A Green and Efficient Electrocatalytic Route for the Highly-Selective Oxidation of C-H Bonds in Aromatics over 1D Co3O4-Based Nanoarrays.

Electrocatalytic oxidation of C-H bonds in hydrocarbons represents an efficient and sustainable strategy for the synthesis of value-added chemicals. Herein, a highly selective and continuous-flow electrochemical oxidation process of toluene to various oxygenated products (benzyl alcohol, benzaldehyde, and benzyl acetate) is developed with the electrocatalytic membrane electrodes (ECMEs). The selectivity of target products can be manipulated via surface and interface engineering of Co3O4-based electrocatalysts. We achieved a high benzaldehyde selectivity of 90% at a toluene conversion of 47.6% using 1D-Co3O4 nanoneedles (NNs) loaded on a microfiltration (MF) titanium (Ti) membrane, i.e, Co3O4 NNs/Ti. In contrast, the main product shifted to benzyl alcohol with a selectivity of 90.1% at conversion of 32.1% after modifying MnO2 nanosheets (NSs) on Co3O4 NNs/Ti (Co3O4@MnO2/Ti) catalyst. Moreover, benzyl acetate product can be obtained with selectivity of 92% at a conversion of 58.5% at high current density (> 1.5mA cm-2), demonstrating that the pathway of toluene oxidation is readily maneuvered. DFT results reveal that modifying MnO2 on Co3O4 optimizes the electron structure of Co3O4@MnO2/Ti and modulates the adsorption behavior of intermediate species. This work demonstrates a sustainable, and continuous-flow process for precise control over production selectivity of value-added oxygenated derivatives in electrochemical oxidation of aromatic hydrocarbons.

Microfiltered red-purple pitaya concentrate: A promising multifunctional food-derived colorant.

Red pitaya fruit has become a source of natural colorant, because it is rich in betalains, a pigment that imparts a red-purple color that interests the food and cosmetics industries. This fruit also possesses high nutritional value, with a range of bioactive compounds known to confer potential health benefits and prevent chronic diseases, such as diabetes, which makes it useful for use as pharmaceutical agents and dietary supplements. In order to improve its technological and biological effects, a concentration will be required. Thus, the microfiltration, followed by vacuum concentration, can be an interesting strategy for this purpose. This study aimed to explore tangential microfiltration to produce microfiltered material, which is an important step to obtain the microfiltered red-purple pitaya concentrate. Therefore, physicochemical and chemical characterization (including 1H NMR analysis) and biological properties (toxicity and diabetes) of this concentrate were assessed, using adult zebrafish as a model. The results show that microfiltration was carried out efficiently, with an average consumption of 95.75 ± 3.13 and 74.12 ± 3.58 kW h m-3, varying according to the material used ("unpeeled pitaya pulp" or "pitaya pulp with peel," respectively). The in vivo tests indicated non-toxicity and hypoglycemic effect of the concentrate, since the blood glucose levels were significantly lower in the zebrafish groups treated with this concentrate in comparison with that of control group. Thus, this study suggests the potential of microfiltered red-purple pitaya concentrate as a promising multifunctional food-derived colorant, exhibiting beneficial biological effects far beyond its attractive color. PRACTICAL APPLICATION: Hylocereus polyrhizus (F.A.C. Weber) Britton & Rose has attracted attention as a potential source of natural colorants because of its red-purple skin and flesh color. In addition, this fruit has a range of bioactive compounds, which make it a valuable resource for providing potential health benefits and preventing chronic diseases such as diabetes. In this paper, the microfiltered red-purple pitaya concentrate showed beneficial biological effects far beyond its attractive color. Thus, this product can be considered a promising multifunctional food-derived colorant to use in the food, pharmaceutical, or cosmetics industries.

Enhancing microfiltration membrane performance by sodium percarbonate-based oxidation for hydraulic fracturing wastewater treatment.

Low pressure membrane takes a great role in hydraulic fracturing wastewater (HFW), while membrane fouling is a critical issue for the stable operation of microfiltration (MF). This study focused on fouling mitigation by sodium percarbonate (SPC) oxidation, activated by ultraviolet (UV) and ferrous ion (Fe(II)). The higher the concentration of oxidizer, the better the anti-fouling performance of MF membrane. Unlike severe MF fouling without oxidation (17.26 L/(m2·h)), UV/SPC and Fe(II)/SPC under optimized dosage improved the final flux to 740 and 1553 L/(m2·h), respectively, and the latter generated Fe(III) which acted as a coagulant. Fe(II)/SPC oxidation enabled a shift in fouling mechanism from complete blocking to cake filtration, while UV/SPC oxidation changed it to standard blockage. UV/SPC oxidation was stronger than Fe(II)/SPC oxidation in removing UV254 and fluorescent organics for higher oxidizing capacity, but the opposite was noted for DOC removal. The deposited foulants on membrane surface after oxidation decreased by at least 88% compared to untreated HFW. Correlation analysis showed that UV254, DOC and organic fraction were key parameters responsible for membrane fouling (correlation coefficient＞0.80), oxidizing capacity and turbidity after oxidation were also important parameters. These results provide new insights for fouling control during the HFW treatment.

Impact of Diafiltration Media and Filtration Modes on Fouling and Performance in Skim Milk Microfiltration: A Comparative Study.

This research utilized a customized laboratory setup to compare the filtration performance and fouling buildup during microfiltration with polymeric membranes of skim milk using 2 diafiltration media: ultrafiltration permeate and ultrapure water. Two filtration modes were evaluated: in stage 1, the diafiltration media was added in a 1:1 ratio, with the collection of permeate continuing until the initial protein concentration was restored. In stage 2, retentates and permeates were recycled to simulate fouling accumulation in a steady-state without altering the retentate composition. Utilizing water as the diafiltration medium resulted in higher flux and lower resistance values compared with using ultrafiltration permeate, irrespective of the filtration mode. The concentration had a significant impact on membrane resistance, with no noticeable time-dependent effect on fouling layer development after 60 min of filtration when the retentate composition remained constant. The protein composition of the permeate and extracted foulants were comparable between the 2 media, with caseins predominating in the fouling layer.

Towards sustainable water management for Galdieria sulphuraria cultivation.

The red microalga Galdieria sulphuraria has emerged as a promising biotechnological platform for large-scale cultivation and production of high-value compounds, such as the blue pigment phycocyanin. However, a large amount of freshwater and a substantial supply of nutrients challenge both the environmental and the economic sustainability of algal cultivation. Additionally, the extremophilic nature of Galdieria sulphuraria requires cultivation in an acidic culture medium that directly leads to strongly acidic wastewater, which in turn generally exceeds legal limits for industrial wastewater discharge. This research aims to address these challenges, by investigating cultivation water reuse as a strategy to reduce the impacts of Galdieria sulphuraria management. The results indicated that a 25 % water reuse may be easily implemented and showed to be effective at the pilot scale, providing no significant changes in microalgae growth (biomass productivity ~0.21 g L-1 d-1) or in phycocyanin accumulation (~ 10.8 % w/w) after three consecutive cultivation cycles in reused water. Moreover, a single cultivation cycle with water reuse percentages of 71 and 98 %, achieved with membrane filtration and with centrifugation, respectively, was also successful (biomass productivity ~0.24 g L-1 d-1). These findings encourage freshwater reuse implementations in the microalgae sector and support further investigations focusing on coupling cultivation and harvesting in continuous, real-scale configurations. Centrifugation and membrane filtration required substantially different specific electrical energy consumption for water reuse and biomass concentration: in real applications, the former technique would roughly span from 1 to 10 kWh m-3 while the latter is expected to fall within the ample range 0.1-100 kWh m-3, strongly dependent on system size. For this reason, the most suitable separation train should be chosen on a case-by-case basis, considering the prevailing flow rate and the target biomass concentration factor targeted by the separation process.

Treatment of Synthetic Wastewater Containing Polystyrene (PS) Nanoplastics by Membrane Bioreactor (MBR): Study of the Effects on Microbial Community and Membrane Fouling.

The persistent presence of micro- and nanoplastics (MNPs) in aquatic environments, particularly via effluents from wastewater treatment plants (WWTPs), poses significant ecological risks. This study investigated the removal efficiency of polystyrene nanoplastics (PS-NPs) using a lab-scale aerobic membrane bioreactor (aMBR) equipped with different membrane types: microfiltration (MF), commercial ultrafiltration (c-UF), and recycled ultrafiltration (r-UF) membranes. Performance was assessed using synthetic urban wastewater spiked with PS-NPs, focusing on membrane efficiency, fouling behavior, and microbial community shifts. All aMBR systems achieved high organic matter removal, exceeding a 97% COD reduction in both the control and PS-exposed reactors. While low concentrations of PS-NPs did not significantly impact the sludge settleability or soluble microbial products initially, a higher accumulation increased the carbohydrate concentrations, indicating a protective bacterial response. The microbial community composition also adapted over time under polystyrene stress. All membrane types exhibited substantial NP removal; however, the presence of nano-sized PS particles negatively affected the membrane performance, enhancing the fouling phenomena and increasing transmembrane pressure. Despite this, the r-UF membrane demonstrated comparable efficiency to c-UF, suggesting its potential for sustainable applications. Advanced characterization techniques including pyrolysis gas chromatography/mass spectrometry (Py-GC/MS) were employed for NP detection and quantification.

Removal of Microplastics in a Hybrid Treatment Process of Ceramic Microfiltration and Photocatalyst-Mounted PES Spheres with Air Backwashing.

Microplastics (MPs), which are defined as plastics with a size of less than 5 mm, cannot be treated completely in wastewater treatment plants (WWTPs) and discharged to a water body because they are too small in size. It has been reported that MPs can have adverse effects on human beings and water ecosystems. There is a need to combine existing drinking water treatment plants (DWTPs) and WWTPs with the traditional treatment process and technology with high removal efficiency of MPs or to develop a new technology to separate MPs from water and wastewater. In this study, the effects of MPs (polyethylene (PE), 125 µm) and organic matter (humic acid) were researched in a hybrid treatment process of ceramic microfiltration (MF) and photocatalyst (TiO2)-mounted polyether sulfone (PES) spheres with air backwashing. The roles of the MF, photooxidation, and adsorption of PES spheres were confirmed in a single MF process (MF), an MF process with UV irradiation (MF+UV), MF and PES sphere adsorption without UV irradiation (MF+PES), and a hybrid process incorporating MF and PES spheres with UV irradiation (MF+PES+UV). The impact of the air backwashing cycle (filtration time, FT) on filtration characteristics and treatment efficiencies in the hybrid process was studied. In the MF process, membrane fouling increased with increasing organic matter (HA, humic acid). The treatment efficiency of MPs increased; however, that of dissolved organic matter (DOM) decreased with increasing HA. As MPs increased, the membrane fouling decreased; however, total filtration volume (VT) remained almost constant. The treatment efficiency of MPs increased a little, and that of DOM showed a dropping trend. In the hybrid process, the membrane fouling was controlled via the adsorption and UV photooxidation of the PES spheres, and the DOM treatment efficiency increased by combining processes from MF to MF+PES+UV. The optimal FT was 10 min at BT 10 s in this hybrid process. The results could be applied to separate MPs effectively in DWTPs/WWTPs.

Removal of Heavy Metals from Wastewaters and Other Aqueous Streams by Pressure-Driven Membrane Technologies: An Outlook on Reverse Osmosis, Nanofiltration, Ultrafiltration and Microfiltration Potential from a Bibliometric Analysis.

A bibliometric study to analyze the scientific documents released until 2024 in the database Scopus related to the use of pressure-driven membrane technologies (microfiltration, ultrafiltration, nanofiltration and reverse osmosis) for heavy metal removal was conducted. The work aimed to assess the primary quantitative attributes of the research in this field during the specified period. A total of 2205 documents were identified, and the corresponding analysis indicated an exponential growth in the number of publications over time. The contribution of the three most productive countries (China, India and USA) accounts for more than 47.1% of the total number of publications, with Chinese institutions appearing as the most productive ones. Environmental Science was the most frequent knowledge category (51.9% contribution), followed by Chemistry and Chemical Engineering. The relative frequency of the keywords and a complete bibliometric network analysis allowed the conclusion that the low-pressure technologies (microfiltration and ultrafiltration) have been more deeply investigated than the high-pressure technologies (nanofiltration and reverse osmosis). Although porous low-pressure membranes are not adequate for the removal of dissolved heavy metals in ionic forms, the incorporation of embedded adsorbents within the membrane structure and the use of auxiliary chemicals to form metallic complexes or micelles that can be retained by this type of membrane are promising approaches. High-pressure membranes can achieve rejection percentages above 90% (99% in the case of reverse osmosis), but they imply lower permeate productivity and higher costs due to the required pressure gradients.

Structural and physical-chemical properties of milk fat globules fractionated by a series of silicon carbide membranes.

Driven by the acknowledged health and functional properties of milk fat globules (MFGs), there is a growing interest to develop gentle methodologies for separation of fat from milk. In this study, separation of fat from raw milk and fractionation in streams containing MFGs of different size was achieved using a series of two silicon carbide ceramic membranes. A first step consisting of a 1.4 µm membrane aimed to concentrate the bulk of the fat, i.e. the larger MFGs (D[4,3] âˆ¼ 4 µm) followed by a 0.5 µm fractionation aimed to concentrate the residual milk fat in the permeate, i.e. fraction with the smaller MFGs (D[4,3] âˆ¼ 1.8-2.4 µm. The fat separation performance showed a yield of 92 % for the 1.4 µm membrane and 97 % for the 0.5 µm membrane. Both fat enriched retentates showed, by the confocal laser scanning microscopy, intact MFGs with limited damage in the MFG membrane. The fatty acid profile analysis and SAXS showed minor differences in fat acid composition and the crystallization behavior was related to differences in the fat content. The 0.5 µm permeate containing the smallest MFGs however showed larger aggregates and a trinomial particle size distribution, due to probably pore pressure induced coalescences. The series of silicon carbide membranes showed potential to concentrate some of MFGM proteins such as Periodic Schiff base 3/4 and cluster of differentiation 36 especially in the 0.5 µm retentates. A shift in casein to whey protein ratio from 80:20 (milk) to 50:50 was obtained in the final 0.5 µm permeate, which opens new opportunities for product development.

Enhanced filtration membranes with graphene oxide and tannic acid for textile industry wastewater dye removal.

A novel modification technique employing a layer-by-layer (LbL) self-assembly method, integrated with a pressure-assisted filtration system, was developed for enhancing a commercial polyethersulfone (PES) microfiltration (MF) membrane. This modification involved the incorporation of tannic acid (TA) in conjunction with graphene oxide (GO) nanosheets. The effectiveness of the LbL method was confirmed through comprehensive characterization analyses, including ATR-FTIR, SEM, water contact angle (WCA), and mean pore size measurements, comparing the modified membrane with the original commercial one. Sixteen variations of PES MF membranes were superficially modified using a three-factorial design, with the deposited amount of TA and GO as key factors. The influence of these factors on the morphology and performance of the membranes was systematically investigated, focusing on parameters such as pure water permeability (PWP), blue corazol (BC) dye removal efficiency, and flux recovery rate (FRR). The membranes produced with the maximum amount of GO (0.1 mg, 0.55 wt%) and TA as the inner and outer layers demonstrated remarkable FRR and significant BC removal, exceeding 80%. Notably, there was no significant difference observed when using either 0.2 (1.11 wt%) or 0.4 mg (2.22 wt%) in the first layer, as indicated by the Tukey mean test. Furthermore, the modified membrane designated as MF/TA0.4GO0.1TA0.4 was evaluated in the filtration of a simulated dye bath wastewater, exhibiting a BC removal efficiency of 49.20% and a salt removal efficiency of 27.74%. In conclusion, the novel PES MF membrane modification proposed in this study effectively enhances the key properties of pressure-driven separation processes.

Stretch-Induced Spin-Cast Membranes Based on Semi-Crystalline Polymers for Efficient Microfiltration.

Microfiltration membranes derived from semi-crystalline polymers face various challenges when synthesized through the extrusion-casting technique, including the use of large quantities of polymer, long casting times, and the generation of substantial waste. This study focuses on synthesizing these membranes using spin-casting, followed by stretch-induced pore formation. Recycled high-density polyethylene (HDPE) and virgin polyethylene powder, combined with a calcium carbonate filler, were used as the source materials for the membranes. The influence of the polymer-filler ratio with and without stretching on the morphology, tensile strength, and water flow rate was investigated. Optimal conditions were determined, emphasizing a balance between pore structure and mechanical integrity. The permeable membrane exhibited a water flow rate of 19 mL/min, a tensile strength of 32 MPa, and a water contact angle of 126°. These membranes effectively eliminated suspended particles from water, with their performance evaluated against that of commercially available membranes. This research, carried out utilizing the spin-casting technique, outlines a synthesis route for microfiltration membranes tailored to semi-crystalline polymers and their plastic forms.

The interactions of pectin with TiO2 nanoparticles measured by FT-IR are confirmed in a model of the gastrointestinal tract.

The presence of nanoparticle fractions (<100 nm, NPs) in the food additive TiO2 (E171) rises concerns about its potential harmful impact on human health. The knowledge about the interaction of TiO2 NPs with food components is limited to proteins or polyphenols. The present paper is the first to report on interactions between TiO2 NPs and high molecular pectins that form gels in boluses and are remain nearly intact during digestion until they reach the colon. Direct interactions were studied using Fourier Transform Infrared Spectroscopy while indirect ones were monitored by measuring the "absorption" of TiO2 using a 0.2 microfiltration membrane, during in vitro digestion in a model of the gastro-intestinal tract. The FT-IR spectra registered for pectin-TiO2 NPs solutions confirmed changes in band intensities at 1020, 1100, 1610, and 1740 cm-1, suggesting interactions taking place mainly via the COO- groups. Furthermore, the I(1020)/I(1100) ratio was decreased (C-O stretching vibrations), suggesting partial blocking of the skeletal vibrations caused by interactions between pectin and TiO2. The modelled in vitro digestions confirmed that the "availability" of Ti was reduced when TiO2 NPs were combined with pectin, as compared to TiO2 NPs "digested" alone.

Role of Microfiltration Membrane Morphology on Nanoparticle Purification to Enhance Downstream Purification of Viral Vectors.

In the rapidly advancing realms of gene therapy and biotechnology, the efficient purification of viral vectors is pivotal for ensuring the safety and efficacy of gene therapies. This study focuses on optimizing membrane selection for viral vector purification by evaluating key properties, including porosity, thickness, pore structure, and hydrophilicity. Notably, we employed adeno-associated virus (AAV)-sized nanoparticles (20 nm), 200 nm particles, and bovine serum albumin (BSA) to model viral vector harvesting. Experimental data from constant pressure normal flow filtration (NFF) at 1 and 2 bar using four commercial flat sheet membranes revealed distinct fouling behaviors. Symmetric membranes predominantly showed internal and external pore blockage, while asymmetric membranes formed a cake layer on the surface. Hydrophilicity exhibited a positive correlation with recovery, demonstrating an enhanced recovery with increased hydrophilicity. Membranes with higher porosity and interpore connectivity showcased superior throughput, reduced operating time, and increased recovery. Asymmetric polyether sulfone (PES) membranes emerged as the optimal choice, achieving ∼100% recovery of AAV-sized particles, an ∼44% reduction in model cell debris (200 nm particles), an ∼35% decrease in BSA, and the fastest operating time of all membranes tested. This systematic investigation into fouling behaviors and membrane properties not only informs optimal conditions for viral vector recovery but also lays the groundwork for advancing membrane-based strategies in bioprocessing.

The Use of Microfiltration for the Pretreatment of Backwash Water from Sand Filters.

Tests of microfiltration efficiency used for the pretreatment of backwash water from sand filters were conducted at two water treatment plants treating surface water and infiltration water. Microfiltration efficiency was evaluated for three membrane modules: two with polymeric membranes and one with a ceramic membrane. This study showed that the contaminants that limit the reuse of backwash water from both plants by returning them to the water treatment line are mostly microorganisms, including pathogenic species (Clostridium perfringens). Additionally, in the case of backwash water from infiltration water treatment, iron and manganese compounds also had to be removed before its recirculation to the water treatment system. Unexpectedly, organic carbon concentrations in both types of backwash water were similar to those present in intake waters. Microfiltration provided for the removal of organic matter, ranging from 19.9% to 44.5% and from 7.2% to 53.9% for backwash water from the treatments of surface water and infiltration water, respectively. Furthermore, the efficiency of the iron removal from backwash water from infiltration water treatment was sufficient to ensure good intake water quality. On the other hand, manganese concentrations in the backwash water, from infiltration water treatment, pretreated using the microfiltration process exceeded the levels found in the intake water and were, therefore, an additional limiting factor for the reuse of the backwash water. In both types of backwash water, the number of microorganisms, including Clostridium perfringens (a pathogenic one), was a limiting parameter for backwash water reuse without pretreatment. The results of the present study showed the possibility for using microfiltration for the pretreatment of backwash water, regardless of its origin but not as the sole process. More complex technological systems are needed before recirculating backwash water into the water treatment system. The polyvinylidene fluoride (PVDF) membrane proved to be the most effective for DOC and microorganism removal from backwash water.

Micro(nano)plastics from synthetic oligomers persisting in Mediterranean seawater: Comprehensive NMR analysis, concerns and origins.

The presence in seawater of low-molecular-weight polyethylene (PE) and polydimethylsiloxane (PDMS), synthetic polymers with high chemical resistance, has been demonstrated in this study for the first time by developing a novel methodology for their recovery and quantification from surface seawater. These synthetic polymer debris (SPD) with very low molecular weights and sizes in the nano- and micro-metre range have escaped conventional analytical methods. SPD have been easily recovered from water samples (2 L) through filtration with a nitrocellulose membrane filter with a pore size of 0.45 µm. Dissolving the filter in acetone allowed the isolation of the particulates by centrifugation followed by drying. The isolated SPD were analysed by 1H nuclear magnetic resonance spectroscopy (1H NMR), identifying PE and PDMS. These polymers are thus persisting on seawater because of their low density and the ponderal concentrations were quantified in mg/m3. This method was used in an actual case study in which 120 surface seawater samples were collected during two sampling campaigns in the Mediterranean Sea (from the Gulf of Salerno to the Gulf of Policastro in South Italy). The developed analytical protocol allowed achieving unprecedented simplicity, rapidity and sensitivity. The 1H and 13C NMR structural analysis of the PE debris indicates the presence of oxidised polymer chains with very low molecular weights. Additionally, the origin of those low molecular weight polymers was investigated by analysing influents and effluents from a wastewater treatment plant (WWTP) in Salerno as a hot spot for the release of SPD: the analysis indicates the presence of low molecular weight polymers compatible with wax-PE, widely used for coating applications, food industry, cosmetics and detergents. Moreover, the origin of PDMS debris found in surface seawater can be ascribed to silicone-based antifoamers and emulsifiers.

The removal of pathogenic bacteria and dissolved organic matter from freshwater using microporous membranes: insights into biofilm formation and fouling reversibility.

Pathogenic bacteria in drinking-water pose a health risk to consumers, as they compromise the quality of portable water. Chemical disinfection of water containing dissolved organic matter (DOM) causes harmful disinfection by-products. In this work, 4-hydroxybenzoic acid (4-HBA) blended polyethersulfone membranes were fabricated and characterised using microscopic and spectroscopic techniques. The membranes were evaluated for the removal of bacteria and DOM from synthetic and environmental water. Permeate flux increased from 287.30 to 374.60 l m-2 h-1 at 3 bars when 4-HBA increased from 0 to 1.5 wt.%, suggesting that 4-HBA influenced the membrane's affinity for water. Furthermore, 4-HBA demonstrated antimicrobial properties by inhibiting bacterial growth. The membrane with 1 wt.% 4-HBA recorded 99.4 and 100% bacteria removal in synthetic and environmental water, respectively. Additionally, DOM removal of 55-73% was achieved. A flux recovery ratio (FRR) of 94.6% was obtained when a mixture of bacteria and humic acid was filtered, implying better fouling layer reversibility during cleaning. Furthermore, 100% FRR was achieved when a multimedia granular filtration step was installed prior to membrane filtration. The results illustrated that the membranes had a high permeate flux with low irreversible fouling. This indicated the potential of the membranes in treating complex feed streams using simple cleaning protocols.

Functionalization of cellulose acetate nanofibrous membranes for removal of particulate matters and dyes.

Particulates and organic toxins, such as microplastics and dye molecules, are contaminants in industrial wastewater that must be purified due to environmental and sustainability concerns. Carboxylated cellulose acetate (CTA-COOH) nanofibrous membranes were fabricated using electrospinning followed by an innovative one-step surface hydrolysis/oxidation replacing the conventional two-step reactions. This approach offers a new pathway for the modification strategy of cellulose-based membranes. The CTA-COOH membrane was utilized for the removal of particulates and cationic dyes through filtration and adsorption, respectively. The filtration performance of the CTA-COOH nanofibrous membrane was carried out; high separation efficiency and low pressure drop were achieved, in addition to the high filtration selectivity against 0.6-µm and 0.8-µm nanoparticles. A cationic Bismarck Brown Y, was employed to challenge the adsorption capability of the CTA-COOH nanofibrous membrane, where the maximum adsorption capacity of the membrane for BBY was 158.73 mg/g. The self-standing CTA-COOH membrane could be used to conduct adsorption-desorption for 17 cycles with the regeneration rate as high as 97.0 %. The CTA-COOH nanofibrous membrane has excellent mechanical properties and was employed to manufacture a spiral wound adsorption cartridge, which exhibited remarkable separation efficiency in terms of treated water volume, which was 5.96 L, and retention rate, which was 100 %.

Production of low-lactose and low-serum-protein milk protein beverages using microfiltration.

Our objective was to determine the effect of simultaneous removal of lactose plus low-molecular weight solutes and milk serum proteins from skim milk by microfiltration (MF) on the chemical, physical, and sensory properties of 3.4%, 7.5%, and 10.5% milk protein-based beverages before and after a direct steam injection thermal process. Skim milk was microfiltered at 50°C using 0.1-µm ceramic membranes with a diafiltration ratio of water to milk of about 2.5. Milk lactose, serum proteins, and soluble minerals were removed simultaneously to produce protein beverages containing from 3.4% to 10.5% true protein from skim milk and this process was replicated twice with different skim milks. The soluble mineral plus lactose content was very low and the aqueous phase of the beverages had a freezing point very close to water (i.e., -0.02°C). Beverage pH ranged from 7.19 to 7.41, with pH decreasing with increasing protein concentration. Overall, the beverages were whiter and blander than skim milk. When UHT processed with direct steam injection at a holding temp of 140°C for 2 to 3 s, there was some protein aggregation detected by particle size analysis (volume mean diameter of protein particles was 0.16 µm before and 22 µm after UHT). No sulfur or eggy flavor was detected, and no browning was observed, due to the UHT thermal treatment. Both apparent viscosity and sensory viscosity increased with increasing protein concentration and heat treatment.

Feasibility evaluation of near dissolved organic matter microfiltration (NDOM MF) for the efficient removal of microplastics in the water treatment process.

Microfiltration (MF) using membranes with a mean pore size smaller than 0.45 µm has generally been used for particle removal from water, given that materials larger and smaller than 0.45 µm are regarded as particulates and dissolved organic matter (DOM), respectively. It is also the case for removing small-size microplastics (MPs). However, given their sizes (ca. 1 µm), there is room for further improvement of the productivity (i.e., water flux) in the pore size range of 0.45-1 µm on the condition that the removal rate is maintained. With this in mind, MF's water flux and removal rate were tested using seven different MF membranes, and the right pore, with the size of 0.8 µm, was found for MP removal, which is called near DOM (NDOM) MF. In the filtration test using polystyrene surrogate beads with an average particle diameter of 1.20 µm, NDOM MF exhibited a 1.7 to 13 times higher permeate flux than the conventional MF using 0.1, 0.2, and 0.45 µm membranes while maintaining a higher removal rate than 2 log. The excellent removal rate of the NDOM MF was attributable to the following three factors: (1) smaller mean pore size than the average particle diameter, (2) particle screening effect enhanced by the secondary layer formed by surface deposition, and (3) 3D mesh sublayer structure favorable for capturing penetrated particles. Furthermore, the outstanding filtration performance also appeared in a low-temperature (< 10°C) process, demonstrating that NDOM MF is feasible independently of temperature. Additionally, in constant flux filtration, NDOM MF demonstrated the long-term feasibility by lowering the transmembrane pressure and specific filtration energy by more than 2 times.

An investigation on the effect of ultrasonication and microfiltration processing on the quality of king coconut (Cocos nucifera var. aurantiaca) water compared to minimal and thermal processing.

The study aimed to investigate the effect of thermal and non-thermal processing on the physicochemical, microbial, and sensory characteristics of king coconut water. King coconut water samples were subjected to ultrasonication (50 kHz, 30 min at 35 °C), microfiltration (0.5 µm), and thermal treatments (at 90 °C for 10 min) with sodium metabisulfite (0.1 g/L) except the fresh sample (control). Samples were tested for physiochemical, microbial, and sensory parameters. Storage studies were conducted at 4 °C for 28 days. pH, titratable acidity, and total sugar of all treated samples were within the Sri Lankan Standard (SLS) limit (4.6-5.5, 0.07-0.1%, 4.1-6.5%, respectively) during the 28 days of storage. Sodium metabisulfite addition was significant in lowering the browning index. Antioxidant and phenolic contents of microfiltered and ultrasonicated samples varied between 49%-65% and 2.5-2.8 GAE mg/100 mL, respectively, during 4 weeks of storage, which was significantly higher compared to the heat-treated samples. Sensory evaluation scored the lowest attribute values for thermally treated samples. Microbial analyses indicated that microfiltered and ultrasonicated king coconut water remained safe for consumption for up to 4 weeks. Ultrasound and microfiltration, with the integration of sodium metabisulfite, were identified as effective methods for processing king coconut water while preserving its wholesome properties.