Search Results (334)

This study evaluates the partial dealcoholization of red wine using reverse osmosis (ACM3) and nanofiltration (TS80) membranes at 25 and 35 bar, targeting 2% and 4% ethanol reductions. Membrane performance was assessed through fouling analysis and ethanol partitioning, while wine phenolic (flavan-3-ols, anthocyanins) and color characteristics (CIELab parameters) were determined. The 2% reduction process with ACM3 at 25 bar resulted in minimal phenolic changes. The 4% reduction process revealed distinct performance profiles: ACM3 exhibited exceptional stability (3.35–5.30% permeability loss, linear flux decline with R² > 0.93) and ethanol rejection of 17.6–25.5%, while TS80 achieved processing rates three to six times faster with moderate fouling (16.3% loss, 7.7–13.3% rejection). Decreases in flavan-3-ols and anthocyanin concentrations correlated with fouling intensity rather than processing duration. Proanthocyanidin structure remained stable, and color shifts reflected changes in polymeric pigments rather than anthocyanin loss. Reverse osmosis at low transmembrane pressure proved most suitable for quality preservation. The operational trade-off is clear: TS80 offers three to six times faster processing but with greater phenolic loss, while ACM3 requires longer batch times with minimal fouling. Both processes demonstrate that membrane-based dealcoholization without fluid replacement is feasible, providing winemakers with a valuable method to reduce alcohol while preserving quality. Full article

High regeneration energy demand remains a critical barrier to the large-scale deployment of ethanolamine-based (MEA-based) CO₂ capture. This study adopts an Al₂O₃ ceramic-membrane heat exchanger (CMHE) to recover both sensible and latent heat from the stripped gas. Experiments confirm that heat and mass transfer within the CMHE follow a coupled mechanism in which capillary condensation governs trans-membrane water transport, while heat conduction through the ceramic membrane dominates heat transfer, which accounts for more than 80%. Guided by this mechanism, systematic structural optimization was conducted. Alumina was identified as the optimal heat exchanger material due to its combined porosity, thermal conductivity, and corrosion resistance. Among the tested pore sizes, CMHE-4 produces the strongest capillary-condensation enhancement, yielding a heat recovery flux (q value) of up to 38.8 MJ/(m² h), which is 4.3% and 304% higher than those of the stainless steel heat exchanger and plastic heat exchanger, respectively. In addition, Length-dependent analyses reveal an inherent trade-off: shorter modules achieved higher q (e.g., 14–42% greater for 200-mm vs. 300-mm CMHE-4), whereas longer modules provide greater total recovered heat (Q). Scale-up experiments demonstrated pronounced non-linear performance amplification, with a 4 times area increase boosting q by only 1.26 times under constant pressure. The techno-economic assessment indicates a simple payback period of ~2.5 months and a significant reduction in net capture cost. Overall, this work establishes key design parameters, validates the governing transport mechanism, and provides a practical, economically grounded framework for implementing high-efficiency CMHEs in MEA-based CO₂ capture. Full article

Silicalite nanosheet (SN) laminated membranes are promising for pervaporation (PV) desalination of concentrated brines for water purification and critical material concentration and recovery. However, scaling up the SN-based membranes is limited by inefficient synthesis of monodispersed open-pore SN single crystals (SNS). Here, we report a scalable approach to fabricate multilayered silicalite nanosheet plate (SNP) laminated membranes on porous alumina and PVDF substrates and demonstrate their excellent PV desalination performance for simulated brines containing lithium and high total dissolved salts (TDS). At 73 ± 3 °C, the SNP laminated membrane on alumina support achieved a remarkable water flux ($J_w$) of nearly 20 L/m²·h, significantly outperforming the alumina-supported SNS laminated membrane ($J_w$ = 9.56 L/m²·h), while both provided near-complete salt rejection ($r_i$ ~99.9%) when operating with vacuum pressure on the permeate side. The PVDF-supported SNS and SNP laminated membranes exhibited excellent $J_w$ (14.0 L/m²·h) and near-complete $r_i$ (>99.9%), surpassing the alumina-support SNP laminated membranes when operating by air sweep on the permeate side. However, the $r_i$ of the PVDF-supported membranes was found to decline when operating with vacuum pressure on the permeate side that was apparently caused by minimal liquid permeation through the inter-SNP spaces driven by the transmembrane pressure. With scalable SNP production, SNP-A membranes show potential for PV desalination of high-TDS solutions, especially in harsh environments unsuitable for polymer membranes. Full article

In whey valorization, membrane separation stands out as a highly effective technique for purifying and isolating the various components of whey. The efficiency of whey ultrafiltration and diafiltration (UF/DF) largely depends on the balance between membrane selectivity, hydrodynamic conditions, and solute interactions at the membrane interface. In this study, sweet whey was fractioned using 10, 30 and 50 kDa polyether sulfone (PES) membranes under identical transmembrane pressure (TMP = 2.5 bar) with ultrafiltration and a subsequent 4-step constant volume diafiltration stages. The resulting compositional and dielectric changes were evaluated to identify optimal separation conditions and assess the applicability of dielectric parameter measurement as a rapid, non-destructive monitoring technique. Results showed that, regardless of the applied molecular weight cut-off (MWCO), using three DF cycles can wash out almost all the removable lactose from the retentates, and the dielectric assessment of both permeate and retentate fractions showed a strong, linear relationship between the change in dielectric behavior and the composition of each fraction. Analysis of the dielectric spectra confirmed that the ratio of the dielectric constant to the loss factor (ε′/ε″) exhibited a strong linear correlation (R² > 0.98, r > 0.99) with lactose concentration in the permeate fractions of all three MWCO membranes, as well as a similarly strong correlation (R² > 0.975, r > 0.98) with the total chemical oxygen demand (TCOD) measured in the retentate fractions. Full article

Reverse osmosis (RO) is the key process for textile dyeing wastewater reuse applications. Membrane fouling reduces both permeability and rejection capability, negatively affecting the technological economy of RO process. Membrane cleaning is critical to recovery of the permeability of fouled RO membranes. Based on multi-batch filtration and cleaning experiments, this study systematically evaluated the RO membrane fouling potential of pre-treated textile dyeing wastewater by a membrane bioreactor and the recovery performance of fouled RO membranes after different cleaning methods. A significant decline (more than 15%) in RO membrane permeability occurred after RO membrane permeate production of 625 L/m² at a water recovery ratio of 60%. Protein-like substances and soluble microbial products were identified as the primary organic foulants via three-dimensional fluorescence excitation-emission matrix spectrometry (3D-FEEM). The single forward flushing with either pure water, acid, alkaline, or sodium hypochlorite solutions with a low active chlorine concentration showed very limited recovery of fouled RO membrane permeability. The combined forward flushing with acid followed by alkaline solutions restored fouled membrane permeability by up to 87% of a new RO membrane. The addition of pure water backwashing at a transmembrane pressure (TMP) of 0.5 MPa after both acid and alkaline solutions combined forward flushing restored fouled membrane permeability by up to 97% of a new RO membrane but deteriorated the rejection capability of the RO membrane. The backwashing parameters were further optimized at a TMP of 0.125 MPa and crossflow velocity (CFV) of 0.5 m/s, achieving fouled RO membrane permeability by up to 96% of a new RO membrane, and there were no negative effects on the rejection capability of the RO membrane. Alkaline forward flushing followed by pure water backwashing was the dominant contributor for fouled RO membrane permeability recovery. A preliminary economic analysis showed that the total chemical cost per RO production was 0.763 CNY/m³ and could be further reduced via removing acid cleaning and replacing combined alkaline flushing and pure water backwashing with alkaline backwashing. Full article

In a standard diffuser system in a membrane bioreactor (MBR), uneven air distribution scouring the membrane surface causes transmembrane pressure to reach its ultimate value earlier, which requires membrane cleaning more frequently. In this study, a Venturi-integrated innovative diffuser design is proposed to improve membrane bioreactor (MBR) technology. The proposed design aims to increase filtration efficiency by creating a homogeneous scouring effect on the membrane surface. To compare the performance of the proposed diffuser configuration (V-MBR) with that of a conventional diffuser (S-MBR), computational fluid dynamics models were established for each of the two configurations. The results showed that the V-MBR model produced about 50% higher average shear stress on the membrane surfaces. Statistical analysis also showed that the V-MBR model generally produced low variance and non-zero shear stress values. Along with shear stress distribution, other parameters such as volume fraction, velocity, turbulent kinetic energy, and turbulent eddy distribution were evaluated to compare the performance of two diffuser system configurations. These parameters also supported the superior performance of the new V-MBR model over the conventional S-MBR. It is concluded that homogeneous shear stress distribution on the membrane surface is an important parameter that increases filtration efficiency by preventing the formation of dead zones. Full article

This work assesses the viability of ultrafiltration (UF) membranes as a substitution for classic tertiary technologies for municipal wastewater (MWW) treatment. UF membranes can offer efficient MWW filtration, meeting quality standards regarding solids, bacteria, viruses and emerging pollutants, such as microplastics. All of these make UF not only an attractive competitor regarding tertiary treatments but also a potential quaternary treatment according to the latest legislation. Indeed, the achieved permeate quality meets the more stringent parameters for water reuse in agriculture according to the European standard (A-type water). The UF membrane’s feasibility when used as an MWW tertiary/quaternary treatment was assessed in a semi-industrial plant with commercially available industrial membrane modules under different operating conditions: (1) transmembrane flux, (2) air sparging intensity and filtration/relaxation periodicities, (3) the concentration of solids reached in the membrane tank and (4) the efficacy of chemically enhanced backwashing (CEB) to mitigate fouling. Increasing the air intensity (around 0.25 m³ m⁻² h⁻¹), increasing the solids concentration (3–4 g L⁻¹) and using acid chemicals for backwashing at low concentrations but high periodicities (about 25–50 ppm of HCl/citric acid at a pH of 2.5 once or twice every 15 days) displayed great effectiveness in minimizing fouling, which was found to be mainly reversible. Thanks to the stablished conditions, semi-industrial UF membrane filtration was possible for more than 30 days when operating at relatively high transmembrane fluxes (21.5 LMH), achieving an average transmembrane pressure of around 120 mbar with an extremely low fouling growth rate of 0.024 mbar d⁻¹. Full article

A hollow fiber-supported polymeric mixed-matrix membrane, consisting of a Pebax-1657 matrix and graphene nanoplatelet (GNP) fillers as the selective layer, was tested for CO₂/CH₄ gas separation at transmembrane pressures up to 30 bar(a). Using a custom, novel, membrane module, we simultaneously performed permeability/selectivity and in situ electric impedance spectroscopy measurements. This in situ technique is proposed here for the first time. Furthermore, stable mixed-gas selectivities, for 10% CO₂ in CH₄ gas, reaching up to 61.4 (M0) and 68.5 after heat treatment (M2) were observed at 20–30 bar(a), whereas the stressed state (M1) dropped to ~22. Throughout the whole procedure of the three (initial, degraded, and restored) membrane testing assessments, a gradual decline in gas permeability coupled with a corresponding increase in the membrane’s AC resistance, due to membrane compaction, was evident. More specific, the membrane’s AC resistance, R₁, increased from ~96–147 ΜΩ (M0) to ~402–435 ΜΩ (M1) and ~5390–5700 ΜΩ (M2), while the peak-phase frequency f_p decreased from ~1.25 kHz (M0) to ~340 Hz (M1) and ~115 Hz (M2). Overall, this work proposes a new tool/method for connecting membrane’s deterioration phenomena with AC resistance and demonstrates that a facile heat treatment can restore selectivity following compaction, despite the absence of full permeance recovery. Full article

The recovery of copper from metallurgical effluents is critical for advancing sustainable mining and circular economy practices. This study evaluated a hybrid process combining copper sulfide precipitation with clarification using polymeric polyvinylidene fluoride (PVDF) microfiltration membranes. Laboratory-scale experiments were performed under controlled cyanide conditions (100 mg/L free CN⁻, 1800 mg/L Cu²⁺), focusing on permeate flux behavior, fouling mechanisms, and cleaning strategies. Optimal performance was achieved at moderate transmembrane pressures (<2.0 bar) and higher flow rates, which provided a balance between productivity and fouling control. Flux decline was attributed to a combination of pore blocking and cake layer formation, confirming the multifactorial nature of fouling dynamics. Cleaning tests revealed that oxidizing solutions (HCl + H₂O₂) restored up to 96% of the initial permeability, while combined treatments with NaCN achieved complete recovery (>100%), albeit with potential risks of membrane aging under prolonged exposure. A techno-economic assessment comparing polymeric and ceramic membranes revealed similar capital and operational costs, with polymeric membranes offering slight reductions in CAPEX (10%) and OPEX (2.3%). Overall, the findings demonstrate the technical feasibility and economic competitiveness of polymeric membranes for copper sulfide clarification, while emphasizing the need to improve long-term chemical resistance to ensure reliable industrial-scale implementation. Full article

The success and impact of biological invasions depend on adaptations to novel abiotic and biotic selective pressures. However, the genetic mechanisms underlying adaptations in invasive species are inadequately understood. Taenioides sp. is an invasive worm goby, originally endemic to brackish waters in the estuaries of Southeastern China, and now colonizes multiple inland freshwaters of North China within decades as a byproduct of the East Route of South-to-North Water Transfer (ESNT) project. However, the molecular mechanisms underlying their adaptations to the climate of North China, especially the temperature regime, are unknown. Here, we performed genomic resequencing analysis to assess genetic diversity and population genetic structure, and further investigated the genomic signatures of local adaptation in the invasive population of Taenioides sp. during their northward invasion. We revealed that all invasive populations exhibited no genetic differentiation but low gene flow and an obvious signal of population bottleneck. Yangtze River estuary may serve as the source population, while Gaoyou Lake serves as a potential bridgehead of the invasion. Selective sweep analyses revealed 117 genomic regions, containing 673 candidate genes, under positive selection in populations at the invasive front. Redundancy analysis suggested that local temperature variables, particularly the monthly minimum temperature, represent critical evolutionary forces in driving adaptive divergence. Functional enrichment analyses revealed that multiple biological processes, including metabolism and energy production, substance transmembrane transport, and neural development and synaptic transmission, may play important roles in adaptation to regional temperature conditions. Our findings revealed a scenario of adaptive evolution in teleost species that underpins their regional climate adaptation and successful establishment of invasive populations in a human-facilitated invasion context. Proper management strategies should be established to manage Taenioides sp invasion as soon as possible. Full article

The filtration behaviors of dynamic membrane (DM) under gravity-driven and pump-driven modes were investigated in a pilot-scale DM bioreactor (DMBR) for domestic wastewater treatment. After DM formation, both modes achieved effective solid–liquid separation, producing effluent with turbidity below 1 NTU, with the gravity-driven module exhibiting marginally lower turbidity than the pump-driven system. Although the flux in the gravity-driven mode (30–48 L/m²·h) was approximately half that of the pump-driven mode, the transmembrane pressure (TMP) required was only 10–20% of that under the pump-driven operation. The DM formed under pump-driven conditions was thicker and more compact, leading to more frequent and rapid TMP increases. Inorganic content accounted for 85% of the pump-driven DM mass, significantly higher than that in the gravity-driven DM (50%) and activated sludge (15%), indicating a pronounced accumulation of inorganic solids on the mesh filter surface, particularly under the pump-driven operation. This accumulation increased filtration resistance and elevated TMP. Therefore, enhancing the removal of inorganic solids prior to the DMBR can improve system stability and facilitate broader application of the DMBR technology. Full article

Introduction: TPE (therapeutic plasma exchange) has proven to be an extremely effective treatment for a range of conditions, especially over the past 20 years. Anticoagulation with heparin is currently the accepted recommendation for therapeutic plasma exchange sessions. However, the hypercoagulable state and hyperviscosity in some patients requiring TPE present a challenge, particularly during the first session, due to an increased risk of circuit clotting. Citrate anticoagulation has been proposed for extracorporeal therapies such as hemodiafiltration where heparin is contraindicated. Nevertheless, citrate anticoagulation is still generally avoided in patients undergoing TPE. Materials and Methods: A total of 26 patients underwent 52 TPE sessions using citrate. Fifteen patients received citrate from the beginning of therapy, accounting for 29 sessions, and eleven patients were switched to citrate after initially starting with heparin, when an imminent risk of circuit clotting quickly became evident—23 sessions in total. The imminent risk of circuit clotting was assessed by a continuous and accelerated increase in transmembrane pressure despite heparin anticoagulation. The effectiveness of citrate anticoagulation and its safety for patients were evaluated. Results: Of the 23 sessions where there was a risk of circuit clotting, citrate was added on top of heparin in those sessions; 21 sessions were successfully completed. It can be said that the kits were saved in these cases. Among the 29 TPE sessions that used citrate from the start, 27 were completed successfully, even though the patients were considered to have a hypercoagulable status. No cases of citrate toxicity were identified. Conclusions: TPE with citrate is a safe option for patients. It can preserve TPE kits from the beginning or during treatment in patients with hypercoagulability. Citrate can be also be used when heparin is contraindicated or ineffective. Full article

The GXXXG motif, also called the glycine zipper, is a common sequence pattern that facilitates tight packing of secondary structures, especially through helix–helix interactions in both membrane and soluble proteins. However, its overall distribution, sequence variation, and structural preferences depending on context are not fully understood. Here, we offer a detailed, large-scale analysis of GXXXG motifs, examining over 25,000 unique UniProt sequences with structural data. We classified the motifs as transmembrane (TM), non-transmembrane (non-TM), or shared, based on their TM coverage, and analyzed them via statistical models, diversity measures, and compositional profiling. Our findings show that ≥60% TM coverage is a reliable cutoff to distinguish TM-specific motifs, which tend to have less sequence diversity, lower entropy, more hydrophobic residues (notably leucine, isoleucine, and valine), and rank–frequency distributions that follow a heavy-tailed pattern, indicating strong selective pressure. Conversely, non-TM motifs are more varied, with higher entropy and a preference for polar or flexible residues. Shared motifs have intermediate features, reflecting their functional versatility. Power-law and Zipfian analyses support the distinct statistical signatures of TM and non-TM motifs at the 60% coverage threshold. These results enhance our understanding of the structural and evolutionary roles of the GXXXG motif, setting clear standards for identifying TM-specific motifs and offering insights into membrane protein biology, synthetic design, and functional annotation. Full article

A comparative study was conducted to investigate membrane fouling control and treatment performance using natural surface water as the feed source. The evaluated processes included: (1) direct filtration–tubular ceramic membrane (DF-TCM, control); (2) coagulation–tubular ceramic membrane (C-TCM); and (3) coagulation–tubular ceramic membrane with concentrate recycling (C-TCM-CR). Experimental results demonstrated that under constant flux operation at 75 L/(m²·h) for 8 h, the C-TCM-CR process reduced the transmembrane pressure (TMP) increase by 83% and 35% compared to DF-TCM and C-TCM, respectively. Floc size distribution analysis and cake layer characterization revealed that the C-TCM-CR process enhanced coagulation efficiency and formed high-porosity cake layers on membrane surfaces, thereby mitigating fouling development. Notably, the coagulation-assisted processes demonstrated improved organic matter removal, with 13%, 10%, and 10% enhancement in COD_Mn, UV₂₅₄, and medium molecular weight organics (2000–10,000 Da) removal compared to DF-TCM, along with a moderate enhancement in fluorescent substances removal efficiency. All three processes achieved over 99% turbidity removal efficiency, as the ceramic membranes demonstrate excellent filtration performance. Full article

The integration of computational intelligence techniques into pharmaceutical wastewater treatment offers promising opportunities to improve process efficiency and minimize operational costs. This study compares the predictive capabilities of Response Surface Methodology (RSM) and Artificial Neural Network (ANN) models in forecasting the rejection efficiencies of caffeine and paracetamol using AFC 40 and AFC 80 nanofiltration (NF) membranes. Experiments were conducted under varying operating conditions, including transmembrane pressure, feed concentration, and flow rate. The predictive performance of both models was evaluated using statistical metrics such as the Coefficient of Determination (R²), Root Mean Square Error (RMSE), Marquardt’s Percentage Squared Error Deviation (MPSED), Hybrid fractional error function (HYBRID), and Average Absolute Deviation (AAD). Both models demonstrated strong predictive accuracy, with R² values of 0.9867 and 0.9832 for RSM and ANN, respectively, in AFC 40 membranes, and 0.9769 and 0.9922 in AFC 80 membranes. While both approaches closely matched the experimental results, the ANN model consistently yielded lower error values and higher R² values, indicating superior predictive performance. These findings support the application of ANNs as a robust modelling tool in optimizing NF membrane processes for pharmaceutical removal. Full article