Demulsification with simultaneous water purification by coupling filtration and enhanced oil droplet coalescence at anode interface in an electrochemical reactor.

With the increasing demand of recycling disposal of industrial wastewater, oil-in-water (O/W) emulsion has been paid much attention in recent years owing to its high oil content. However, due to the presence of surfactant and salt, the emulsion was usually stable with complex physicochemical interfacial properties leading to increased processing difficulty. Herein, a novel flow-through electrode-based demulsification reactor (FEDR) was well designed for the treatment of saline O/W emulsion. In contrast to 53.7% for electrical demulsification only and 80.3% for filtration only, the COD removal efficiency increased to 92.8% under FEDR system. Moreover, the pore size of electrode and the applied voltage were two key factors that governed the FEDR demulsification performance. By observing the morphology of oil droplets deposited layer after different operation conditions and the behavior of oil droplets at the electrode surface under different voltage conditions, the mechanism was proposed that the oil droplets first accumulated on the surface of flow-through electrode by sieving effect, subsequently the gathered oil droplets could further coalesce with the promoting effect of the anode, leading to a high-performing demulsification. This study offers an attractive option of using flow-through electrode to accomplish the oil recovery with simultaneous water purification.

Extracellular vesicle isolation and counting system (EVics) based on simultaneous tandem tangential flow filtration and large field-of-view light scattering.

Although the isolation and counting of small extracellular vesicles (sEVs) are essential steps in sEV research, an integrated method with scalability and efficiency has not been developed. Here, we present a scalable and ready-to-use extracellular vesicle (EV) isolation and counting system (EVics) that simultaneously allows isolation and counting in one system. This novel system consists of (i) EVi, a simultaneous tandem tangential flow filtration (TFF)-based EV isolation component by applying two different pore-size TFF filters, and (ii) EVc, an EV counting component using light scattering that captures a large field-of-view (FOV). EVi efficiently isolated 50-200 nm-size sEVs from 15 µL to 2 L samples, outperforming the current state-of-the-art devices in purity and speed. EVc with a large FOV efficiently counted isolated sEVs. EVics enabled early observations of sEV secretion in various cell lines and reduced the cost of evaluating the inhibitory effect of sEV inhibitors by 20-fold. Using EVics, sEVs concentrations and sEV PD-L1 were monitored in a 23-day cancer mouse model, and 160 clinical samples were prepared and successfully applied to diagnosis. These results demonstrate that EVics could become an innovative system for novel findings in basic and applied studies in sEV research.

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.

Multifactorial evaluation of an ultra-fast process for electrospinning of recycled expanded polystyrene to manufacture high-efficiency membranes for nanoparticle air filtration.

The increased production of polystyrene waste has led to the need to find efficient ways to dispose of it. One possibility is the use of solid waste to produce filter media by the electrospinning technique. The aim of this work was to develop an ultra-fast electrospinning process applied to recycled polystyrene, with statistical evaluation of the influence of polymeric solution parameters (polymer concentration and percentage of DL-limonene) and process variables (flow rate, voltage, and type of support) on nanoparticle collection efficiency, air permeability, and fiber diameter. An extensive characterization of the materials and evaluation of the morphology of the fibers was also carried out. It was found that recycled expanded polystyrene could be used in electrospinning to produce polymeric membranes. The optimized condition that resulted in the highest nanoparticle collection efficiency was a polymer concentration of 13.5%, percentage of DL-limonene of 50%, voltage of 25 kV, and flow rate of 1.2 mL/h, resulting in values of 99.97 ± 0.01%, 2.6 ± 0.5 × 10-13 m2, 0.19 Pa-1, and 708 ± 176 nm for the collection efficiency of nanoparticles in the range from 6.38 to 232.9 nm, permeability, quality factor, and mean fiber diameter, respectively. All the parameters were found to influence collection efficiency and fiber diameter. The use of DL-limonene, a natural solvent, provided benefits including increased collection efficiency and decreased fiber size. In addition, the electrostatic filtration mechanism was evaluated using the presence of a copper grid as a support for the nanofibers. The findings demonstrated that an electrospinning time of only 5 min was sufficient to obtain filters with high collection efficiencies and low pressure drops, opening perspectives for the application of polystyrene waste in the development of materials with excellent characteristics for application in the area of atmospheric pollution mitigation.

Determination of low carbon aldehydes and ketones in cigarette smoke by MXene membrane enrichment-liquid chromatography.

Low carbon aldehydes and ketones are typical substances harmful to human body produced during cigarette smoking. Their contents in cigarette smoke are important indicators for evaluating its toxicity and the filtration effect of cigarette filter tips, which provides important guidance for its rational design. In this work, MXene membrane with unique lamellar structure was synthesized and loaded onto glass fiber filters to achieve effective enrichment of low carbon aldehydes and ketones. Compared to commercial Cambridge filters, the MXene-loaded filters exhibited higher extraction efficiency towards low-carbon aldehydes and ketones, making viable the detection of butyraldehyde, which was not detected by that enriched with Cambridge filters. Therefore, a MXene-based membrane enrichment-HPLC method was developed for the determination of low-carbon aldehydes and ketones in cigarette smoke with detection limits ranging from 0.133 µg/mL to 0.285 µg/mL. The applicability of the method was verified by analyzing three different types of filter cigarettes with the concentration in the range of 0.5-140 µg/branch for all the analytes, which were in good agreement with the manufacturer's results. The method is accurate and sensitive, and can be used for the quantitative determination of low carbon aldehydes and ketones in cigarette smoke.

Reduction of Helicobacter pylori cells in rural water supply using slow sand filtration.

Helicobacter pylori is a microorganism that infects 60% of the population and is considered the main cause of atrophic gastritis, gastric and duodenal ulcers, and gastric cancer. Different emerging pathogens have been found in drinking water and their presence is considered to be an important public health problem. For this reason, it is necessary to carry out the validation of reliable technologies for this type of pathogens and evaluate their performance. This paper reports, for the first time, H. pylori reduction in a drinking water pilot plant of two slow sand filters (SSF). Inlet water was taken from a gravel filtration system of a rural water supply in Colombia and then inoculated with viable cells of H. pylori. By determining the Genomic Units (GU) through quantitative Polymerase Chain Reaction (qPCR), the concentration of GU/sample was measured. In the inlet water amplification for SSF1 and SSF2 were 5.13 × 102 ± 4.48 × 102 and 6.59 × 102 ± 7.32 × 102, respectively, while for the treated water they were 7.0 ± 5.6 and 2.05 × 101 ± 2.9 × 101 GU/sample for SSF1 and SSF2, respectively. The SSF pilot plant reached up to 3 log reduction units of H. pylori; therefore, since there is not an H. pylori contamination indicator and its periodic monitoring is financially complicated, the SSF could guarantee the drinking water quality necessity that exists in rural areas and small municipalities in developing countries, where infection rates and prevalence of this pathogen are high.

Continuous UV-C/H2O2 and UV-C/Chlorine applied to municipal secondary effluent and nanofiltration retentate: Removal of contaminants of emerging concern, ecotoxicity, and reuse potential.

As global effects of water scarcity raise concerns and environmental regulations evolve, contemporary wastewater treatment plants (WWTPs) face the challenge of effectively removing a diverse range of contaminants of emerging concern (CECs) from municipal effluents. This study focuses on the assessment of advanced oxidation processes (AOPs), specifically UV-C/H2O2 and UV-C/Chlorine, for the removal of 14 target CECs in municipal secondary effluent (MSE, spiked with 10 µg L-1 of each CEC) or in the subsequent MSE nanofiltration retentate (NFR, no spiking). Phototreatments were carried out in continuous mode operation, with a hydraulic retention time of 3.4 min, using a tube-in-tube membrane photoreactor. For both wastewater matrices, UV-C photolysis (3.3 kJ L-1) exhibited high efficacy in removing CECs susceptible to photolysis, although lower treatment performance was observed for NFR. In MSE, adding 10 mg L-1 of H2O2 or Cl2 enhanced treatment efficiency, with UV-C/H2O2 outperforming UV-C/Chlorine. Both UV-C/AOPs eliminated the chronic toxicity of MSE toward Chlorella vulgaris. In the NFR, not only was the degradation of target CECs diminished, but chronic toxicity to C. vulgaris persisted after both UV-C/AOPs, with UV-C/Chlorine increasing toxicity due to potential toxic by-products. Nanofiltration permeate (NFP) exhibited low CECs and microbial content. A single chlorine addition effectively controlled Escherichia coli regrowth for 3 days, proving NFP potential for safe reuse in crop irrigation (<1 CFU/100 mL for E. coli; <1 mg L-1 for free chlorine). These findings provide valuable insights into the applications and limitations of UV-C/H2O2 and UV-C/Chlorine for distinct wastewater treatment scenarios.

Purifying surface water contaminated with azo dyes using nanofiltration: Interactions between dyes and dissolved organic matter.

In this research, the interactions of two azo dyes, Methyl Orange (MO) and Eriochrome Black T (EBT), with dissolved organic matter (DOM) in surface water were studied, emphasizing their removal using nano-filtration membranes (NF-270 and NF-90). High-Performance Size Exclusion Chromatography (HPSEC) findings indicated that the dyes' molecular weight in deionized (DI) water ranged from 500 to 15k Dalton (Da), adjusting peak intensities with Jingmi River (JM) water Beijing. Notably, when dyes were diluted in JM water, ultraviolet (UV533 & 466, and UV254), together with total organic carbon (TOC) parameters, revealed color removal rates of 99.49% (EBT), 94.2% (MO), 87.6% DOM removal, and 86% TOC removal for NF-90. The NF-90 membrane demonstrated a 75% flux decline for 50 mL permeate volume due to its finer pore structure and higher rejection effectiveness. In contrast, the NF-270 membrane showed a 60% decline in flux under the same conditions. Attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) analysis of dye-treated membranes in JM water revealed that the NF-270 showed a CC bond peak at 1660 cm-1 across various samples, while analyzing NF-90, the peaks at 1400 cm-1, 1040 cm-1, 750 cm-1, and 620 cm-1 disappeared for composite sample removal. The hydrophobicity of each membrane is measured by the contact angle (CA), which identified that initial CAs for NF-270 and NF-90 were 460 and 700, respectively, that were rapidly declined but stabilized after a few seconds of processing. Overall, this investigation shows that azo dyes interact with DOM in surface waters and enhance the removal efficiency of NF membranes.

Cellulose acetate, a source from discarded cigarette butts for the development of mixed matrix loose nanofiltration membranes for selective separation.

This study presents an environmentally friendly method for extracting cellulose acetate (CA) from discarded cigarette filters, which is then utilized in the fabrication of cellulose-based membranes designed for high flux and rejection rates. CA membranes are likeable to separate dyes and ions, but their separation efficiency is exposed when the contaminant concentration is very low. So, we have integrated graphene oxide (GO) and carboxylated titanium dioxide (COOH-TiO2) in CA to develop mixed matrix membranes (MMMs) and studied them against dyes and most used salts. The CA has been extracted from these butts and added GO and COOH-TiO2 nanoparticles to develop MMMs. The present work administers the effective separation of five dyes (methyl orange, methyl violet, methylene blue, cresol red, and malachite green) and salts (NaCl and Na2SO4) along with the high efficiency of water flux by prepared CA membranes. The prepared membranes rejected up to 94.94 % methyl violet, 91.28 % methyl orange, 88.28 % methylene blue, 89.91 % cresol red, and 91.70 % malachite green dye. Along with the dyes, the membranes showed ∼40.40 % and âˆ¼ 42.97 % rejection of NaCl and Na2SO4 salts, respectively. Additionally, these membranes have tensile strength up to 1.54 MPa. Various characterization techniques were performed on all prepared CA membranes to comprehend their behaviour. The antibacterial activity of MMMs was investigated using the Muller-Hinton-Disk diffusion method against the gram-positive bacterium Staphylococcus aureus (S. aureus) and the gram-negative bacterium Escherichia coli (E. coli). We believe the present work is an approach to utilizing waste materials into valuable products for environmental care.

Simultaneous removal of ammonia and sulfur odorants in biotrickling filters and N2O production.

Research on the stability evaluation of biotrickling filters (BTFs) under harsh conditions and the bacterial adaptation process still needs to be improved. Herein, BTFs with polypropylene plastic (PP) and ceramic raschig rings (CRR) were investigated for a better understanding of the biodegradation of ammonia (NH3), hydrogen sulfide (H2S), and dimethyl sulfide (DMS). The results showed an excellent performance in removal efficiency (RE) for NH3 (91.6 %-99.9 %), H2S (RE: 55.3 %-99.5 %), and DMS (RE: 10.6 %-99.9 %). It was found that a more apparent positive correlation between N2O emission and pressure drop in CRR BTF (R2 = 0.92) than in PP BTF (R2 = 0.79) (P < 0.01). Low temperature promotes an increase in the abundance ofComamonasandBacillus. The polysaccharides in PP and CRR reactors decreased by 78.6 % and 68.1 % when temperature reduced from 25℃ to 8℃. This work provides a novel insight into understanding bacterial survival under harsh BTF environments.

A new sustainable filtration membrane extraction method based on nanoconfined liquid phase extraction: Determination of organochlorinated pesticides and pyrethroids in tea samples.

BACKGROUND: Pesticides are used in agricultural production for prevent and control crop diseases and pests, but it is easy to cause excessive pesticides residues in agricultural products, polluting the environment and endangering human health. Due to their unmatched and sustainable capabilities, nanoextraction procedures are becoming every day more important in Analytical Chemistry. In particular, nanoconfined liquid phase extraction has shown extraction capabilities toward polar, medium polar, and/or nonpolar substances, which can be easily modulated depending on the nanoconfined solvent used. Furthermore, this "green" technique showed excellent characteristics in terms of recoveries, extraction time (≤1 min), reliability, and versatility. (97) RESULTS: In this work, the advantages of this technique have been coupled with those of filtration membrane extraction, making use of carbon nanofibers (CnFs) growth on carbon microspheres (CµS). This substrate has been deposited on a filter, which combined with gas chromatographic mass spectrometry (GC-MS) analysis successfully employed for the nanoextraction of 30 pesticides (18 organochlorine and 12 pyrethroids) in tea samples. Under the optimized extraction conditions, the linear range with standard solutions was from 1 to 1000 ng mL-1 (R2 ≥ 0.99), the limit of detections in tea samples were in the range 0.56-17.98 µg kg-1. The accuracy of the developed method was evaluated by measuring the extraction recovery of the spiked tea samples, and recoveries between 74.41 % and 115.46 %. (119) SIGNIFICANCE: Considering the versatility of nanoconfined liquid phase extraction and the functionality of the filtration membrane extraction procedure, this new extraction method can be considered a powerful candidate for automatized high-throughput analyses of real samples. (34).

Robust construction of polyvinyl alcohol intercalated graphene oxide nanofiltration membrane for desalination via pervaporation.

The construction and modification of a Graphene Oxide (GO) membrane, incorporating polyvinyl alcohol (PVA) cross-linked with maleic acid (MA) and supported by a nylon membrane, have been successfully completed. Systematic variations in PVA and MA concentrations were conducted to achieve membranes with favorable characteristics, stability, and excellent desalination performance. Optimization studies utilizing the Central Composite Design (CCD) revealed that the most optimal desalination results were obtained with 10 mL of PVA (0.1 mg mL-1) and 0.9 M of MA (GO-MA0.9-PVA10/Nylon membrane). Experimental findings demonstrated that the inclusion of PVA and MA resulted in an increased interlayer distance of GO and enhanced membrane stability. The addition of PVA increases GO membrane hydrophilicity, while the addition of MA reduces membrane hydrophilicity. The GO-MA0.9-PVA10/Nylon membrane exhibited the highest desalination performance, boasting a rejection value exceeding >99.9% and a permeance of 18.76 kg m-2.h-1 under 1% NaCl feed at a temperature of 50 °C. This membrane demonstrated consistent desalination performance stability over an extended period of up to 70 h. Moreover, it exhibited durability through 8 cycles of 24-h usage with washing treatment. In conclusion, the GO-MA0.9-PVA10/Nylon membrane is strongly recommended for practical applications, outperforming other membrane options based on the comprehensive evaluation of its stability and desalination efficiency.

Accelerated dissemination of antibiotic resistant genes via conjugative transfer driven by deficient denitrification in biochar-based biofiltration systems.

Biofiltration systems harbored and disseminated antibiotic resistance genes (ARGs), when confronting antibiotic-contained wastewater. Biochar, a widely used environmental remediation material, can mitigate antibiotic stress on adjoining microbes by lowering the availability of sorbed antibiotics, and enhance the attachment of denitrifiers. Herein, bench-scale biofiltration systems, packed with commercial biochars, were established to explore the pivotal drivers affecting ARG emergence. Results showed that biofiltration columns, achieving higher TN removal and denitrification capacity, showed a significant decrease in ARG accumulation (p < 0.05). The relative abundance of ARGs (0.014 ± 0.0008) in the attached biofilms decreased to 1/5-folds of that in the control group (0.065 ± 0.004). Functional analysis indicated ARGs' accumulation was less attributed to ARG activation or horizontal gene transfer (HGT) driven by sorbed antibiotics. Most denitrifiers, like Bradyrhizobium, Geothrix, etc., were found to be enriched and host ARGs. Nitrosative stress from deficient denitrification was demonstrated to be the dominant driver for affecting ARG accumulation and dissemination. Metagenomic and metaproteomic analysis revealed that nitrosative stress promoted the conjugative HGT of ARGs mainly via increasing the transmembrane permeability and enhancing the amino acid transport and metabolism, such as cysteine, methionine, and valine metabolism. Overall, this study highlighted the risks of deficient denitrification in promoting ARG transfer and transmission in biofiltration systems and natural ecosystems.

Refractory degradable dissolved organic matter (R-DOM) driving nitrogen removal by the electric field coupled iron­carbon biofilter (E-ICBF): Performance and microbial mechanisms.

Researches on the advanced nitrogen (N) removal of municipal tailwater always overlooked the value of refractory degradable dissolved organic matter (R-DOM). In this study, a novel electric field coupled iron­carbon biofilter (E-ICBF) was utilized to explore the performance and microbial changes with polyethylene glycol (PEG) as the representative R-DOM. Results demonstrated that the removal efficiencies of E-ICBF for nitrate nitrogen (NO3--N), ammonia nitrogen (NH4+-N), and total nitrogen (TN) improved by 28.76 %, 12.96 %, and 28.45 %, compared to quartz sand biofilter (SBF). Moreover, removal efficiencies of NO3--N and TN in E-ICBF with R-DOM went up by 12.11 % and 14.02 % compared to methanol. Additionally, both PEG and the electric field reduced the microbial richness and diversity. However, PEG promoted the increase of denitrifying bacteria abundance including unclassified_f_Comamonadaceae, Thauera, and unclassified_f_Gallionellaceae. The electric field improved the abundances of genes related to N removal (hao, nasC, nasA, nifH, nifD, nifK) and PEG further enhanced the effect. The abundances of key enzymes [EC:1.7.5.1], [EC:1.7.2.1], [EC:1.7.2.4], and [EC:1.7.2.5] decreased due to the addition of PEG and the electric field mitigated the negative influence. Additionally, the electric field changed relationships between microorganisms and pollutant removal, and improved interspecific relationships between denitrifying bacterial genera and other genera in E-ICBF.

Removal of 6-methylquinoline from shale gas wastewater using electrochemical carbon nanotubes filter.

6-Methylquinoline (6-MQ) is identified as a high-concentration organic compound pervasive in shale gas wastewater (SGW) and poses a significant risk of environmental pollution. In response, this study aimed to address these challenges by introducing an innovative electrochemical membrane constructed with multi-walled carbon nanotubes (CNTs) for the removal of 6-MQ. The investigation systematically explored the impact of voltage, initial pollutant concentration, and salinity on the performance of the electrochemical CNTs filter. It was found a positive correlation between removal efficiency and increasing voltage and salinity levels. Conversely, as the initial concentration of pollutants increased, the efficiency showed a diminishing trend. The electrochemical CNTs filter exhibited remarkable efficacy in both adsorption removal and electrochemical oxidation of 6-MQ. Notably, the CNTs membrane exhibited robust adsorption capabilities, evidenced by the sustained adsorption of 6-MQ for over 33 h. Furthermore, applying an electrochemical oxidation voltage of 3 V consistently maintained a removal rate exceeding 34.0% due to both direct and indirect oxidation, underscoring the sustained efficacy of the electrochemical membranes. Besides, real wastewater experiments, while displaying a reduction in removal efficiency compared to synthetic wastewater experiments, emphasized the substantial potential of the electrochemical CNTs filter for practical applications. This study underscores the significant promise of electrochemical membranes in addressing low molecular weight contaminants in SGW, contributing valuable insights for advancing SGW treatment strategies.

Loss of micropollutants on syringe filters during sample filtration: Machine learning approach for selecting appropriate filters.

Prefiltration before chromatographic analysis is critical in the monitoring of environmental micropollutants (MPs). However, in an aqueous matrix, such monitoring often leads to out-of-specification results owing to the loss of MPs on syringe filters. Therefore, this study investigated the loss of seventy MPs on eight different syringe filters by employing Random Forest, a machine learning algorithm. The results indicate that the loss of MPs during filtration is filter specific, with glass microfiber and polytetrafluoroethylene filters being the most effective (<20%) compared with nylon (>90%) and others (regenerated-cellulose, polyethersulfone, polyvinylidene difluoride, cellulose acetate, and polypropylene). The Random Forest classifier showed outstanding performance (accuracy range 0.81-0.95) for determining whether the loss of MPs on filters exceeded 20%. Important factors in this classification were analyzed using the SHapley Additive exPlanation value and Kruskal-Wallis test. The results show that the physicochemical properties (LogKow/LogD, pKa, functional groups, and charges) of MPs are more important than the operational parameters (sample volume, filter pore size, diameter, and flow rate) in determining the loss of most MPs on syringe filters. However, other important factors such as the implications of the roles of pH for nylon and pre-rinsing for PTFE syringe filters should not be ignored. Overall, this study provides a systematic framework for understanding the behavior of various MP classes and their potential losses on syringe filters.

Synchronous removal of gaseous toluene and benzene and degradation process shifts in microbial fuel cell-biotrickling filter system.

Illustrating the biodegradation processes of multi-component volatile organic compounds (VOCs) will expedite the implication of biotechnology in purifying industrial exhaust. Here, performance shifts of microbial fuel cell and biotrickling filter combined system (MFC-BTF) are investigated for removing single and dual components of toluene and benzene. Synchronous removal of toluene (95 %) and benzene (97 %) are achieved by MFC-BTF accompanied with the output current of 0.41 mA. Elevated content of extracellular polymeric substance facilitates the mass transfer of benzene with the presence of toluene. Strains of Bacteroidota, Proteobacteria and Chloroflexi contribute to the removal of dual components VOCs. Empty bed reaction time and the VOCs concentration are the important factors influencing their dissolution in the system. The biodegradation of toluene and benzene proceeds with 2-hydroxymuconic semialdehyde and o-hydroxybenzoic acid as the main intermediates. These results provide a comprehensive understanding of multi-component VOCs removal by MFC-BTF and guide the system design, optimization, and scale-up.

Synthesis of MOF-5/polyethersulfone (PES) mixed matrix membranes for enhancing membrane filtration performance in polyphenol purification.

The various apple products industries produce a large amount of apple residue, which is easily fermented, causes environmental pollution, and its disposal cost is high, but is rich in nutrients, such as polyphenols. Polyphenols can be purified to realize high-value deep processing of apple pomace and to promote energy reuse of food waste. In this study, the highly selective purification of polyphenols was achieved by membrane filtration using prepared Metal-organic framework (MOF)-5/PES mixed matrix membranes with apple peels as raw material. The polyethersulfone mixed matrix membrane was loaded with MOF-5 by the phase inversion method, and their structural and physicochemical properties were characterized by scanning electron microscopy (SEM), and X-ray diffraction (XRD). Zeta potential and specific surface area of MOF-5 particles were measured, as well as the water contact angle and anti-fouling properties of the mixed matrix membrane were analyzed. It was confirmed that the membrane loaded with MOF-5 showed better hydrophilicity and mechanical properties compared with the pristine polyether sulfone membrane. Under practical conditions, the increased hydrophilicity could enhance the anti-fouling properties of membranes, which would improve the flux recovery ratio of membranes. In addition, the prepared MOF-5/PES mixed matrix membrane was applied to the purification of polyphenols, showing excellent purification performance of polyphenols. In particular, the purity of polyphenol after membrane filtration could reach 70.45% when the additional amount of MOF-5 was 10%. This research provides a method to prepare MOF-5/PES mixed matrix membranes, which effectively solves the problem of unstable and unsatisfactory purification effect of commercially available membranes, promotes the development of new materials in membrane science, and realizes high-value deep processing and comprehensive resource development of food waste using membrane filtration.

Removal of multiple pesticides from water by different types of membranes.

Pesticides are used in agriculture to protect crops from pathogens, insects, fungi and weeds, but the release of pesticides into surface/groundwater by agriculture runoff and rain has raised serious concerns not only for the environment but also for human health. This study aimed to investigate the impact of surface properties on the performance of seven distinct membrane types utilized in nanofiltration (NF), reverse osmosis (RO) and forward osmosis (FO) processes in eliminating multiple pesticides from spiked water. Out of the membranes tested, two are self-fabricated RO membranes while the rest are commercially available membranes. Our results revealed that the self-fabricated RO membranes performed better than other commercial membranes (e.g., SW30XLE, NF270, Duracid and FO) in rejecting the targeted pesticides by achieving at least 99% rejections regardless of the size of pesticides and their log Kow value. Despite the marginally lower water flux exhibited by the self-fabricated membrane compared to the commercial BW30 membrane, its exceptional ability to reject both mono- and divalent salts renders it more apt for treating water sources containing not only pesticides but also various dissolved ions. The enhanced performance of the self-fabricated RO membrane is mainly attributed to the presence of a hydrophilic interlayer (between the polyamide layer and substrate) and the incorporation of hydrophilic nanosheets in tuning its surface characteristics. The findings of the work provide insight into the importance of membrane surface modification for the application of not only the desalination process but also for the removal of contaminants of emerging concern.

Iron-enhanced microscale laboratory aerated filters in the treatment of artificial mariculture wastewater: A study on nitrogen removal performance and the impact on microbial community structure.

This study investigates the nitrogen removal efficacy and microbial community dynamics in seawater aquaculture effluent treatment using three different substrate combinations of microscale laboratory aerated filters (MFs) - MF1 (LECA), MF2 (LECA/Fe-C), and MF3 (LECA/Pyrite). The findings indicated that the COD removal exceeded 95% across all MFs, with higher removal efficiencies in MF2 and MF3. In terms of nitrogen removal performance, MF2 exhibited the highest average nitrogen removal of 93.17%, achieving a 12.35% and 3.56% increase compared to MF1 (80.82%) and MF3 (89.61%), respectively. High-throughput sequencing analysis revealed that the Fe-C substrate significantly enhanced the diversity of the microbial community. Notably, in MF2, the salinophilic denitrifying bacterium Halomonas was significantly enriched, accounting for 42.6% of the total microbial community, which was beneficial for nitrogen removal. Moreover, an in-depth analysis of nitrogen metabolic pathways and microbial enzymes indicated that MF2 and MF3 possessed a high abundance of nitrification and denitrification enzymes, related to the high removal rates of NH4+-N and NO3--N. Therefore, the combination of LECA with iron-based materials significantly enhances the nitrogen removal efficiency from mariculture wastewater.