Filtration Flux Research Articles

Facile construction of a core-shell structured metal-organic frameworks nanofiber membrane for removing Co(II) from simulated radioactive wastewater

A novel core–shell structured composite of UiO-66-Tu/PAN nanofiber membranes (NFMs) functionalized with thiourea (Tu) was developed for the efficient separation of Co(II) from simulated radioactive wastewater. Various analytical techniques were employed to characterize the structure and properties of the NFMs. The filtration performance, flux, and hydrophilicity of the membrane were evaluated using a membrane flux tester and contact angle (CA) measurements, respectively. The adsorption performance of UiO-66-Tu/PAN for Co(II) was investigated through batch adsorption experiments. The results indicate that at a UiO-66-Tu/PAN content of 7 %, the UiO-66-Tu/PAN NFMs exhibit better hydrophilicity (CA of 37.8°) and a higher cobalt ion retention rate (77.41 %). Under optimal conditions, the theoretical maximum adsorption capacity for cobalt ions is 51.2 mg/g. X-ray photoelectron spectroscopy (XPS) analysis was utilized to clarify the adsorption mechanism of Co(II) by the 7 %UiO-66-Tu/PAN composite, showing a coordination mechanism that involves the participation of oxygen, nitrogen, and sulfur atoms in the ligand. In addition, the material also demonstrates excellent radiation stability (50–100 kGy). It should be pointed out that this is the first time that metal–organic frameworks (MOFs) core–shell nanofibers membranes have been used for cobalt ion separation. The development of this new material effectively addresses the challenges associated with using MOFs as powdered adsorbents, achieving efficient purification of wastewater and providing important engineering significance for the treatment and disposal of trace amounts of 60Co radioactive wastewater.

Dynamics of soil water and nitrate within the vadose zone simulated by the WHCNS model calibrated based on deep learning

Excessive application of water and nitrogen fertilizer during farmland management practices leads to serious groundwater nitrate pollution. A field experiment was conducted during the spring maize growth period in Alxa, Inner Mongolia, China. The soil Water Heat Carbon Nitrogen Simulator (WHCNS) model was calibrated by the ensemble smoother method (ES(DL)) based on the field experiment. Then dynamics of soil water content, soil water percolation flux, soil nitrate concentration and soil nitrate leaching flux were simulated with the calibrated WHCNS model under different water and nitrogen fertilization treatments within the vadose zone. The main conclusions are as follows: ES(DL) is feasible for the calibration of the WHCNS model. RMSE_Maximum a posteriori (RMSE_MAP) of soil water content are 0.0301 cm3 cm−3 and 0.0302 cm3 cm−3 for model calibration and model validation, respectively. RMSE_MAP of soil nitrate concentration are 5.49 mg N kg−1 and 3.86 mg N kg−1 for model calibration and model validation, respectively. Both average soil nitrate concentration and average nitrate leaching flux increase with increasing irrigation amount under the same nitrogen fertilization level for the depths of 1.2 m and 1.8 m. However, average soil nitrate concentration decreased and leaching flux increased with increasing irrigation amount under the same nitrogen fertilization level for the depths of 10 m and 20 m. The study of nitrate dynamics in the deep vadose zone contributes to better understand the procedure of nitrate pollution in groundwater caused by excessive water and nitrogen application.

Combination of activated carbon/ultrafiltration as pre-treatment for seawater reverse osmosis plants

Seawater Reverse Osmosis (SWRO) is a common technology to treat seawater to comply high freshwater demand. Currently, the main issue of seawater/brackish water as the potential sources for drinking water is vulnerable to organic pollutants. An effective pre-treatment is crucial to maintain the efficiency of SWRO for sustainable operation. Optimization of the process could be performed by a hybrid membrane combination using commercial Activated Carbon (AC) with based material coconut shell/coal and Ultrafiltration membrane (UF). For hybrid process, the activated carbon was continuously dosed into the pilot scale filtration employing PES Hollow Fiber membrane with active area of 4 m² and average pore size of 10 nm that represents a real operation filtration process (i.e., filtration flux, filtration time, backwashing, and cleaning in place), and was performed until 8 filtration cycle sequence. This study investigated membrane performance with combination technique PAC/UF and GAC/UF in Pilot scale experiments within resistance membrane and retention membrane. Combination of Activated Carbon/Ultrafiltration showed synergistic effects in the removal of organic content for COD 40%-96%, UV-VIS 43%-92% and Turbidity 73%-99%. High removal of organics pollutants (COD, UV-VIS and Turbidity) was attributed to small average pore distribution of Activated Carbon (<10 µm) that increase adsorption process. Moreover, hybrid Activated Carbon/UF adsorption kinetics can reduce filtration times to achieved optimal retention. Related to membrane performance, hybrid AC/UF resulted in less permeability declines almost double in first two filtration cycle and slightly less permeability decline until fifth cycle in comparison with single UF process. Better membrane performance can furtherly be explained from less irreversible fouling in case of AC/UF. Combination AC/UF enhanced the control of Irreversible fouling and resulted in better filtration performance as well as higher organic substance removal. Therefore, hybrid AC/UF could be seen as an effective system as pretreatment for SWRO.

Exploration of ferrate (VI) pretreatment and ultrasonication combined with gravity-driven membrane filtration for shale gas wastewater treatment

Gravity-driven membrane (GDM) filtration has gained attention as a promising technology for the decentralized treatment of wastewater. However, one major limitation of GDM filtration is its relatively low permeate flux. In this work, we investigated the application of GDM filtration, combined with ferrate (VI) pretreatment and ultrasonication, for the shale gas wastewater (SGW) treatment, and evaluated their respective impacts on the GDM performance. The results of our study revealed that ultrasonication played a significant role in enhancing the flux of GDM filtration, with an observed increase of 265%. This improvement can be attributed to the effective removal of pollutants from the membrane surface and the reduction of the fouling layer thickness caused by ultrasonication. Compared to a GDM alone, ferrate (VI) pretreatment could notably change the microbial community structure and reduce the extracellular polymeric substances accumulation, which may be linked with an enhancement in stable flux. Ferrate (VI) pretreatment selectively enriched particular microorganisms in SGW, which might perform a role in specific organics degradation. These findings provide valuable insights and suggestions for enhancing the overall performance of GDM systems in wastewater treatment. Notably, the ultrasonically enhanced GDM system, which confers the characteristics of simple operation, low energy supply and no chemical pollution, has great application potential in wastewater treatment.

Study on the mechanism of hydrodynamic manipulation of floc structure to achieve high-flux of coagulation macro-filtration for the rapid removal of Aphanizomenonflos-aquae

Coagulation-filtration hybrid process has been widely used in algae removal treatment to improve the water quality and alleviate the membrane fouling. However, the intricate interplay of how floc structure induced by coagulation hydraulic shear influences the cake layer and filtration performance in coagulation macro-filtration of microalgae remains unexplored. In this study, a novel coagulation filtration with macro-pore of 75 μm was first adopted for the rapid removal of Aphanizomenonflos-aquae, and the floc structure was artificially manipulated through various velocity gradients to explore the effect mechanism of the coagulation hydrodynamic shear on the macro-filtration performance from the perspectives of floc characteristics (size and fractal dimension) and cake layer structure (thickness and roughness). The results showed that an optimal average flux of 31257.64 ± 2776.28 L·m−2·h−1 can be achieved at a manipulated appropriate velocity gradient (19 s−1), which is 1.1–2.3 times the flux achieved at higher or non-velocity gradients. The flocs formed at low velocity gradient were large and loose, while those formed at high velocity gradient were small and compact. Subsequently, the cake layer stacked by loose flocs was thicker and coarser than that by compact flocs, and exhibited a lower specific cake resistance, yielding a higher average flux. Moreover, a theoretical model for average flux was developed by introducing the velocity gradient, which directly elucidates how hydrodynamic shear affects floc characteristic, cake structure and filtration flux for the coagulation macro-filtration of Aphanizomenonflos-aquae. This study lays a theoretical foundation for the optimization of coagulation macro-filtration performance of microalgae and provides a new solution for the large flux removal of cyanobacteria by artificially regulating the coagulation hydrodynamic shear.

Enhancing filtration flux and antifouling performance of PVDF membrane constructed from semi-interpenetrating network and block copolymers

Organic fouling causes the filtration property and serve life decrease of the PVDF membrane and is the challenge for filtration applications. Therefore, it is an urgency desire to construct a PVDF membrane with good filtration and antifouling for researchers. To this end, a based PVDF and poly(N-isopropyl acrylamide)(PNIPA) semi-interpenetrating network polymer was synthesized and used as membrane matrix for preparing semi-interpenetrating network/block copolymers blend membrane. The membrane composition, structure and performance were systematically characterized and investigated by FTIR spectrum, XPS, SEM, contact angle instrument and the other experimental techniques etc. Results indicate that the prepared membrane contains PVDF, PNIPA and block copolymer poly(ethylene oxide)-b-poly(propylene oxide)-b- poly(ethylene oxide) (F127) components, shows a porous cross section comprising a thin top surface layer with small pores, a finger-shape lower layer and a sponge-shape pore bottom layer. When the membrane are used for the filtration of bovine serum albumin(BSA) in aqueous solution at 25 ℃, the rejection can exceed 95.0% at a high flux of 307 L/(m2·h·bar). Simply raising filtration temperature to 60 °C, the flux can reach 606 L/(m2·h·bar) while the rejection barely changes, significantly improving the filtration ability of the membrane. Furthermore, the flux can recover above 93% of the original value after a BSA filtration and a subsequent water washing. Undoubtedly, the prepared membrane displays great potential for filtering BSA aqueous solution and the reason can be ascribed to the synergy between PNIPA and F127 of the membrane.

Enhanced landfill leachate treatment performance by adsorption-assisted membrane distillation

Membrane fouling and high-strength membrane concentrate production are two limitations of membrane distillation (MD) for landfill leachate treatment. In this study, activated carbon- and biochar-based adsorption processes were integrated into a conventional MD system to overcome these limitations. The organic matter fractionations of the leachate were thoroughly investigated during the treatment. Membrane-reversible and irreversible foulants differed remarkably from the inlet leachate in the non-assisted MD system. Specifically, reversible foulants were characterized by a high abundance of humic-like fluorescent components, high-molecular-weight humic-size constituents, peptides, and unsaturated compounds. In contrast, irreversible foulants were enriched with fulvic-like fluorescent components, low-molecular-weight neutrals, unsaturated compounds, and polyphenols. The adsorption-based pre-treatment effectively removed foulant precursors from landfill leachate, with a relatively higher (20%) adsorption performance for specific biochar used in this study than for activated carbon. Compared with the non-assisted MD system, the biochar-assisted MD system showed improved performance, achieving 40% overall membrane flux recovery, 42% higher filtration fluxes, and 53% lower concentrate production. In addition, a 15% higher removal of irreversible foulants was observed as compared to the reversible foulants, which can potentially increase the membrane lifespan. This study demonstrates the effectiveness of an adsorption-assisted MD system supported by increased filtration, membrane fouling alleviation, and low-strength leachate concentrate generation.

A hydrophilic near dissolved organic matter microfiltration (NDOM MF) membrane prepared using multifunctional porogen synthesized via metal-free atom transfer radical polymerization for highly efficient microplastic removal

Microplastic (MP) pollution has emerged as a global concern. One of the practical alternatives is a microfiltration (MF) process using MF membranes with a high MP removal rate and high water permeability simultaneously. In this study, we developed a highly permeable PVC-based MF membrane capable of effectively separating MP by using amphiphilic PVC, which can serve as a pore-forming agent during phase separation and as a hydrophilic modifier after solidification. We developed a new organic photocatalyst under UV light to synthesize amphiphilic PVC via metal-free atom transfer radical polymerization. With 3 wt% amphiphilic PVC, the mean pore size increased to 0.86 µm, which was 3 times larger than the control PVC membrane (0.25 µm). Furthermore, the modified PVC (m-PVC) membrane reduced the contact angle of the membrane from 80.6° to 58.3°, indicating a significant improvement in the hydrophilicity of the membrane. The larger pores and increased hydrophilic properties made the m-PVC membrane 15 times more permeable than the control, while still maintaining a removal rate of approximately 99.9 % in a water filtration test with a 1 µm bead solution. The modified PVC membrane also operated consistently under varying pH conditions. Lastly, the m-PVC membrane exhibited a 12 times lower transmembrane pressure than the control during the constant flux filtration test, resulting in a 5 times lower specific filtration energy despite a 2 times longer filtration time. We hope this study could contribute to creating a new trend in MP removal utilizing a highly porous MF membrane, which is cut out for highly efficient removal of particulate pollutants and high water permeability simultaneously.

Anti-fouling tight ultrafiltration membrane for gastrodin purification

The issues of flux decline and irreversible membrane fouling must be considered in membrane separation. In this paper, the culture medium, bacterial cells, and proteins were removed using a one-step tight ultrafiltration (UF) membrane separation process. Although the membrane resistance of the tight UF membranes increased owing to their smaller pore size, the stable flux of the 6 nm membrane during fermentation broth filtration of gastrodin was 28.0% higher than that of loose UF membranes, and the flux recovery ratio reached 97.3%. During purification, a higher filtration flux was obtained by retaining the operating pressure within the range of 2–3 bar and the operating temperature range of 50–60 °C. The average flux of a 6 nm 19-channel membrane reached 56 L·m−2·h−1, and the total yield of gastrodin reached 96.2%. This study provides a basis for the large-scale application of tight UF membrane in food industry.

A comparison of micro-flocculation and ozonation as pretreatments for ultrafiltration: organic removal and membrane fouling.

Micro-flocculation and ozone were applied as pretreatments of ultrafiltration to treat sodium alginate (SA) and humic acid (HA) simulated water, respectively, to investigate the effects of different pretreatments of ultrafiltration (UF) on filtration flux and removal of organic matters. Regarding the SA simulated water, micro-flocculation helped to improve the dissolved organic carbon (DOC) removal efficiency highly, maximum DOC removal efficiency reached to 79.77%, due to the rejection of gel layer introduced by the alginate-aluminum complexes, but the gel layer had a negative impact on membrane flux. Compared with micro-flocculation, ozone as pretreatments had better ability to enhance the membrane specific flux, the maximum final specific flux remained as 0.786, larger than that of MF-UF process (0.574). Ozonation oxidizing SA into small organic molecules significantly reduced membrane fouling and filtration resistance, but also produced some dissolved organic matters hindering DOC removal of effluent. As for HA simulated water, both the micro-flocculation and ozone could effectively improve the specific flux, the final specific flux of MF-UF and ozone-UF were about 0.930, but MF-UF exhibited better DOC removal than ozone-UF, which avoided the introduction of additional dissolved organic matters.

Ceramic membrane filtration of water samples from Ain Fayda Lake and cement factory (Al‐Ain), United Arab Emirates

AbstractThis article presents a Ceramic Membrane‐based Produced Water Treatment Technology and its application to water samples from Al‐Ain (Abu Dhabi Emirate, United Arab Emirates). The samples were collected during the summer of 2022 from Ain Fayda (lake water) and Al‐Ain cement factory (groundwater). This study investigates the effectiveness of the ceramic membrane for treating water samples and removing solid particles. A dead‐end filtration mode with a filtration flux of 3 m3/m2/d was used. For the Ain Fayda Lake water sample, the transmembrane pressure during filtration reached 120 kPa (temperature adjusted to 25°C); air blowing was used to reduce the transmembrane pressure to around 70 kPa and Total Suspended Solids were reduced from 1.4 to <1 mg/L during 160 min of filtration. For the Al‐Ain cement factory water sample, the transmembrane pressure during filtration reached 160 kPa (temperature adjusted to 25°C); air blowing reduced the transmembrane pressure to around 65 kPa and the Total Suspended Solids from 9.1 to <1 mg/L during 130 min of filtration. Both water samples belong to the Na‐Cl water type. Overall, this work shows the effectiveness of the Ceramic Membrane‐based Produced Water Treatment Technology for reducing Total Suspended Solids in sampled waters; thus, we recommend this approach for treating surface waters in Al‐Ain to improve the environment and possible usage in agriculture.

Manufacture and filtration performance of glass filters made from capillary suspensions

This research highlights the potential of capillary suspensions in tailoring the properties of glass filters and improving filtration performance. Borosilicate glass 3.3 filters fabricated in a wet processing route based on capillary suspensions were developed. Their filter properties and filtration performance as well as control of shrinkage and porosity gradients during sintering were investigated. The use of capillary suspensions significantly reduced green body shrinkage. Long residence times and spatially inhomogeneous heat transfer during sintering favored the formation of porosity gradients. Pore size, porosity, permeability and flexural strength of the filters could be tailored by adjusting capillary suspension composition and sintering conditions. Glass filters with particularly high permeability and small pore sizes were successfully developed. Filtration experiments with Oenococcus oeni and polystyrene spheres (diameter ≈ 1 μm) were conducted, showing that filtration efficiency and flux depend on pore size and open porosity. Crack-free asymmetric glass membranes with improved filtration performance were developed. Compared to dry processed commercial benchmark filters, the capillary suspension-based filters made from the same glass powder had higher pore sizes and permeability. At similar pore size and porosity, filters based on capillary suspensions showed significantly higher filtrate flux than the commercial benchmarks due to a more uniform pore structure.

Effect of Mold Cooling Intensity on the Depression-Type Crack Formation and Mold Flux Infiltration During Continuous Casting Process

Effect of Mold Cooling Intensity on the Depression-Type Crack Formation and Mold Flux Infiltration During Continuous Casting Process

The role of intermolecular interactions on monoclonal antibody filtration through virus removal membranes.

The removal of viruses by filtration is a critical unit operation to ensure the overall safety of monoclonal antibody (mAb) products. Many mAbs show very low filtrate flux during virus removal filtration, although there are still significant uncertainties regarding both the mechanisms and antibody properties that determine the filtration behavior. Experiments were performed with three highly purified mAbs through 3 different commercial virus filters (Viresolve ® Pro, Viresolve® NFP, and Pegasus™ SV4) with different pore structures and chemistries. The flux decline observed during mAb filtration was largely reversible, even under conditions where the filtrate flux with the mAb was more than 100-fold smaller than the corresponding buffer flux. The extent of flux decline was highly correlated with the hydrodynamic diameter of the mAb as determined by dynamic light scattering. The mAb with the lowest filtrate flux for all 3 membranes showed the largest attractive intermolecular interactions and the greatest hydrophobicity, with the latter determined by binding to a butyl resin in an analytical hydrophobic interaction chromatography column. These results strongly suggest that the flux behavior is dominated by reversible self-association of the mAbs, providing important insights into the design of more effective virus filtration processes and in the early identification of problematic mAbs / solution conditions. This article is protected by copyright. All rights reserved.

Analyzing the role of soil and vegetation spatial variability in modelling hydrological processes for irrigation optimization at large scale

The main purpose of this paper was to study the effect of spatial variability of soil hydraulic properties (HP) and vegetation parameters (VP) (e.g., leaf-area index, LAI, and crop coefficient, Kc) on modelling agro-hydrological processes and optimising irrigation volumes at large scale. Based on this analysis, the effect of partly overlooking the spatial variability of soil HP and/or VP inputs was verified on a 140 ha irrigation sector in “Sinistra Ofanto” irrigation system in Apulia Region, Southern Italy. Five soil profiles were excavated and the HP were measured in all the soil horizons. Additionally, measurements of soil HP were taken in the surface soil layer in ninety sites distributed over the whole irrigation sector. All the HP measurements were carried out using tension infiltrometer. Remote sensing applications were used to obtain LAI and Kc using European Space Agency’s (ESA) Sentinel-2 images with 10 m resolutions. First, distributed (on ninety polygons with an average area of about 1.5 ha) optimal irrigation volumes and related deep percolation volumes at a depth of 80 cm, were computed using an agro-hydrological model and accounting for the actual observed variability of soil HP and VP inputs. The sector scale irrigation and deep percolation volumes were obtained by aggregating the distributed irrigation volumes. This was considered as the reference scenario (hereafter DVS—Detailed Variability Scenario). Then, reduced variability scenarios (hereafter RVS—Reduced Variability Scenario) were considered, where the information on the actual spatial variability of the soil HP and VP was gradually overlooked to find the minimum data set needed to still have sector scale irrigation volumes and related deep percolation volumes comparable to those obtained under the DVS. Results showed that overlooking VP (RVS-VP) variability did not significantly change the optimal irrigation volumes and the deep percolation fluxes. By contrast, neglecting the HP variability (RVS-HP) showed significant effects on both the irrigation and percolation volumes compared to the DVS. The main practical finding was that, at least for the area investigated in this study, hydraulic characterization of one soil profile in an area of approximately 30 ha provides sector scale irrigation volumes and percolation fluxes comparable to those obtained under the DVS, thus by accounting for all the observed local variability.

Nitrate rejection of sulfonic acid group incorporated polyethersulfone‐type nanofiltration membrane and reutilization of the concentrated solution

AbstractThe nanofiltration (NF) membrane technology has attracted considerable attention for the rejection removal of various salts. However, the practical application of this membrane separation process has been severely retarded due to the ineffective rejection of monovalent ions (such as nitrate and chloride), undesirable filtration flux, and insufficient disposal of the concentrated solution. In this work, three polyethersulfone‐type NF membranes were fabricated and their morphologies, functional groups, chemical components, wettabilities, chargeabilities, and rejection molecular weights were characterized. Among them, the membrane of NF_M3 bearing sulfonic acid group (SO3H) shows the desirable rejection efficiency of nitrate (90.32%), acceptable solution filtration flux (10.15 L m−2 h−1 at 0.6 MPa), and the decent pure water permeation flux (50.8 L m−2 h−1 at 0.6 MPa). The introduction of SO3H can significantly enhance the performances of NF_M3 membrane in hydrophilicity, chargeability, anti‐fouling, and the oxidation resistance. Promisingly, the concentrated nitrate was ingeniously recycled for the electrochemical intercalation of flake graphite to prepare expandable graphite, and the obtained expanded graphite has an acceptable expanded volume (243 mL g−1 via the microwave expansion process), thereby achieving the resource utilization of NF concentrated solution.

Concept and Design of a Bearingless Spinfilter

In many separation processes, filtration performance degrades over time due to retained particles blocking the flow through the filter membrane. A novel bearingless spinfilter extends the long-term performance by self-cleaning effects. The filter rotor is magnetically levitated and actuated by two self-bearing motors inside a hermetically sealed housing, which eliminates the need for bearings and rotary sealings, that both lead to process fluid contamination. Both bearingless motors have integrated electronics and independently control the levitation of the spinfilter rotor. A first prototype is designed and the concept is validated by the separation of a yeast cell culture. Special focus is placed on the internal rotary seal between the feed and filtrate regions, that is inevitably created when the filter membrane is in motion. Any leakage flow through the seal leads to filtrate impurities, which is minimized in this article with an embedded impeller as a pressure compensation method. A constant filtrate flux of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$1750 \,\mathrm{L}\mathrm{h}^{-1}\text{m}^{-2}$</tex-math></inline-formula> and a filtrate purity of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$75 \%$</tex-math></inline-formula> was achieved in a first series of tests.

Protein fouling during constant-flux virus filtration: Mechanisms and modeling.

As biomanufacturers consider the transition from batch to continuous processing, it will be necessary to re-examine the design and operating conditions for many downstream processes. For example, the integration of virus removal filtration in continuous biomanufacturing will likely require operation at low and constant filtrate flux instead of the high (constant) transmembrane pressures (TMPs) currently employed in traditional batch processing. The objective of this study was to examine the effect of low operating filtrate flux (5-100 L/m2 /h) on protein fouling during normal flow filtration of human serum Immunoglobulin G (hIgG) through the Viresolve® Pro membrane, including a direct comparison of the fouling behavior during constant-flux and constant-pressure operation. The filter capacity, defined as the volumetric throughput of hIgG solution at which the TMP increased to 30 psi, showed a distinct minimum at intermediate filtrate flux (around 20-30 L/m2 /h). The fouling data were well-described using a previously-developed mechanistic model based on sequential pore blockage and cake filtration, suitably modified for operation at constant flux. Simple analytical expressions for the pressure profiles were developed in the limits of very low and high filtrate flux, enabling rapid estimation of the filter performance and capacity. The model calculations highlight the importance of both the pressure-dependent rate of pore blockage and the compressibility of the protein cake to the fouling behavior. These results provide important insights into the overall impact of constant-flux operation on the protein fouling behavior and filter capacity during virus removal filtration using the Viresolve® Pro membrane.

Virus breakthrough behavior during virus filtration: Effects of virus/protein concentration and operating conditions

Virus filtration in biopharmaceutical downstream process ensures viral safety with removal efficiency greater than 99.99%. Despite its robust performance, it has been reported that viruses can escape through the membrane under certain conditions. This study aimed to investigate virus breakthrough using Viresolve® Pro membrane with PP7 bacteriophage under high bacteriophage titer, high protein concentration, flow interruption, and low-flux operation. The results show high virus removal performance (LRV >6.8) up to 109 PFU/mL for 200 L/m2, with the first phage breakthrough observation over 1012 PFU/m2 of phage challenge in the membrane. As the protein concentration increased in the coexistence condition, a greater number of phages passed through the membrane. During the post-buffer flush and the operation at low filtrate flux, diffusion plays an important role in the escape of phages, which were detected as high as 1012 PFU/m2, but as low as 109 PFU/m2. These results suggest that the virus-retentive membrane may become susceptible to undesired virus breakthrough when exposed to phage challenges of > 1012 PFU/mL, providing important key factors to ensure viral safety during the downstream process of biopharmaceutical production.

Phase inverted hydrophobic polyethersulfone/iron oxide-oleylamine ultrafiltration membranes for efficient water-in-oil emulsion separation

Exploration and transportation of oil offshore can result in oil spills that cause a wide range of adverse environmental consequences and destroy aquatic life. Membrane technology outperformed the conventional procedures for oil emulsion separation due to its improved performance, reduced cost, removal capacity, and greater eco-friendly. In this study, a hydrophobic iron oxide-oleylamine (Fe-Ol) nanohybrid was synthesized and incorporated into polyethersulfone (PES) to prepare novel PES/Fe-Ol hydrophobic ultrafiltration (UF) mixed matrix membranes (MMMs). Several characterization techniques were performed to characterize the synthesized nanohybrid and fabricated membranes, including scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), Fourier transform-infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), contact angle, and zeta potential. The membranes' performance was assessed using a surfactant-stabilized (SS) water-in-hexane emulsion as a feed and a dead-end vacuum filtration setup. The incorporation of the nanohybrid enhanced the hydrophobicity, porosity, and thermal stability of the composite membranes. At 1.5 wt% Fe-Ol nanohybrid, the modified PES/Fe-Ol MMM membranes reported high water rejection efficiency of 97.4% and 1020.4 LMH filtrate flux. The re-usability and antifouling properties of the membrane were examined over five filtration cycles, demonstrating its great potential for use in water-in-oil separation.