Forward Osmosis Membrane Research Articles

Enhancing Milk Concentration Process Using Conductive Forward Osmosis Membranes: A Study on Membrane Fouling Mitigation

Enhancing Milk Concentration Process Using Conductive Forward Osmosis Membranes: A Study on Membrane Fouling Mitigation

Concept and investigation of Selective Forward Osmosis (SFO) for Salt-Salt Separation as a Pretreatment of Seawater for Resource Utilization

Seawater utilization is crucial for the sustainable human development. Despite growing interest in forward osmosis (FO) due to its unique properties, conventional FO membranes with salt-water selectivity have limitations in applying to specific salt-salt separation processes, which hinders their application in resource utilization. In this work, a new concept, “selective forward osmosis (SFO)”, was proposed, which ingeniously employed an SFO membrane consisting of an ion-selective layer on a denser substrate. The denser substrate is designed to control water flux so as to alleviate the solution dilution and improve the salt-salt separation. Moreover, the sucrose and pure water were used separately as feed solution to provide different water flux to influence the various salt fluxes, showing that pure water feed could enhance the salt-salt separation efficiency, although it could dilute the draw solution to some extent. Therefore, pure water was selected as feed in the subsequent experiments. The optimized SFO membrane achieved high Na2SO4/NaCl selectivity (∼54.8) and MgCl2/NaCl selectivity (∼9.2) in single-salt draw solutions. With mixed-salt and heavy-metal-mixed-salt draw solutions, the Mg2+/Na+ selectivity was enhanced to ∼14.5, and further to 29.3. In real seawater tests, the SFO system effectively permeated monovalent elements (such as Na flux of ∼68.6 g m−2 h−1) while maintaining a higher rejection for bivalent elements (such as Mg flux of ∼0.08 g m−2 h−1), showing high selectivities for Mg/Na, U/Na, Sr/Na, Ni/Na, and Ca/Na. These results demonstrate the potential of SFO for resource utilization, especially in complex saline environments. This work contributes a new route for salt-salt separation in the pretreatment of seawater resources.

High-performance thin film composite forward osmosis membrane for efficient rejection of antimony and phenol from wastewater: Characterization, performance, and MD-DFT simulation

The effective removal of heavy metals and phenolic pollutants from aqueous solutions has received widespread attention in the field of wastewater treatment. In this work, a novel PAN/CNTs/UiO-66-NH2 modified forward osmosis (FO) membrane was prepared for efficient removal of antimony (Sb) and phenol from wastewater. The membrane was synthesized using a facile and cost-effective method. The PAN/CNTs substrate membrane was prepared using electrospinning technology, and UiO-66-NH2 MOF particles were loaded onto the surface of the active layer during the interfacial polymerization (IP) process. The presence of CNTs in the spinning solution regulated the pore structure and properties of nanofibers. Characterization of the membrane confirmed its unique structure and enhanced properties. When the CNTs addition was 0.01 g, and UiO-66-NH2 addition was 0.05 wt%, the FO membrane exhibited the optimal operational performance. In the AL-FS mode, the water flux, reverse salt flux (RSF), and Js/Jw ratio were 14.68 LMH, 0.17 gMH, and 0.01 g/L, respectively. As a comparison, the water flux, RSF, and Js/Jw ratio were 21.19 LMH, 0.65 gMH, and 0.032 g/L in the AL-DS mode, respectively. Simultaneously, efficient removal of antimony and phenol was achieved in both modes, with antimony removal efficiencies of 99.26 % and 97.98 %, and phenol removal efficiencies of 96.61 % and 93.18 %, respectively. The modified membrane exhibited excellent performance in rejecting Sb and phenol. Molecular dynamics simulations and density functional theory calculations provide theoretical support for the excellent performance of membranes. The membrane demonstrated a high water flux, making it promising for practical applications. Additionally, it exhibited remarkably low reverse salt flux, highlighting its suitability for desalination processes. The exceptional removal efficiency of Sb and phenol, coupled with the membrane's impressive hydraulic performance, makes it a promising candidate for the treatment of industrial effluents containing these challenging contaminants. The results presented in this study underscore the potential of PAN/CNTs/UiO-66-NH2 FO membranes as an advanced solution for addressing water pollution challenges.

Resilient forward osmosis membranes against microplastics fouling enhanced by MWCNTs/UiO-66-NH2 hybrid nanoparticles

The escalating presence of microplastics (MPs) in wastewater necessitates the investigation of effective tertiary treatment process. Forward osmosis (FO) emerges as an effective non-pressurized membrane process, however, for the effective implementation of FO systems, the development of fouling-resistance FO membranes with high-performance is essential. This study focuses on the integration of MWCNT/UiO-66-NH2 as metal-organic frameworks (MOFs) and multi-wall carbon nanotubes (MWCNT) nanocomposites in thin film composite (TFC) FO membranes, harnessing the synergistic power of hybrid nanoparticles in FO membranes. The results showed that the addition of MWCNT/UiO-66-NH2 in the aqueous phase during polyamide formation changed the polyamide surface structure, and enhanced membranes’ hydrophilicity by 44%. The water flux of the modified FO membrane incorporated with 0.1 wt% MWCNTs/UiO-66-NH2 increased by 67% and the reverse salt flux decreased by 22% as in comparison with the control membrane. Moreover, the modified membrane showed improved antifouling behavior against both organic foulant and MPs. The MWCNT/UiO-66-NH2 membrane experienced 35% flux decline while the control membrane experienced 65% flux decline. This proves that the integration of MWCNT/UiO-66-NH2 nanoparticles into TFC FO membranes is a viable approach in creating advanced FO membranes with high antifouling propensity with potential to be expanded further to other membrane applications.

Metal-phenolic network as precursor complex coating for forward osmosis membrane with enhanced antifouling property.

In this study, a multi-functional layer was developed based on the commercially available cellulose triacetate (CTA) forward osmosis (FO) membrane to improve its antifouling property. Tannic acid/ferric ion (TA/Fe3+) complexes were firstly coated as a precursor layer on the membrane surface via self-assembly. Afterwards, the tannic acid/diethylenetriamine (TA/DETA) hydrophilic functional layer was further coated, following Ag/polyvinylpyrrolidone (PVP) anti-bacterial layer was formed in situ through the reducibility of TA to obtain TA/Fe3+-TA/DETA-Ag/PVP-modified membrane. The optimized precursor layer was acquired by adjusting the buffer solution pH to 8, TA/Fe3+ ratio to 4 and the number of self-assembled layers to 5. The permeability testing results illustrated that the functional layer had an insignificant effect on the membrane transport parameters. The TA/Fe3+-TA/DETA-Ag/PVP-modified membrane simultaneously exhibited excellent physical and chemical stability. The coated membrane also demonstrated enhanced anti-bacterial properties, achieving 98.63 and 97.30% inhibition against Staphylococcus aureus and Escherichia coli, respectively. Furthermore, the dynamic fouling experiment showed a 12% higher water flux decrease for the TA/Fe3+-TA/DETA-Ag/PVP CTA membrane compared to the nascent CTA membrane, which proved its excellent antifouling performance. This work provides a feasible strategy to heighten the antifouling property of the CTA FO membrane.

Impact of temperature and forward osmosis membrane properties on the concentration polarization and specific energy consumption of hybrid desalination system.

This study investigates how temperature and forward osmosis (FO) membrane properties, such as water permeability (A), solute permeability (B), and structural parameter (S), affect the specific energy consumption (SEC) of forward osmosis-reverse osmosis system. The results show that further SEC reduction beyond the water permeability of 3 LMH bar-1 is limited owing to high concentration polarization (CP). Increasing S by 10-fold increases FO recovery by 177.6%, causing SEC decreases by 33.6%. However, membrane with smaller S also increases external CP. To reduce SEC, future work should emphasize mixing strategies to reduce external CP. Furthermore, increasing the temperature from 10 to 40 °C can reduce SEC by 14.3%, highlighting the energy-saving potential of temperature-elevated systems. The factorial design indicates that at a lower temperature, increasing A and decreasing S have a more significant impact on reducing SEC. This underlines the importance of developing advanced FO membranes, particularly for lower-temperature processes.

Defect-Healed Carbon Nanomembranes for Enhanced Salt Separation: Scalable Synthesis and Performance.

Carbon nanomembranes (CNMs), with a high density of subnanometer channels, enable superior salt separation performance compared to conventional membranes. However, defects that occur during the synthesis and transfer processes impede their technical realization on a macroscopic scale. Here, we introduce a practical and scalable interfacial polymerization method to effectively heal defects while preserving the subnanometer pores within CNMs. The defect-healed freestanding CNMs show an exceptional performance in forward osmosis (FO), achieving a water flux of 105 L m-2 h-1 and a specific reverse salt flux of 0.1 g L-1 when measured with 1 M NaCl as draw solution. This water flux is 10 times higher than that of commercially available FO membranes, and the reverse salt flux is 70% lower. Through successful implementation of the defect-healing method and support optimization, we demonstrate the synthesis of fully functional, centimeter-scale CNM-based composite membranes showing high water permeance and a high salt rejection. Our defect-healing method presents a promising pathway to overcome limitations in CNM synthesis, advancing their potential for practical salt separation applications.

Enhancing proton conduction by regulating proton carrier position in polyamide layer of forward osmosis membrane in osmotic microbial fuel cell

Osmotic microbial fuel cell (OsMFC) encounters the problem of slow transport of proton, which results in a pH imbalance between the anode and cathode, and then a decreased cell performance. Forward osmosis (FO) membrane plays a critical role in proton transport in OsMFC, but the proton transmembrane migration is greatly hindered by the absence of particular proton transfer unit in FO membrane. In this study, high proton conductive carrier sulfo (−SO3H) was imported in the polyamide (PA) layer of FO membrane. The results demonstrated that the position of sulfo on benzene ring in PA polymer chain had a significant effect on proton migration and further the OsMFC property. As sulfo is in the ortho and para of the amino group on benzene ring, the optimal FO-1 membrane was acquired. It indicated that the OsMFC loaded with FO-1 membrane completed 88.31 % increase of water extraction, 50.72 % promotion of maximum power density and 6.02 % enhancement of chemical oxygen demand (COD) removal compared to those of the OsMFC with commercial FO membrane. The molecular dynamics simulation elucidated that the hydrogen bond and electrostatic interaction between atoms both played crucial roles in the proton-transfer process. This method of introducing proton carrier at molecular level aiming to alleviate the rising catholyte pH is economical and convenient for the potential scale-up applications of the OsMFC.

Improving antifouling performance of FO membrane by surface immobilization of silver nanoparticles based on a tannic acid: diethylenetriamine precursor layer for municipal wastewater treatment.

In this study, a facile method for multifunctional surface modification on forward osmosis (FO) membrane was constructed by surface immobilization of AgNPs based on tannic acid (TA)/diethylenetriamine (DETA) precursor layer. The cellulose triacetate (CTA) FO membranes modified by TA and DETA with different co-deposition time (6 h, 12 h, 24 h) were investigated. Results indicated that the TA/DETA (24)-Ag CTA membrane with a TA/DETA co-deposition time of 24 h was identified to be optimal, which attained more hydrophilic. And it had the bacterial mortality of Escherichia coli and Staphylococcus aureus reaching 98.23% and 99.83% respectively and possessed excellent physical and chemical binding stability. Meanwhile, the coating layer resulted in the antifouling ability without damaging the membrane intrinsic transport characteristics. As for synthetic municipal wastewater treatment, the water flux of CTA FO membrane decreased approximately 49% of the initial flux after running for 14 days. In contrast, the flux decline rate of TA/DETA (24)-Ag CTA membrane was about 37%. Furthermore, less foulant deposition and higher recovery rate of water flux was observed for TA/DETA (24)-Ag CTA membrane, implying that the modified membrane effectively alleviated membrane fouling and processed a lower flux decline during municipal wastewater treatment. It was attributed to the enhanced surface hydrophilicity and antibacterial property of the coating layer, which improved antifouling property.

A comprehensive review on the use of Ti3C2Tx MXene in membrane-based water treatment

Population growth, industrial activities, and the energy demands of water production intensify the global challenge of accessing clean water. Membrane-based water treatment processes have emerged as crucial solutions to address this crisis, these include microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), forward osmosis (FO), reverse osmosis (RO), and membrane distillation (MD). This review summarizes the properties and use of Ti3C2Tx MXene, a material with notable chemical stability, specific surface area, hydrophilicity, thermal conductivity, and environmental compatibility. Ti3C2Tx fills in the class of two-dimensional materials, it is promising in various membrane processes by offering enhancement in hydrophilicity, permeability, and selectivity. In UF, Ti3C2Tx-based membranes have superior antifouling properties and high rejection rates of contaminants. Meanwhile, in NF, MXene nanosheets elevate the rejection of organics, dyes, and salts, and present valuable nanocomposite membranes. In desalination, incorporating Ti3C2Tx in RO membranes is found to increase water permeability while maintaining high salt rejection in desalination. Also, MXene-modified FO membranes had lower fouling and improved water flux compared with plain membranes, presenting a promising avenue for water purification. Additionally, Ti3C2Tx enhanced water vapor transport and resistance against wetting, which is favorable in MD.This review underscores the transformative potential of Ti3C2Tx MXene in revolutionizing membrane-based water treatment processes, providing innovative solutions to meet the escalating global demand for clean water. Future research directions should optimize MXene-based membrane designs and scale up their production for practical applications in water treatment, thereby contributing to a more sustainable water future.

Optimal synergy between FO membrane and draw solute for high-efficient fruit juice concentration and simultaneous fruiter fertigation

The technology of forward osmosis (FO) has garnered increasing research interest for its excellent advantages in producing high-quality concentrated juice. However, the practical application of FO to concentrate juice is hindered by the lack of an appropriate FO membrane and matched draw solution. To address this challenge, several additives containing high-valence ions were investigated to improve the feasibility of the FO process for juice concentration, using a nanofiltration(NF)-like FO membrane with an interlayer constructed by MOFs-based nanoparticles. The prepared NF-like FO membranes exhibited negative potential, superior hydrophilicity, and uneven crosslinking, which matched well with five selected additives (C6H8O7, K2SO4, C6H5K3O7, MgSO4, and KH2PO4), potentially preventing bacterial growth on the membrane surface during the concentration process and contributing to the growth of plants. A comprehensive comparison of selected five additives indicated that, with the exception of MgSO4, these additives at their saturated concentration exhibited marginally higher osmotic pressure than that of the fresh juice, indicating their limited suitability for further concentration of the fresh juice. However, during the pre-concentration phase of the fresh juice, the juice concentration is lower than that of the fresh juice due to the additional water incorporated during the juice production process. C6H5K3O7 was the optimal draw solution for pre-concentrating apple juice, while MgSO4 was better suited for further concentrating fresh juice. The concentrations of C6H5K3O7 and MgSO4 in the final juice were well below their limit value. Based on these results, a proposal for a dual-stage and dual-cycle FO process has demonstrated to achieve highly efficient concentration of fruit juice and seamless integration of juice production and fertigation of fruit trees, without the need to consider draw solution recovery.

Self-sustaining alkaline seawater electrolysis via forward osmosis membranes

Seawater electrolysis for hydrogen production faces inherent challenges, including side reactions, corrosion, and scaling, stemming from the intricate composition of seawater. In response, researchers have turned to continuous water splitting using forward osmosis (FO)-driven seawater desalination. However, the necessity of a neutral electrolyte hampers this strategy due to the limited current density and scarcity of precious metals. Herein, this study applies alkali-durable FO membranes to enable self-sustaining seawater splitting, which can selective withdraw water molecules, from seawater, via concentration gradient. The membranes demonstrated outstanding perm-selectivity of water/ions (∼5830 mol mol−1) during month-long alkaline resistance tests, preventing electrolyte leaching (>97% OH− retention) while maintaining ∼95% water balance (VFO = Velectrolysis) via preserved concentration gradient for consistent forward-osmosis influx of water molecules. With the consistent electrolyte environment protected by the polyamide FO membranes, the NiFe-Ar-P catalyst exhibits promising performance: a sustain current density of 360 mA cm−2 maintained at the cell voltage of 2.10 V and 2.15 V for 360 h in the offshore seawater, preventing Cl/Br corrosion (98% rejection) and Mg/Ca passivation (99.6% rejection). This research marks a significant advancement towards efficient and durable seawater-based hydrogen production.

Sustainable and eco-friendly membranes from sugarcane bagasse: An upcycling approach for wastewater treatment and energy storage

Developing eco-friendly alternatives to synthetic membranes is crucial in advancing modern membrane technology for water purification. In a pioneering effort, sustainable free-standing Forward Osmosis (FO) membranes composed of cellulose-derived from waste agricultural sugarcane bagasse (SBC) and PVA were developed. These membranes represent a novel upcycling approach, offering both biodegradability and sustainability while ensuring the production of high-quality water. Various analytical techniques were employed to characterize the SBC and membranes. The SBC exhibited a surface area of 1.9 m2 g−1, as determined by BET analysis and was rich in various functionalities. Membrane contact angle measurements revealed their hydrophilic nature. The optimized membrane, SBC-15-DS, demonstrated remarkable performance with an osmotic water flux (OWF) of 9.5 ± 0.2 L m−2h−1, reverse solute flux (RSF) of 0.23 ± 0.01 mol m−2h−1, and specific solute flux (SSF) of approximately 0.009 mol L−1, achieving > 99 % retention for all pollutants. Notably, flux rates of 11 to 14 L m−2h−1 with 99 % rejection were attained for various real industry wastewaters. The SBC-15-DS membrane exhibited excellent stability over 216 h without backwashing, and its biodegradability was confirmed through mulching. Furthermore, fouled membranes were recycled through pyrolyzing at 900 °C, yielding carbon for fabricating supercapacitor electrodes. These electrodes exhibited a specific capacitance of 115 F g−1 at a current density of 0.1 A g−1. Thus, these membranes hold promise for the advancement of sustainable and eco-friendly water purification methods in FO processes.

Performance Evaluation of Forward Osmosis Membranes for Desalination Applications

Forward osmosis (FO) has become a technology with great potential for numerous applications, including water desalination. One of the critical factors in determining the FO performance is the selection of the appropriate membrane material that compatible with draw solution. In this study, commercial cellulose triacetate (CTA) and aquaporin-based membranes, as well as a fabricated PES/PVP membrane, were used, with 1-Butyl-3-methylimidazolium tetrafluoroborate ([Bmim][BF4]) as the thermo-responsive ionic liquid (TRIL) draw solution. The bench scale of FO system was setup upon co-currently flow rate of 60.0 mL/ min at room temperature. The 7 % PVP with 15 % PES had the best performance, with the highest water flux (Jw) (4.93 LMH), lowest reverse solute diffusion (RSD) (0.43 gMH). The fabricated membrane demonstrated a significantly higher performance compared to the commercial aquaporin-based FO membrane, with an improvement of approximately 60%.

Anaerobic acidification membrane bioreactor operating at acidic condition for treating concentrated municipal wastewater: Performance and implication

To address the low-carbon treatment requirements for municipal wastewater, a novel anaerobic acidification membrane bioreactor (AAMBR) was developed for recovering organic matter in terms of volatile fatty acids (VFAs). While the AAMBR successfully generated VFAs from municipal wastewater through forward osmosis (FO) membrane concentration, its operation was limited to a single pH value of 10.0. Here, performance of the AAMBR operating at acidic condition was evaluated and compared with that at alkaline condition. The findings revealed that the AAMBR with pH 5.0 efficiently transformed organic matter into acetic acid, propionic acid, and butyric acid, resulting in a VFAs yield of 0.48 g/g-CODfeed. In comparison with the AAMBR at pH 10.0, this study achieved a similar VFAs yield, a lower fouling tendency, a lower loss of nutrients and a lower controlling cost. In conclusion, this study demonstrated that a pH of 5.0 is optimal for the AAMBR treating municipal wastewater.

Lignosulfonate-Coated ZIF-8 as an Effective Nanofiller to Prepare High-Performance Thin-Film Nanocomposite Forward Osmosis Membrane for Heavy Metal Ions Removal

Lignosulfonate-Coated ZIF-8 as an Effective Nanofiller to Prepare High-Performance Thin-Film Nanocomposite Forward Osmosis Membrane for Heavy Metal Ions Removal

Carbon dots regulating microstructure of polyamide layer of forward osmosis membrane for anti-biofouling and unexpected dual-enhancement in water flux and salt rejection

The introduction of hydrophilic nanomaterials into the polyamide (PA) layer of forward osmosis (FO) membranes usually leads to the enhancement in water flux but a reduction in salt rejection. The decrease in salt rejection, however, inevitably influences the osmotic efficiency and operation cost. In this work, m-phenylenediamine (MPD), one of the chemicals of interfacial polymerization, was utilized as a precursor to synthesize carbon dots (MPD-C-dots) with a good photosensitization functionality. The MPD-C-dots were introduced into the PA layer of FO membranes through co-interfacial polymerization (denoted as Single-C-dots-M), and further grafted onto the PA layer by the conjugation of the residual acyl chloride of trimesoyl chloride with the amine of MPD-C-dots (denoted as Double-C-dots-M). The as-prepared Double-C-dots-M exhibited more outstanding FO performances than the pristine membrane (Control-M) and Single-C-dots-M. Most unexpectedly, the dual-enhancement in water flux and salt rejection of Double-C-dots-M was found. The further studies reveal that Double-C-dots-M had smaller and more uniform pore size, but larger porosity than the other two. In addition, the biofouling-resistance tests demonstrate that MPD-C-dots-M had an excellent anti-biofouling performance by generating singlet oxygen (1O2) under light irradiation. The proposed Double-C-dots-M provided a typical protocol for improving the performances of FO membrane, especially for the synchronous enhancement in water flux and salt rejection.

Thermo‐responsive polymer to clean fouled forward osmosis membrane after wastewater treatment: Excellent flux recovery

AbstractThermally responsive polymers (TRPs) have gained significant attention in the past decade due to their unique phase transition behavior, those exhibiting changes in properties with temperature variations. In water, hydrophilic block copolymers form helical structures that can transform into hydrophobic globules above the lower critical solution temperature (LCST). Fouling is one of the limiting issues for the forward osmosis (FO) process in wastewater treatment. In this work, after the treatment of wastewater from the paper and pulp industries, foulants were removed from the surface of the commercial polyamide thin‐film composite membrane of the FO process using polyvinyl methyl ether (PVME), a TRP with an LCST of 35–37°C. PVME was mixed with different aqueous solutions to form cleaning solutions. Foulant cleaning experiments utilized a 1% PVME (w/v) solution in 300 mL of de‐ionized (DI) water, while 1 M NaCl solution served as the draw solution (DS) in the FO process. Comparing the water flux (J) and change in membrane hydraulic resistance (Rf) among pristine, fouled, and cleaned membranes revealed a 56.67% increase in water flux and a 51.68% decrease in membrane resistance after PVME mixed with DI water cleaning solution showcasing its effectiveness in improving membrane performance and reducing fouling. The cleaning efficiency of two solutions, that is, 1% PVME mixed in DI water and 1% PVME mixed in 1 M aqueous urea solution, is compared. Results showed that the former cleaning solution helped to obtain 32.62% higher water flux and 56.05% less membrane resistance. Various membrane characterizations are performed, such as field emission scanning electron microscopy (FE‐SEM), which characterizes the membrane's pore structure and surface morphology, while a contact angle analyzer assesses hydrophilicity. This research highlights the use of TRPs as effective cleaning agents, enhancing membrane performance by effectively removing foulants on the membrane surface. Investigating alternative cleaning solutions also provides insights for optimizing water treatment processes.Highlights Cleaning of fouled thin‐film composite membrane using thermal‐responsive polymers (TRPs). Polyvinyl methyl ether, a TRP with an lower critical solution temperature of 35–37°C used as a cleaning agent. 60% increase in water flux was observed after the single‐step cleaning process. Multiple uses of TRP for cleaning performed with no membrane damage.

Synergistic regulation of nanocomposite interlayered forward osmosis membranes with 1D/2D nanostructures for enhanced heavy metal retention

The treatment of heavy metal wastewater poses a significant challenge due to its adverse environmental consequences and potential hazards to human well-being, necessitating effective and sustainable solutions. Forward osmosis (FO) is an efficient and low-energy separation technology that serves as an effective strategy to address this issue. However, it still faces the trade-off between water permeability and selectivity, which directly impacts the solute separation efficiency and retention characteristics. In this study, a covalent organic framework (COF) interlayer was introduced via in-situ growth, and the surface properties of polyamide (PA) were synergistically regulated by amine-functionalized multi-wall carbon nanotubes (MWCNT-NH2), resulting in a 1D/2D nanocomposite interlayered FO membrane with a high crosslinking density, improved hydrophilicity, excellent stability, and antifouling properties. The synergistic effect of COF and MWCNT-NH2 led to an increase in the concentration of MPD participating in interfacial polymerization (IP) and a decrease in MPD diffusion rate. These improvements led to enhanced water permeability and selectivity, as well as outstanding retention efficiencies for heavy metal ions (Cr3+, Ni2+), exceeding 99.2 %. Therefore, this study holds significant implications for targeted application development of high-efficiency FO membranes in the future, demonstrating practical value in the treatment of heavy metal wastewater and environmental pollution control.

Tuning Fabrication Factors for Reduced Graphene Oxide Forward Osmosis Membranes

Tuning Fabrication Factors for Reduced Graphene Oxide Forward Osmosis Membranes