Hollow Fiber Membrane Research Articles

Evaluation of the impact of hollow fiber pore size and membrane material on virus concentration using a handheld hollow fiber method.

Virus concentration using hollow fibers is widely used for vaccine production to maintain viral infectivity with low shear stress and to allow for easier scale-up of production. However, research laboratories often have limited available viral materials at the early stage of vaccine development, making it difficult to find an optimal hollow-fiber. In addition, few research articles have reported on optimizing hollow fiber pore size and membrane structure for virus concentration. In this study, the previously established handheld hollow fiber virus concentration method was modified to reduce the sample volume required and to enable simple and easy hollow fiber screening. The handheld hollow fiber screening method for virus concentration was confirmed to be effective using Zika as a model virus.

Effect of hollow fiber membrane packing on the performance of modules formed with fiber tows

ABSTRACT Membrane processes are being considered for carbon dioxide capture from concentrated point sources. The processes often use hollow fiber membranes. Modules are formed by gathering fibers together in a bundle. The fibers may be supplied individually or in small groups (i.e. tows) for module fabrication. The use of tows can introduce nonuniform fiber packing due to the size and spacing of the tows. The potential for flow maldistribution and its detrimental effect on module performance is evaluated by solving the governing conservation equations. For the first time, the performance of a module formed from fiber tows is evaluated. Two performance metrics are reported: 1) recovery and 2) required area as a function of carbon dioxide removal. The effects of tow size and tow spacing are evaluated. The results indicate performance is better for smaller tows. Furthermore, lower packings, both intra- and inter-tow, are preferred. The concept of an equivalent planar bundle (EPB) for fiber tow modules is introduced to potentially reduce simulation time and costs. The simple procedure for creating the EPB is validated by comparing the performance metrics calculated using the EPB to the results obtained from full simulations.

Membranes fouling propensity of PSF/GO hollow fiber mixed matrix membranes for water treatment ultrafiltration application.

The study investigated the fouling propensity of polysulfone (PSF) hollow fiber (HF) mixed matrix membranes modified with 1.0 wt.% graphene oxide (GO). Using scanning electron microscopy (SEM), atomic force microscopy (AFM), water contact angle (WCA), and mechanical assessments, the structural characteristics of both untreated and GO-modified PSF HF membranes were examined. Filtration experiments included pure water and model contaminants such as bovine serum albumin (BSA), humic acid (HA), E. coli, and oil-in-water emulsion. The GO-modified membranes demonstrated a significant enhancement in antifouling performance, recovering over 90% of their initial pure water flux with HA and oil, indicating high resistance to irreversible fouling. Additionally, the GO-modified membranes showed superior oil separation efficiency. However, fouling parameters for BSA were similar for both membrane types, suggesting that GO does not significantly affect membrane-BSA interactions. Both types of membranes displayed high retention capabilities for E. coli, with no noticeable improvement due to GO addition. This study highlights the potential of GO-modified PSF HF membranes in enhancing antifouling performance and oil separation efficiency.

Comparison of Hollow Fiber and Flat Sheet Membranes for Removing TDS and Turbidity of Palm Oil Mill Effluent Wastewater

The most significant pollutant produced from agricultural industry in Kalimantan, Indonesia is Palm Oil Mill Effluent (POME). Due to the high levels of suspended particles and organic matter, POME has become a brownish color with high turbidity, color, chemical oxygen demand, and oil and grease content. To recycle the POME wastewater as clean water, these pollutants must be eliminated. In this study, we compare the effectiveness of hollow fiber (HF) and flat sheet (FS) membrane to remove total dissolved solid (TDS) and turbidity from POME with varied filtration pressure. HF and FS membrane were prepared from PVDF and nylon66 polymer, respectively. The PVDF HF membrane was modified using TiO2 and SBE (spent bleaching earth) to improve HF membrane properties to maintaining fouling. Meanwhile, FS membrane was added by pectin to increase the hydrophilic properties. Overall membrane’s morphology was determined by Scanning Electron Microscopy (SEM) to investigate the membrane structure. Both of HF and FS membrane were operated via ultrafiltration (UF) under cross flow system. The filtration pressures were varied at 1-3 bar and followed by flux and rejection evaluation. The results show both HF and FS membranes has stability flux. In addition, TDS rejection up to 25% while turbidity is excellent high over 95% for all membranes. The fabrication HF membrane has finger like-sponge structure and FS membrane exhibits sponge asymmetric structure. Overall, all membranes perform highest water flux (FS membrane) while highest rejection conducted by HF membrane for POME wastewater treatment.

Application of Hybrid Conventional Filter and PVDF-TiO<sub>2</sub>/SBE Hollow Fibre Membrane for Peat Water Treatment

South Kalimantan-Indonesia is known to have extensive peatlands reaching 15% of a total peatland in Kalimantan. Due to that peat land water is mostly found and claim as abundant water sources. However, based on quality, peat land water has poor characteristic with high natural organic matter content. Therefore, peat water treatment is necessary to treat using effective method such as hybrid conventional filter and membrane using hollow fibre PVDF-TiO2/SBE. This study aims to investigate the variation of media filter thickness and filtration pressure of hollow fibre (HF) PVDF-TiO2/SBE membrane peat water treatment by filtration pre-treatment and HF membrane ultrafiltration. HF PVDF-TiO2/SBE membrane was prepared by wet spinning method using spinneret set up. Hybrid process was divided into two steps: 1) conventional filter as pre-treatment and 2) HF ultrafiltration membrane under cross flow system. The filter media was used in this work is silica sand and activated carbon with varied thickness 30:10 and 10:30 cm. The HF membrane structure was analysed via scanning electron microscopy (SEM) to investigate the membrane morphology. The results show the fabricated HF membrane has a finger like-sponge sandwich structure morphology. In addition, 30:10 cm (silica sand: activated carbon) thickness exhibits TDS and turbidity removal of 92.18 and 61.37%, respectively as conventional filter pre-treatment. In other hand, HF membrane successfully removed TDS and turbidity of peat water up to 98.68% and 92.41% at 2 bar of filtration pressure. The highest permeate flux of HF membrane conducted of 13.055 Kg.m-2.h-1 at 3 bar. Conclusion of this work is the peat water treatment using activated carbon: silica filtration pre-treatment and HF membrane ultrafiltration can provide clean water with maximum turbidity and TDS removal.

Global techno-economic analysis of MBR for hospital wastewater treatment

This study comprehensively examines and characterizes global membrane bioreactor (MBR) practices for hospital wastewater treatment, focusing on development trends, technical performance (pollutant removal and carbon emissions), and economic costs, including both capital expenditures (CAPEX) for civil engineering and equipment procurement, and operational expenditures (OPEX) for electricity, membrane replacement, labor, and chemical costs, as well as system footprint. The results show that MBR has been widely used for hospital wastewater treatment for over two decades, with global applications and scales significantly increasing, especially after the COVID-19 pandemic. A notable shift in membrane types has occurred, with hollow fiber membranes dominating before 2010 and flat inorganic membranes gaining prominence after 2020. MBR not only effectively removes conventional pollutants but also greatly reduces pathogens, ARBs and ARGs before disinfection, thus alleviating the subsequent disinfection burden. In addition, MBR is a crucial step in the process of completely removing emerging contaminants (ECs) that pose significant environmental and health risks. The CAPEX of MBR has decreased at the technical level in recent years. MBR requires only 62 % and 21 % of footprint for conventional activated sludge (CAS) and biofilm-based processes, respectively. MBR's land-saving advantage offsets the CAPEX gap with CAS in high land-cost areas. From before 2010 to after 2020, membrane costs saw the largest reduction in OPEX, dropping by 71 %, while electricity consumption saw a 10.71 % reduction, now comparable to biofilm-based processes. Currently, MBR's OPEX (0.158 USD/m3) is only slightly higher than that of biological contact oxidation (0.138 USD/m3). MBR also minimizes sludge production, reducing both treatment costs and associated disposal risks. MBR exhibit minimal concerns of excessive carbon emissions, with a carbon emission intensity (1.11 kg CO2eq·m−3), only slightly higher than biofilm-based processes (0.92 kg CO2eq·m−3). This study demonstrates that MBR is the valuable and practical solution for hospital wastewater treatment, as well as a preferred choice for upgrading existing facilities.

Enhanced plasticization resistance of hollow fiber membranes via metal ion coordination for advanced helium recovery

Plasticization can significantly impair the gas separation performance of gas separation membranes, especially for hollow fiber membranes (HFMs) with ultrathin skin layer. While conventional thermal crosslinking is an effective method to address this issue, it often leads to the transition layer collapse in HFMs, resulting in a significant decrease in gas permeance. Herein, we fabricate polyimide-cerium (PI-Ce) complex HFMs using a carboxylic group-containing 6FDA-mPDA0.65-DABA0.3-TFMB0.05 copolyimide through metal ion coordination to achieve plasticization-resistance helium recovery from natural gas. We optimized dope compositions and spinning conditions to produce defect-free hollow fiber membranes with a skin layer as thin as 300 nm. The coordination between carboxyl groups and cerium ions was characterized using Fourier Transform Infrared Spectroscopy (FTIR) and Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy. The polymer-metal coordinated membranes exhibited enhanced gas selectivities compared to the pristine HFMs due to the tailored microporosity achieved through polymer-metal coordination. Furthermore, the PI-Ce HFMs demonstrated only a 10.8% decline in mixed-gas He/CH4 selectivity, which is significantly lower than the 55.4% decline observed in pristine HFMs when exposed to CO2-containing feed pressures below 400 PSIA. Molecular dynamics simulations confirmed that coordination confined molecular chain swelling, thereby suppressing plasticization caused by CO2. The exceptional plasticization resistance of the PI-Ce complex HFMs provides a novel strategy for recovering helium from aggressive natural gas environments.

Hollow microporous organic network fiber membrane for efficient extraction of okadaic acid from marine organisms

Membrane-based micro-solid phase extraction (M-μSPE) has garnered great attention in sample pretreatment, suffering an inherent contradiction between permeability and adsorption capacity. In this study, a pure microporous organic network (TEB-DIB-MON) fiber membrane was prepared by combining electrostatic spinning technology, Sonogashira-Hagihara reaction and template sacrifice method. The prepared TEB-DIB-MON membrane exhibited a large specific surface area with a hollow and porous structure, thereby providing excellent solvent permeability and high adsorption capacity for okadaic acid (OA, an algal toxin). Under the optimized conditions, a sensitive analytical method was established by coupling M-μSPE with high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The established method has a low detection limit (0.5 pg mL-1), a wide linear range (1.5-1000 pg mL-1, R ≥ 0.9991), and good reproducibility (RSD ≤ 9.4 %, n = 6), which was then successfully applied for OA detection in marine organisms. Trace amounts of OA (59.3-89.0 pg mL-1) was detected in the oyster and prawn samples. This work demonstrated that the excellent application potential of MON membranes in sample pretreatment, while also presents a novel synthesis strategy for MONs membranes.

Modelling of Carbon Dioxide Absorption in Hollow Fiber Membrane Contactor for Different Flow Configurations

Modelling of Carbon Dioxide Absorption in Hollow Fiber Membrane Contactor for Different Flow Configurations

Developing PVDF hollow fiber membrane enhanced by braided tube and modified by bionic coating for treating aldehyde-containing wastewater

This study originates from the difficulties encountered in the wastewater treatment from a large-scale methionine production line. Despite the superior performance of the polytetrafluoroethylene (PTFE) membrane, significant issues still persist. The PTFE layer tend to peer off leading to substandard effluent quality, and membrane fouling rate is relatively rapid. To overcome the peeling issue, braided tubes were used to enhance the mechanical strength. To improve the interface bonding between the PVDF layer and braided tubes, two modifiers are introduced to modify the surfaces of braided tubes. Then, the embedded braided tube enhanced PVDF membrane is prepared. On this basis, the one-step bionic coating PVDF (OSBC-PVDF) membrane was prepared by utilizing the polydopamine coating, polyethylene glycol and Cu nanoparticles. It was found that the embedded structure resembling “teeth and gums” formed, significantly improving the mechanical properties to prevent the peeling off of the separation layer. The optimal reaction temperature, reaction time and modifier dosage for preparing the OSBC-PVDF membrane are separately 25 °C, 2 h and 20 g. More importantly, the OSBC-PVDF membrane has withstood the test of 300 days of continuous operation. The stable water quality of the effluent demonstrated that the above issues had been overcome.

Environmental and economic assessment of urban wastewater reclamation from ultrafiltration membrane-based tertiary treatment: Effect of seasonal dynamic

This study aimed to assess the environmental and economic performance of an ultrafiltration (UF) tertiary treatment of effluent from an urban wastewater treatment facility. Data from a UF demonstration plant composed of commercially available equipment, including industrial hollow-fiber membranes was used to project a full-scale facility. The results from the demonstration plant recommended different ranges of transmembrane fluxes and sparging air demands under summer and winter conditions to prevent excessive fouling. The energy balance of the full-scale facility would be 0.308 ± 0.112 kWh·m−3 in summer and 0.140 ± 0.040 kWh·m−3 in winter, with blowers' being the main consumers (86–93 %). CAPEX accounted for €0.030 ± 0.002·m−3 in summer and €0.027 ± 0.002·m−3 in winter and membrane acquisition represented 66–69 % of the investment cost. Energy expenditure was the major OPEX cost (66–79 %), with a total operating cost of €0.077 ± 0.023·m−3 and €0.042 ± 0.008·m−3 in summer and winter, respectively. The final average value obtained for the TAC was €0.107 m−3 in summer and €0.068 m−3 in winter. The environmental assessment confirmed optimizing energy consumption and membrane requirements as the main factors influencing environmental sustainability. Specifically, summer and winter emissions of 0.079–0.175 and 0.043–0.079 kgCO2eq·m−3 (Global warming potential); 8.1 · 10−4–1.7 · 10−3 and 4.8 · 10−3–8.1 · 10−3 m3·m−3 (water consumption); 0.019–0.041 and 0.010–0.019 kg oileq·m−3 (fossil fuel scarcity); and 1.4 · 10−4–2.9 · 10−4 and 7.7 · 10−4–1.4 · 10−4 kg Cueq·m−3 (mineral resource scarcity) were calculated, respectively. The obtained permeate quality complied with the most stringent Spanish and EU regulations.

Recent advances in H2 purification and CO2 capture: Evolving from flat sheet to hollow fiber membranes

Hydrogen (H2) production and demand have steadily increased, leading to a rise in carbon dioxide (CO2) emissions since fossil fuels are the current raw material for H2 production. Thin film composite (TFC) hollow fiber membranes have become significant in H2 purification and CO2 capture, playing a critical role in developing next-generation fuels and supporting the United Nations Sustainable Development Goal 7 (SDG 7) – Affordable and Clean Energy, with the goal of providing universal access to clean, advanced, and renewable energy for all. However, the polymeric selective layer of TFC membranes faces a trade-off between permeability and selectivity, as well as challenges including CO2 plasticization and physical aging. Additionally, H2/CO2 separation remains particularly challenging because H2, being diffusivity-selective, permeates more quickly through the membrane due to its smaller molecular size and higher kinetic energy, while CO2, being solubility-selective, has a high affinity for dissolving in most polymeric membranes. Herein, this review provides an in-depth exploration of innovative modification strategies designed to overcome these challenges in glassy polymeric membranes and enhance H2 separation performance in the recent 10 years. Various nanofillers, such as metal-organic frameworks (MOFs) such as University of Oslo (UiO), Materials Institute Lavoisier (MILs), and Zeolitic Imidazolate Frameworks (ZIFs), have shown remarkable potential in boosting gas separation capabilities due to their superior compatibility with polymer matrices and tunable properties. The review also explores different types of hollow fiber membranes, including single layer, dual-layer, and TFC, alongside fabrication techniques like interfacial polymerization and dip-coating. Critically, the analysis highlights cutting-edge strategies to improve membrane performance, such as (i) thermal cross-linking, (ii) chemical cross-linking, (iii) ultraviolet (UV) cross-linking, (iv) polymer blends, and (v) modified fillers, along with their objectives and expected outcome. Furthermore, the review spotlights breakthroughs in H2/CO2, H2/CH4, and H2/N2 separation technologies, emphasizing the critical need for continued innovation to drive sustainable H2 production and meet the growing clean energy demand.

Electroextraction of Large Volume Samples Using Paper Points Coupled With Hollow Fiber Membranes: Study of Parameters and Strategies to Enhance Analytical Performance.

Electroextraction (EE) encompasses a range of sample preparation methods whose effectiveness, selectivity, and efficiency are significantly influenced by the physical-chemical characteristics of analytes, samples, and instrumental conditions. This article explores, for the first time, various strategies aimed at enhancing the extraction efficiency of a recent approach of EE utilizing a paper point (PP) combined with a hollow fiber (HF) (abbreviated as PP-HF-EE) to extract various cationic and anionic model compounds from water samples. The study also explores, experimentally, the impact of agitation, organic filter composition, PP diameter, and PP brand on extraction performance, and proves that all these factors are quite important, especially when digital image analysis is utilized for determination. Furthermore, this work demonstrates the ease and feasibility of simultaneously extracting cations and anions using PP-HF-EE and proposes a straightforward method to enhance analyte concentration on the vertex of the PP through a base-to-vertex focusing. Lastly, it is demonstrated, using capillary electrophoresis coupled to a UV-Vis detector, that for PP-HF-EE, the extraction efficiency and pre-concentration factor are less dependent on other parameters when multiple PPs per sample are utilized, with signal enhancement values of up to 111 and 339 for nortriptyline and haloperidol, respectively. All the findings and strategies presented herein constitute significant contributions that can facilitate future research in method development, particularly in the utilization of PP-HF-EE and similar EE approaches.

Low chemical-expansion and self-catalytic nickel-substituted strontium cobaltite perovskite four-channel hollow fibre membrane for partial oxidation of methane

In membrane reactors, the thermo-mechanical stability of the membrane determines the operability of the reaction, while the permeability and catalytic performance dictate the reaction process. A high chemical expansion coefficient can exacerbate the mismatch in the thermal expansion behaviour between the two sides of the membrane, potentially resulting in fracture. The low permeability and slow catalytic activity can slow the reaction process and result in an unsatisfactory product composition. Here, a Ba0.5Sr0.5Co0.7Fe0.2Ni0.1O3-δ (BSCFN) four-channel hollow fibre membrane with a low chemical-expansion and high oxygen permeation flux has been successfully fabricated by phase inversion and a one-step thermal process (OSTP). Reaction sintering during the OSTP forms an NiO in-situ exsolution phase on the membrane surface, and A-site stoichiometry excess occurs, improves the oxygen permeation flux, and provides the membrane with self-catalytic ability during the partial oxidation of methane (POM) reactions. Consequently, the BSCFN membrane shows excellent performance; exhibiting an oxygen flux of 11.75 mL cm−2·min−1 at 900 °C. Furthermore, the self-catalytic BSCFN membrane has a good hydrogen production of 10.1 mL cm−2·min−1 during the POM process, which is 7.5 times higher than that of Ba0.5Sr0.5Co0.8Fe0.2O3-δ membranes (1.87 mL cm−2·min−1). This offers a viable strategy for the development of membrane reactor applications.

Biogas purification using cellulose nanocrystals/polyvinyl alcohol coated facilitated transport hollow fiber membranes with L‐arginine as CO2 carrier

AbstractThe composition of biogas consists mainly of CH4 (~60%) and CO2 (40%). To be considered a clean fuel, CH4 concentration in biogas must be increased to over 95%. In this study, membranes which were stacked in a chamber were utilized to purify biogas by passing biogas over them. These membranes were composed of polyethersulfone hollow fiber substrate coated with a “selective layer” made of cellulose nanocrystals (CNC‐0–2 wt) in polyvinyl alcohol (PVA) and l‐arginine as a CO2 carrier. Of the different CNC concentrations in PVA‐LA, CNC1/PVA‐LA (1.0 wt% CNC in PVA‐LA) displayed the lowest water contact angle of 17° (corresponding to higher moisture absorbing ability). With further increase in CNC concentration, even though CNC1.5/PVA‐LA showed the higher crystallinity (66%), and water contact angle increased (20°); reducing the chances of facilitated transport of CO2 through it. Biogas separation experiments were conducted at 90% RH and different feed pressures (0.8–1 bar) for various CNC concentrations. Increasing the CNC concentration led to a thicker selective layer, enhancing the CO2 permeability and selectivity up to CNC1/PVA‐LA. However, with the further addition of CNC, both permeability and selectivity decreased. At 90% RH and 1 bar feed pressure, the CNC1/PVA‐LA setup demonstrated a CO2 permeability of 20,522 Barrer and a selectivity of 33, making it suitable for low‐pressure biogas storage systems with lower energy requirements.

Influence of irregular fiber filling on the performance of hollow fiber membrane modules for cold water production

The countercurrent hollow fiber membrane-based evaporative water cooler (MEWC) offers an eco-friendly and compact solution for cold water generation. This study introduces a random sequential addition algorithm to model the real-world irregular fiber filling within the MEWC. Inspired by the honeycomb structure, the developed 3-D numerical model adopts a calculation unit featuring a hexagonal prism comprising multiple fibers. Validation against experimental data reveals an average relative error of 2.81 % concerning outlet water temperature. The effects of fiber filling patterns (regular layout and random layout) on the velocity and temperature fields of the MEWC are investigated. Comparisons of outlet water temperature, cooling efficiency, consumptive electric power ratio, and heat and mass transfer resistance composition between these layouts under various operating conditions are conducted. The results indicate that the random layout fosters severe channeling effect and large flow dead zones, impairing air side heat and moisture transfer. The random layout exhibits over 15.9 % reduction in cooling efficiency and 36.3 % decrease in consumptive electric power ratio compared to the regular layout. Irregular fiber filling leads to a notable 158.6 % increase in air side heat transfer resistance and a 35.9 % rise in mass transfer resistance. Although irregular filling compromises the cooling performance, it demonstrates potential for energy savings under certain conditions. Design schemes should be carefully tailored to meet specific application requirements by considering these trade-offs.

Impact of drug incorporation into micelle on reduced griseofulvin and meloxicam permeation across a hollow fiber membrane

A hollow fiber membrane (HFM) was previously characterized as a potential permeation component of a dissolution/permeation system. Two objectives were to assess the impact of micellization on drug permeation across HFM and identify a preferred permeation model from three models: permeation from only free drug, permeation from both free drug and micelle-bound drug, and permeation with enhancement from micelle shuttling. HFM studies were conducted under unsaturated drug conditions, using griseofulvin and the more hydrophilic drug meloxicam, with and without surfactant [sodium lauryl sulfate, polysorbate 80, and polyoxyethylene (10) lauryl ether]. Griseofulvin was micelle incorporated to a greater extent than meloxicam, such that griseofulvin flux decreased to a greater extent than for meloxicam. The griseofulvin permeation model from only free drug was rejected, since griseofulvin flux required free drug to be about 5-20 fold higher in HFM flux studies than supported by solubility studies, depending on surfactant. Permeation from both free griseofulvin and micelle-bound griseofulvin successfully accommodated observed flux, where micelle permeability was about 5-fold lower than free drug permeability for HFM with 10KDa MWCO. Permeation with enhancement from micelle shuttling was not the preferred explanation, although the model accommodated flux data and provided aqueous boundary layer thicknesses similar to other setups.

Preparation of Thermosensitive Lignocellulose Hollow Fiber Membrane Grafted With PNIPAAm and Its Application as a Cell Culture Carrier in a RSOC Dynamic Culture.

Currently, the cells, which are urgently required for large-scale application in biomedical-related fields, harvested by traditional trypsin digestion are usually subject to repeated digestion, leading to a reduction of cell activity. In this study, poly (N-isopropylacrylamide) (PNIPAAm) was grafted onto the lignocellulose hollow fiber membranes (HFMs) with cerium ammonium nitrate (CAN) as the initiator to prepare thermosensitive HFMs, which was combined with a rotation system of culture (RSOC) to achieve dynamic culture and non-destructive harvesting of cells from the HFMs. The results of ATR-FTIR, elemental analysis, and SEM confirmed the successful preparation of PNIPAAm-grafted-HFMs, which also showed good biocompatibility to apply for cell culture carriers. In cooling detachment, the HFMs-0.01 group could completely detach the cells within 1h with a cell separation efficiency of more than 90%. The laminin (LN) and fibronectin (FN) harvested by cooling detachment of P8 generation PC12 cells reached 0.0531±0.0032 and 2.5045±0.0001pg/cell, respectively, which were significantly higher than that by trypsin digestion. In addition, the cells on the thermosensitive HFMs proliferated fastest in RSOC at 30rpm with higher glucose consumption and lactate metabolism than in static conditions. Moreover, the cells that had dynamic detachment at 20rpm had the highest cell density and activity. Therefore, the thermosensitive HFMs could be applied as cell culture carriers in RSOC for cell culturing at 30rpm and harvesting at 20rpm, which would provide considerable potential for large-scale cell culture in vitro.

Exploration of Daptomycin Adsorption by Polymethylmethacrylate Hemofilter In Vitro.

Blood purification therapy with cytokine-adsorbing hemofilters has been used to treat sepsis-associated hypercytokinemia. Polymethylmethacrylate (PMMA) hemofilters are frequently used for this purpose; however, adsorption and removal of teicoplanin, a therapeutic agent, have been reported. Similar concerns have been shared regarding daptomycin because its structure resembles that of teicoplanin; nevertheless, there have been no reported effects associated with daptomycin in this context. We studied the adsorption of daptomycin onto a PMMA hemofilter in vitro and investigated its adsorption onto hollow fiber membranes by adding cut PMMA membranes to a daptomycin solution. Additionally, the daptomycin solution was circulated in a dialysis circuit connected to a PMMA hemofilter, and changes in daptomycin content were examined. The daptomycin content decreased immediately after adding the hollow fiber membranes, similar to that observed for teicoplanin. The daptomycin content was lower than that of the standard reagent in the dialysis circuit model, reaching values below the measurement limit after 20 min. These results suggested that daptomycin was adsorbed and removed by the PMMA hemofilter. Encountering this effect during clinical use is plausible; therefore, daptomycin administration via a PMMA hemofilter should be avoided during blood purification therapy.

Three-dimensional CFD modeling for hollow fiber gas separation membrane modules based on a dual porous media model

Mathematical modeling is crucial to optimizing the design of the hollow fiber membrane (HFM) module. A Computational Fluid Dynamics (CFD) model enables efficient three-dimensional (3D) simulations of HFM modules, which integrates a dual porous media approach, significantly reducing computational costs. Validation against alternative simulations and experimental data confirms its prediction capability (<7% deviation). Comparative analyses demonstrate the superior reliability of the 3D approach over one-dimensional simulations. Detailed velocity, pressure, and concentration profiles for the shell and tube sides reveal optimization opportunities such as dead zones within the module. Aerometric studies show significant pressure drops (>30%) for smaller fiber diameters (<100μm) on the permeate side. The model's adaptability suggests broader applications in membrane gas separation processes with modifications. This research highlights the efficacy of CFD modeling in enhancing the design and optimization of HFM modules, highlighting the cost savings of the dual porous media approximation.