, electric-migration effect along with convection and diffusion were found to be dominant mechanisms for arsenic removal. Donnan Steric Pore Model was selected to estimate the membrane parameters including pore radius (0.313 nm), membrane thickness (2.17 μm), and membrane charge density (−3.56 mol/m3).Excellent agreements were found between the experimental and simulated values for all the studied pH range. Selected model works satisfactorily within 10 % of error for both rejection percentage and permeate flow. Economic feasibility study was carried out for the rural population (India) and total annualized cost was found to be USD 0.90/m3 that seems both reasonable and affordable for arsenic free drinking water. It can be concluded that annualized production cost was dependent on membrane lifespan, electricity tariff, per capita, population size, arsenic feed concentration, etc. The result obtained in the study suggests the feasibility of using the NF process in removing arsenic from contaminated water. Overall, the study provides valuable insights into the mechanisms governing arsenic (III) removal through nanofiltration process using spiral wound polyethersulfone nanofiltration membrane at pilot scale, demonstrating the effectiveness of pH optimization and membrane modelling in improving removal efficiency, which can contribute to the development of cost-effective solutions for safe drinking water in arsenic-affected rural areas.

Incorporations of 2,2′‐benzidinedisulfonic acid and forward osmotic extraction‐favored nanoparticles in polyethersulfone nanofiltration membrane for the simultaneous enhancements in nitrate rejection and water permeation

Incorporations of 2,2′‐benzidinedisulfonic acid and forward osmotic extraction‐favored nanoparticles in polyethersulfone nanofiltration membrane for the simultaneous enhancements in nitrate rejection and water permeation

Fabrication of hyperbranched polyamidoamine functionalized with cucurbituril to improve dyes and heavy metals removal capability of the polyethersulfone nanofiltration membrane

A new hyperbranched polyamidoamine polymer functionalized with cucurbituril (HBPA@Cucurbituril) was fabricated to enhance the antifouling properties of polyethersulfone (PES) membrane to remove dye pollutants and heavy metal ions (e.g., As3+ and Hg2+). ATR-FTIR, TGA, SEM, zeta potential, AFM, water contact angle (WCA), and SEM analyses were used to investigate the morphology of modified membranes. The WCA evaluations indicated that the 0.5 wt% HBPA@cucurbituril membranes showed the best hydrophilicity improvement compared to the bare membrane (decrement from 66.6° to 37.9°). In the best case, the optimally modified membrane (0.5 wt%) indicated the best permeability (8.5 L/m2.h.bar), fouling resistance (flux recovery ratio of 92.42 %), dye rejection (Direct Red 16: 98.7 %, Reactive Blue 19: 99.8 %, Crystal Violet: 97.3 % and Methylene Blue: 98.4 %) and heavy metal removal of (As3+: 99.7 % and Hg2+: 99.2 %). This study offers a clear perspective on the treatment of industrial effluents.

A negatively charged polyethersulfone nanofiltration membrane enriched with Ag-functionalized titanium silicon carbide for the removal of organic pollutants from water

Developing high-performance nanofiltration membranes for treating wastewater contaminated with organic pollutants requires special attention. The toxic nature and side effects of organic pollutants, such as dyes and antibiotics, make them hazardous. Therefore, wastewater containing organic pollutants must be treated properly before entering water environments. Herein, we synthesized the Ti3SiC2 MAX phase via the reactive sintering technique. To make the Ti3SiC2 more hydrophilic and compatible with the polyethersulfone (PES) membrane, its surface was modified in one step with Ag NPs/polyvinyl alcohol (Ag-MAX). Different quantities (0–1 wt%) of Ag-MAX filler were embedded into the PES membrane via the phase inversion process. The presence of 0.75 wt% Ag-MAX filler enhanced hydrophilicity, porosity, surface roughness, pore size, and negative charge of PES membrane, which are beneficial for permeance and antifouling features of Ag-MAX mixed matrix membranes (MMMs). The optimized membrane containing 0.75 wt% of Ag-MAX demonstrated the uppermost pure water flux of 72.5 L/m2 h with a flux recovery ratio of 82.8 %. The optimized membrane showed rejection efficiency of 99.4, 99.6, and 99.7 % for Direct Black 38, Acid Blue 113, and Disperse Red 153 dye solutions, along with a satisfactory rejection of 70.7, 65.9, and 58.5 % for Basic Violet 1, Alizarin Red S, and Ceftriaxone solutions, respectively. Furthermore, the effects of various pH values, various salt types, and cyclic filtration experiments on the separation performance of 0.75 wt% Ag-MAX MMM were investigated. The rejection efficiency of 0.75 wt% Ag-MAX MMM toward Acid Blue 113 is almost constant and higher than 98.5 % in different conditions, demonstrating that the Ag-MAX MMM could be a suitable candidate for the treatment of wastewater contaminated with organic pollutants.

Efficient removal of dyes by light‐responsive graphene oxide‐blended polyethersulfone nanofiltration membranes

AbstractOne of the popular, low‐cost, efficient, and environmentally friendly methods for separating pollutants and water purification are membrane‐based processes. In this study, nanofiltration membranes were modified using the photo‐responsive graphene oxide‐spiropyran (GO‐SP) nanosheets as novel additive. Graphene oxide was employed to improve permeability, antifouling, and mechanical properties of the membranes. Spiropyran was added due to the increase in the self‐cleaning properties of the PES membranes. First, spiropyran (SP) as a photochromic compound was chemically immobilized onto the graphene oxide (GO) surface. Different examinations such as ultraviolet–visible (UV–Vis) spectroscopy, energy‐dispersive X‐ray spectroscopy (EDS), field emission scanning electron microscopy (FE‐SEM), and atomic force microscopy (AFM) were used to check the effective grafting of spiropyran. Then, nanofiltration membranes containing polyethersulfone (PES) and GO‐SP additive with different weight percentages (0.15, 0.25, 0.5, and 0.75 wt.%) were prepared. Membranes comprising 0.5 wt.% GO‐SP exhibited the best surface properties, and at concentrations above 0.5 wt.%, aggregation of GO‐SP additive occurred on the surface of the membrane. The Young modulus increased from 45.11 MPa for pure PES membrane to 82.63 MPa for PES/GO‐SP‐0.75. The flux of pure water, rejection of bovine serum albumin (BSA) protein, and separation of anionic dyes including Congo Red (CR) and Coomassie Brilliant Blue (CBB) were measured to show the filtration performance of the fabricated membranes. It was observed that the addition of 0.5 wt.% GO‐SP increased the flux of pure water of the PES‐based membrane from 2.97 to 14.6 L/m2 h. All prepared membranes rejected more than 94% of CBB and CR dyes. The addition of GO‐SP also developed the performance of the membranes against fouling. In addition, the effects of UV light on membrane fouling, dye rejection, and contact angle were investigated. According to the results, irradiation of GO‐SP with UV light decreased the contact angle and increased the flux of pure water. In the presence of UV light, the membrane containing 0.5 wt.% GO‐SP exhibited 58.74% reversible fouling, 8.30% irreversible fouling, and 93% flux recovery ratio, indicating its better performance than the pure membrane.

Chromium (III) and chromium (VI) removal and organic matter interaction with nanofiltration

Chromium (Cr) is a toxic inorganic contaminant for drinking water, in which the concentration has to be controlled for human health and safety. Cr retention was investigated with stirred cell experiments using sulphonated polyethersulfone nanofiltration (NF) membranes of different molecular weight cut-off (MWCO). Cr(III) and Cr(VI) retention follow the order of the MWCO of the studied NF membranes; HY70–720 Da > HY50–1000 Da > HY10–3000 Da with a pH dependency, especially for Cr(III). The importance of the charge exclusion was highlighted when Cr(OH)4− (for Cr(III)) and CrO42− (for Cr(VI)) was the predominant species in the feed solution.In presence of organic matter, namely humic acid (HA), Cr(III) retention increased by 60 %, while no influence of HA was observed for Cr(VI). HA did not induce major modifications on the membrane surface charge for these membranes. Solute-solute interaction, in particular Cr(III)-HA complexation, was the responsible mechanism for the increase in Cr(III) retention. This was confirmed by asymmetric flow field-flow fractionation, coupled with inductively coupled plasma mass spectrometry (FFFF-ICP-MS) analysis. Cr(III)-HA complexation was significant at HA concentrations as low as 1 mgC/L. The chosen NF membranes were able to achieve the EU guideline (25 μg/L) for Cr in drinking water for a feed concentration of 250 μg/L.

Effect of activated carbon nanoparticles on the performance of PES nanofiltration membranes to separate kraft lignin from black liquor

In this work, activated carbon nanoparticles (AC) at concentrations ranging from 0 to 1 wt% were used to prepare polyethersulfone nanofiltration membranes. The effectiveness of these membranes in separating lignin from black liquor (BL) was evaluated under various operating conditions. The addition of AC improved all desirable properties. For instance, water permeability was increased by 57.50 % with the addition of 1 % AC and surface hydrophilicity was improved by reducing the contact angle from 66.8° to 55.2° for 0.5 % AC-based membranes compared to simple polymeric membranes. For BL filtration, 0.1 % AC-based membranes offered the highest flux with an improvement of 120 % at 24 bar and high lignin rejection compared to simple polymeric membranes. In addition, these membranes exhibited the highest water permeability recovery of 98.02 % when used for BL filtration followed by cleaning. During optimization tests of the main operating variables (temperature, pressure and pH) using 0.1 % AC-based membranes, it was found that extremely high conditions for each variable resulted in decreased performance in terms of fouling and lignin rejection. The best performance of these membranes in terms of flux, lignin rejection and fouling resistance was observed around 40 °C, 20 bar and 11.5 pH within the studied range. In this study, a new application for AC-based NF membranes was established for the separation of lignin from BL. The results of this study also showed that under optimal conditions, the performance of AC-based (0.1 %) membranes was improved for the efficient separation of lignin from BL with lower membrane fouling.

Design of a new polyethersulfone nanofiltration membrane with anti-fouling properties using supported protic ionic liquid modification for dye/salt removal.

Facile techniques to fabricate the nanofiltration membranes with ideal molecular sieving is one of the most interesting subjects in membrane separation technology. In this study, the application of modified graphene oxide (GO) with triethylenetetramine (TETA), CuFe2 O4 , and acetic acid (AC) (supported GO-TETA-CuFe2 O4 @AC) as a supported protic ionic liquid (PIL) modifier for polyethersulfone (PES) membrane was evaluated to approve the improvement of anti-fouling properties and wastewater rejection of the fabricated membranes. To enhance the key properties of graphene oxide, it was modified by hydrophilic nanomaterials (TETA-CuFe2 O4 ). High flux and promising flux recovery ratio (up to 95% compared to the unmodified membrane) can be observed in the modified membranes. The modified membranes by GO-TETA-CuFe2 O4 @AC were studied at optimum concentrations (0.5 wt.%) for salt rejection and different dyes. The obtained data indicated that the modified membranes by GO-TETA-CuFe2 O4 @AC indicated higher salt removal (up to 97% for BaCl2 than the unmodified membrane), which was related to the efficient modification. The obtained pure water flux (PWF) for bare and optimal modified membrane from 13.11 to 27.87 kg/m2 ·h, respectively. To exact evaluate the effect of membrane modification on performance examination, the modified membranes were evaluated for chlorine resistance testing. This study aimed to develop cost-effective nanofiltration (NF) membranes with high anti-fouling properties and to determine the maximum filtration capacity of in-time dyes and salts in effluents. PRACTITIONER POINTS: A GO-TETA-CuFe2O4 mixed matrix membrane was prepared for removal of salts and dyes. The effect of GO-TETA-CuFe2O4 enhanced the hydrophilicity and porosity. The membrane exhibited superior antifouling properties and ions rejection.

Development of Polyethersulfone Nanofiltration Membrane with Layer-by-Layer Method for Xylitol Purification

This work is aimed to develop polyethersulfone (PES) nanofiltration (NF) membrane with layer-by-layer (LBL) polyelectrolytes of chitosan (CHI) and poly(acrylic acid) (PAA) for xylitol purification from fermentation broth. Different number of bilayers and type of terminating layer were manipulated for producing more hydrophilicity, negatively charged with improved performance compared to pristine PES membrane. Successful deposition of polyelectrolyte layers onto PES membrane was able to be proven using various tests such as contact angle, Zetasizer and FT-IR. The results obtained have proven that LBL can develop PES membrane with higher resistance to fouling. From Zeta potential analysis, the value of pristine PES membrane's negativity confirmed the theory of negatively charged substrate for LDL. The negative value of PES membrane increased from -16.5 mV to -32.7 mV after being modified to PES (CHI/PAA)6. From FT-IR spectra, the formation of CHI/PAA complexes on the membrane's surface is confirmed through the presence of stretching peaks of -COOH, -NH3+ and -NH2+ groups The pure water flux reduces from 47.40 ±6.30 L⁄m2.h to 7.40 ±1.64 L⁄m2.h after being modified to PES (CHI/PAA)2. The rejection performance of xylitol for PES (CHI/PAA)2 is higher (84.95%) than pure PES membrane (66.17%), while (CHI/PAA)4 offered the lowest selectivity towards xylitol than arabinose and thus able to obtain higher purity of xylitol as retentate. LBL surface modification using CHI/PAA can develop PES membrane with higher hydrophilicity, negatively charge, and is able to give better xylitol rejection compared to pure PES.

A highly promoted nanofiltration membrane by incorporating of aminated Zr-based MOF for efficient salts and dyes removal with excellent antifouling properties

Nowadays, effective removal of dye and salt from aqueous solutions has received widespread attention in the field of wastewater treatment. In this study, Zr-based nanofillers were used to create high-flux polyethersulfone nanofiltration membranes with impressive anti-fouling performance. Three different levels of UiO-66-NH2 concentration (0.01, 0.1, 1 wt%) were used in membrane body. Solvothermal method was used to synthesize the nanoparticles, and their physical and chemical characteristics were examined through FTIR, XRD, EDAX, and FESEM analyses. Membranes properties also were investigated by SEM, porosity, water content, roughness, water contact angle, flux, separation efficiency, and fouling studies. The surface roughness of the blended membrane with 0.01 wt% nanoparticles (M2) was almost halved compared to the pristine membrane (M1). The water contact angle was also reduced from 70.98° for M1 to 39.09° for M2. The water flux of M2 with 0.01 wt% nanoparticles was 2.31 times higher than that of the pristine membrane. The MB, RhB, and RB21 dyes, as well as Na2SO4, MgSO4, MgCl2, and NaCl solutions, were used to investigate the membrane separation efficiency. All modified membranes showed significant dye retention for both cationic and anionic dyes, and sodium sulfate rejection reached up to> 93.2%. The M2 exhibited the best performance for removal of MB (95.8%), RhB (94.2%), and RB21 (83.6%). The FRR was 46.51% for bare membrane, whereas it was increased significantly for the modified samples up to> 86%. The total resistance of the optimal membrane was remarkably reduced compared to the PES pristine membrane.

Preparation and characterization of a novel polyethersulfone nanofiltration membrane modified with Bi2O3 nanoparticles for enhanced separation performance and antifouling properties

The nanofiltration membranes were prepared based on Poly Ether Sulfone (PES) via the phase inversion method in the study. The membranes were subsequently fabricated through interfacial polymerization between Piperazine (PIP) and Trimesoyl Chloride (TMC) monomers. Consequently, the fabricated membranes were modified using Bismuth Oxide (Bi2O3) nanoparticles. Bi2O3 nanoparticles were dispersed in PIP aqueous solution (Nano Bi2O3-TFCaq) and in TMC organic solution (Nano Bi2O3-TFCorg) by two different procedures to investigate the effect of nanoparticles and the manufacturing process on membrane properties. The prepared membranes were characterized via Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) analysis, atomic force microscopy (AFM), tensile strength, and zeta potential analysis. The tests were performed to check the surface structure, chemical composition, and hydrophilicity of the modified membrane. Also, the salt and BSA rejection rate of the membranes were investigated. Besides, both modified membranes were used to remove Hydrochlorothiazide (HCTZ) drug as the target pollutant. Eventually, it was concluded that the novel Nano Bi2O3-TFC membranes could be so useful in wastewater treatment.

Natural deep eutectic solvent modified nanofiltration membranes with superior antifouling properties for pharmaceutical wastewater treatment

Herein, the L-menthol/10-camphorsulfonic acid (L-M/CSA) natural deep eutectic solvent (NDES) was introduced as an innovative modifier for polyethersulfone (PES) nanofiltration (NF) membrane. Four membranes with different L-M/CSA NDES loadings (0, 0.2, 0.6, and 1 wt%) were prepared and characterized to evaluate the influence of L-M/CSA NDES on the properties of the membranes. The modified membrane with 0.2 wt% L-M/CSA NDES (M-0.2NDES) showed the pure water flux (PWF) of 111.5 L/m2h, which was about 7 times higher than that of the control membrane (M-0NDES). Meanwhile, the mean pore radius was increased from 0.7 nm for the M-0NDES membrane to 0.85 nm for the M-0.2NDES membrane, indicating the good pore forming capability of L-M/CSA NDES. Benefiting from L-M/CSA NDES blending, the modified membranes showed excellent removal efficiency to ceftriaxone (CTX) and amoxicillin (AMOX) solutions. Particularly, the M-0.2NDES membrane possessed 99.6 and 99.2% rejection to CTX and AMOX, respectively, with permeated flux up to about 111 L/m2h, which was far better than the data reported in the literature. M-0.2NDES membrane showed 89.1% chemical oxygen demand (COD), 100% turbidity, and 51.6% total dissolved solids (TDS) removal from the industrial pharmaceutical wastewater. Blending with L-M/CSA NDES was also confirmed to be crucial to ameliorate the membrane antifouling properties. The related results revealed that the flux recovery ratio (FRR) of the M-0.2NDES membrane for milk solution reached 90.2%. The facile fabrication method of L-M/CSA NDES from green materials, good pore forming capability, enhanced antifouling properties, together with the efficient pharmaceuticals removal indicated the good prospect of L-M/CSA NDES for membrane separation applications.

Fouling alleviation and enhanced salt rejection in NF membranes via incorporation of 5-amino-1-phenyl-3-(thiophen-2-yl)-1H-pyrazole-4‑carbonitrile functionalized pectin in PES matrix

In the current study, the facile method of 5-amino-1-phenyl-3-(thiophen-2-yl)-1H-pyrazole-4‑carbonitrile (pyrazole compound) functionalization was introduced to synthesize the new kind of pectin-based material with high functionality and hydrophilicity. The obtained pyrazole compound/pectin (PCPT) hybrid was characterized by SEM, XRD, FTIR, and EDX. Consequently, it was incorporated into the polyethersulfone (PES) nanofiltration (NF) membrane at different loadings. The pectin (PT) composite membranes (PT-0.3 and PT-0.5) were also prepared to further prove the influence of the used PT functionalization method on membrane performance. The surface properties and filtration performance of the composite membranes were studied. All composite membranes showed higher pure water flux compared to the bare membrane (PT-0) and in the best case, the pure water flux value of 43.22 L/m2h was obtained for the 0.3 wt% PCPT composite membrane (PCPT-0.3). PCPT-0.3 showed the highest mean pore size, porosity, surface hydrophilicity, smoothness, and negative charge among all prepared composite membranes. After incorporation of PCPT hybrid, the salt rejection was considerably enhanced with the sequence of Na2SO4 > NaCl, verifying the typical NF behavior of the membranes. For PCPT-0.3, the rejection of direct red 16 (DR16) and crystal violet (CV) was 99.82 and 98.24%, and the corresponding permeate flux was 40.2 and 40.1 L/m2h, respectively. Pb2+, Cu2+, and Cd2+ rejections were measured 31.00, 32.00, and 32.50% for PT-0, whereas they were 98.09, 98.32, and 98.63% PCPT-0.3, respectively. Moreover, PCPT-0.3 exhibited excellent antifouling properties, nominating the PCPT hybrid as a privileged membrane modifier for the treatment of water/wastewater.

Inducing the Skinned-oriented Asymmetrical Nanofiltration Membranes via Controlled Evaporation Times in Dry/Wet Phase Inversion Process

The effect of evaporation time on the fabrication of fine skinned asymmetric polyethersulfone nanofiltration membrane was studied. Nanofiltration experiment and modeling data revealed that the variation of the evaporation time during dry/wet phase inversion process was found to significantly affect the membrane performance and properties. The evaporation times (5 to 25 s) were found to improve the performance and characteristics of the membrane. As good separation performance was achieved, modeling data and morphological analysis discovered that the optimum evaporation time was found to be at 20 s. At these optimal settings, the fabricated membranes demonstrated the finest structural details and morphologies, and the best key properties (rp, Δx/Ak and ζ), which were within the ranges of commercial nanofiltration membranes.

Developing a novel nitrogen-doped hollow porous carbon sphere (N-HPCS) blended nanofiltration membrane with superior water permeance characteristic for high saline and colored wastewaters treatment

• A porous shell of nitrogen-doped hollow carbon sphere (N-HPCS) is synthesized. • The N-HPCS is incorporated in the NF membrane as a novel nanofiller. • Loading 0.25 wt% of N-HPCS manifested an excellent flux, antifouling, and long-term stability. • A novel fabricated membrane is desired for dye rejection with high salt recovery. This study developed a novel mixed matrix polyethersulfone (PES) nanofiltration membrane by blending nitrogen-doped hollow carbon sphere with a mesoporous shell (N-HPCS). By loading only 0.25 wt% of N-HPCS into membrane matrix (M2), hydrophilicity (28.9°), pure water flux (105.6 L/m 2 h), mean pore diameter (1.59 nm), and fouling resistance extensively increased. Compared to the unmodified membrane (M0), the rejection of four studied salts at 3 bar enhanced averagely by 2.4-times using the M2 membrane. M2 showed 97.0%, 98.7%, and 99.2% of dye retention for methylene blue, rhodamine B, and reactive red 195, respectively. In addition, its removal percentage for Pb(II) and Cd(II) was above 98%. The results showed that the Na 2 SO 4 concentration adversely affected its rejection due to the reduction in Debye length at higher ionic strength. While the reactive red 195 retention and Pb(II) removal almost remained constant by increasing their concentration. For studying the potential ability of M2 for high saline textile wastewater treatment, reactive red 195 retention was studied as a function of Na 2 SO 4 concentrations from 100 to 5000 mg/L. At the highest salt concentration of 5000 mg/L, outstanding dye retention of > 97.9% with water permeate > 104.1 L/m 2 was observed. Furthermore, 58 h successful continuous filtration of high concentration of Na 2 SO, reactive red 195, and Pb(II) demonstrated long-term stability of M2. Overall, our study provides a promising new approach for fabricating a high-performance modified membrane by N-HPCS for application in the practical context of wastewater treatment, especially in dye and textile industries.

Polyethersulfone nanofiltration membrane embedded by magnetically modified MOF (MOF@Fe3O4): fabrication, characterization and performance in dye removal from water using factorial design experiments

Polyethersulfone nanofiltration membrane embedded by magnetically modified MOF (MOF@Fe3O4): fabrication, characterization and performance in dye removal from water using factorial design experiments

Novel polyaniline-polyethersulfone nanofiltration membranes: effect of in situ polymerization time on structure and desalination performance.

In this research, novel polyaniline-layered nanofiltration membranes were prepared by phase inversion of base polyethersulfone (PES) membranes and subsequent in situ solution-phase deposition of polyaniline as a thin surface layer. In these composite membranes, the impact of the polyaniline deposition time on steric hindrance and electrostatic interactions during permeation was elucidated. The chemical structure, thermal stability, and mechanical properties of the PES and PANI-PES membranes were investigated using Fourier-transform infrared spectroscopy (ATR-FTIR), thermogravimetric analysis (TGA), and dynamic mechanical analysis (DMA), respectively. The membranes' porosity and pore size decreased as PANI deposition time increased. As PANI deposition time increased, PANI layered nanofiltration membranes exhibited improved thermal stability but deteriorated mechanical characteristics due to free radical destruction from prolonged exposure to the oxidant. These PANI-PES membranes showed 43% rejection (NaCl) at 1.7 bar coupled with a flux of 11.59 L h-1 m2 that is quite promising when comparing with similar Nanofilteration (NF) membranes in the literature and commercial NF membranes, as well. As the deposited layer, PANI is partially doped; hence, permeation results have been interpreted in terms of steric hindrance and electrostatic repulsion by electrochemical PANI layering.

Novel antifouling nanofiltration PES membranes incorporating with C‐KIT‐6 for heavy metal ions removal

AbstractThe removal of Pb2+, Ni2+, and Zn2+ from contaminated water was investigated using the curcumin functionalized KIT‐6 (C‐KIT‐6) incorporated polyethersulfone (PES) nanofiltration (NF) membranes. The prepared C‐KIT‐6 was characterized by scanning electron microscope (SEM), X‐ray powder diffraction (XRD), zeta potential, Energy dispersive X‐Ray (EDX), and Fourier‐transform infrared spectroscopy (FTIR). EDX mapping, SEM, and FTIR were used to show that C‐KIT‐6 mixed in the membrane. Zeta potential, mechanical properties, pore radius, pore radius distribution, and overall porosity were also studied to further characterize the prepared membranes. The hydrophilicity of the membranes was determined by the water contact angle and pure water flux study, and it was increased with respect to increasing C‐KIT‐6 loading. Atomic force microscopy (AFM) images of the C‐KIT‐6 incorporated membranes represented favorable alterations in surface roughness resulting in the amelioration of antifouling behavior. The maximum flux recovery ratio (FRR) and minimum irreversible permeability decay rate (DRir) were attained to be 95.2 and 4.8%, respectively, for the membrane with 0.3 wt% C‐KIT‐6 (M2‐C‐KIT‐6). The rejection of all testing heavy metal ions was maximum (Pb2+ = 91.4%, Ni2+ = 93.1% and Zn2+ = 98.0%) for M2‐C‐KIT‐6. Moreover, M2‐C‐KIT‐6 showed good long‐term reusability performance. The obtained results prove the antifouling C‐KIT‐6 incorporated PES NF membranes are potential candidates for heavy metal ion removal.

Study of Turbulence Promoters in Prolonging Membrane Life.

Nanofiltration membrane technology is an effective method for secondary treated sewage purification. However, membrane fouling, which is inevitable in the membrane-separation process, can reduce membrane performance and shorten membrane life. Installing a turbulence promoter is a promising means of improving the hydraulic conditions inside the membrane chamber. In this study, the effect of turbulence promoter on prolonging membrane life was studied for the first time. Flat-sheet polyethersulfone nanofiltration membrane was used to filter humic acid solution, used for simulating secondary treated sewage. By comparing photographs and SEM images of the membrane before and after the simulated secondary treated sewage filtration, it was found that humic acid tended to be deposited on the low-velocity region, which was reflected by COMSOL simulation. After incorporating a turbulence promoter, the reduction of the humic acid deposition area and membrane fouling resistance indicated that the turbulence promoter could reduce membrane fouling due to the improved hydraulic conditions. Additionally, the turbulence promoter also increased the flux and reduced the flux decay rate. The turbulence promoter was then place in the crossflow flat-sheet membrane filtration module, and the variation of flux with time was tested in simulated secondary treated sewage with different concentrations. The results showed that the membrane life for the filtration of simulated secondary treated sewage comprising 50, 250, and 500 ppm humic acid increased by 23.1%, 80.4%, and 85.7%, respectively. The results of this article can serve as a reference for the prediction of membrane life and the performance enhancement mechanism of membranes containing a turbulence promoter.

MCM-41 mesoporous modified polyethersulfone nanofiltration membranes and their prospects for dyes removal

ABSTRACT This research presents the development of composite membranes incorporating MCM-41 mesoporous material which poses the potential to diminish membrane fouling by organic dyes molecules; a major problematic in leather tanning and textile industries. MCM-41 mesoporous was successfully synthesised and incorporated into polyethersulfone (PES) via the classical non induced phase separation (NIPS) at several loading ratios (0–1 wt.%). Characterisation process was carried out by a series of experimental tools to evaluate the composite membranes. All modified membranes displayed a notable enhancement in their hydrophilicity, roughness, porosity, mechanical strength. Besides that, composite membranes showcased an increase in their antifouling activity against the two dye models, Acid Black and Rose Bengal with increasing the MCM-41 ratio up to 0.5 wt.%. The fabricated PES-NF membranes manifested greater performance in terms of permeation characteristics compared to the pristine PES membrane, while maintained their selectivity against both dye solutions as high as 99%.