Challenges and opportunities for large-scale applications of the electro-Fenton process

As an electrochemical advanced oxidation process, the electro-Fenton (EF) process has gained significant importance in the treatment of wastewater and persistent organic pollutants in recent years. As recently reported in a bibliometric analysis, the number of scientific publications on EF have increased exponentially since 2002, reaching nearly 500 articles published in 2022 (Deng et al., 2022). The influence of the main operating parameters has been thoroughly investigated for optimization purposes, such as type of electrode materials, reactor design, current density, and type and concentration of catalyst. Even though most of the studies have been conducted at a laboratory scale, focusing on fundamental aspects and their applications to degrade specific pollutants and treat real wastewater, important large-scale attempts have also been made. This review presents and discusses the most recent advances of the EF process with special emphasis on the aspects more closely related to future implementations at the large scale, such as applications to treat real effluents (industrial and municipal wastewaters) and soil remediation, development of large-scale reactors, costs and effectiveness evaluation, and life cycle assessment. Opportunities and perspectives related to the heterogeneous EF process for real applications are also discussed. This review article aims to be a critical and exhaustive overview of the most recent developments for large-scale applications, which seeks to arouse the interest of a large scientific community and boost the development of EF systems in real environments.

Promoted electrochemical performance by MOF on MOF composite catalyst of microbial fuel cell: CuCo-MOF@ZIF-8 and the comparison between two-step hydrothermal method and dual-solution method

The microbial fuel cell (MFC) is a device that simultaneously achieves electricity generation and sewage degradation. In this study, a novel cathode catalyst metal-organic frameworks (MOFs) have been fabricated by two-step hydrothermal and dual-solution method (CuCo-MOF@ZIF-8). The synthesized trimetal MOFs exhibited a 3D badminton-like structure morphology and porosity. The results of the characterizations showed that CuCo-MOF@ZIF-8 possesses greater surface area porosity and novel functional groups. The Trimetal MOF-on-MOF mode not only demonstrated the stability of the structure but also enhanced its mechanism. Molecular mechanism analysis revealed changes in the organic ligand and metal binding site due to the transformation of Cu2+ to Cu+, Co2+ to Co3+, and Zn-N to Zn-O organic connection. Furthermore, differences between the two fabrication methods were compared. The solid-state single preparation (CuCo-MOF@ZIF-8-1), was synthesized using the two-step hydrothermal method; the liquid mixed preparation material (CuCo-MOF@ZIF-8-2), was synthesized using the dual-solution method; they exhibited completely different chemical structures and morphologies during material testing and characterization. The maximum output power density of CuCo-MOF@ZIF-8-2-MFC was 246.38 mW/m2, about 2.49 times of ZIF-8 (98.72 mW/m2). The output voltage of CuCo-MOF@ZIF-8-1-MFC was measured at 357 mV over 10 d, while that of CuCo-MOF@ZIF-8-2-MFC reached 365 mV over 12 d.

Stacking self-gluing cellulose II films: A facile strategy for the formation of novel all-cellulose laminates

Cellulose laminates represent a remarkable convergence of natural materials and modern engineering, offering a wide range of versatile applications in sustainable packaging, construction, and advanced materials. In this study, novel all-cellulose laminates are developed using an environmentally friendly approach, where freshly regenerated cellulose II films are stacked without the need for solvents (for impregnation and/or partial dissolution), chemical modifications, or resins. The structural and mechanical properties of these all-cellulose laminates were thoroughly investigated. This simple and scalable procedure results in transparent laminates with exceptional mechanical properties comparable to or even superior to common plastics, with E-modulus higher than 9 GPa for a single layer and 7 GPa for the laminates. These laminates are malleable and can be easily patterned. Depending on the number of layers, they can be thin and flexible (with just one layer) or thick and rigid (with three layers). Laminates were also doped with 10 wt% undissolved fibers without compromising their characteristics. These innovative all-cellulose laminates present a robust, eco-friendly alternative to traditional synthetic materials, thus bridging the gap between environmental responsibility and high-performance functionality.

A novel halloysite nanotubes-based hybrid monolith for in-tube solid-phase microextraction of polar cationic pesticides

The accurate determination of polar cationic pesticides in food poses a challenge due to their high polarity and trace levels in complex matrices. This study hypothesized that the use of halloysite nanotubes (HNTs) can significantly enhance the extraction efficiency and sensitivity of these analytes because of their rich hydroxyl groups and cation exchange sites. Therefore, we chemically incorporated HNTs with organic polymer monoliths for in-tube solid-phase microextraction (SPME). This novel hybrid monolith extended service life, improved adsorption capacity, and exhibited excellent extraction performance for polar cationic pesticides. Based on these advancements, a robust and sensitive in-tube SPME-HILIC-MS/MS method was constructed to determine trace levels of polar cationic pesticides in complex food matrices. The method achieved limits of detection of 1.9, 2.1, and 0.1 μg/kg for maleic hydrazide, amitrole, and cyromazine, respectively. The spiked recoveries in five food samples ranged from 80.2 to 100.8%, with relative standard deviations below 10.7%.

Texture characterization of 3D printed fibrous whey protein-starch composite emulsion gels as dysphagia food: A comparative study on starch type

Texture-modified, multi-nutrient composite foods are essential in clinical treatment for dysphagia individuals. Herein, fibrous whey protein-stabilized emulsion and different crystalline starches (wheat, corn, rice, potato, sweet potato, cassava, mung bean and pea) were used to structure composite emulsion gels (CEGs). These CEGs then underwent 3D printing to explore the feasibility of developing a dysphagia diet. The network of molded CEGs was mainly maintained by hydrophobic interactions and hydrogen bonds. Rice and cassava starches were better suited for structuring soft-textured CEGs. Compared with molded CEGs, 3D printing decreased hydrogen bonds and the compactness of the nano-aggregate structure within the gel system, forming a looser gel network and softening the CEGs. Interestingly, these effects were more pronounced for the CEGs with high initial hardness. This study provided new strategy to fabricate CEGs as dysphagia diet using fibrous whey protein and starch, and to design texture-modified foods for patients using 3D printing.

Gravity-driven membrane integrated with membrane distillation for efficient shale gas produced water treatment

Substantial volumes of hazardous shale gas produced water (SGPW) generated in unconventional natural gas exploration. Membrane distillation (MD) is a promising approach for SGPW desalination, while membrane fouling, wetting, and permeate deterioration restrict MD application. The integration of gravity-driven membrane (GDM) with MD process was proposed to improve MD performance, and different pretreatment methods (i.e., oxidation, coagulation, and granular filtration) were systematically investigated. Results showed that pretreatment released GDM fouling and improved permeate quality by enrich certain microbes' community (e.g., Proteobacteria and Nitrosomonadaceae), greatly ensured the efficient desalination of MD. Pretreatment greatly influences GDM fouling layer morphology, leading to different flux performance. Thick/rough/hydrophilic fouling layer formed after coagulation, and thin/loose fouling layer formed after silica sand filtration improved GDM flux by 2.92 and 1.9 times, respectively. Moreover, the beneficial utilization of adsorption-biodegradation effects significantly enhanced GDM permeate quality. 100 % of ammonia and 53.99 % of UV254 were efficiently removed after zeolite filtration-GDM and granular activated carbon filtration-GDM, respectively. Compared to the surged conductivity (41.29 μS/cm) and severe flux decline (>82 %) under water recovery rate of 75 % observed in single MD for SGPW treatment, GDM economically controlled permeate conductivity (1.39-19.9 μS/cm) and MD fouling (flux decline=8.3 %-27.5 %). Exploring the mechanisms, the GDM-MD process has similarity with Janus MD membrane in SGPW treatment, significantly reduced MD fouling and wetting.

Regulation of macroporous cellulose microspheres via phase separation force induced by carbon nanotubes doping for enhanced protein adsorption

The burgeoning requirement for purified biomacromolecules in biopharmaceutical industry has amplified the exigency for advanced chromatographic separation techniques. Herein, macroporous cellulose microspheres (CCMs) with micron-sized pores are produced by a facile regulation via carbon nanotubes (CNTs). In this strategy, the incorporation of CNTs breaks the homogeneous regeneration of the cellulose, thus providing anisotropic phase force to produce macropores. The CCMs have manifested a faster mass transfer rate and more available adsorption sites owing to well-defined macropores (2.69 ± 0.57 μm) and high specific surface area (147.47 m2 g-1). Further, CCMs are functionalized by quaternary ammonium salts (GTAc-CCMs) and utilized as anion adsorbents to adsorb pancreatic kininogenase (PK). The prepared GTAc-CCMs show rapid adsorption kinetics for PK at pH 6.0, reaching 90 % equilibrium within 60 min. Also, GTAc-CCMs for PK exhibit high adsorptive capacity (632.50 mg g-1), excellent recyclability (> 80 % removal amount after 10 cycles) and selectivity especially at pH 6.0. Notably, the GTAc-CCMs have been successfully applied in a fixed-bed chromatography process, indicating their potential as an effective chromatographic medium for rapid separation of biomacromolecules.

Influence of zwitterionic amphiphilic copolymers on heterogeneous gypsum formation: A promising approach for scaling resistance

This study aims to investigate the influence of zwitterionic amphiphilic copolymers (ZACs) in the nucleation and growth of heterogeneous CaSO4 at the zwitterion-water interface, which is crucial for the prevention of mineral scaling and consequent downtime or suboptimal performance in industries like membrane desalination, heat exchangers, and pipeline transportation. In situ grazing incidence small angle X-ray Scattering (GISAXS), and quartz crystal microbalance with dissipation (QCM-D) techniques were used to analyze the evolution of CaSO4 particles on two new ZAC coatings: poly-(trifluoroethyl methacrylate-random-sulfobetaine methacrylate) (PTFEMA-r-SBMA, or PT:SBMA) and poly(trifluoroethyl methacrylate-random-2-methacryloyloxyethyl phosphorylcholine) (PTFEMA-r-MPC, or PT:MPC). The results showed that PT:MPC coatings promoted nucleation but inhibited crystal growth, resulting in slower overall reaction kinetics on PT:MPC coatings compared to PT:SBMA coatings. Interfacial interactions involving the substrates, sulfate minerals, and ions were examined, revealing that calcium ion adsorption, primarily governed by electrostatic attraction, played a crucial role in the nucleation and growth processes on both ZAC coatings. The crystal characterization revealed a phase transition from bassanite to gypsum on both ZAC coatings, suggesting that these zwitterionic materials can influence the mineral phase of heterogeneously formed CaSO4 crystals. These findings enhance our understanding of the fundamental mechanisms underlying heterogeneous CaSO4 scaling in the presence of zwitterionic materials.

Flexible and scalable photothermal/electro thermal anti-icing/de-icing metamaterials for effective large-scale preparation

Anti-icing and de-icing are vital for infrastructure maintenance. While carbon-based materials with photothermal or electrothermal effects have advanced, they face challenges like environmental dependence, poor resistance, high energy consumption, and complex manufacturing. Here, we developed a scalable, hybrid metamaterial driven by photothermal/electrothermal for all-weather anti-icing/de-icing. Its nanostructured surface delays icing by 360 s at -30°C, breaking records across a wide temperature range. The porous structure enhances light absorption, achieving a delayed icing time of 2500 s at -20°C under one sunlight. The graphene film's high conductivity allows rapid de-icing with 1.6W power. After 720 h of outdoor exposure, the metamaterial retained a contact angle above 150°, confirming durability. More critically, we have demonstrated that the metamaterial can be manufactured on a large scale, which is essential for improving the economics of the anti-icing/de-icing sector.

Nitrogen doped carbon dots and gold nanoparticles mediated FRET for the detection of creatinine in human urine samples

Serum creatinine (CR) is regarded as one of the most sought out prognostic biomarkers in medical evaluation of chronic kidney disease (CKD). In light of the diagnostic significance of CR, the utility of a fluorescence biosensor for its detection in human urine specimens has been explored based on Förster resonance energy transfer (FRET) across nitrogen-doped carbon dots (N-CDs) and gold nanoparticles (GNPs). A straightforward microwave-assisted synthesis procedure has been adopted to prepare N-CDs (λexcitation = 400 nm, λemission = 540 ± 5 nm) with bright green emissions. On addition of pre-synthesized GNPs, the radiative emanation of the N-CDs is completely suppressed on account of FRET across the N-CDs and the GNPs. About 77 % of their fluorescence intensity is recovered after adding CR to GNPs@N-CDs nanocomposite. The limit of detection for CR sensing is estimated as 0.02 µg•mL-1. This biosensor is selective enough to recognize CR in the existence of potential interfering substances (e.g., ascorbic acid, glucose, glutathione, urea, and electrolytes). Its practical utility for CR detection has been validated further on the basis of satisfactory correlation with the benchmark Jaffe method, as observed in artificial/human urine specimens. Consequently, this manuscript marks a pioneering report on employing CDs and GNPs-based FRET for identifying CR in urine specimens of CKD patients.

Long-chain perfluoroalkyl carboxylic acids removal by biochar: Experimental study and uncertainty based data-driven predictive model

Given the persistence and toxicity of long-chain perfluoroalkyl carboxylic acids (PFCAs) and their rising concentrations, there is an urgent need for effective removal strategies. This study investigated the adsorptive removal of PFCAs, specifically perfluorononanoic acid (PFNA) and perfluorodecanoic acid (PFDA), using biochar derived from wood and compost. Factors such as biochar size, weight, and initial PFCA concentrations were analyzed to assess their impact on adsorption efficiency over time. The adsorption of PFDA and PFNA reached 90.13% and 85.8%, respectively, at an initial concentration of 500 μg/L. Advanced machine learning techniques, specifically deep neural networks, were employed to model adsorption behavior, incorporating noise injection to account for data uncertainties and preventing overfitting. Results demonstrated the superior performance of compost-derived biochar due to its higher aromaticity and functional group availability. The longer chain length of PFDA contributed to its higher adsorption efficiency compared to PFNA.

Zirconium and cerium dioxide fabricated activated carbon-based nanocomposites for enhanced adsorption and photocatalytic removal of methylene blue and tetracycline hydrochloride

Activated carbon (AC) is a porous, amorphous form of carbon known for its strong adsorption capacity, making it highly effective for use in wastewater treatment. In this investigation, AC-based nanocomposites (NCs) loaded with zirconium dioxide and cerium dioxide nanoparticles (ZrO2/CeO2 NPs) were successfully synthesized for the effective elimination of methylene blue (MB) and tetracycline hydrochloride (TCH). The AC-ZrO2/CeO2 NCs have a size of 231.83 nm, a zeta potential of -20.07 mV, and a PDI value of 0.160. The adsorption capacities of AC-ZrO2/CeO2 NCs for MB and TCH were proved in agreement with the Langmuir isotherm and pseudo 1st order kinetic model, respectively. The maximum adsorption capacities were determined to be 75.54 mg/g for MB and 26.75 mg/g for TCH. Notably, AC-ZrO2/CeO2 NCs exhibited superior photocatalytic degradation efficiency for MB and TCH under sunlight irradiation with removal efficiencies reaching up to 97.91% and 82.40% within 90 min, respectively. The t1/2 for the photo-degradation process of MB and TCH were 11.55 min and 44.37 min. Analysis of active species trapping confirmed the involvement of hole (h+), superoxide anion (•O2-), and hydroxyl radical (•OH) in the degradation mechanism. Furthermore, the residual solution post-contaminant removal exhibited minimal toxicity towards Artemia salina and NIH3T3 cells. Importantly, the NCs did not exhibit antibacterial activity against tested pathogens post-absorption/degradation of TCH. Thus, AC-ZrO2/CeO2 NCs could be a promising nanomaterial for wastewater treatment applications.

Insights into the controlling factors of the transport of tire wear particles in saturated porous media: The facilitative role of aging and fulvic acid

The widespread distribution and potential adverse effects of tire wear particles (TWPs) on soil and groundwater quality pose a growing environmental concern. This study investigated the transport behavior of TWPs in saturated porous media and elucidated the underlying mechanisms influenced by environmental factors. Additionally, the effects of key environmental factors, such as aging, ionic strength, cation species, medium type, and natural organic matter (NOM), on the transport of TWPs were evaluated. The results showed that aging processes simulated through O3 and UV irradiation altered the physicochemical properties of TWPs, increased the mobility of TWPs at low ionic strengths. However, the high ionic strengths and the presence of Ca2+ significantly inhibited the mobility of TWPs due to enhanced aggregation. The transport mechanism of the original and aged TWPs shifted from blocking to ripening under favorable retention conditions (i.e., high ionic strengths, divalent cations, and fine sands). Interestingly, the presence of fulvic acid (FA) inhibited the ripening of the three TWPs, significantly promoting their transport through a spatial site resistance mechanism. The two-site kinetic attachment model (TSKAM), extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory, and colloid filtration theory (CFT) were applied to describe the transport behavior of the TWPs. The study provided a comprehensive understanding of the transport behavior of TWPs in groundwater environments, highlighting the environmental risks associated with their widespread distribution.

Hydrogen peroxide enhanced glow-type chemiluminescence of hydrazine hydrate modified carbon quantum dots-potassium persulfate system

Most known chemiluminescence (CL) systems are flash-type that generate weak luminescence and decline quickly after dozens of seconds, while the glow-type CL systems have stable emission for an extended period to achieve accurate quantitation. In this work, a long-term CL system based on hydrazine-hydrate (N2H4·H2O) modified carbon quantum dots (N-CQDs) as a luminescent probe, with K2S2O8 and H2O2 as co-reactants, was proposed. The CL emission enhanced by H2O2 increased 18-fold more than that of N-CQDs and K2S2O8 direct reaction, and decayed by 5% of the maximum intensity over 700 s. In the reaction system, K2S2O8 and H2O2 co-reactants can promote each other to continuously generate corresponding radicals (•OH, O2•-, 1O2), which in turn trigger the CL emission of N-CQDs. This phenomenon was identified as the primary cause for the production of persistent CL. In addition, a stable and selective CL sensor based on the N-CQDs-K2S2O8-H2O2 CL enhancing system was developed for ascorbic acid quantitation in the linear range from 0.1 to 10.0 mM with a detection limit of 0.036 mM. The method has been applied to the analysis of tablet samples and holds potential in pharmaceutical analysis field.

Strong binding between nanoplastic and bacterial proteins facilitates protein corona formation and reduces nanoplastics toxicity

The interaction and combination of nanoplastics with microorganisms, enzymes, plant proteins, and other substances have garnered considerable attention in current research. This study specifically examined the interaction and biological effects of NPs and proteins. The findings indicated that the presence of externally wrapped proteins alters the original morphology and surface roughness of nanoplastics, leading to the formation of unevenly distributed coronas on the surface. This confirms that nanoplastics can interact with proteins to form protein coronas. The study characterized the adsorption behavior of bacterial proteins on unmodified, amino-modified, and carboxyl-modified nanoplastics using Langmuir and Freundlich isotherm models, showing that the adsorption process of the three nanoplastics on bacterial proteins was mainly controlled by chemisorption. Fluorescence spectroscopy revealed a higher binding affinity of unmodified nanoplastics. Nearly 40 % of the proteins in the protein corona of unmodified NPs are involved in metabolite production and electron transport processes. Nearly 50 % of the proteins in the protein corona of amino-modified NPs are involved in cellular metabolic processes, followed by enzymes that carry out redox reactions. The protein corona of carboxyl-modified NPs has the highest number of proteins involved in metabolic pathways, followed by proteins involved in energy-electron transfer. The formation of protein coronas on NPs with different surface modifications can reduce the toxicity of nanoplastics to bacteria to a certain extent compared to pure nanoplastics, especially amino-modified NPs, which show a significant increase in bacterial survival. The formation of protein coronas on NPs leads to varying degrees of decrease in bacterial ROS and MDA generation, with amino-modified NPs showing the most reduction; SOD and CAT exhibit varying degrees of increase and decrease. These findings not only advance our understanding of the biological impacts of NPs but also provide a basis for future in-depth investigations into the pathways of NP contamination in real environments.

Causes of negatively charged meso-colloids formed in the coagulation process: Implication of the origin of foulants in the coagulation-membrane filtration process

Tiny colloids with a size similar to that of membrane pores are responsible for irreversible fouling in the pre-coagulation microfiltration membrane filtration process for drinking water treatment. Such colloidal particles are defined here as meso‑colloids, and the charge neutralization of meso‑colloids is demonstrated to be a key to controlling irreversible fouling. However, meso‑colloids remain negatively charged at neutral pH, the reason for which is still unclear. To increase the efficiency of membrane operation, additional knowledge about the causes and behaviors of meso‑colloids during pre-coagulation is indispensable. Therefore, in this study, meso‑colloids are fractionated after a series of jar tests, and their exact composition and charge properties are characterized. Two natural water samples, the adjusted water consisting of meso‑colloid fraction separated from one of the natural water samples and additional inorganic chemicals, and the adjusted water by the addition of appropriate inorganic chemicals into pure water are used for jar tests, which are conducted with and without the addition of the coagulant polyaluminum chloride (PACl). After the jar tests using two natural water samples, all of the meso‑colloids exhibit a negative charge under the conditions applied for the jar tests, indicating that charge neutralization is difficult. The composition of the meso‑colloids is found to be completely different depending on the water source used. Organic-rich water tends to generate meso‑colloids with a low Al/C (mass ratio of aluminum and organic carbon) ratio. In contrast, organic-poor water tends to produce meso‑colloids with a high Al/C ratio. From the results of the jar tests using two kinds of adjusted water samples, it is found challenging to neutralize meso‑colloids by PACl at neutral pH, because the overdose and underdose of PACl result in negatively charged biopolymer or negatively charged aluminum species. Therefore, the development of a new coagulant for specific use in the coagulation membrane filtration process is proposed, which can minimize the formation of negatively charged species even at neutral pH.

Interaction of Pb(II) with microplastic-sediment complexes: Critical effect of surfactant

In this study, the impact of surfactants on the adsorption behavior of Pb(II) onto microplastics-sediment (MPs-S) complexes was investigated. Firstly, virgin polyamide (VPA) and polyethylene (VPE) were placed in Xiangjiang River sediment for six months to conduct in-situ aging. The results indicated that the biofilm-developed polyamide (BPA) and polyethylene (BPE) formed new oxygen-containing functional groups and different biofilm species. Furthermore, the adsorption capacity of Pb(II) in sediment (S) and MPs-S complexes was in the following order: S > BPA-S > VPE-S > VPA-S > BPE-S. The addition of sodium dodecyl benzenesulfonate (SDBS) promoted the adsorption of Pb(II), and the adsorption amount of Pb(II) increased with the higher concentration of SDBS, while adding cetyltrimethylammonium bromide (CTAB) showed the opposite result. The adsorption process of MPs-S complexes to Pb(II) was dominated by chemical adsorption, and the interaction between MPs-S complexes and Pb(II) was multilayer adsorption involving physical and chemical adsorption when the surfactants were added. Besides, the pH exerts a significant effect on Pb(II) adsorption in different MPs-S complexes, and the highest adsorption amount occurred at pH 6. Noteworthy, CTAB promoted the adsorption ability of Pb(II) when the exogenous FA was added. The binding characteristic of sediment endogenous DOM components and Pb(II) was influenced by the addition of MPs and surfactants. Finally, it confirmed that adsorption mechanisms mainly involve electrostatic and hydrophobic interaction. This study provides a new perspective to explore the environmental behaviors of Pb(II) by MPs and sediments with the addition of surfactants, which was conducive to evaluating the ecological risks of MPs and heavy metals in aquatic environments.

Treatment of wastewater from oil palm industry in Malaysia using polyvinylidene fluoride-bentonite hollow fiber membranes via membrane distillation system

Membrane distillation (MD) is gaining increasing recognition within membrane-based processes for palm oil mill effluent (POME) treatment. This study aims to alter the physicochemical characteristics of polyvinylidene fluoride (PVDF) membranes through the incorporation of bentonite (B) at varying weight concentrations (ranging from 0.25 wt% to 1.0 wt%). Characterization was conducted to evaluate changes in morphology, thermal stability, surface characteristics and wetting properties of the resulting membranes. The resulting membranes were also tested using direct contact membrane distillation (DCMD) with POME as the feed solution, aiming to generate high-purity water. Results indicated that the PVDF-0.3B and PVDF-0.5B membranes achieved the highest water vapor flux. The finger-like structure and macrovoids present in these membranes aid in minimizing mass resistance during vapor transport and enhancing permeate flux. All membranes demonstrated exceptional performance in removing contaminants, eliminating total dissolved solids (TDS) and achieving over 99% rejection of chemical oxygen demand (COD), nitrate nitrogen (NN), color, and turbidity from the feed solution. The permeate water analysis showed that the PVDF-0.3B membrane had superior removal efficiency and met the standards set by the local Department of Environment (DOE). The PVDF-0.3B membrane was chosen as the preferred option because of its consistent flux and high removal efficiency. This study demonstrated that incorporating bentonite into PVDF membranes significantly enhanced their properties and performance for POME treatment.

Progress and obstacles in employing carbon quantum dots for sustainable wastewater treatment

We explored the potential of carbon quantum dots (CQDs) as novel materials for wastewater treatment and their role towards environmental sustainability. The advantages of CQDs over other carbon-based materials, when synthesized using the same precursor material and for the same contaminant are discussed, enabling future researchers to choose the appropriate material. CQDs have demonstrated exceptional adaptability in various wastewater treatment, acting as efficient adsorbents for contaminants, exhibiting excellent photocatalytic properties for degradation of organic pollutants, and functioning as highly sensitive sensors for water quality monitoring. We found that bottom-up approach has better control over particle size (resulting CQDs: 1-4 nm), whereas top-down synthesis approach (resulting CQDs: 2-10 nm) have more potential for large scale applications and tunability. Transmission electron microscopy (TEM) remains the most expensive characterization technique, which provides the best resolution of the CQD's surface. The study emphasizes on the environmental impact and safety considerations pertaining to CQDs by emphasizing the need for thorough toxicity evaluation, and necessary environmental precautions. The study also identifies the lacunae pertaining to critical challenges in practical implementation of CQDs, such as scalability, competition of co-existing contaminants, and stability. Finally, future research directions are proposed, advocating green synthesis approaches, tailored surface functionalization, and, lowering the overall cost for analysis, synthesis and application of CQDs.

Fabrication of a novel macrophage-targeted biomimetic delivery composite hydrogel with multiple-sensitive properties for tri-modal combination therapy of rheumatoid arthritis

In this study, a porous polydopamine (PDA) nanoparticle-decorated β-glucan microcapsules (GMs) nanoplatform (PDA/GMs) were developed with macrophage-targeted biomimetic features and a carriers-within-carriers structure. Indocyanine green (ICG) and catalase (CAT) were subsequently co-encapsulated within the PDA/GMs to create a multifunctional nanotherapeutic agent, termed CIPGs. Furthermore, CIPGs and sinomenine (SIN) were co-loaded within a thermo-sensitive hydrogel to design an injectable delivery system, termed CIPG/SH, with potential for multi-modal therapy of rheumatoid arthritis (RA). Photothermal studies indicated that the CIPGs hold excellent photothermal conversion ability and thermal stability, as they combined the photothermal performance of both PDA and ICG. Meanwhile, the CIPGs displayed favorable oxygen self-supplying and photodynamic performance. The CIPGs showed near-infrared (NIR)-induced phototoxicity, effectively inhibiting macrophage proliferation and displaying remarkable antibacterial activity. In vitro drug release from the prepared CIPG/SH showed a controlled release pattern. Animal experiments conducted on an RA mice model confirmed that the formulated CIPG/SH exhibited significant therapeutic effects. By integrating the biological advantages, photothermal/photodynamic performance of the CIPGs, and controlled drug release performance of the thermo-sensitive hydrogels in a single delivery system, the prepared injectable CIPG/SH represents a novel versatile delivery system with great potential for multi-modal combination targeting therapy in RA.

Characterisation of colloidal structures and their solubilising potential for BCS class II drugs in fasted state simulated intestinal fluid

A suite of fasted state simulated intestinal fluid (SIF), based on variability observed in a range of fasted state human intestinal fluid (HIF) samples was used to study the solubility of eight poorly soluble drugs (three acidic drugs (naproxen, indomethacin and phenytoin), two basic drugs (carvedilol and tadalafil) and three neutral drugs (felodipine, fenofibrate, griseofulvin)). Particle size of the colloidal structures formed in these SIF in the presence and absence of drugs was measured using dynamic light scattering and nanoparticle tracking analysis. Results indicate that drug solubility tends to increase with increasing total amphiphile concentration (TAC) in SIF with acidic drugs proving to be more soluble than basic or neutral drug in the media evaluated. Dynamic light scattering showed that as the amphiphile concentration increased, the hydrodynamic diameters of the structures decreased. The scattering distribution confirmed the polydispersity of the simulated intestinal fluids compared to the monodisperse distribution observed for FaSSIF v1). There was a large difference in the size of the structures found based on the composition of the SIF, for example, the diameter of the structures measured in felodipine in the minimum TAC media was measured to be 170 ± 5 nm which decreased to 5.1 ± 0.2 nm in the maximum TAC media point. The size measured of the colloidal structures of felodipine in the FaSSIF v1 was 86 ± 1 nm. However, there was no simple correlation between solubility and colloidal size. Nanoparticle tracking analysis was used for the first time to characterise colloidal structures within SIF and the results were compared to those obtained by dynamic light scattering. The particle size measured by dynamic light scattering was generally greater in media with a lower concentration of amphiphiles and smaller in media of a higher concentration of amphiphiles, compared to that of the data yielded by nanoparticle tracking analysis. This work shows that the colloidal structures formed vary depending on the composition of SIF which affects the solubility. Work is ongoing to determine the relationship between colloidal structure and solubility.

Application of high-dose UV irradiation as nanofiltration pretreatment for drinking water production: Organic fouling mitigation and micropollutant removal

Nanofiltration (NF) is being increasingly applied to produce high-quality drinking water; however, its cost-effective operation remains challenging due to the perennial membrane fouling. On account of the low tolerance of common NF membranes to chemical oxidants, this study proposed high-dose UV irradiation as a pretreatment strategy for organic fouling mitigation. Results showed that the permeate flux decline of the membrane with UV-treated feedwater (with a dose of 750 mJ cm-2) was less drastic than that with raw feedwater, but slightly faster as compared to that with UV/Cl2 pretreatment. The final normalized fluxes were 0.69, 0.79, and 0.82, respectively, after 10 h of operation with raw, UV- and UV/Cl2-treated feedwaters. With the characterization of feedwaters and membranes, the fouling was found to be initiated by the adsorption of hydrophilic biopolymers onto the membrane, followed by the deposition of hydrophobic humic substances. Reduction of the "glue" biopolymers was crucial to membrane fouling mitigation. The applicability of UV pretreatment in practice was testified with a pilot-scale UV-NF system where permeate flux of the NF module decreased by 37% after six-week continuous operation. Moreover, UV pretreatment could remove most of the identified pesticides in the feedwater with a removal efficiency over 80% for metolachlor and imidacloprid, but had no or even a negative effect on perfluorinated compounds. This work discloses the efficacy and mechanism of high-dose UV irradiation for NF membrane fouling control, which facilitates future research and application of NF technology.

Implications of liquid-liquid phase separation and ferroptosis in Alzheimer's disease

Neuronal cell demise represents a prevalent occurrence throughout the advancement of Alzheimer's disease (AD). However, the mechanism of triggering the death of neuronal cells remains unclear. Its potential mechanisms include aggregation of soluble amyloid-beta (Aβ) to form insoluble amyloid plaques, abnormal phosphorylation of tau protein and formation of intracellular neurofibrillary tangles (NFTs), neuroinflammation, ferroptosis, oxidative stress, liquid-liquid phase separation (LLPS) and metal ion disorders. Among them, ferroptosis is an iron-dependent lipid peroxidation-driven cell death and emerging evidences have demonstrated the involvement of ferroptosis in the pathological process of AD. The sensitivity to ferroptosis is tightly linked to numerous biological processes. Moreover, emerging evidences indicate that LLPS has great impacts on regulating human health and diseases, especially AD. Soluble Aβ can undergo LLPS to form liquid-like droplets, which can lead to the formation of insoluble amyloid plaques. Meanwhile, tau has a high propensity to condensate via the mechanism of LLPS, which can lead to the formation of NFTs. In this review, we summarize the most recent advancements pertaining to LLPS and ferroptosis in AD. Our primary focus is on expounding the influence of Aβ, tau protein, iron ions, and lipid oxidation on the intricate mechanisms underlying ferroptosis and LLPS within the domain of AD pathology. Additionally, we delve into the intricate cross-interactions that occur between LLPS and ferroptosis in the context of AD. Our findings are expected to serve as a theoretical and experimental foundation for clinical research and targeted therapy for AD.

Enhancing bioremediation of petroleum-contaminated soil by sophorolipids-modified biochar: Combined metagenomic and metabolomic analyses

In this study, sophorolipids (SLs)-modified biochar (BC-SLs) was used to enhance the bioremediation of petroleum hydrocarbons (PHs) contaminated soil. The biodegradation rate of petroleum hydrocarbons (PHs) by BC-SLs and BC treatments were 62.86 % and 52.64 % after 60 days of remediation experiments, respectively, higher than non-biochar treatment group (24.09 %). The metagenomic analysis showed that the abundance of petroleum-degrading bacteria Actinobacteria and Proteobacteria were increased by 3.8 % and 5.3 %, respectively in BC-SLs treatment, and the abundance of functional genes for PHs degradation, such as alkB, nidA and pcaG, were significantly increased by 12.85 %, 30.08 % and 21.01 %, respectively. The metabolomic analysis showed that BC-SLs facilitated the metabolic process of PHs, the microbial metabolism of petroleum hydrocarbons (PHs) became more active. Fatty acid degradation and polycyclic aromatic hydrocarbons (PAHs) degradation were up-regulated, indicating the promoting effect of the BC-SLs for PHs metabolism. The combined metagenomic and metabolomic analysis demonstrated the strong positive correlations between PHs metabolites and PHs-degrading bacteria, such as lauric acid vs. Actinobacteria, benzoic vs. Proteobacteria. The strong positive correlations between PHs metabolites and PHs-degrading genes were also observed, such as o-ehyltoluene vs. nahD, 4-isopropylbenzoic acid vs. etbAa. The modification of biochar with SLs increased the oxygen-containing functional groups on the surface of biochar. Meanwhile, the emulsification and solubilization of SLs promoted the bioavailability of PHs. The effects of BC-SLs on the nitrogen cycle during PHs remediation showed that it facilitated the accumulation of nitrogen-fixing genes, promoted nitrification but inhibited denitrification process. This study confirms that the application of BC-SLs is an effective remediation of PHs contamination and a sustainable method for controlling agricultural waste resources.

Quercetin encapsulation and release using rapid CO2-responsive rosin-based surfactants in Pickering emulsions

Emulsion-based delivery systems are extensively employed for encapsulating functional active ingredients, protecting them from degradation, and enhancing bioavailability and release efficiency. Here, a CO2-responsive surfactant synthesized from rosin displays rapid responsiveness to CO2 at room temperature, transitioning reversibly switches between active and inactive states multiple times. The dual tertiary amines on the rosin rigid structure contributes to its CO2 sensitivity. When in its active cationic form, in conjunction with silica nanoparticles, it exhibits desired Pickering emulsification performance across various oil phases. In the Pickering emulsion loaded with quercetin, the encapsulation efficiency and loading efficiency reached 80.50% and 0.69%, respectively, with stability lasting at least 30 days. The system provides robust protection for quercetin against external factors, such as UV and heat, revealing sustained release effects. This study investigated the potential of using rosin-based CO2-responsive surfactants alongside nanoparticles to design stable Pickering emulsion systems for active substance encapsulation and sustained release.

Development and validation of an adsorption process for phosphate removal and recovery from municipal wastewater based on hydrotalcite-related materials

In the current international context characterized by the tendency to stricter limits for P concentration in treated wastewater and a strong drive towards phosphate recovery, it is crucial to develop cost-effective technologies to remove and recover phosphate from municipal wastewater (MWW). In this study, an initial screening of the phosphate adsorption performances of 9 sorbents including several hydrotalcites led to the selection of calcined pyroaurite - an innovative material composed of mixed Mg/Fe oxides - as the best-performing one. The assessment of calcined pyroaurite by means of isotherms and continuous-flow adsorption/desorption tests conducted with actual MWW resulted in a high P sorption capacity (12 mgP g-1 at the typical phosphate concentration in MWW), the capacity to treat 730 BVs at the 1 mgP L-1 breakpoint imposed by the current EU legislation, and a 93 % phosphate recovery. Calcined pyroaurite resulted in satisfactory performances also in a test conducted with a saline MWW deriving from a hotspot of seawater intrusion, a rapidly increasing phenomenon as a result of climate change. Five consecutive adsorption/desorption cycles conducted in a 20-cm column at a 5-min empty bed contact time resulted stable in terms of P adsorption/recovery performances, specific surface area and chemical structure of calcined pyroaurite. In the perspective to apply phosphate recovery with calcined pyroaurite at full scale, the process scale-up to a 60-cm packed bed - close to the column heights of industrial applications - resulted in stable performances. Calcium phosphate, widely used to produce phosphate-based fertilizers, can be obtained from the desorbed product by precipitation with Ca(OH)2. These results point to calcined pyroaurite as a very promising material for phosphate removal and recovery from MWW and from other P-rich effluents in a circular economy perspective.

A critical review of biochar for the remediation of PFAS-contaminated soil and water

Per- and polyfluoroalkyl substances (PFAS) present significant environmental and health hazards due to their inherent persistence, ubiquitous presence in the environment, and propensity for bioaccumulation. Consequently, the development of efficacious remediation strategies for soil and water contaminated with PFAS is imperative. Biochar, with its unique properties, has emerged as a cost-effective adsorbent for PFAS. Despite this, a comprehensive review of the factors influencing PFAS adsorption and immobilization by biochar is lacking. This narrative review examines recent findings indicating that the application of biochar can effectively immobilize PFAS, thereby mitigating their environmental transport and subsequent ecological impact. In addition, this paper reviewed the sorption mechanisms of biochar and the factors affecting its sorption efficiency. The high effectiveness of biochars in PFAS remediation has been attributed to their high porosity in the right pore size range (>1.5 nm) that can accommodate the relatively large PFAS molecules (>1.02-2.20 nm), leading to physical entrapment. Effective sorption requires attraction or bonding to the biochar framework. Binding is stronger for long-chain PFAS than for short-chain PFAS, as attractive forces between long hydrophobic CF2-tails more easily overcome the repulsion of the often-anionic head groups by net negatively charged biochars. This review summarizes case studies and field applications highlighting the effectiveness of biochar across various matrices, showcasing its strong binding with PFAS. We suggest that research should focus on improving the adsorption performance of biochar for short-chain PFAS compounds. Establishing the significance of biochar surface electrical charge in the adsorption process of PFAS is necessary, as well as quantifying the respective contributions of electrostatic forces and hydrophobic van der Waals forces to the adsorption of both short- and long-chain PFAS. There is an urgent need for validation of the effectiveness of the biochar effect in actual environmental conditions through prolonged outdoor testing.

Interaction of drug molecules with surfactants below (Benesi-Hildebrand equation) and above the critical micelle concentration (Kawamura equation)

Drug molecules can interact with surfactant molecules either in their monomeric form, where the Benesi-Hildebrand equation determines the binding constant, or when a micellar pseudophase is formed, where the Kawamura equation assesses the partition coefficient. Benesi-Hildebrand plots represent the differential absorbance as a function of surfactant concentration below the critical micelle concentration (CMC), while Kawamura plots show this relationship above the CMC, where the drug can influence the CMC and needs consideration. This review aims to provide an overview of methods for evaluating drug-surfactant interactions in aqueous solutions, particularly below and above the CMC, using spectroscopic data. Understanding these interactions is crucial for pharmacodynamics, affecting drug binding, enzymatic activity, and formulation. Various surfactants were analyzed with diphenhydramine hydrochloride, levofloxacin, phenothiazine, moxifloxacin, and chlorpromazine hydrochloride to determine monomeric binding constants, while sulfathiazole, sodium valproate, cefotaxime, losartan, and metformin hydrochloride were assessed for partitioning coefficient values. Errors in Benesi-Hildebrand plots may arise from considering surfactant concentrations above the CMC, while mistakes in Kawamura plots may stem from neglecting to determine the CMC in the presence of drug molecules, which can alter the surfactant's behavior.

Natural product-loaded lipid-based nanocarriers for skin cancer treatment: An overview

The skin is essential for body protection and regulating physiological processes. It is the largest organ and serves as the first-line barrier against UV radiation, harmful substances, and infections. Skin cancer is considered the most prevalent type of cancer worldwide, while melanoma skin cancer is having high mortality rates. Skin cancer, including melanoma and non-melanoma forms, is primarily caused by prolonged exposure to UV sunlight and pollution. Currently, treatments for skin cancer include surgery, chemotherapy, and radiotherapy. However, several factors hinder the effectiveness of these treatments, such as low efficacy, the necessity for high concentrations of active components to achieve a therapeutic effect, and poor drug permeation into the stratum corneum or lesions. Additionally, low bioavailability at the target site necessitates high doses, leading to skin irritation and further obstructing drug absorption through the stratum corneum. To overcome these challenges, recent research focuses on developing a medication delivery system based on nanotechnology as an alternative to this traditional approach. Nano-drug delivery systems have demonstrated great promise in treating skin cancer by providing a more effective means of delivering drugs with better stability and drug absorption. An overview of various lipid-based nanocarriers is given in this review article that are utilized to carry natural compounds to treat skin cancer.

Nano/micro flexible fiber and paper-based advanced functional packaging materials

Recently, fiber-based and functional paper food packaging has garnered significant attention for its versatility, excellent performance, and potential to provide sustainable solutions to the food packaging industry. Fiber-based food packaging is characterized by its large surface area, adjustable porosity and customizability, while functional paper-based food packaging typically exhibits good mechanical strength and barrier properties. This review summarizes the latest research progress on food packaging based on fibers and functional paper. Firstly, the raw materials used for preparing fiber and functional paper, along with their physical and chemical properties and roles in food packaging, were discussed. Subsequently, the latest advancements in the application of fiber and paper materials in food packaging were introduced. This paper also discusses future research directions and potential areas for improvement in fiber and functional paper food packaging to further enhance their effectiveness in ensuring food safety, quality, and sustainability.

Magnetic biochar as a revolutionizing approach for diverse dye pollutants elimination: A comprehensive review

The term "biomass" encompasses all substances found in the natural world that were once alive or derived from living organisms or their byproducts. These substances consist of organic molecules containing hydrogen, typically oxygen, frequently nitrogen, and small amounts of heavy, alkaline earth and alkali metals. Magnetic biochar refers to a type of material derived from biomass that has been magnetized typically by adding magnetic components such as magnetic iron oxides to display magnetic properties. These materials are extensively applicable in widespread areas like environmental remediation and catalysis. The magnetic properties of these compounds made them ideal for practical applications through their easy separation from a reaction mixture or environmental sample by applying a magnetic field. With the evolving global strategy focused on protecting the planet and moving towards a circular, cost-effective economy, natural compounds, and biomass have become particularly important in the field of biochemistry. The current research explores a comparative analysis of the versatility and potential of biomass for eliminating dyes as a sustainable, economical, easy, compatible, and biodegradable method. The elimination study focused on the removal of various dyes as pollutants. Various operational parameters which influenced the dye removal process were also discussed. Furthermore, the research explained, in detail, adsorption kinetic models, types of isotherms, and desorption properties of magnetic biochar adsorbents. This comprehensive review offers an advanced framework for the effective use of magnetic biochar, removing dyes from textile wastewater.

Recent advances in nanoagents delivery system-based phototherapy for osteosarcoma treatment

Osteosarcoma (OS) is a prevalent and highly malignant bone tumor, characterized by its aggressive nature, invasiveness, and rapid progression, contributing to a high mortality rate, particularly among adolescents. Traditional treatment modalities, including surgical resection, radiotherapy, and chemotherapy, face significant challenges, especially in addressing chemotherapy resistance and managing postoperative recurrence and metastasis. Phototherapy (PT), encompassing photodynamic therapy (PDT) and photothermal therapy (PTT), offers unique advantages such as low toxicity, minimal drug resistance, selective destruction, and temporal control, making it a promising approach for the clinical treatment of various malignant tumors. Constructing multifunctional delivery systems presents an opportunity to effectively combine tumor PDT, PTT, and chemotherapy, creating a synergistic anti-tumor effect. This review aims to consolidate the progress in the application of novel delivery system-mediated phototherapy in osteosarcoma. By summarizing advancements in this field, the objective is to propose a rational combination therapy involving targeted delivery systems and phototherapy for tumors, thereby expanding treatment options and enhancing the prognosis for osteosarcoma patients. In conclusion, the integration of innovative delivery systems with phototherapy represents a promising avenue in osteosarcoma treatment, offering a comprehensive approach to overcome challenges associated with conventional treatments and improve patient outcomes.

Neurological effects of carbon quantum dots on zebrafish: A review

Fluorescent carbon dots have emerged as promising nanomaterials for various applications, including bioimaging, food safety detection and drug delivery. However, their potential impact on neurological systems, especially in-vivo models, remains a critical area of investigation. This review focuses on the neurological effects of carbon dots and carbon quantum dots on zebrafish, an established vertebrate model with a conserved central nervous system. Recent studies have demonstrated the efficient uptake and distribution of carbon dots in zebrafish tissues, with a particular affinity for neural tissues. The intricate neural architecture of zebrafish allows for the precise examination of behavioral changes and neurodevelopmental alterations induced by fluorescent carbon dots. Neurotoxicity assessments reveal both short-term and long-term effects, ranging from immediate behavioral alterations to subtle changes in neuronal morphology. The review discusses potential mechanisms underlying these effects highlights the need for standardized methodologies in assessing neurological outcomes and emphasizes the importance of ethical considerations in nanomaterial research. As the field of nanotechnology continues to advance, a comprehensive understanding of the impact of fluorescent carbon dots on neurological function in zebrafish is crucial for informing safe and sustainable applications in medicine and beyond.

Contemporary strategies in glioblastoma therapy: Recent developments and innovations

Glioblastoma multiforme (GBM) represents one of the most prevailing and aggressive primary brain tumors among adults. Despite advances in therapeutic approaches, the complex microenvironment of GBM poses significant challenges in its optimal therapy, which are attributed to immune evasion, tumor repopulation by stem cells, and limited drug penetration across the blood-brain barrier (BBB). Nanotechnology has emerged as a promising avenue for GBM treatment, offering biosafety, sustained drug release, enhanced solubility, and improved BBB penetrability. In this review, a comprehensive overview of recent advancements in nanocarrier-based drug delivery systems for GBM therapy is emphasized. The conventional and novel treatment modalities for GBM and the potential of nanocarriers to overcome existing limitations are comprehensively covered. Furthermore, the updates in the clinical landscape of GBM therapeutics are presented in addition to the current status of drugs and patents in the same context. Through a critical evaluation of existing literature, the therapeutic prospect and limitations of nanocarrier-based drug delivery strategies are highlighted offering insights into future research directions and clinical translation.

Static magnetic field effects on the secondary structure and elasticity of collagen molecules; a possible biophysical approach to treat keratoconus

Type I collagen is among the major extracellular proteins that play a significant role in the maintenance of the cornea's structural integrity and is essential in cell adhesion, differentiation, growth, and integrity. Here, we investigated the effect of 300 mT Static Magnetic Field (300 mT SMF) on the structure and molecular properties of acid-solubilized collagens (ASC) isolated from the rat tail tendon. The SMF effects at molecular and atomic levels were investigated by various biophysical approaches like Circular Dichroism Spectropolarimetery (CD), Fourier Transform Infrared Spectroscopy (FTIR), Zetasizer light Scattering, and Rheological assay. Exposure of isolated type I collagen to 300 mT SMF retained its triple helix. The elasticity of collagen molecules and the keratoconus (KCN) cornea treated with SMF decreased significantly after 5 min and slightly after 10, 15, and 20 min of treatments. The exposure to 300 mT SMF shifted the Amid I bond random coil to antiparallel wave number from 1647 to 1631 cm-1. The pH of the 300 mT SMF treated collagen solution increased by about 25 %. The treatment of the KCN corneas with 300 mT SMF decreased their elasticity significantly. The promising results of the effects of 300 mT SMF on the collagen molecules and KCN cornea propose a novel biophysical approach capable of manipulating the collagen's elasticity, surface charges, electrostatic interactions, cross binding, network formation and fine structure. Therefore, SMF treatment may be considered as a novel non-invasive, direct, non-chemical and fast therapeutic and manipulative means to treat KCN cornea where the deviated physico-chemical status of collagen molecules cause deformation.

A critical review on leaching of contaminants from asphalt pavements

Contaminant leaching from asphalt pavements poses a significant environmental concern, potentially damaging soil and groundwater quality. The growing interest in incorporating recycled materials in asphalt pavements has further raised concerns over the potential environmental hazards due to contaminant leaching. Consequently, this paper offers a comprehensive review of the literature over the past three decades structured into six sections: groundwater contamination via leaching, methodologies for evaluating leaching, analysis of contaminants, contaminants and leaching from road materials incorporating recycled waste, other factors affecting leaching of pollutants from asphalt pavements, and mathematical models to predict leaching from asphalt pavements. Despite the importance of addressing leaching issues, there is a lack of standardised leaching tests and guidelines specific to asphalt materials, limited attention to evaluating contaminants beyond heavy metals and PAHs in asphalt leachates, insufficient understanding of optimal instrument parameters for asphalt leachate analysis, and a scarcity of mathematical models to predict future leaching potential.

Synthesis of melanin-like amino acid surfactant with enzymatic hydrolysates from silk degumming water

The degummed wastewater from silk processing contains a huge amount of amino acids and polypeptides from sericin. The silk degumming water is far from being exploited fully. Sericin in the degumming water is generally wasted and causes environmental pollution. In this study, simulated silk degumming water was hydrolyzed by alkaline protease to produce abundant amino acids and polypeptides. After enzymatic hydrolysis, the maximum free amino groups concentration in the silk degumming water was approximately 54 mM. It facilitated the recycling of silk degumming water for the production of melanin-like amino acid surfactants as raw materials. 4-Tert-butylcatechol was used as the starting material to generate o-quinone via oxidation by ceric ammonium nitrate. o-Quinone was coupled with free amino groups in enzymatic hydrolysates of silk degumming water to synthesize a sericin-based amino acid surfactant as hydrophobic and hydrophilic group, respectively. Through the green and simple synthesis route, the product was characterized to have a novel melanin-like structure. The product exhibited superior surface-active properties by lowering the surface tension to 32.39 mN m-1. Furthermore, it demonstrated good foaming ability and foam stability, with the initial foam volume of 37 mL and the foam half-life time of more than 25 min. The product owned a good emulsification ability in the oil-water emulsion with delamination time of 297 s and 291 s for emulsion formed by soybean oil and liquid paraffin, respectively. The wetting time of the canvas sheet was only 134 s. Consequently, the product showed low surface tension, good foaming, emulsifying, and wetting properties.

Single-molecule profiling of per- and polyfluoroalkyl substances by cyclodextrin mediated host-guest interactions within a biological nanopore

Biological nanopores are increasingly used in molecular sensing due to their single-molecule sensitivity. The detection of per- and polyfluoroalkyl substances (PFAS) like perfluorooctanoic acid and perfluorooctane sulfonic acid is critical due to their environmental prevalence and toxicity. Here, we investigate selective interactions between PFAS and four cyclodextrin (CD) variants (α-, β-, γ-, and 2-hydroxypropyl-γ-CD) within an α-hemolysin nanopore. We demonstrate that PFAS molecules can be electrochemically sensed by interacting with a γ-CD in a nanopore. Using HP-γ-CDs with increased steric resistance, we can identify homologs of the perfluoroalkyl carboxylic acid and the perfluoroalkyl sulfonic acid families and detect common PFAS in drinking water at 0.4 to 2 parts per million levels, which are further lowered to 400 parts per trillion by sample preconcentration. Molecular dynamics simulations reveal the underlying chemical mechanism of PFAS-CD interactions. These insights pave the way toward nanopore-based in situ detection with promises in environmental protection against PFAS pollution.

Separation of C6 hydrocarbons on sodium dithionite reduced graphene oxide aerogels

The ability of reduced graphene oxide aerogels (rGOAs) for challenging gas-phase separation was investigated with hexane isomers and benzene (C6 hydrocarbons) using inverse gas chromatography (IGC). For the first, rGOAs were synthesized with sodium dithionite (DTN) as a reductant. Experiments revealed that the most optimal DTN to graphene oxide mass ratio was 2:1, resulting in the highest specific surface area of 432.3 m2 g-1 and the highest degree of graphitization among analyzed samples. C6 hydrocarbon adsorption tests demonstrated the dominant role of the kinetic effect for the adsorption of branched and cyclic hexane isomers - the partition coefficient decreased as the molecule kinetic diameter increased. The contribution of thermodynamic effects was distinguished for molecules with uneven charge distribution. A comparison of the partition coefficient ratios for different pairs of hydrocarbons demonstrated the potential of rGOAs in separating various C6 hydrocarbons. The selectivity, calculated from binary-component adsorption tests of benzene (Bz)/cC6 equimolar mixture, was 13.7, 8.5 and 2.8 for DTN4, DTN2, and DTN1. The research indicates that rGOAs may have potential as adsorbents for the selective separation of hydrocarbons, however, the competitive adsorption and performance at high surface coverages of adsorbates have to be accounted for in further research to assess the applicability of rGOAs reliably.

Surface accumulation and acid-base equilibrium of phenol at the liquid-vapor interface

We have investigated the surfactant properties of phenol in aqueous solution as a function of pH and bulk concentration using liquid-jet photoelectron spectroscopy (LJ-PES) and surface tension measurements. The emphasis of this work is on the determination of the Gibbs free energy of adsorption and surface excess of phenol and its conjugate base phenolate at the bulk pKa (9.99), which can be determined for each species using photoelectron spectroscopy. These values are compared to those obtained in measurements well below and well above the pKa, where pure phenol or phenolate, respectively, are the dominant species, and where the Gibbs free energy of adsorption determined from surface tension and LJ-PES data are in excellent agreement. At the bulk pKa the surface-sensitive LJ-PES measurements show a deviation of the expected phenol/phenolate ratio in favor of phenol, i.e., an apparent upward shift of the at the surface. In addition, the Gibbs free energies of adsorption determined by LJ-PES at the bulk pKa for phenol and phenolate deviate from those observed for the pure solutions. We discuss these observations in view of the different surface propensity of phenol and phenolate as well as potential cooperative interactions between them in the near-surface region.

Construction and Properties Evaluation of the Binary Flooding System Based on Lipid Peptide

To enhance crude oil recovery under complex reservoir conditions and reduce the environmental impact of the oil displacement system, a biosurfactant lipid peptide (TH) was combined with four chemical surfactants. From these combinations, those capable of achieving an ultralow interfacial tension region (<10-2 mN/m) were selected. The selected surfactant mixtures were then combined with polyacrylamide (HPAM) to construct a surfactant-polymer binary oil displacement system. The results showed that TH/OAB(2:1), TH/OAB(3:1), and TH/EAO(3:1) could reduce IFT to the ultralow interfacial tension region. Compound surfactants are easier to form mixed micelles than single surfactants, and the EACN of TH/OAB(2:1) and TH/EAO(3:1) is consistent with EACNOil, which can achieve higher surface activity at lower concentrations. The three compound surfactants have a wide range of ultralow interfacial tension concentrations and excellent antidilution performance. TH/OAB(2:1) and TH/EAO(3:1) have better antiformation adsorption performance than TH/OAB(3:1), and the oil washing rate of TH/OAB(2:1) is up to 80.30%. TH and OAB have spatial complementarity, which can increase the molecular packing density at the oil-water interface and reduce the IFT. In CaCl2 and NaCl solutions, the IFT of the two binary flooding systems constructed by TH/OAB(2:1) and TH/EAO(3:1) and HPAM remained in the ultralow interfacial tension region, with excellent salt resistance. When aged in the reservoir for 90 days, the IFT slightly increased but the viscosity decreased significantly. Adding a viscosity retaining agent (JW) was required to maintain the viscosity of the system. In the simulated oil displacement experiment, the recovery improvement of the two binary oil displacement systems was higher than those of surfactant and polymer alone. This study provides a new idea for the alkali-free surfactant-polymer binary oil flooding system and provides theoretical support for the practical application of TH in tertiary oil recovery.

Cyclization of alanyl-valine dipeptides in the solid state. The effects of molecular radiator and heat capacity

Heating of linear dipeptides above a critical temperature initiates their cyclization even in the solid state. This method of obtaining cyclic dipeptides meets the requirements of "green chemistry", provides a high yield of the main product and releases only water as a by-product of the reaction, and does not require solvents. However, to date, the cyclization of only a small number of dipeptides in the solid state has been studied, and some correlations of the process were discovered. The influence of the structure of dipeptide molecules and their crystal packing on the kinetics of solid-state cyclization is still not fully understood. In this work, the cyclization of L-alanyl-L-valine in the solid state upon heating was studied. Using non-isothermal kinetic approaches, the kinetic parameters of this reaction and the optimal kinetic model describing this process were determined. The effect of the features of the crystal packing of dipeptides and their heat capacity on the temperature of the cyclization in the solid state was analyzed. This study expands our knowledge about solid-state reactions involving dipeptides and the ability to control such reactions.

Paper-based colorimetric sensor using a single-atom nanozyme for the ultrasensitive detection of Cr(VI) in short-necked clams

Single-atom nanozymes (SAzymes) as a class of highly active nanozymes with the advantages of high atom utilization, high catalytic activity and stability have attracted great attention. In this work, Fe-N-C SAzymes with exceptional oxidase (OXD)-like activity were achieved utilizing polyvinylpyrrolidone (PVP) as a template. The Fe-N-C SAzymes with remarkable OXD-like activity could oxidize TMB to blue oxTMB, but 8-hydroxyquinoline (8-HQ) as a metal chelator is capable of discoloring oxTMB. Thus, the addition of 8-HQ decolorized the solution. However, upon the introduction of Cr(VI) ions, 8-HQ preferentially chelated with the Cr(VI) ions, reversing the inhibition of the color reaction and restoring the blue color. Based on this phenomenon, we constructed a novel paper-based analytical device (PAD) that exhibited a linear range of 5-1000 μM and an LOD of 1.2 μM. Importantly, the PAD used in this study shows the merits of simplicity, low preparation costs, and rapid reaction times. When combined with smartphone RGB analysis, it enables the simultaneous analysis of eight different Cr(VI) concentrations without the need for large-scale instrumentation. Moreover, the proposed PAD displays high selectivity, accuracy and utility in testing actual short-necked clam samples. This work not only provides a simple and cost-effective method to detect Cr(VI) but also makes a contribution to rapid food testing.

Preparation of Silver Nanoparticles in a Water-in-Oil Microemulsion Stabilized by Ecosurf EH3 and Determination of Their Electrophoretic Mobility

This work describes a study on the electrophoresis of silver nanoparticles in reverse microemulsions with varying water content. The microemulsion was stabilized using a nonionic ethoxylated surfactant, 2-ethylhexanol triethoxylate (Ecosurf EH3). This study represents the second example of electrophoresis research conducted in media with a low dielectric constant for etoxylated surfactants. The study also determined the boundaries of thermodynamic stability and the conditions required to obtain nanoparticles with a high yield. The hydrodynamic diameter and electrophoretic mobility of nanoparticles were measured using dynamic light scattering and laser Doppler electrophoresis. The study determined the boundary conditions for applying these methods to laser-absorbing samples. The electrophoretic mobility of nanoparticles was found to be dependent on the fraction of water in the range of 2-5% vol. (equivalent to a metal content of 10-25 mM), as determined by electrophoresis in a free medium. The increase in volume fraction of water leads to agglomeration of micelles, which causes a decrease in the electrokinetic potential of nanoparticles, likely due to the blurring of the diffuse part of the electrical double layer.

Influence of Aqueous Phase Salt and Oil Phase Surfactants and Viscosity on the Dynamic Interfacial Tension and Coalescence Timescales

Liquid-liquid separation is a critically important process in the treatment of emulsions that can occur in our environment, such as oily stormwater, shipboard bilgewater, or off-shore oil spill treatment. Effective filtration systems, including coalescing filters, are essential for mitigating these environmental pollutants. Achieving this requires a comprehensive understanding of liquid-liquid interface dynamics influenced by additives and surfactants. Furthermore, understanding the impact of surfactants on emulsion stability in saline environments is vital for optimizing filtration processes and ensuring the protection of marine and freshwater ecosystems. In this work, these effects are highlighted using measurements performed across a range of droplet size, surfactant concentration, viscosity ratios, and saline presence. Dynamic IFT measurements are conducted using the pendant drop method for water in light mineral oil, with and without salt in the water phase. The effect of salt addition is also highlighted by using microfluidic coalescence experiments, in which it was found that the addition of salt increases the dimensionless drainage time below the critical micelle concentration. The second focus of this work is to study the effect of bulk phase viscosity on the stability. Dynamic IFT measurements are performed at both millimeter and micrometer scales using pendant drop experiments and microfluidic tensiometry, respectively, involving light and heavy mineral oils with varying SPAN80 surfactant concentrations. The surfactant diffusivity and interfacial adsorption and desorption rates are then extracted by fitting a surfactant diffusion and equation of state equations to the dynamic IFT measurements. The results of the IFT decay, surfactant diffusivity, and adsorption rates are compared at two different viscosity ratios. This study also compares the times required for IFT relaxation with the film drainage times in water-in-oil systems. The comparison aids in comprehending the impact of competing timescales during film drainage. The findings presented in this paper offer valuable insights into the design and optimization of liquid-liquid filtration systems, especially when operating under challenging environmental conditions, such as in saline environments. The principles explored here can be applied to improving industrial water treatment and in the design of advanced filtration technologies for chemical and petrochemical industries, particularly those involving flow, contributing to more sustainable and efficient practices in handling emulsified waste streams.

Experimental and simulation study of reverse micelles formed by aerosol-OT and water in non-polar solvents

The formation of reverse micelles by aerosol-OT [sodium bis(2-ethylhexyl) sulfosuccinate] in hydrocarbon solvents, and in the presence of water, is studied using a combination of atomistic molecular-dynamics simulations and small-angle neutron scattering (SANS). There have been many previous studies of aerosol-OT and its self-assembly in both water and non-aqueous solvents, but this work is focused on a combined experimental and simulation study of reverse-micelle formation. The effects of hydration (with water-to-surfactant molar ratios in the range 0-60) and solvent (cyclohexane and n-dodecane) are investigated. A force field is adapted that results in spontaneous formation of reverse micelles starting from completely randomized configurations. The computed dimensions of the reverse micelles compare very favourably with those determined in SANS experiments, providing validation of the simulation model. The kinetics of reverse-micelle formation are studied with a 50-ns, 1.7-million-atom system which contains, in the steady state, about 50 reverse micelles. The internal structures of reverse micelles are characterized with mass density profiles, and the effects of solvent, and the structural crossover from highly structured water to 'bulk' water in the core, are detailed. The corresponding changes in the molecular reorientation times of sequestered water are also determined. Overall, the combination of experiment and simulation gives a detailed picture of reverse-micelle self-assembly and structure.

Studying the properties of green synthesized silver oxide nanoparticles in the application of organic dye degradation under visible light

In present study the green synthesis of silver oxide nanoparticles has been effectively achieved using novel plant extract Phragmanthera Macrosolen. This method provides sustainable alternative for nanoparticle synthesis, demonstrating the potential of Phragmanthera Macrosolen as a reducing and stabilizing agent in the production of Ag2O NPs. The synthesized nanoparticles were characterized for their structural, morphological, and optical properties, confirming their successful formation and potential applications in various fields. The effects of different pH values and annealing temperature of the samples on the properties of Ag2O NPs formations, as well as photo-catalytic activities towards Toluidine Blue dye degradations, were studied. Powder XRD reveals that the crystallite natures of Ag2O NPs a long with crystalline size ranges from 25.85 to 35.90 nm. FIB-SEM and HR-TEM images displayed that the Ag2O NPs as spherical shapes. UV-vis spectroscopy displayed that Ag2O NPs belong to a direct-band gap of 2.1-2.6 eV. FTIR- study shown that the green synthesized Ag2O NPs may be steadied via the interfaces of -OH as well as C = O groups in the carbohydrate, flavonoid, tannin, as well as phenolic acid existing in P. macrosolen L. leaf. The chemical states, electron-hole recombinations and purity of Ag and O in the synthesized Ag2O NPs were confirmed through X-ray Photoelectron Spectroscopy (XPS) and PL analysis respectively. Fascinatingly, the synthesized Ag2O NPs at pH 12 displayed high photo-catalytic degradations for TB dyes. The photo-catalytic degradations of the TB dyes were monitored spectro-photo-metrically in wave-length ranges of 200-900 nm, as well as high efficiency (98.50%) with half-life of 9.5798 min and kinetic rate constant of 0.07234 min-1, was obtained after 45 min of reactions. From this study, it can be concluded that Ag2O NPs synthesized from Phragmanthera Macrosolen aqueous extract are promising in the remediation of environmental pollution and water treatment. In this light, the study reports that Phragmanthera Macrosolen green synthesis of Ag2O NPs can effectively address environmental pollution in cost-effective, eco-friendly, and sustainable ways.

Construction of Durable, Colored, Superhydrophobic Wood-Based Surface Coatings Using the Sand-In Method

Highly durable color superhydrophobic coatings have attracted much attention in indoor and outdoor decorative applications. In this paper, colorful superhydrophobic coatings with excellent durability were prepared using silane coupling agent-modified iron oxide as the pigment and polydimethylsiloxane-compounded epoxy resin as the base material by the three-step method of "spraying-sanding-spraying". The method is low cost, has a simple preparation process, enables large-area preparation, and has a restorative function. The use of red, yellow, blue, and green four kinds of modified iron oxides through the single color or multicolor into the sand can be obtained by a variety of color coatings, and silica mixed with a variety of colors can be obtained from light to dark coatings. The coating has excellent superhydrophobicity and self-cleaning ability to withstand sandpaper abrasion, water impact, sand impact, UV exposure, and environmental testing. The coating is suitable for interior and exterior decoration and for protection of wooden buildings.

Developing a High-Throughput Platform for the Discovery of Sustainable Antibacterial Materials

Healthcare-associated infections (HCAIs) pose a significant global health challenge, exacerbated by the rising threat of antimicrobial resistance (AMR). This study introduces a high-throughput platform designed to identify sustainable antibacterial surfaces, exemplified by a copper-silver-zirconium (CuAgZr) alloy library. Utilizing combinatorial synthesis and advanced characterization techniques, material libraries (MatLibs) are generated and evaluated to rapidly screen diverse alloy compositions. The results demonstrate the ability to reproducibly create alloys with significant antimicrobial properties and high hardness, making them suitable for biomedical applications. The study highlights the critical role of compositional precision in developing materials that balance mechanical strength with antibacterial efficacy. Additionally, this approach ensures significant cost-effectiveness, facilitating the identification of economically viable alloy compositions. This research underscores the potential of high-throughput materials science to expedite the discovery of sustainable solutions for reducing HCAIs and addressing AMR, signaling a leap forward in sustainable healthcare material development.

Photocatalytic Degradation of Bacterial Lipopolysaccharides by Peptide-Coated TiO2 Nanoparticles

In this study, we report the degradation of smooth and rough lipopolysaccharides (LPS) from Gram-negative bacteria and of lipoteichoic acid (LTA) from Gram-positive bacteria by peptide-coated TiO2 nanoparticles (TiO2 NPs). While bare TiO2 NPs displayed minor binding to both LPS and LTA, coating TiO2 NPs with the antimicrobial peptide LL-37 dramatically increased the level of binding to both LPS and LTA, decorating these uniformly. Importantly, peptide coating did not suppress reactive oxygen species generation of TiO2 NPs; hence, UV illumination triggered pronounced degradation of LPS and LTA by peptide-coated TiO2 NPs. Structural consequences of oxidative degradation were examined by neutron reflectometry for smooth LPS, showing that degradation occurred preferentially in its outer O-antigen tails. Furthermore, cryo-TEM and light scattering showed lipopolysaccharide fragments resulting from degradation to be captured by the NP/lipopolysaccharide coaggregates. The capacity of LL-37-TiO2 NPs to capture and degrade LPS and LTA was demonstrated to be of importance for their ability to suppress lipopolysaccharide-induced activation in human monocytes at simultaneously low toxicity. Together, these results suggest that peptide-coated photocatalytic NPs offer opportunities for the confinement of infection and inflammation.