Iron Nanoparticles Research Articles

Activation of periodate by biocarbon-supported multiple modified nanoscale iron for the degradation of bisphenol A in high-temperature aqueous solution.

As reported, the persistent toxic and harmful pollutant bisphenol A (BPA) from industrial emissions has been consistently found in aquatic environments inhabited by humans. Periodate (PI)-based advanced oxidation processes (AOPs) have been employed to degrade BPA, although activating PI proves more challenging compared to other oxidants. A novel nano iron metal catalyst, sulfided nanoscale iron-nickel bimetallic nanoparticle supported on biocarbon (S-(nFe0-Ni)/BC) was synthesized and utilized to activate PI for the removal of BPA. The morphology, structure, and composition of S-(nFe0-Ni)/BC were characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy-energy dispersive spectrometer (SEM-EDS), and fourier-transform infrared spectrum (FTIR). The catalyst demonstrates an excellent ability to activate PI, achieving a BPA removal efficacy of 86.4%, accompanied by a 33% reduction in total organic carbon (TOC) in the {S-(nFe0-Ni)/BC}/PI system. BPA degradation exhibited a significant change at the 5-min mark. In the first stage (0-5min), nonlinear dynamic fitting research, combined with scavenging experiments, unveiled the competitive degradation of pollutants primarily driven by iodate radical ( ), singlet oxygen , and hydroxyl radical ( ). The competitive dynamics aligned with the ExpAssoc model. The contribution rates of different active species during the second stage (5-120min) were calculated. The contributions of main species to BPA removal follow the order of > > throughout the entire process. The influence of various parameters, such as the dosage of S-(nFe0-Ni)/BC, initial PI concentration, BPA concentration, pH, temperature, and the presence of coexisting anions, was also examined. Finally, a plausible reaction mechanism in the system is proposed, suggesting that the {S-(nFe0-Ni)/BC}/PI system involves a heterogeneous synergistic reaction occurring primarily on the surface of S-(nFe0-Ni)/BC. Therefore, this study proposes a promising approach for PI-based AOPs to degrade organic pollutants, aiming to mitigate the irreversible harm caused by such pollutants to organisms and the environment.

Monte Carlo study of magnetic behaviour of single Fe and Ni nanoparticles

ABSTRACT The exchange integral in the magnetic response of a spherical metallic iron (Fe) and nickel (Ni) nanoparticle is theoretically studied by using Monte Carlo simulations. To this end, using the nanoparticles model in spherical coordinates, we compute magnetization, magnetic susceptibility, specific heat, internal energy, and hysteresis loop over a wide range of temperatures for an Fe and Ni nanoparticle with a size of about 2 nm. The phase transition temperatures are interpolated versus the exchange parameters, and it is observed that the dependence on the coupling parameter is completely linear. Moreover, from the susceptibility results of the samples, the sharpest peak with the least fluctuation gives us the most appropriate Curie temperature and exchange integral for this system. However, the peak related to the heat capacity is also in the Curie temperature range. From the internal energy results, it can be understood that with the increase in phase transition and interaction, the system reaches equilibrium. The magnetic coercive field and remanent magnetization caused by nanoparticles indicate superparamagnetic properties at room temperature. At the end, the obtained results allow us to theoretically determine the magnetic properties of spherical nanoparticles and pave the way for the development of nanoparticles for many applications.

Iron nanoparticles surface decorated MXene via molten salts etching as selenium host for ultrafast sodium ion storage

Sodium-selenium (Na-Se) batteries have gained attention due to their high energy density and power density, resulting from the liquid–liquid reaction at the interface in the dimethoxyethane electrolyte. Nevertheless, the pronounced shuttle effect of polyselenides causes low coulomb efficiency and inadequate cycling stability for Na-Se batteries. Herein, the iron nanoparticles surface modified accordion-like Ti3C2Tx MXene (MXene/Fe) synthesized via the molten salt etching is utilized as the host of Se species for high-performance Na-Se battery cathode. Benefiting from the layered structure and chemical adsorption of accordion-like MXene, the shuttle effect of the cathode is effectively inhibited. Simultaneously, electrochemical kinetics is boosted due to the catalytic effect of Fe nanoparticles, which facilitate the transformation of polyselenide from long-chain to short-chain, contributing to pseudocapacitive capacity. Consequently, the Se-based cathode delivers a steady capacity of 575.0 mA h g−1 at 0.2 A/g, and even a high capacity of 500 mAh/g at 50 A/g based on the mass of Se@MXene/Fe electrode, indicating the ultrafast Na+ ion storage. Most notably, this structure demonstrated remarkable long-term cycling stability for 5000 cycles with a high capacity retention of 97.4 %. The electrochemical energy storage mechanism is further revealed by in situ Raman. Herein, the confinement-catalysis structure shines light on inhibiting shuttling and facilitating ultrafast ion storage.

Influence of Iron Nanoparticle and Multifaceted Endophytic Fungus Piriformospora indica on Zea mays L. - A Novel Approach toward Innovative Yet Sustainable Farming

The amalgamation of nanotechnology and biotechnology holds immense potential for developing innovative and essential products beneficial to mankind. Nanoparticles, particularly iron nanoparticles, exhibit the capacity to enhance plant growth and yield in various crops. Rather than employing nanomaterials alone, combining them with beneficial microorganisms can offer a more effective approach to promoting plant growth and yield. Piriformospora indica, a versatile endophytic fungus serves as a biofertilizer, bioregulator, stimulant, and biocontrol agent upon colonizing plant roots. The present study focuses on the synthesis and characterization of iron-modified multiwalled carbon nanotubes, mesoporous carbon, and alumina materials and their impact on the growth and yield of Zea mays L. in conjunction with Piriformospora indica under greenhouse conditions. The nanomaterials were prepared using the impregnation method and were characterized to confirm their nano size. Under greenhouse conditions, plants treated with nanomaterials and colonized by Piriformospora indica exhibited improvements in root length (≌2.5 times), shoot length (≌1.8 times), root biomass (≌3.5 times), shoot biomass (≌ 2.3 times), chlorophyll content (≌ 3 times), proline accumulation (≌ 2.5 times), and a reduction in lipid peroxidation compared to untreated Zea mays L. plants. This suggests that the combined application of nanomaterials and the multifaceted fungus can positively influence plant growth and yield.

Debundling and reorganization of CNT networks under high temperature treatment

Highly purified and uniformly distributed carbon nanotube (CNT) network is one of the key issues for developing advanced nanocomposites. However, the challenge for mitigation of the aggregation of CNT bundles during the CNT film fabrication still remained. In this work, debundling and reorganization of CNT bundles have been realized simultaneously by using a high-temperature thermal treatment. The debundling of large CNT bundles into small ones started after they were heat treated under 1400 °C and uniformly distributed CNT networks with small bundles were obtained after heat treated under 1800 °C. The tensile strength of the CNT film significantly increased by about 64% compared to the pristine film. Microstructural observations showed that the iron nanoparticles started to evaporate at 1400 °C and were completely removed at 1800 °C. Hollow amorphous carbon shells wrapped on the nanoparticles were left inside the CNT networks after the removal of the iron nanoparticles. Interestingly, these amorphous carbon shells act as carbon source for the deposition of a carbon layer on the CNT surface when the heat treatment temperature was up to 2000 °C, and they were completely consumed after being treated at 2800 °C. The microstructural evolution process of CNT bundles during heat treatment suggests the simple high-temperature treatment strategy could be applied for fabrication of highly purified CNT networks with well-distributed small bundles, enabling the development of advanced multifunctional nanocomposites in the near future.

An intelligent insole based on wide-range flexible pressure sensor

In this paper, an intelligent insole that contains five wide-range flexible capacitive pressure sensors is developed. The output signal of these five sensors is collected and processed by a portable microprocessor system, which is then transmitted to a cloud platform via a Wi-Fi module. The ensuing data visualization is constructed with a WeChat mini-program. The wide-range flexibility is achieved by employing composition materials with a high pressure-sensitive effect. A novel approach is proposed to fabricate flexible pressure-sensitive dielectrics, thereby significantly enhancing the sensitivity and detection range of pressure sensors. The fabrication process involves utilizing polydimethylsiloxane (PDMS) as a flexible substrate, incorporating nano-iron powder and polyvinylidene fluoride as sensitizing materials, and applying an external magnetic field to control the distribution of iron nanoparticles during the curing process of PDMS. Furthermore, a motion detection system tailored for these flexible sensors is developed. By integrating sensor networks with Internet of things technology, the application potential of wide-range flexible pressure sensors in kinematics and medical rehabilitation fields can be effectively realized.

Isotherm and Kinetic Studies on Adsorption of Yellow Azo Dyes (Sunset Yellow, Tartrazine) using <i>Kigelia africana</i> (Lam.) Benth., Leaf Extract Mediated Iron Nanoparticles

Sunset yellow and tartrazine are commonly used azo dyes extensively employed in beverages and food products such as soda, fruit juices, confectionery, and cakes. These dyes hold the distinction of being the second and third most frequently utilized colour additives in a wide array of beverage products. The discharge of these synthetic food dyes into industrial wastewater can lead to significant environmental and health issues. Due to its aromatic structure, this dye is resistant to breaking down into harmless compounds, and its removal through effective adsorption presents an economical and efficient solution. The use of renewable bioresources for the eco-friendly production of metallic nanoparticles represents a recent and growing trend in nanotechnology research, offering enhanced environmental safety. In this current research, we achieved the green and cost-effective synthesis of monodispersed Iron Nanoparticles (FeNPs) with exceptional stability by utilizing an aqueous extract of Kigelia africana (Lam.) Benth is the primary bioresource for this synthesis. The FeNPs were noticed to be uniformly distributed spherical-shaped particles having smooth surfaces with a 26-34 nm size range and an average particle size of 28 ± 0.86 nm. The XRD results confirm that the FeNPs were rhombohedral phase structures with 71.43% of elemental iron. These synthesized nanoparticles were applied for the removal of sunset yellow and tartrazine dyes were investigated and more than 90% were removed. The adsorption isotherm study was best fitted with the Langmuir model, and the maximal adsorption capacity was found to be 76.29 and 47.22 mg/g for sunset yellow and tartrazine respectively. The adsorption reaction follows pseudo-first-order kinetics with a high correlation coefficient. Repeated cycles of regeneration, reuse and stability showed very high removal efficiency and stability. In conclusion, the biosynthesis of metal nanoparticles demonstrates substantial promise for applications in environmental protection.

Removal of Heavy Metals from Contaminated Aquatic Streams Using a Resin Supported Green nZVI

This study addresses the escalating demand for clean water resources driven by population growth and water quality deterioration. The research focuses on evaluating the efficacy of a nanocomposite material, incorporating zero valent iron nanoparticles into a chelating cation exchange resin matrix, for selectively removing heavy metals from polluted aquatic environments. The selected resin, featuring iminodiacetic acid functional groups, demonstrates notable selectivity for heavy metal cations over alkali earth metals. Column experiments were conducted to assess the nanocomposite’s performance, utilizing a feed solution spiked with heavy metals at concentrations ten times higher than Greek legislation limits for wastewater effluent recycling. The nanocomposite exhibited significant effectiveness for Cu, Cr(VI), and Pb, consistently maintaining Cu levels below detection limits and demonstrating limited breakthrough of Cr(VI) and Pb depending on experimental conditions. However, the removal efficiency was lower for Ni and insufficient for Cd, Zn, and As in this complex multicomponent solution. This research contributes valuable insights into the potential application of the developed nanocomposite for targeted removal of specific heavy metals in contaminated water sources, providing a foundation for further exploration and application in water remediation technologies.

Green synthesis, characterization, and application of iron and molybdenum nanoparticles and their composites for enhancing the growth of Solanum lycopersicum

Abstract Nanomaterials have become integral in various aspects of agricultural practices, including the development of nano-fertilizers for optimized crop nutrition. This study explores the application of green-synthesized iron (Fe) and molybdenum (Mo) nanoparticles, as well as their composites, using a guava leaf extract (GLE). The focus is on assessing their impact on nitrogen fixation and growth in tomato plants (Solanum lycopersicum). The nanoparticles were characterized through Fourier Transform Infrared Spectroscopy, Ultraviolet Diffused Reflectance Spectroscopy, Raman Spectroscopy, and X-ray diffraction analysis. The experiment involved two application methods (soil and direct plant spraying) with varying nanoparticle concentrations. Results indicate that the 1% composite nanoparticles applied to the soil and 3% Mo directly on plants yield the most favorable growth and nitrogen uptake in S. lycopersicum. Notably, the 1% composite treatment demonstrated significant enhancement in shoot length, number of branches, and shoot diameter at all three growth stages. Conversely, the 3% Mo treatment when applied directly to plants exhibited optimal results showing substantial shoot length, number of branches, and shoot diameter. Post-experimental soil nutrient analysis further revealed the nuanced effects of nanoparticle applications with 1% composite treatments enhancing nutrient availability compared to control and other concentrations. This research contributes to the evolving field of agri-nanotechnology emphasizing the importance of nanoparticle concentration and application method in influencing plant development and nutrient uptake, paving the way for sustainable agricultural practices.

NiFe layered double hydroxide (LDH) anchored, Fe single atom and nanoparticle embedded on nitrogen-doped carbon-CNT (carbon nanotube) framework as a bifunctional catalyst for rechargeable zinc-air batteries

Zinc-air batteries (ZAB) have significant potential for practical energy storage, but their rechargeability has been limited by the lack of a suitable bifunctional catalyst. Here, we developed NiFe LDH-A-Fe/NC-CNT, a remarkable bifunctional catalyst that is built on a hierarchically porous nitrogen-doped carbon and carbon nanotube (NC-CNT) framework enriched with iron single atoms and nanoparticles, with nickel‑iron layered double hydroxides (NiFe LDH) anchored onto it. The NiFe LDH-A-Fe/NC-CNT exhibited remarkable performance in the ORR, with Eonset of 0.94 V, a half-wave potential of 0.84 V, and a limited current of 6.89 mA cm−2. A remarkable Eonset of 1.47 V and a potential of 1.59 V at 10 mA cm−2 (Ej = 10) in the OER were also observed. Significantly, the difference in potential (ΔE) between the ORR and OER was only 0.74 V. The stability tests, tolerance assessments, and poisoning experiments consistently demonstrated the superior performance of this cutting-edge catalyst in comparison to the commercial Pt/C and RuO2. In ZAB tests, it achieves a discharge capacity of 818 mAhg−1 and an impressive power density of 293 mWcm−2, enduring nearly 1000 cycles (320h). Flexible ZABs with this catalyst maintain a 629 mAhg−1 capacity, a power density of 195 mWcm−2, and a lifespan of 95 h (280 cycles), outperforming benchmark catalysts. In conclusion, a remarkable bifunctional catalyst was synthesized, demonstrating its immense capacity for utilization in zinc-air batteries.

Comparative Environmental and Economic Analysis of Biomethane Production from Co-Digestion of Rice Straw and Spent Mushroom Compost: Application of Zero-Valent Iron Nanoparticles

Abstract Spent mushroom compost is one of the main potentials for biogas production. In recent years, several studies employed adding nanoparticles and alkaline pretreatment for improving biogas production. The present study is one of the pioneer studies that employ hybrid alkaline pretreatment (0, 5, and 15 mg of NaOH) and zero-valent iron nanoparticles (0, 10, 20, 30, and 40 mg) for improving the co-digestion of spent mushroom compost and rice straw. According to the results, retention time (RT) and nanoparticle (NP) concentrations have the most significant impact on biomethane production (significant at 1% probability level), while the NaOH concentration has the lowest impact on biomethane production (significant at 5% probability level) in comparison with RT and NP concentration. Also, the maximum biomethane production is related to NP40Na15 (about 200% higher than the control). The minimum cumulative biomethane production is related to NP0Na15 (about 30% lower than the control). The lowest relative environmental midpoint impact is related to NP40Na15, which was on average about 60% lower than the control. Adding NPs at high concentrations of NaOH reduces the midpoint impacts. The results of the study could lead to new, ecologically friendly biomethane production methods that make better use of agricultural and organic wastes.

Iron nanoparticle coating and plasma-activated water cleaning as a biofouling removal method for reverse osmosis membranes suitable for desalination

Desalination provides crucial freshwater, but biofouling on reverse osmosis (RO) membranes is a major challenge due to hard-to-remove biofilms. Conventional treatments are often ineffective, prompting a shift to coatings with nanoparticles like copper, silver, and iron to combat fouling. This study demonstrates a unique combination of coating RO membranes with iron nanoparticles (FeNPs) and treatment with plasma-activated water (PAW) for the removal of biofilm formation. Pure and unbound FeNPs showed no significant inhibition of Escherichia coli biofilms. However, the attachment of FeNPs to RO membranes led to a decrease in biofilm growth on the membrane, and an additional PAW treatment was shown to significantly inhibit mature biofilms. SEM imaging revealed a higher density and uniform distribution of FeNPs on the RO membranes after PAW treatment. Zeta potential measurements showed positively charged FeNPs in PAW, enhancing their attraction with the negative membrane surfaces. The coated membrane using PAW solution with FeNPs exhibited no degradation in terms of pure water flux, saline water flux, and salt rejection compared to the immersion process in DI with FeNPs.

Selective cytotoxic effects of nitrogen-doped graphene coated mixed iron oxide nanoparticles on HepG2 as a new potential therapeutic approach

New selective therapeutics are needed for the treatment of hepatocellular carcinoma (HCC), the 7th most common cancer. In this study, we compared the cytotoxic effect induced by the release of pH-dependent iron nanoparticles from nitrogen-doped graphene-coated mixed iron oxide nanoparticles (FexOy/N-GN) with the cytotoxic effect of nitrogen-doped graphene (N-GN) and commercial graphene nanoflakes (GN) in Hepatoma G2 (HepG2) cells and healthy cells. The cytotoxic effect of nanocomposites (2.5–100 ug/ml) on HepG2 and healthy fibroblast (BJ) cells (12–48 h) was measured by Cell Viability assay, and the half maximal inhibitory concentration (IC50) was calculated. After the shortest (12 h) and longest incubation (48 h) incubation periods in HepG2 cells, IC50 values of FexOy/N-GN were calculated as 21.95 to 2.11 µg.mL−1, IC50 values of N-GN were calculated as 39.64 to 26.47 µg.mL−1 and IC50 values of GN were calculated as 49.94 to 29.94, respectively. After 48 h, FexOy/N-GN showed a selectivity index (SI) of 10.80 for HepG2/BJ cells, exceeding the SI of N-GN (1.27) by about 8.5-fold. The high cytotoxicity of FexOy/N-GN was caused by the fact that liver cancer cells have many transferrin receptors and time-dependent pH changes in their microenvironment increase iron release. This indicates the potential of FexOy/N-GN as a new selective therapeutic.Graphical abstract

The effect of combining green iron nanoparticles and algae on the sustainability of broiler production under heat stress conditions.

Natural feed additives in broiler feed contribute to the overall health, productivity, and economic viability of broiler chickens while meeting consumer demands and preferences for natural products. The purpose of this research was to determine the effect of green iron nanoparticles (Nano-Fe) and Halimeda opuntia supplementation in broiler diets on performance, ammonia excretion in excreta, Fe retention in tissues and serum, carcass criteria, and meat quality under hot environmental conditions. A total of 256 one-day-old male Ross 308 broiler chicks were randomly assigned to one of four feeding treatments for 42 days. Each treatment had eight replications, with eight chicks per replicate. The treatments were Negative control (CON), positive control (POS) supplemented with 1 g/kg Halimeda opuntia as a carrier, POS + 20 mg/kg Nano-Fe (NFH1), POS + 40 mg/kg Nano-Fe (NFH2). When compared to CON and POS, dietary Nano-Fe up to 40 mg/kg enhanced (p < 0.001) growth performance in terms of body weight (BW), body weight gain (BWG), and feed conversion ratio (FCR). Nano-Fe had the highest BWG and the most efficient FCR (linear, p < 0.01, and quadratic, p < 0.01) compared to POS. Without affecting internal organs, the addition of Nano-Fe and POS enhanced dressing and reduced (p < 0.001) abdominal fat compared to control (CON). Notably, the water-holding capacity of breast and leg meat was higher (p < 0.001), and cooking loss was lower in broilers given Nano-Fe and POS diets against CON. In comparison to POS, the ammonia content in excreta dropped linearly as green Nano-Fe levels increased. When compared to CON, increasing levels of Nano-Fe levels boosted Fe content in the breast, leg, liver, and serum. The birds fed on POS showed better performance than the birds fed on CON. Green Nano-Fe up to 40 mg/kg fed to broiler diets using 1 g/kg Halimeda opuntia as a carrier or in single can be utilized as an efficient feed supplement for increasing broiler performance, Fe retentions, carcass characteristics, meat quality, and reducing ammonia excretions, under hot conditions.

Encapsulating carboxymethyl cellulose stabilized nanoscale ferrous sulfide with layered magnesium hydroxide shell for controlled reactivity release and long-term sequestration of Cr(Ⅵ)

Nanoparticulate iron sulfide (nano-FeS) is a highly effective and environmentally-friendly reducing agent for decontamination. However, challenges such as aggregation, poor mobility, and oxidative aging limit its application of in situ groundwater and soil remediation. Herein, we present a novel approach to enhance the feasibility and effectiveness of nano-FeS for in situ remediation by encapsulating carboxymethyl cellulose stabilized FeS nanoparticles with a layered magnesium hydroxide shell (referred to as CMC-FeS@Mg(OH)2). The novel CMC-FeS@Mg(OH)2 nanoparticles, with a suitable coating ratio (10 %–50 %), demonstrate considerably increased colloidal stability and enhanced mobility in porous media. This is mainly due to steric hindrance, and decreased attachment, blocking, and straining effects. The Mg(OH)2 shell obviously protects the reactivity of FeS nanoparticles and enhances their resistance to oxidation, ensuring their longevity and long-term decontamination effectiveness during practical field applications. The preserved reactivity of FeS core can be progressively released and fully recovered by modulating the Mg(OH)2 coating ration and the extent of dissolution. After the complete dissolution of the Mg(OH)2 shell, CMC-FeS@50 % Mg(OH)2 exhibits enhanced efficiency in Cr(VI) sequestration, increasing from 58 % to 92 % compared to bare FeS. The removal of Cr(VI) by CMC-FeS@Mg(OH)2 is a synergistic process, and the main mechanisms includes adsorption, reduction, ion exchange, and subsequent precipitation. These results demonstrate a promising and effective method to improve the mobility and longevity of FeS and enable the controlled reactivity release for in situ remediation of subsurface contamination.

Green synthesis of iron nanoparticles using mulberry leaf extract: characterization, identification of active biomolecules, and catalytic activity.

The synthesis of iron-based nanoparticles (Fe NPs) using traditional preparation methods suffered from the disadvantages of high cost, environmental harm, and easy agglomeration. In this study, a novel eco-friendly method was proposed for the synthesis of iron nanomaterials (ML-Fe NPs): using antioxidant components extracted from mulberry leaf to reduce divalent iron (II). The preparation conditions of ML-Fe NPs were optimized by orthogonal tests. The prepared ML-Fe NPs exhibited an amorphous core-shell structure, displaying excellent dispersion and stability. During the synthesis process of ML-Fe NPs, the polyphenol molecules in mulberry leaf extract played a dominant role. A possible synthetic mechanism involving complexation, reduction, and encapsulation was proposed. Furthermore, the ML-Fe NPs were utilized to construct an ML-Fe NPs/peroxymonosulfate catalytic system for the degradation of Rhodamine B dye wastewater. The ML-Fe NPs demonstrated remarkable catalytic potential, achieving a 99% degradation efficiency for Rhodamine B within a span of 40min.

A self-assembled FeNPs/metal polyphenol structured superhydrophilic PVDF membrane with capability to activate PMS for efficient oil-water separation

Despite the membrane technology as an efficient method for treating emulsified oily wastewater, the issue of membrane fouling remains an enormous challenge during extended operation. Hence, a unique self-assembled method was proposed to clean membrane fouling for oil/water (O/W) separation, where the tannic acid/iron (TA/Fe) coating layer improved hydrophilicity and doped with iron nanoparticles to activate peroxymonosulfate (PMS) for removing of the irreversible oil fouling. The TA/Fe coating, which contained phenolic hydroxyl groups, rendered the modified membrane superhydrophilic and underwater oleophobic properties to resist membrane surface oil droplets. The iron nanoparticles/TA/polyvinylidene fluoride (FeNPs/TA/PVDF) achieved notable permeation flux of 1571.13 L m−2 h−1 and 1490 L m−2 h−1 in O/W mixture and oil-in-water emulsion (liquid paraffin as oil phase), respectively. Meanwhile, the membrane exhibited a distinguished oil removal rate, surpassing 98 % for various emulsions (e.g. N-hexane, isooctane, soybean oil). Notably, in the pollution and cyclic experiments, the regeneration water flux of FeNPs/TA/PVDF increased from 71.7 % of pristine PVDF to 91.5 % after final modification, which proved the enhancement of the membrane anti-oil-fouling capability through the deposition of the hydrophilic coating. Moreover, after catalytic cleaning, the water permeation flux of FeNPs/TA/PVDF could reach approximately 90 % of its original value. Obviously, we observed that FeNPs/TA/PVDF exhibited a high regenerative capacity during the PMS-assisted catalytic cleaning process, where the radical and nonradical pathways coexisted. Generally, the research offered a simple approach to creating functional membranes suitable for efficient O/W separation.

Integrated approaches for heavy metal-contaminated soil remediation: harnessing the potential of Paulownia elongata S. Y. Hu, Oscillatoria sp., arbuscular mycorrhizal fungi (Glomus mosseae and Glomus intraradices), and iron nanoparticles.

In recent years, researchers have extensively investigated the remediation of heavy metal-contaminated soil using plants, microorganisms, and iron nanoparticles. The objective of this study was to investigate and compare the individual and simultaneous effects of Paulownia elongata S. Y. Hu, cyanobacteria (Oscillatoria sp.), arbuscular mycorrhizal fungi (AMF) including Glomus mosseae and Glomus intraradices, and zero-valent iron nanoparticles (nZVI) on the remediation of heavy metal-contaminated soil containing chromium (Cr VI and Cr III) and nickel (Ni). The study found significant variations in parameters such as pH (acidity), electrical conductivity (EC), nitrogen (N), phosphorus (P), potassium (K), and organic carbon (OC) among different treatments. The addition of cyanobacteria, AMF, and nZVI influenced these properties, resulting in both increases and decreases compared to the control treatment. The treatment involving a combination of cyanobacteria, AMF, and nZVI (CCAN25) exhibited the highest increase in growth parameters, such as total dry mass, root length, stem diameter, and leaf area, while other treatments showed varied effects on plant growth. Moreover, the CCAN25 treatment demonstrated the highest increase in chlorophyll a, chlorophyll b, and carotenoid levels, whereas other treatments displayed reductions in these pigments compared to the control. Moderate phytoaccumulation of Cr and Ni in P. elongata samples across all treatments was observed, as indicated by the bioconcentration factor and bioaccumulation coefficient values being less than 1.0 for both metals. The findings provide insights into the potential application of these treatments for soil remediation and plant growth enhancement in contaminated environments.

Effect of iron nanoparticles on chromium adsorption in aqueous solution using magnetic biochar: A site energy distribution analysis

The effects of adding green-synthesized magnetic iron-containing nanoparticles (GSMFe) onto biochar in aqueous solution for the adsorptive removal of hexavalent chromium [Cr(VI)] were investigated in this study. Nanocomposites, denoted as green synthesis magnetic biochar (GSMB), were created using a green synthesis technique with white tea residue to introduce GSMFe into biochar. Six adsorbents, varying in GSMFe content, were tested for their effectiveness in eliminating Cr(VI), a globally significant hazardous heavy metal. The results demonstrated that incorporating GSMFe into biochar led to significant improvements in adsorption capacity and saturation magnetization. With an increasing amount of GSMFe, the maximum adsorption capacity increased from 2.47 mg/g (EWTWB) to 9.11 mg/g (GSMB4). The highest saturation magnetization was achieved at 13.4 Am2/kg at GSMB4. Similarly, surface areas rose up to 72.9 m2/g at GSMB3 but declined thereafter due to GSMFe aggregation and pore blockage. Sorption behavior for Cr(VI) was assessed using five isotherm models, with the Redlich-Peterson model showing the best fit. The analysis of approximate site energy distribution (SED) indicates that the incorporation of GSMFe enhances the frequency of the entire range of sorption energy sites, while the biochar matrix contributes to a slight increase in medium sorption energy sites within the GSMFe. Among the GSMBs, the difference were more pronounced at low-energy sites than at high-energy sites. At higher energy sites (27,500–40,000 J/mol), sorption site frequencies remained similar, regardless of GSMFe content and associated physicochemical properties. For sorption energy site values exceeding 17,500 J/mol (Cr(VI) concentration below 50 mg/L), GSMB2 is regarded as a more practical choice due to its relatively large area under the frequency distribution curve and commendable cost-effectiveness.

Iron nanoparticles as food additives and food supplements, regulatory and legislative perspectives.

Recently, the use of nanotechnology in food has gained great interest. Iron nanoparticles with unique chemical, physical and structural properties allow their potential use mainly as iron fortifiers, colorants and antimicrobial agents. However, in the market we can find only supplements and food colorants based on iron nanoparticles. Their use in food fortification has so far been focused only on in vitro and in vivo experimental studies, since the toxicological evaluation of these studies has so far been the basis for the proposals of laws and regulations, which are still in an early stage of development. Therefore, the aim of this work was to summarize the use of the different forms of iron nanoparticles (oxides, oxyhydroxides, phosphates, pyrophosphates and sulfates) as food additives and supplements and to resume the perspectives of legislation regarding the use of these types of nanoparticles in the food industry.