Promoted production of Fe(IV)/Fe(V) intermediates in the calcium peroxide/ferrate(VI) process for low-damage removal of algal contaminants and membrane fouling control.

Ultrafiltration (UF) is widely employed for harmful algae rejection, whereas severe membrane fouling hampers its long-term operation. Herein, calcium peroxide (CaO2) and ferrate (Fe(VI)) were innovatively coupled for low-damage removal of algal contaminants and fouling control in the UF process. As a result, the terminal J/J0 increased from 0.13 to 0.66, with Rr and Rir respectively decreased by 96.74 % and 48.47 %. The cake layer filtration was significantly postponed, and pore blocking was reduced. The ζ-potential of algal foulants was weakened from -34.4 mV to -18.7 mV, and algal cells of 86.15 % were removed with flocs of 300 µm generated. The cell integrity was better remained in comparison to the Fe(VI) treatment, and Fe(IV)/Fe(V) was verified to be the dominant reactive species. The membrane fouling alleviation mechanisms could be attributed to the reduction of the fouling loads and the changes in the interfacial free energies. A membrane fouling prediction model was built based on a long short-term memory deep learning network, which predicted that the filtration volume at J/J0= 0.2 increased from 288 to 1400 mL. The results provide a new routine for controlling algal membrane fouling from the perspective of promoting the generation of Fe(IV)/Fe(V) intermediates.

A multi-technique analytical approach to support (eco)toxicological investigation of zinc oxide nanoparticles.

Understanding the mechanism of toxicity of nanoparticles and their behavior in biological environments is crucial for designing materials with reduced side effects and improved performance. Among the factors influencing nanoparticle behavior in biological environments, the release and bioavailability of potentially toxic metal ions can alter equilibria and cause adverse effects. In this study, we applied two on-line Field-Flow Fractionation (FFF) strategies and compared the results with off-line benchmarking centrifugal ultrafiltration to assess a key descriptor, namely the solubility of zinc oxide (ZnO) nanoparticles. We found that, at the highest nanoparticle concentrations, the nanoparticle-ion ratio quickly reaches equilibrium, and the stability is not significantly affected by the separation technique. However, at lower concentrations, dynamic, non-equilibrium behavior occurs, and the results depend on the method used to separate the solid from the ionic fraction, where FFF yielded a more representative dissolution pattern. To support the (eco)toxicological profiling of the investigated nanoparticles, we generated experimental data on colloidal stability over typical (eco)toxicological assay durations. The Zeta Potential vs pH curves revealed two distinct scenarios typical of surfaces that have undergone significant modification, most likely due to pH-dependent dissolution and re-precipitation of surface groups. Finally, to enhance hazard assessment screening, we investigated ion-dependent toxicity and the effects of exposure to fresh water. Using an in vitro human skin model, we evaluated the cytotoxicity of fresh and aged ZnO nanoparticles (exposed for 72 h in M7), revealing time-dependent, dose-dependent, and nanoparticle-dependent cytotoxicity, with lower toxicity observed in the case of aged samples.

Treatment of pulp and paper mill effluent through combined aerobic and anaerobic suspended fixed-bed bioreactor.

This study explored using ultrafiltration (UF) membranes to treat pulp and paper mill wastewater, implementing a novel Taguchi experimental design to optimize operating conditions for pollutant removal and minimal membrane fouling. Researchers examined four factors: pH, temperature, transmembrane pressure, and volume reduction factor (VRF), each at three levels. Optimal conditions (pH 10, 25°C, 6 bar, VRF 3) led to a 35% reduction in flux due to fouling and high pollutant rejections: total hardness (83%), sulfate (97%), spectral absorption coefficient (SAC254) (95%), and chemical oxygen demand (COD) (89%). Conductivity had a lower rejection rate of 50%. Advanced imaging techniques like atomic force microscopy (AFM) and scanning electron microscopy (SEM) revealed reduced membrane fouling under these conditions. The Taguchi method effectively identified optimal conditions, significantly improving wastewater treatment efficiency and promoting environmental sustainability in the pulp and paper industry. PRACTITIONER POINTS: This study optimized UF membrane conditions for pulp and paper mill wastewater, reducing fouling and enhancing pollutant removal, offering practical strategies for industrial treatment. AFM and SEM provided key insights into membrane fouling and mitigation, promoting real-time diagnosis and optimization for enhanced treatment efficiency. Prioritizing anaerobic fixed-bed systems in wastewater treatment is beneficial for achieving high COD removal efficiency. Optimizing hydraulic retention time (HRT) in these systems can further improve their overall effectiveness and sustainability.

Microplastics and dye removal from textile wastewater using MIL-53 (Fe) metal-organic framework-based ultrafiltration membranes.

Microplastics (MPs) and other organic matters in textile wastewater have posed a formidable challenge for treatment processes, particularly in the primary stages such as ultrafiltration (UF). UF plays a crucial role in preventing the entry of pollutants into subsequent treatment steps. However, the performance efficiency of UF membranes is compromised by the potential fouling of membrane pores by MPs, dyes and other organic pollutants such as bovine serum albumin (BSA). This study focuses on enhancing UF membrane performance, specifically its antifouling properties, through the development of high-performance membranes using MIL-53(Fe) metal-organic framework (MOF) particles (noted as MIL-53 here). Various concentrations of the MIL-53 (0.05, 0.1, 0.2, and 0.5 wt%) were integrated into the membrane structure through phase inversion process. Streaming zeta potential results confirmed the negatively charged surface of the membranes and their high hydrophilicity was validated through contact angle analysis. FTIR, SEM, EDS, and XRD confirmed the presence of MIL-53 particles on the surface of membranes. The developed membranes were tested for 24 h to assess their antifouling properties, with a subsequent 30-min hydraulic flush to measure their flux recovery ratios. Methylene Blue (MB) dye was used as a cationic dye present in textile wastewater to evaluate the efficiency of the developed membranes in dye removal and the synergistic effects of dye rejection in the presence of organic matters (i.e., MPs and BSA). Since previous studies have not fully addressed the combination of dyes and organic matter, this study thoroughly investigated the effect of particle-type foulants (MPs) and their interactions with dye (MB), as well as water soluble protein-type foulants (BSA) and their interaction with MB. The results indicated that the developed membranes exhibited higher MB rejection when the dye was present with either MP or BSA, along with improved antifouling properties. The optimised UF membrane integrated with 0.1 wt% MIL-53 demonstrated nearly 96% BSA rejection and around 86% MB rejection in the mixed foulant case (BSA-MB). The modified membrane exhibited a substantial increase in water flux from 176 L m-2.h-1 to 327 L m-2.h-1. The findings of this research show the potential of iron-based MOFs in improving the performance of UF membranes and provide a platform for future studies on significant areas such as long-term stability studies and testing with other pollutants found in textile wastewater.

Closed Loop Ultrafiltration Feedback Control in Hemodialysis: A Narrative Review.

While life-sustaining, hemodialysis is a non-physiological treatment modality that exerts stress on the patient, primarily due to fluid shifts during ultrafiltration. Automated feedback control systems, integrated with sensors that continuously monitor bio-signals such as blood volume, can adjust hemodialysis treatment parameters, e.g., ultrafiltration rate, in real-time. These systems hold promise to mitigate hemodynamic stress, prevent intradialytic hypotension, and improve the removal of water and electrolytes in chronic hemodialysis patients. However, robust evidence supporting their clinical application remains limited. Based on an extensive literature research, we assess feedback-controlled ultrafiltration systems that have emerged over the past three decades in comparison to conventional hemodialysis treatment. We identified 28 clinical studies. Closed loop ultrafiltration control demonstrated effectiveness in 23 of them. No adverse effects of closed loop ultrafiltration control were reported across all trials. Closed loop ultrafiltration control represents an important advancement towards more physiological hemodialysis. Its development is driven by innovations in real-time bio-signals monitoring, advancement in control theory, and artificial intelligence. We expect these innovations will lead to the prevalent adoption of ultrafiltration control in the future, provided its clinical value is substantiated in adequately randomized controlled trials.

Techno-functional properties and structural characteristics of cricket protein concentrates affected by pre-treatments and ultrafiltration/diafiltration processes.

This study aimed to evaluate different pre-treatments on cricket flour (CF), solvent-defatting (CFH), and supercritical-defatting (CFS) to obtain cricket protein concentrate (CPC) by ultrafiltration (UF)-diafiltration (DF) and evaluate the UF-DF performance, techno-functional properties, and digestibility. Results showed that defatting efficiency was 63 % and 85 % for solvent-defatting and supercritical fluid defatting, respectively. The supercritical fluid extraction process decreased the protein solubility and affected the UF performance, decreasing protein retention by 33 %. However, the soluble protein of the generated concentrates was higher than 90 %. Protein concentrates showed a better foaming capacity at pH 5.0 and 7.0, while the oil-holding capacity (1.95-2.20 g/g) decreased in defatted concentrates but was higher than water-holding (0.30-0.60 g/g). Emulsion activity (45-50 %) was not affected by pre-treatments (p > 0.05). Protein digestibility ranged from 71 to 75 % (p < 0.05). Supercritical fluid defatting and ultrafiltration-diafiltration processes were suitable for obtaining cricket protein concentrates.

Novel visible-light activated photocatalytic ultrafiltration membrane for simultaneous separation and degradation of emerging contaminants.

Emerging contaminants (ECs) in secondary effluent of wastewater treatment plants (WWTPs) have received increasing attention due to their adverse effects on aquatic ecosystems and human health. Herein, visible-light responsive photocatalyst TM (TiO2 @NH2-MIL-101(Fe)) and resultant photocatalytic ultrafiltration (PUF, PVDF/TM) membrane were prepared to remove 32 typical compounds of antibiotics, 296 compounds of antibiotic resistance genes (ARGs), and their corresponding bacterial hosts. The construction of heterojunction photocatalyst promoted the electron transfer from NH2-MIL-101(Fe) to TiO2 and the formation of N-TiO2, enhancing visible-light (λ ≥ 420 nm) photocatalytic activity. With highly-hydrophilic surface and delicately-regulated pore structure, the initial water permeance of optimal PUF membrane significantly increased to 3912.2 L/m2/h at 1.0 bar. Meanwhile, membrane retention (via adsorption, electrostatic interaction, and steric hindrance) was improved due to the narrowed pore size, highly-negative surface charge and abundant functional groups. Additionally, hydroxyl radical (•OH) was the dominant active reactive oxygen species (ROS) for ECs degradation, and the narrowed pore structure could serve as microreactors to increase ROS concentration and reduce migration distance. Consequently, the removal efficiencies of antibiotics, bacteria and ARGs were 86.5 %, 91.4 % and 91.8 %, respectively. Overall, this novel visible-light-activated PUF membrane expands membrane application, and has great potential in ECs treatment.

High-exchange ULTrafiltration to enhance recovery after paediatric cardiac surgery (ULTRA): study protocol for a Canadian double-blinded randomised controlled trial.

INTRODUCTION: Surgical repair is the standard of care for most infants and children with congenital heart disease. Cardiopulmonary bypass (CPB) is required to facilitate these operations but elicits a systemic inflammatory response, leading to postoperative organ dysfunction, morbidity and prolonged recovery after the surgery. Subzero-balance ultrafiltration (SBUF) has been shown to extract proinflammatory cytokines continuously throughout the CPB exposure. We hypothesize that a high-exchange SBUF (H-SBUF) will have a clinically relevant anti-inflammatory effect compared with a low-exchange SBUF (L-SBUF). METHODS AND ANALYSIS: The ULTrafiltration to enhance Recovery After paediatric cardiac surgery (ULTRA) trial is a randomised, double-blind, parallel-group randomised trial conducted in a single paediatric cardiac surgery centre. Ninety-six patients less than 15 kg undergoing cardiac surgery with CPB will be randomly assigned to H-SBUF during CPB or L-SBUF during CPB in a 1:1 ratio with stratification by The Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery (STAT) score 1 and STAT score 2-5. The primary outcome is peak postoperative vasoactive-ventilation-renal score. Time series and peak values of vasoactive-ventilation renal score, vasoactive-inotrope score, ventilation index and oxygenation index will be collected. Secondary clinical outcomes include acute kidney injury, ventilator-free days, inotrope-free days, low cardiac output syndrome, mechanical circulatory support, intensive care unit length of stay and operative mortality. Secondary biomarker data include cytokine, chemokine and complement factor concentrations at baseline before CPB, at the end of CPB exposure and 24 hours following CPB. Analyses will be conducted on an intention-to-treat principle. ETHICS AND DISSEMINATION: The study has ethics approval (#1024932 dated August 31, 2021) and enrolment commenced in September 2021. The primary manuscript and any subsequent analyses will be submitted for peer-reviewed publication. TRIAL REGISTRATION NUMBER: NCT04920643.

Evaluation of an Automated Ultrafiltration System for Concentrating a Range of Viruses from Saline Waters.

Pathogenic viruses in environmental water are usually present in levels too low for direct detection and thus, a concentration step is often required to increase the analytical sensitivity. The objective of this study was to evaluate an automated filtration device, the Innovaprep Concentrating Pipette Select (CP Select) for the rapid concentration of viruses in saline water samples, while considering duration of process and ease of use. Four bacteriophages (MS2, P22, Phi6, and PhiX174) and three animal viruses (adenovirus, coronavirus OC43, and canine distemper virus) were seeded in artificial seawater, aquarium water, and bay water samples, and processed using the CP Select. The recovery efficiencies of viruses were determined either using a plaque assay or droplet digital PCR (ddPCR). Using plaque assays, the average recovery efficiencies for bacteriophages ranged from 4.84 ± 3.8% to 82.73 ± 27.3%, with highest recovery for P22 phage. The average recovery efficiencies for the CP Select were 39.31 ± 26.6% for adenovirus, 19.04 ± 11.6% for coronavirus OC43, and 19.84 ± 13.6% for canine distemper virus, as determined by ddPCR. Overall, viral genome composition, not the size of the virus, affected the recovery efficiencies for the CP Select. The small sample volume size used for the ultrafilter pipette of the system hinders the use of this method as a primary concentration step for viruses in marine waters. However, the ease of use and rapid processing time of the CP Select are especially beneficial when rapid detection of viruses in highly contaminated water, such as wastewater or sewage-polluted surface water, is needed.

Surface modification of PVDF ultrafiltration membranes using spacer arms and synthetic receptors for virus capturing and separation.

Although membrane technology has demonstrated outstanding pathogen removal capabilities, current commercial membranes are insufficient for removing small viruses at trace levels due to certain limitations. The theoretical and practical significance of developing a new form of hydrophilic, anti-fouling, and virus-specific ultra-purification membrane with high capturing and separation efficiency, stability, and throughput for water treatment is of the utmost importance. In this study, molecularly imprinted membranes (MIMs) were fabricated from polyvinylidene fluoride (PVDF) membranes utilizing novel surface hydrophilic modification techniques, followed by the immobilization of virus-specific molecularly imprinted nanoparticles (nanoMIPs) as synthetic receptors. Three distinct membrane functionalization strategies were established and optimized for the first time: membrane functionalization with (i) polyethyleneimine (PEI) and dopamine (DOP), (ii) PEI and 3-(chloropropyl)-trimethoxysilane (CTS), and (iii) chitosan (CS). Hydrophilicity was enhanced significantly as a result of these modification strategies. Additionally, the modifications enabled spacer arms between the membrane surface and the nanoMIPs to decrease steric hindrance. The surface chemistry, morphology, and membrane performance results from the characterization analysis of the MIMs demonstrated excellent hydrophilicity (e.g., the functionalized membrane presented 37.84° while the unmodified bare membrane exhibited 128.94° of water contact angle), higher permeation flux (145.96 L m-2 h-1 for the functionalized membrane), excellent uptake capacity (up to 99.99 % for PEI-DOP-MIM and CS-MIM), and recovery (more than 80 % for PEI-DOP-MIM). As proof of concept, the cutting-edge MIMs were able to eliminate the model adenoviruses up to 99.99 % from water. The findings indicate that the novel functionalized PVDF membranes hold promise for implementation in practical applications for virus capture and separation.

Zwitterionic nanospheres engineered co-polymer composite membrane for precise protein-protein separation via dynamic self-assembly micelle deposition.

The accurate protein-protein separation is important but technically challenging. Achieving such a precise separation using membrane requires the selective channels with appropriate pore geometry structure and high anti-fouling property. In this study, polyethersulfone-b-poly(sulfobetaine methyl methacrylate) (PES-b-PSBMA) was synthesized and engineered onto polysulfone (PSF) ultrafiltration (UF) membrane to fabricate zwitterionic nanospheres engineered co-polymer (ZN-e-CoP) composite membrane via dynamic self-assembly micelle deposition. On the one hand, self-assembly zwitterionic nanospheres were used as blocks to construct hydrophilic layers with size-dependent sieving channels, endowing ZN-e-CoP composite membranes with enhanced permselectivity and protein-protein separation abilities, meanwhile zwitterionic groups from nanospheres reinforced the structure stability of nanospheres/nanospheres and nanospheres/membrane via multiple intermolecular interactions. On the other hand, zwitterionic nanospheres can induce to produce the hydration layer enveloping themselves by binding water molecules, where hydration layer acts as a protective barrier on the membrane surface, impeding the protein adhesion. Hence, ZN-e-CoP_1a composite membrane exhibited superior separation properties with Lysozyme/Bovine Serum Albumin (BSA) separation factor of 18.1 and 95.4 % rejection against BSA, 10.1 and 2.3 times, respectively, higher these of pristine PSF membrane (1.8 and 42.1 %), without obviously sacrificing water flux. Simultaneously, hydration layer enables the ZN-e-CoP_1a membrane with enhanced anti-fouling performance and durability during the long-term operations. The proposed approach opens new pathways to fabricate excellent anti-fouling membranes for precise protein-protein separation.

Free serum concentrations of antibiotics determined by ultrafiltration: extensive evaluation of experimental variables.

Aim: To assess the impact of experimental conditions on free serum concentrations as determined by ultrafiltration and HPLC-DAD analysis in a wide range of antibiotics.Materials & methods: Relative centrifugation force (RCF), temperature, pH and buffer were varied and the results compared with the standard protocol (phosphate buffer pH 7.4, 37°C, 1000 × g).Results: Generally, at 10,000 × g the unbound fraction (fu) decreased with increasing molecular weight, and was lower at 22°C. In unbuffered serum, the fu of flucloxacillin or valproic acid was increased, that of basic or amphoteric drugs considerably decreased. Comparable results were obtained using phosphate or HEPES buffer except for drugs which form metal chelate complexes.Conclusion: Maintaining a physiological pH is more important than strictly maintaining body temperature.

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Role of reactive manganese and oxygen species in the KMnO4/Na2SO3 process for purification of algal-rich water and membrane fouling alleviation.

Ultrafiltration (UF) is a highly efficient technique for algal-rich water purification, but it is heavily contaminated due to the complex water characteristics. To solve this problem, potassium permanganate (KMnO4) oxidation enhanced with sodium sulfite (Na2SO3) was proposed as a pretreatment means. The results showed that the end-normalized flux was elevated from 0.10 to 0.91, and the reversible fouling resistance was reduced by 99.95%. The membrane fouling mechanism also changed obviously, without the generation of cake filtration. Regarding the properties of algal-rich water, the zeta potential was decreased from -29.50 to -5.87 mV after KMnO4/Na2SO3 pretreatment, suggesting that the electrostatic repulsion was significantly reduced. Meanwhile, the fluorescent components in algal-rich water were significantly eliminated, and the removal of dissolved organic carbon was increased to 67.46%. In the KMnO4/Na2SO3 process, reactive manganese species (i.e., Mn(V), Mn(III) and MnO2) and reactive oxygen species (i.e., SO4•- and •OH) played major roles in purifying algal-rich water. Specifically, SO4•-, •OH, Mn(V) and Mn(III) could effectively oxidize algal pollutants. Simultaneously, the in-situ adsorption and coagulation of MnO2 could accelerate the formation of flocs by decreasing the electrostatic repulsion between cells, and protect the algal cells from being excessive oxidized. Overall, the KMnO4/Na2SO3 process showed significant potential for membrane fouling alleviation in purifying algal-rich water.

New insights into membrane fouling in coagulation-ultrafiltration by cake characteristics analysis: A case study with PACl-Al13 and PACl.

Membrane fouling is a bottleneck issue that hindered the further application of ultrafiltration technology. To alleviate membrane fouling, coagulation-ultrafiltration (C-UF) process using polyaluminum chloride (PACl) and PACl-Al13 with high proportion of Al13O4(OH)247+ as coagulants, respectively, were investigated at various pH conditions. Results indicated that an increase in solution pH contributed to larger floc size and looser floc structure for both PACl and PACl-Al13. It was conducive to the formation of more porous cake, as evidenced by mean pore area and pore area distribution of cake, leading to lower reversible fouling. Furthermore, humic acid (HA) removal presented a trend of first increasing and then decreasing with the increase of pH. The optimal HA removal was achieved at pH 6 regardless of coagulant type, suggesting that the slightest irreversible fouling should be occurred at this point. Interestingly, the irreversible fouling with PACl coagulant achieved a minimum value at pH 9, while the minimal irreversible fouling with PACl-Al13 was observed at pH 6. We speculated that the cake formed by PACl could further intercept HA prior to UF process at alkaline pH. Furthermore, compared with PACl, PACl-Al13 had a stronger charge neutralization ability, thus contributing to more compact floc structure and higher HA removal at various pH conditions. By UF fractionation measurement, higher HA removal for PACl-Al13 was due to higher removal of HA with molecular weight less than 50 kDa.

Determination of unbound platinum concentrations in human plasma using ultrafiltration and precipitation methods.

Quantification of the unbound portion of platinum (Pt) in human plasma is important for assessing the pharmacokinetics of the chemotherapeutic drug cisplatin. In this study, we sought to compare the recovery of unbound Pt using Nanosep® filters to 1) traditional filters (Centrifree®, Centrisart®, Amicon®) or trichloroacetic acid (TCA) protein precipitation, and 2) unbound, bound, and total Pt concentrations in clinical specimens. For the tested filters, the impact of 1) molecular weight cut-offs, 2) centrifugation force, and 3) total Pt concentration on Pt binding in human plasma was evaluated. Pt was quantified using inductively coupled-plasma mass spectrometry. In human plasma spiked with 0.9 µg/mL Pt, the percent of unbound Pt increased at higher centrifugation speeds. By comparison, the percent of unbound Pt was highest (42.1%) following TCA protein precipitation. When total Pt was ≤0.9 µg/mL, unbound Pt (∼20-30%) was consistent across filters. Conversely, when plasma was spiked with Pt exceeding 0.9 µg/mL, the percent of unbound Pt increased from 36.5 to 48% using ultrafiltration, compared to 63.4% to 79% with TCA precipitation. In patients receiving cisplatin-containing chemotherapy, the fraction of unbound Pt at concentrations exceeding 0.9 µg/mL ranged between 35 and 90%. Moreover, the unbound fraction of Pt in plasma correlated with the concentration of unbound (R2 = 0.738) and total Pt (R2 = 0.335). In summary, this study demonstrates that 1) the percent of unbound Pt is influenced by total and unbound Pt levels in vitro and in clinical specimens, and 2) ultrafiltration with Nanosep® filters is a feasible method for quantifying unbound Pt concentrations in human plasma.

Sodium lignosulfonate as an extracting agent of methylene blue dye using a polymer-enhanced ultrafiltration technique.

The purpose of this research was to evaluate the efficacy of sodium lignosulfonate (LS) as a dye adsorbent in the removal of methylene blue (MB) from water by polymer-enhanced ultrafiltration. Various parameters were evaluated, such as membrane molecular weight cut-off, pH, LS dose, MB concentration, applied pressure, and the effect of interfering ions. The results showed that the use of LS generated a significant increase in MB removal, reaching an elimination of up to 98.0 % with 50.0 mg LS and 100 mg L-1 MB. The maximum MB removal capacity was 21 g g-1 using the enrichment method. In addition, LS was reusable for up to four consecutive cycles of dye removal-elution. The removal test in a simulated liquid industrial waste from the textile industry was also effective, with a MB removal of 97.2 %. These findings indicate that LS is highly effective in removing high concentrations of MB dye, suggesting new prospects for its application in water treatment processes.

Hybrid process combining ultrafiltration and electro-oxidation for COD and nonylphenol ethoxylate removal from industrial laundry wastewater.

Laundry wastewater is a significant source of nonylphenol ethoxylate (NPEO) at wastewater treatment plants, where its breakdown forms persistent nonylphenol (NP). NP poses risks as an endocrine disruptor in wildlife and humans. This study investigates the degradation of NPEO and COD in industrial laundry wastewater (LWW) using a two-stage process combining ultrafiltration (UF) and electro-oxidation (EO). UF was used to remove suspended solids, while soluble COD (COD0 = 239 ± 6 mg.L-1) and NPEO (NPEO0 = 341 ± 8 µg.L-1) were oxidized by the EO process. Different operating parameters were studied such as current density, electrolysis time, type of cathode and supporting electrolyte concentration. Using an experimental design methodology, the optimal conditions for COD and NPEO3-17 degradation were recorded. This included achieving 97% degradation of NPEO3-17 and 61% degradation of COD, with a total operating cost of 3.65 USD·m-3. These optimal conditions were recorded at a current density of 15 mA cm-2 for a 120-min reaction period in the presence of 4 g·Na2SO4 L-1 using a graphite cathode. The EO process allowed for reaching the guidelines required for water reuse (NPEO <200 µg.L-1, COD <100 mg.L-1) in the initial laundry washing cycles. Furthermore, our results demonstrate that both NP and NPEO compounds, including higher and shorter ethoxylate chains (NPEO3-17), were effectively degraded during the EO process, with removal efficiencies between 94% and 98%. This confirms the EO process's capability to effectively degrade NP, the by-product of NPEO breakdown.

Quality and efficiency assessment of five extracellular vesicle isolation methods using the resistive pulse sensing strategy.

Extracellular vesicles (EVs) have attracted great interest due to their great potential in disease diagnosis and therapy. The separation of EVs from complex biofluids with high purity is essential for the accurate analysis of EVs. Despite various methods, there is still no consensus on the best method for high-quality EV isolation and reliable mass production. Therefore, it is important to offer a standardized method for characterizing the properties (size distribution, particle concentration and purity) of EV preparations from different isolation methods. Herein, we employed a NanoCoulter Counter based on the resistive pulse sensing (RPS) strategy that enabled multi-parameter analysis of single EVs to compare the quality and efficiency of different EV isolation techniques including traditional differential ultracentrifugation, ultrafiltration, size exclusion chromatography, membrane affinity binding and polymer precipitation. The data revealed that the NanoCoulter Counter based on the RPS strategy was reliable and effective for the characterization of EVs. The results suggested that although higher particle concentrations were observed in three commercial isolation kits and ultrafiltration, traditional differential ultracentrifugation showed the highest purity. In conclusion, our results from the NanoCoulter Counter provided reliable evidence for the assessment of different EV isolation methods, which contributed to the development of EV-based disease biomarkers and treatments.

Purification and Quality Control of Recombinant Proteins Expressed in Mammalian Cells: A Practical Review.

In the recent years, there has been a rapid development of new technologies and strategies when it comes to protein purification and quality control (QC), but the basic technologies for these processes go back a long way, with many improvements over the past few decades. The purpose of this chapter is to review these approaches, as well as some other topics such as the advantages and disadvantages of various purification methods for intracellular or extracellular proteins, the most effective and widely used genetically engineered affinity tags, solubility-enhancing tags, and specific proteases for removal of nontarget sequences. Affinity chromatography (AC), like Protein A or G resins for the recovery of antibodies or Fc fusion proteins or immobilized metals for the recovery of histidine-tagged proteins, will be discussed along with other conventional chromatography techniques: ion exchange (IEC), hydrophobic exchange (HEC), mixed mode (MMC), size exclusion (SEC), and ultrafiltration (UF) systems. How to select and combine these different technologies for the purification of any given protein and the minimal criteria for QC characterization of the purity, homogeneity, identity, and integrity of the final product will be presented.