Nanofiltration System Research Articles

Desferrioxamine B (DFOB) assisted nanofiltration system for the recycling of gallium from low concentrated wastewater

Gallium is classified as a technology metal as it is important for technological innovations. It is also referred to as a strategic metal, which emphasizes its economic relevance. In addition, gallium is a critical raw material that is strategically important but only available in limited quantities. However, recycling dissolved gallium from low-concentration wastewater is often not done due to the lack of suitable technologies. This research presents a membrane-based approach using the siderophore Desferrioxamine B for the recycling of gallium. Nanofiltration membranes were used to separate gallium from other metal impurities (such as arsenic). The membranes recovered about 70 % of gallium from low-concentrated synthetic wastewater. Afterward, the membranes were tested using industrial wastewater, and a similar recovery rate was observed. A model was developed to predict operation parameters that would lead to the highest recovery rate of gallium with the minimum impurities. The model showed that recycling more than 90 % of gallium from wastewater is possible using this approach. Therefore, the siderophore-assisted nanofiltration approach demonstrated in this research showed great potential for the sustainable recycling of gallium from industrial wastewater.

Enhancing nanofiltration performance with tannic acid and polyvinyl alcohol interlayers for improved water permeability and selective solute rejection

Global water shortages have significantly intensified the demand for efficient and sustainable water purification technologies. Nanofiltration (NF) plays a crucial role in desalination, providing distinct advantages by removing a variety of pollutants including heavy metals and organic compounds, all while consuming minimal energy. Traditional NF membranes often struggle to balance high rejection with satisfactory permeability. This study advances NF technology by utilizing polysulfone as a durable substrate and introducing tannic acid (TA)-polyvinyl alcohol (PVA) interlayer to enhance structural robustness and functional capabilities of membranes. Through streamlined one-step coating followed by precise interfacial polymerization, this approach optimizes monomer piperazine storage and dispersion on substrate, effectively controlling its diffusion rate, resulting in a thinner polyamide (PA) layer. These strategic enhancements not only lead to a significant increase in permeability to 216.3 L·m−2·h−1·MPa−1 and an impressive rejection for Na2SO4 of 99.04 % but also ensure enhanced long-term operational stability. The innovative TA-PVA interlayer sets new benchmarks for high-performance NF membranes by combining environmental friendliness with cost-effectiveness, making it ideal for large-scale industrial applications. This unique composition promotes sustainability and economic efficiency in water treatment technologies, and underscoring the vast potential for expanding the production and application of advanced NF systems.

Performance evaluation of nanofiltration membranes for SWRO brine valorisation: Insights from a pilot plant under real conditions

The success of a desalination brine valorisation process heavily depends on the effectiveness of the pre-treatment stage, which purifies the brine by reducing the concentration of ions that could form insoluble compounds and hinder system performance. This study focused on testing an innovative nanofiltration (NF) pilot plant operating with 144 m3/d of actual brine from an upstream seawater reverse osmosis (SWRO) pilot plant located in the Canary Islands (North Atlantic Ocean). The NF membranes tested (NE8040-40) played a critical role, demonstrating exceptional rejection rates for divalent ions, therefore also increasing their concentration in the divalent-rich stream, setting the stage for future valorisation of the related by-products. Simultaneously, these NF membranes allowed the achievement of a high-purity monovalent-rich stream with Na+ and Cl– concentrations reaching approximately 98 %, potentially enabling the generation of valuable commercial products in subsequent stages. The NF system was thoroughly assessed under different conditions of flow, pressure, and recovery rates, incorporating extensive process monitoring with comprehensive sensor data.

Novel nanofiltration-reverse osmosis-high pressure nanofiltration membrane brine concentration (NF-RO-HPNF MBC) system for producing high purity high concentration sodium chloride brine from seawater

A pilot-scale study of a nanofiltration (NF) - reverse osmosis (RO) - membrane brine concentration (MBC) system was carried out using novel NF membranes for the NF and MBC systems. Two commercially available NF membranes with high magnesium rejection were tested for the removal of divalent ions from seawater. These membranes exhibited 81–87 % rejection of Ca and 95–97 % rejection of Mg at an 85 % recovery rate, resulting in a 4.3–5.3 times higher concentration of Ca and 5.4–6.7 times higher concentration of Mg in the NF reject than in the feed. Accordingly, the NF permeate had a high NaCl/TDS index of 96.7–97.8 %, facilitating the downstream production of high-purity NaCl salt. The potential of using NF membranes for brine concentration was investigated, and it was found that if a NF membrane could be operated at 75 bar, the NaCl solution could be concentrated to over 230 g/L. A pilot-scale trial was carried out on a 3-stage high pressure NF (HPNF) system, which achieved a concentration of 220 g/L from 78 g/L SWRO brine and 80 days of continuous operation. At a higher operating pressure, the system successfully concentrated the brine to 251 g/L as designed. The specific power consumption of the industrial 3-stage HPNF MBC system was estimated to be 111.0–123.3 kWh/t NaCl while concentrating from 75 g/L to 225 g/L and producing diluted steam at 43 g/L. This demonstrates competitiveness with conventional concentration methods such as thermal evaporation and electrodialysis.

Silver nanoparticle-decorated reduced graphene oxide/ nanocrystalline titanium metal-organic frameworks composite membranes with enhanced nanofiltration performance and photocatalytic ability

Nanofiltration (NF) has garnered significant attention for removing persistent dyes from industrial wastewater. However, limited membrane separation efficiency and performance deterioration due to membrane fouling are the primary challenges hindering the broader application of NF technology. Herein, we developed high-performance silver nanoparticle-coated reduced graphene oxide/nanocrystalline MIL125(Ti) composite NF membranes (nAg-rGO/n-MIL), which feature self-cleaning capabilities through photocatalytic activity. This was achieved by intercalating nanocrystalline MIL-125(Ti) (n-MIL) metal-organic frameworks between graphene oxide (GO) nanosheets, followed by reducing the GO nanosheets and decorating them with silver nanoparticles (nAg) via UV exposure. The nAg-rGO/n-MIL demonstrated high water permeability (21.7 LMH/bar) and achieved excellent removal efficiencies for targeting dyes with relatively small molecular weights ranging from 300 to 500 Da. Additionally, when operated in an NF system equipped with a UV side-emitting optical fiber, the nAg-rGO/n-MIL exhibited significantly reduced water flux decline and enhanced removal efficiencies, achieving up to 97.5 % for methylene blue. Moreover, the nAg-rGO/n-MIL demonstrated high durability under the tested operating conditions, indicating its potential for long-term use in industrial applications. The GO composite membrane, with nanosized MOF-intercalated nanochannels and photocatalytic activity via nAg decoration and GO reduction, offers a promising solution to performance limitations and fouling issues in current nanofiltration membranes.

Anaerobic biodegradation enables zero liquid discharge of two-stage nanofiltration system for microelectronic wastewater treatment

Nanofiltration (NF) is a promising technology in the treatment of microelectronic wastewater. However, the treatment of concentrate derived from NF system remains a substantial technical challenge, impeding the achievement of the zero liquid discharge (ZLD) goal in microelectronic wastewater industries. Herein, a ZLD system, coupling a two-stage NF technology with anaerobic biotechnology was proposed for the treatment of tetramethylammonium hydroxide (TMAH)-contained microelectronic wastewater. The two-stage NF system exhibited favorable efficacy in the removal of conductivity (96 %), total organic carbon (TOC, 90 %), and TMAH (96 %) from microelectronic wastewater. The membrane fouling of this system was dominated by organic fouling, with the second stage NF membrane experiencing a more serious fouling compared to the first stage membrane. The anaerobic biotechnology achieved a near-complete removal of TMAH and an 80 % reduction in TOC for the first stage NF concentrate. Methyloversatilis was the key genus involved in the anaerobic treatment of the microelectronic wastewater concentrate. Specific genes, including dmd-tmd, mtbA, mttB and mttC were identified as significant players in mediating the dehydrogenase and methyl transfer pathways during the process of TMAH biodegradation. This study highlights the potential of anaerobic biodegradation to achieve ZLD in the treatment of TMAH-contained microelectronic wastewater by NF system.

Antibacterial and cytotoxicity activity of green synthesized silver nanoparticles using aqueous extract of naartjie (Citrus unshiu) fruit peels

The application of plant extracts in the green synthesis of silver nanoparticles (AgNPs) has attracted significant attention owing to their eco-friendliness and cost-effective features. However, nanoparticles synthesized from plant materials may also display unique physicochemical properties. This study described an improved synthesis process for silver nanoparticles (AgNPs) from the peel of the Citrus unshiu fruit, an agricultural waste product. In addition to evaluating the produced AgNPs' physico-chemical characteristics, the research also examines their antibacterial and cytotoxic/anticancer capabilities. The color change from yellow to dark brown was observed immediately when 20 ml of Citrus unshiu fruit peel extract was added to 0.5 g of silver nitrate. A surface plasmon resonance band at 424 nm revealed by ultra-violet spectroscopy was used as additional confirmation that AgNP had formed. The scanning electron microscope (SEM), and the transmission electron microscope (TEM), revealed spherical-shaped NPs with a mean size of 23 nm. Furthermore, X-ray diffraction (XRD) confirmed the high crystallinity of the obtained NPs while Fourier transform infrared spectroscopy (FTIR) confirmed the bioreducing capacity of the Citrus unshiu fruit peel extract. The minimum inhibitory concentration (MIC) (31.25 μg/mL) of AgNPs significantly revealed a strong dose-dependent antibacterial effect on Staphylococcus aureus and Bacillus cereus. In contrast, their impact on gram-negative bacteria, such as Escherichia coli and Salmonella typhimurium, displayed an MIC of 250 μg/mL. The assessment of cytotoxicity on human embryonic kidney cells (HEK293) and lung cancer cells (A549) through a 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide assay revealed no detectable cytotoxic effects. The IC50 values were determined as 37.73 ± 0.34 μg/mL for HEK293 and 56.37 ± 0.73 μg/mL for A549, indicating the absence of significant adverse impacts on these cell lines. The anticancer drug doxorubicin was used as a reference standard, and had an IC50 value of 1.22 ± 0.09 and 0.76 ± 0.12 μg/mL against HEK293 and A549 cells, respectively. The results show that AgNPs synthesized from Citrus unshiu fruit peel could serve as antibacterial agents that may in the future be optimized for us in for example nanofiltration systems.

Expression of Concern: Sustainable wastewater treatment by RO and hybrid organic polyamide membrane nanofiltration system for clean environment

Expression of Concern: Sustainable wastewater treatment by RO and hybrid organic polyamide membrane nanofiltration system for clean environment

Study of the structure and characterization of membranes reinforced with CuO-NPs/Graphene Oxide using bacterial cellulose extracted from Sargassum sp. for water nanofiltration system

Bacterial cellulose membranes find extensive applications in industries involving water purification, wastewater treatment, and biomedical uses. Nevertheless, prevailing membranes suffer from drawbacks like water flow hindrances and fouling susceptibility. Hence, the pressing need for more efficient and robust BC membranes. This study aims to assess the impact of a hybrid treatment involving Copper Oxide nanoparticles (CuO-NPs) and Graphene Oxide (GO) on bacterial nanocellulose membranes. The research employed two treatments: (1) control (BNCA), and (2) Bacterial cellulose infused with 0.5 wt% CuO-NPs/GO. The nanocellulose production involved a high-pressure homogenizer, followed by acetate nanocellulose synthesis and nanocomposite membrane functionalization with CuO nanoparticles. SEM, FTIR, and XRD analyses characterized the membranes. Successfully formed seaweed-derived bacterial cellulose had a thickness of 1-3 cm. Characterization showed it belonged to Cellulose type I with a crystalline degree ranging from 82.3% to 83.1%. FTIR analysis of dry BNCA membranes indicated changes in transmittance at 1738, 1554, and 764 cm-1 due to CuO-NPs/GO addition, altering the O-H bond in bacterial cellulose. Based on the results of the above research, it is evident that the Membrane Reinforced with CuO-NPs/Graphene Oxide has been successfully developed and holds potential as a water nanofiltration system.

A modeling and experimental comparative study of a closed-loop forward osmosis-nanofiltration and standalone nanofiltration systems for fouling-prone wastewater treatment

The forward osmosis-nanofiltration (FO-NF) process presents a potential alternative for the treatment of wastewater effluents, compared to pressure-driven systems like reverse osmosis (RO)/nanofiltration (NF). This work bridges the gap in exploring the impact of continuous draw solute regeneration in FO-NF hybrid, and its influence on the performance over standalone NF at module-scale. The Speigler-Kedem model, along with the concentration polarization model, is used to describe the local mass transport in the membrane. Following this, the combined mathematical models for FO and NF are integrated into the hybrid FO-NF system at module-scale. Subsequent process optimization reveals that NF hydraulic pressure and inlet draw concentration control the NF retentate concentration and then simulate the desired operating conditions for the hybrid system when the NF retentate stream is directly used as a draw solution for the FO process. Further results show that in non-fouling feed solution, the FO-NF system is inferior to standalone NF in terms of SEC. In contrast, for fouling-prone feed solution, the standalone-NF performance degrades with time, which gradually mitigates water recovery from 40 to 15.6 % while increasing the SEC from 0.89 to 2.38 kWh/m3. At the same time, the FO-NF hybrid system performs better with Na2SO4 and MgSO4 as draw solutes with nearly constant water recovery of 32.6 % and 28.6 %, and negligible SEC fluctuations of 3.26 kWh/m3 and 4.70 kWh/m3 for the two draw solutes respectively. Despite this, compared with other state-of-the-art desalination technologies, the FO-NF hybrid exhibits comparably lower water cost (average 0.31 USD/m3) and effectively handles fouling-prone wastewater.

An integrated electrocatalytic membrane reactor and nanofiltration system for highly efficient removal of arsenic (III) from water

Arsenic (As) contamination in drinking water and groundwater has become as a major environmental concern due to extremely strong toxicity of As. Herein, a facile, efficient and energy-saving integrated membrane process via coupling the electrocatalytic membrane reactor (ECMR) and nanofiltration (NF) membrane is developed for the arsenic removal from As(III)-contained water. The ECMR, constructed with the one-dimensional (1D) MnO2 nanowires (NWs) loaded in the flat carbon membrane as anode, exhibits superior catalytic activity for the electro-oxidation of As(III). The maximum conversion rate of As(III) to As(V) achieves 96.0 % in the ECMR. The NF membrane is employed to filter the resultant permeate from ECMR. The concentration of As(V) after NF treatment is reduced to below 10 μg L−1 (99.5 % removal rate of As(V)) even if the As(III) concentration in the feed solution of ECMR is up to 2000 μg L−1, under a reaction temperature of 20 °C, a current density of 0.4 mA cm−2, a residence time of 10 min, an electrolyte Na2SO4 concentration of 15 g L−1 reaction conditions. The energy consumption of the whole integrated process was only 0.00211 kWh/μgAs. The superior catalytic performance of ECMR with 1D MnO2 NWs can be attributed to large electrochemical active surface area, 1D nanostructure with highly exposed (310) plane of 1D MnO2 NWs as well as strong interaction of oxide with the carbon membrane surface and the porous structure.

Multistage nanofiltration system for supplementing Shoaiba Ph.4 product water with magnesium extracted from seawater

A multi-stage nanofiltration (NF) system was developed with an inter-stage dilution feature for efficient magnesium (Mg) harvest from seawater or brine. The CaMg/NaCl and Mg/Cl ratios at each stage were used to design and evaluate its performance, while keeping the CaSO4 scale deposition risk within the controllable range using anti-scalant. The pilot experiment was conducted using commercial-size 8-inch NF membranes, demonstrating its performance of divalent ions concentration while lowering the concentration of monovalent ions. This new NF system (NF-Mg) was then firstly introduced on a commercial scale in the Shoaiba Ph.4 SWRO desalination plant in Saudi Arabia, to supplement ≥15 mg/L Mg in the Shoiaba Ph.4 product water of 400,000 m3/d. During the NF-Mg commissioning period, the CaMg/NaCl, Mg/Cl, and stage-wise ion rejections by the NF membrane were evaluated, and operating conditions were identified to meet the desired Mg supplementation level. Finally, the Shoaiba NF-Mg system could demonstrate successful performance through its long-term operational data from Jun. to Dec. 2022. A techno-economic study shows the cost-effective supplement of Mg (13.2–23.4 (average 18.3) mg/L) in drinking water at the cost of 0.009–0.019 USD/m3.

Impact of a nanofiltration system on microplastic contamination in Geneva groundwater (Switzerland)

Microplastics (MPs) have been observed in the oceans, fresh waters, karstic water and remote water bodies. However, little is known on groundwater contamination, which is a natural resource of utmost importance for millions of people and is often perceived as a reliable source of water. Moreover, nanofiltration is perceived as a reliable technology to remove contaminants from water. In this study, large sample volumes of a silty-sandy gravel aquifer and the corresponding nanofiltered water were analysed for the presence of MPs (> 20 µm) using Fourier transform infrared (FTIR) microscopy. Concentration in ground water was 8 ± 7 MPs/m3 and increased to 36 ± 11 MPs/m3 in nanofiltered water. All MPs had a maximum Ferret diameter lower than 500 µm. Size distribution of MPs was towards the small size class (20–50 µm). In groundwater, 33% of MPs were detected in the smallest size class (20–50 µm) and 67% in the 50–100-µm-size class. In comparison, around 52% of MPs in nanofiltered water were observed in the 20–50 µm size class. Moreover, 33% of the MPs observed in nanofiltered water were in the 50–100 µm size class and 15% in the 100–500-µm-size class. From a chemical point of view, different plastic polymers were identified in groundwater and in nanofiltered water, such as polypropylene (PP), polyvinyl chloride (PVC), ethylene (vinyl acetate) copolymer (EVA), polyethylene (PE), polyethylene terephthalate (PET), polymethyl methacrylate (PMMA) and other polymer materials (such as polystyrene-based copolymers, vinyl-based copolymers). Fibres were observed in all samples, but only a small number of fibres (near 1%) were identified as PP synthetic fibres in nanofiltered water. Furthermore, no clear difference of fibre concentrations was observed between groundwater (232 ± 127 fibres/m3) and nanofiltered water (247 ± 118 fibres/m3). Groundwater had extremely low levels of microplastics, and although the nanofiltration effectively removes suspended particulate matter, it slightly contaminates the filtered water with MPs.

Investigation of nanofiltration systems efficiency for removal of chromium and copper from groundwater resources

AbstractThere is a vital need and constraint for providing water of good quality all around the world. Thus, with the aim of groundwater treatment, different methods of water treatment have been reviewed. Considering modern methods of membrane filtration, in this study efficiency of nanofiltration for removing heavy metals (copper and chromium) has been examined. The investigation has been accomplished in two separate phases for removing copper and chromium. To prepare the samples of groundwater, urban waters have been utilized and for preparation of chromium‐contaminated and copper‐contaminated waters, powder of chromium‐oxide and powder of copper sulfate pentahydrate have been added into samples, respectively. In this research, system‐operating pressure has been changed, while concentration and pH were kept constant. The effect of pressure on the efficiency of heavy metals removal has been checked and optimum pressure of the process has been achieved. Then, with optimal pressure as system operating pressure, the removal of heavy metals in different pH have been checked and accordingly, the optimal pH for the process was obtained. The Optimum Pressure and pH for chromium and copper are 7.5 bars and 6.3, and 7.5 bars and 6.7, respectively. Taking into account the result of this study, Nano filtration is a suitable method with high efficiency (90% and higher in optimum pressure and pH) for the removal of heavy metals from groundwater.

Quorum Quenching Nanofibers for Anti-Biofouling Applications

Biofilms, complex microbial communities, adept at forming on diverse surfaces within environments, such as membrane technologies, ship hulls, medical devices, and clinical infections, pose persistent challenges. While various biofilm prevention methods, including antimicrobial coatings, physical barriers, and bacteriophage utilization, have been devised for engineered systems, their efficacy fluctuates based on application type and microbial species. Consequently, there remains a pressing need for the development of highly targeted and efficient biofilm control strategies tailored to specific applications remains a pressing need. In our investigation, we disrupt microbial cell-to-cell communication in Pseudomonas aeruginosa through the application of anti-quorum sensing (anti-QS) furanone C-30 molecules. The incorporation of these molecules onto electrospun surfaces yielded substantial reductions of 69% in petri dish assays and 58% on mixed cellulose ester (MCE) membranes in a dead-end nanofiltration system, showcasing the potent anti-biofouling impact. Notably, the functionalization of MCE surfaces with anti-QS molecules resulted in a remarkable 16.7% improvement in filtration output. These findings underscore the potential of this targeted approach to mitigate biofilm formation, offering a technical foundation for advancing tailored strategies in the ongoing pursuit of effective and application-specific biofilm control measures.

Nanofiltration combined with ozone-based processes for the removal of antineoplastic drugs from wastewater effluents

Over the past years, there has been an increasing concern about the occurrence of antineoplastic drugs in water bodies. The incomplete removal of these pharmaceuticals from wastewaters has been confirmed by several scientists, making it urgent to find a reliable technique or a combination of techniques capable to produce clean and safe water. In this work, the combination of nanofiltration and ozone (O3)-based processes (NF + O3, NF + O3/H2O2 and NF + O3/H2O2/UVA) was studied aiming to produce clean water from wastewater treatment plant (WWTP) secondary effluents to be safely discharged into water bodies, reused in daily practices such as aquaculture activities or for recharging aquifers used as abstraction sources for drinking water production. Nanofiltration was performed in a pilot-scale unit and O3-based processes in a continuous-flow column. The peroxone process (O3/H2O2) was considered the most promising technology to be coupled to nanofiltration, all the target pharmaceuticals being removed at an extent higher than 98% from WWTP secondary effluents, with a DOC reduction up to 92%. The applicability of the clean water stream for recharging aquifers used as abstraction sources for drinking water production was supported by a risk assessment approach, regarding the final concentrations of the target pharmaceuticals. Moreover, the toxicity of the nanofiltration retentate, a polluted stream generated from the nanofiltration system, was greatly decreased after the application of the peroxone process, which evidences the positive impact on the environment of implementing a NF + O3/H2O2 process.

Quantifying uncertainty in nanofiltration transport models for enhanced metals recovery.

To decarbonize our global energy system, sustainably harvesting metals from diverse sourcewaters is essential. Membrane-based processes have recently shown great promise in meeting these needs by achieving high metal ion selectivities with relatively low water and energy use. An example is nanofiltration, which harnesses steric, dielectric, and Donnan exclusion mechanisms to perform size- and charge-based fractionation of metal ions. To further optimize nanofiltration systems, multicomponent models are needed; however, conventional methods necessitate large amounts of data for model calibration, introduce substantial uncertainty into the characterization process, and often yield poor results when extrapolated. In this work, we develop a new computational architecture to alleviate these concerns. Specifically, we develop a framework that: (1) reduces the data requirement for model calibration to only charged species measurements; (2) eliminates uncertainty propagation problems present in conventional characterization processes; (3) enables exploration of pH optimization for enhancing metal ion selectivities; and (4) enables uncertainty quantification to assess the sensitivity of partition coefficients and ion driving forces to learned pore size distributions. Our framework captures eight independent datasets comprising over 500 measurements to within ±15%. Our studies also suggest that the expectation-maximization algorithm can effectively learn pore size distributions and that optimizing pH can improve metal ion selectivities by a factor of 3-10×. Our findings also reveal that image charges appear to play a less pronounced role in dielectric exclusion under the studied conditions and that ion driving forces are more sensitive to pore size distributions than partition coefficients.

Recovery of ammonia and phosphate from aquaculture effluent using a reactive vacuum membrane distillation-vacuum membrane distillation/nanofiltration hybrid system

The primary obstacle to extracting nutrients from aquaculture effluent lies in the fact that they are present only in minuscule amounts, rendering the conventional recovery methods inefficient and economically unfeasible. To address the issue, a two-stage membrane system, reactive vacuum membrane distillation-vacuum membrane distillation/nanofiltration (RVMD-VMD/NF) was developed in this work to concentrate ammonia and phosphate simultaneously from low-nutrient fresh aquaculture effluent. RVMD was effective to recover ammonia to a higher concentration factor (59-fold) at 40 °C. The temperature was then increased to 70 °C to further concentrate phosphate using the VMD system, and the results were compared to the pressure-driven nanofiltration (NF) system. VMD demonstrated an excellent capability to concentrate phosphate without any loss to the recovered water and achieved a comparable concentrating effect based on theoretical volume reduction, while NF only achieved half of the targeted value. Considering low-nutrient sources for treatment, RVMD followed by the VMD is a better approach in concentrating both ammonia and phosphate than the RVMD-NF system but RVMD-VMD required a slightly higher total cost (RM 1.68/L) and energy usage (0.53 kWh/L) compared to RVMD-NF of RM 1.66/L and 0.53 kWh/L. The application of the RVMD-VMD system to the fresh aquaculture effluent resulted in a remarkable 77-fold of recovered ammonia (49.33–3790 mg/L) with a separation factor (SF) of 554 and up to 6 factors of phosphate (16.67–92.52 mg/L). Besides, clean water was produced as a by-product. This innovative system provides a sustainable and effective solution for managing aquaculture effluent, with the potential to achieve zero-waste discharge.

Sustainable wastewater treatment by RO and hybrid organic polyamide membrane nanofiltration system for clean environment

One of the environmental pollution is happened by the discharge of industrial wastewater that needs to be adequately filtered. Given that the effluent from the leather industry contains high levels of chromium, heavy metals, lipids, and Sulphur, it is one of the wastewater disposals that are most damaging. This experimental study focuses on reverse osmosis and hybrid organic polyimide membrane for nanofiltration for sustainable wastewater treatment. In the RO and organic polyamide Nano-porous membranes, a thin film of polyamide membrane was used for efficient filtration. Taguchi analysis optimized process parameters such as pressure, temperature, pH, and volume reduction factor. The outcome shows an 89% reduction in total wastewater hardness, an 88% reduction in sulfate, and an 89% efficiency reduction in COD. As a result, the proposed technology significantly increased filtration efficiency.

Cellulose nanocrystal addition in thin film nanocomposite membranes: Which monomer solution is preferred?

AbstractCellulose nanocrystals (CNCs) are biodegradable nanoparticles with a high aspect ratio and abundant surface hydroxyl groups resulting in negatively charged hydrophilic surfaces that make them an ideal candidate to be incorporated in thin‐film nanocomposite (TFN) membranes. In this study, we modified the CNCs via acetylation (ACNCs) to reduce their hydrophilicity and via reaction with L‐cysteine (CysCNCs) to impart them with functionality that promoted their interaction with the trimesoyl chloride organic monomer used in the preparation of the poly(amide) layer of the TFN membranes. These modifications allowed us to question in which monomer solution the nanoparticles should be dispersed. Addition of the unmodified CNCs in either the aqueous or organic monomer solution showed little difference in membrane performance. However, the addition of either the ACNCs or the CysCNCs to the organic monomer solution led to a significant increase in membrane performance in reverse osmosis (RO) and nanofiltration (NF) systems compared to their addition to the aqueous monomer solution. In addition, the CysCNCs exhibited performance very near the upper‐bound line for RO and NF.