Excellent Regeneration Research Articles

Removal of Textile Dye Using a Low‑Cost Composite Film Based on PVA-Clay: Preparation, Characterization and RSM Optimization

The use of adsorbent materials in powder form presents significant challenges for industrial wastewater treatment due to their poor regeneration after use. Our research described here aimed to prepare a low-cost and eco-friendly film with excellent regeneration capabilities for the efficient removal of Telon Orange dye (TO) from water. The film was fabricated by incorporating a natural clay, DD3, into a poly (vinyl alcohol) (PVA) matrix using the solvent casting method. The prepared film was characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermal gravimetric analysis (TGA) techniques. The characterization results confirmed that the DD3 interacts and disperses within the PVA matrix. The influence of film dose and composition, pH, contact time, and initial concentration were studied in batch adsorption. Response surface methodology (RSM) using the Box-Behnken design matrix was then used to find the best conditions for dye adsorption. An ANOVA analysis approved the proposed quadratic model with a high correlation coefficients (R2 = 0.98). The F-value of the model was 46.39, indicating that the model was significant. The PVA/DD3 composite film achieved a 93.45% efficiency in removing TO dye under optimal conditions. The recyclability studies showed a removal efficiency of 90.13% after five uses of the film, making it suitable for large-scale applications and adaptable for use in water purification systems.

Enhancing the Regeneration Performance of Methylene Blue Saturated Biochar in H2O2 System via Fe‐Doping

AbstractTo improve the regeneration efficiency of methylene blue (MB) saturated biochar in H2O2 system, biochar was modified by Fe‐doped by using FeSO4 and Fe(NO3)3 as iron sources. The effects of Fe‐doped on its microstructure were characterized by XRD, SEM, and BET. The adsorption and regeneration performance of biochar before and after Fe‐doped were compared through adsorption and regeneration experiments. X‐ray photoelectron spectroscopy, electron spin resonance, and quenching experiments were used to explore the regeneration mechanism. The results show that Fe‐doped biochar (SP‐GBC) prepared from FeSO4 maintains a high specific surface area of 1205.9 m2/g and a high adsorption capacity of 375.43 mg·g−1 for MB. After adsorption, the MB‐saturated SP‐GBC exhibits excellent regeneration performance in the H2O2 system, in which the regeneration efficiencies for five consecutive cycles are 85.76%, 83.92%, 94.01%, 99.24%, and 100.79%, respectively. The synergistic effect of H2O2 desorption and degradation is the main regeneration mechanism for MB‐saturated SP‐GBC. The zero valent iron and Fe (II) on the surface of SP‐GBC are the main active sites for H2O2 activation, while 1O2 and HO· are the main oxidation species. In summary, this work provides a simple and feasible method for the design and synthesis of adsorbents with highly efficient regeneration performance.

Fabrication of core-shell structural Y@VTMS-DVB composites with enhanced hydrophobicity for toluene capture under humid environment

Zeolite Y serves as an effective adsorbent for VOCs capture due to its ordered porous structure, exceptional thermal stability, chemical resistance and fine-tune key properties. However, the hydrophilicity caused by the low SiO2/Al2O3 ratio seriously limits its industrial application, especially in humid environments. In this work, a series of core-shell composites Y@VTMS-DVBn were prepared through surface grafting and copolymerization. A variety of characterizations were utilized to study the structural and morphological changes of the prepared samples. The dynamic breakthrough adsorption experiment showed that the toluene uptake was significantly improved from 1.77 mg/g to 53.09 mg/g under 30 % relative humidity. Moreover, the core-shell composite exhibited excellent regeneration properties, the adsorption capacity remained 90 % under wet conditions after 6 cycles of regeneration. Adsorption kinetic analysis revealed that the adsorption behavior of toluene on the prepared adsorbents was primarily physical adsorption. These results show that the core-shell composite is a promising candidate for VOCs removal in industrial application.

Biomimetic bilayer phase change hydrogels with enhanced water adsorption and desorption for evaporative cooling

Hygroscopic hydrogels, reliable carriers for water-based evaporative materials, undergo shrinkage after evaporative cooling, and the consequent reduction in hygroscopic sites can significantly impair their recyclability in cooling period. To realize cyclic evaporative cooling for rapid regeneration and evaporation, bilayer phase change hydrogel (BPH) concept combining an upper layer of hygroscopic polymer film (CaCl2@ carboxymethyl cellulose/konjac glucomannan films, CaCl2@CMC/KGM, MAF) with a lower layer of hygroscopic hydrogel (CaCl2@poly(vinyl alcohol)/sodium tetraborate decahydrate hydrogel, CaCl2@PVA/Borax, PCH), is presented in this paper. The high liquid–vapor phase change enthalpy of BPH (1274 J/g) enables it to continuously and rapidly remove heat. Benefiting from the MAF hygroscopic porous skeleton, the saturated BPH exhibited a faster water evaporation rate (2.15 kg m−2 h−1) and comparable water vapor transmission rate (1.61 kg m−2 h−1) at 50 °C. After being heated at 50 °C for 1 h, BPH requires 9h to regain its initial mass at 25 °C, 90 % RH. Fifteen moisture adsorption–desorption cycles demonstrate the excellent cyclic regeneration capability of BPH. COMSOL Multiphysics simulation results indicate that evaporative cooling in BPH provides excellent heat dissipation (reduced by about 27 °C). BPH reduces the peak temperatures of a mobile phone by 7.8 °C while charging and 6.5 °C while gaming. This design will contribute to the future cooling of heat-related devices and global sustainability.

Stable Magnetite@La-Fe Oxide Core-Shell Nanostructures Prepared via Lattice Lock for Reusable Extraction of Phosphate Anions.

Stable magnetic core-shell nanostructures are developed by lattice locking lanthanide-iron (La-Fe) oxide shells with magnetite cores to prevent the release of La from the surfaces of the magnetite nanostructures. The resulting core-shell nanostructures demonstrate excellent outstanding regeneration performance and high adsorption capacity for phosphate (115 mg P·g-1). These nanostructures release minimal La from the magnetite core surfaces after adsorbent regeneration, with a La loss of only 20% compared to the control sample, Mag@La(OH)3. La3+ ions were released at concentrations ranging from 1 to 2.3 μg·L-1 at pH levels of 4 to 8, which is within the metal content range found in natural aquatic environments. These results demonstrate the high stability of the nanostructures after regeneration. Furthermore, the adsorbent exhibits high extraction capacity across a wide pH range of 4 to 10 and performs well even in the presence of interfering anions at phosphate-to-anion molar ratios of 1:5, 1:25, and 1:100. Microscopic and spectroscopic analyses reveal that the primary extraction mechanism of phosphate in the La-containing shells is surface precipitation. This approach not only improves the use of magnetic core-shell nanostructures as adsorbents but also demonstrates the creation of a broad range of stable magnetic functional materials for diverse applications.

Superactivity of Bimetallic CuFeO2 Submicron Particles towards Selective Proteolysis, Depending on their Surface Hydroxyls.

Nano bimetallic oxides as nanoproteases have the great advantages in the heterogeneous hydrolysis of proteins. Here, we report that bimetallic delafossite CuFeO2 submicron particles (CuFeO2 SMPs) display a high protease activity towards selective cleavage of peptide bond involving hydrophobic residue at 25 °C. CuFeO2 SMPs have excellent regeneration performance with high structural stability. The strong Lewis acidity of Fe3+ and the strong nucleophilicity of Cu+ bound hydroxyl groups are both necessary for the high protease activity of CuFeO2 SMPs. Low-valent metal ion has a great advantage in that low-valent Cu+ bound hydroxyl has strong nucleophilicity, resulting in promotion of protein hydrolysis via high-efficient bimetallic catalysis. This study provides evidence that the protease activity of CuFeO2 SMPs depends on metal ion-bound hydroxyls on their surface. Our findings highlight that the valence of metal ions in artificial protease and their surface hydroxyls are two important factors that determine their catalytic efficiency.

Anion-Regulated Ionic Covalent Organic Frameworks for Highly Selective Recovery of Gold from E-Waste.

The existing electronic waste (e-waste) and leaching solutions generated by industries accumulate significant amounts of gold (Au), even in excess of those in natural minerals. Therefore, the recycling of Au is extremely significant for the potential sustainability of chemical industry. By designing ionic covalent organic frameworks (COFs), here we synthesize a series of Ionic-COF-X (X=Cl-, Br-, AcO-, and SO42-) by anion regulation strategy. All these ionic COFs exhibit ultrahigh gold adsorption efficiency and excellent regeneration. Moreover, anion regulation could indeed affect the Au capture performance. In particular, when Cl- ions serve as counter ions, the Au capacity of Ionic-COF-Cl could reach 1270.8 mg g-1. Moreover, in the actual CPU leaching solution test, the selectivity of Ionic-COF-Cl towards Au3+ ion hits 39000 and 4600 times higher than that of Cu2+ and Ni2+ ions, respectively, suggesting that the Ionic-COF-Cl is a promising material for highly selective recovering gold from actual e-waste. DFT calculations further reveal that counter ions can regulate the adsorption affinity of ionic COF framework toward Au. In short, this work provides a useful anion regulation strategy to design ionic COFs as a promising platform for gold selective recovery from actual e-waste.

Anion‐Regulated Ionic Covalent Organic Frameworks for Highly Selective Recovery of Gold from E‐Waste

The existing electronic waste (e‐waste) and leaching solutions generated by industries accumulate significant amounts of gold (Au), even in excess of those in natural minerals. Therefore, the recycling of Au is extremely significant for the potential sustainability of chemical industry. By designing ionic covalent organic frameworks (COFs), here we synthesize a series of Ionic‐COF‐X (X=Cl‐, Br‐, AcO‐, and SO42‐) by anion regulation strategy. All these ionic COFs exhibit ultrahigh gold adsorption efficiency and excellent regeneration. Moreover, anion regulation could indeed affect the Au capture performance. In particular, when Cl‐ ions serve as counter ions, the Au capacity of Ionic‐COF‐Cl could reach 1270.8 mg g‐1. Moreover, in the actual CPU leaching solution test, the selectivity of Ionic‐COF‐Cl towards Au3+ ion hits 39000 and 4600 times higher than that of Cu2+ and Ni2+ ions, respectively, suggesting that the Ionic‐COF‐Cl is a promising material for highly selective recovering gold from actual e‐waste. DFT calculations further reveal that counter ions can regulate the adsorption affinity of ionic COF framework toward Au. In short, this work provides a useful anion regulation strategy to design ionic COFs as a promising platform for gold selective recovery from actual e‐waste.

Ti3C2TX MXene/loofah-derived carbon aerogel for high-efficiency adsorption of organic pollutants in wastewater

The contamination of wastewater by organic pollutants significantly impacts human health and the environment due to their carcinogenic nature and various adverse effects. To address this issue, this study offers a high-efficiency and low-cost biomass-based carbon aerogel adsorbent, which was prepared through the hydrothermal carbonization of loofah, followed by Ti3C2TX MXene impregnation. The aerogel features a porous three-dimensional network structure and a substantial specific surface area, facilitating broad-spectrum adsorption capabilities for various dyes and drugs. The aerogel achieved impressive adsorption capacities of 175.29 and 75.73 mg/g for cationic methylene blue and Rhodamine B dyes, and 106.33 and 93.29 mg/g for anionic methyl orange and Congo red dyes, as well as 86.25 mg/g for tetracycline hydrochloride, surpassing other reported biomass-based aerogels. Furthermore, it demonstrated effective decolorization ability for wastewater containing mixed dyes. Notably, it exhibited excellent recycling and regeneration properties, maintaining a high removal rate after multiple cycles of adsorption–desorption. The adsorption process of dye/drug by the aerogel followed Langmuir’s monomolecular layer adsorption model, exhibiting spontaneous, endothermic, and disorder-increasing behavior in alignment with the pseudo-second-order kinetic model. This study presents an efficient biomass-based aerogel for the removal of organic pollutants from wastewater.

Efficient Removal of Mercury from Wastewater Solutions by a Nitrogen-Doped Hyper-Crosslinked Polyamine.

Mercury, a highly toxic metal and pollutant, poses a significant risk to human health and the environment. This study describes the synthesis of a new nitrogen-doped heteroaromatic hyper-crosslinked polyamine (HCPA) via the polycondensation of 2,6-diaminopyrazine and tris(4-formylphenyl)amine for the efficient removal of mercury ions from aqueous solutions. The HCPA polymer was characterized by solid-state 13C-NMR and FT-IR spectroscopy. A powder X-ray diffraction and thermogravimetric analysis showed that the polymer was semicrystalline in nature and stable up to 500 °C. Adsorption isotherms indicated that mercury adsorption occurred via mono- and multilayer adsorption by HCPA, as depicted by the Langmuir, Freundlich, and Redlich-Peterson isotherm models, with a maximum adsorption capacity of qm = 333.3 mg/g. Adsorption kinetic models suggested that the adsorption process was fast and effective, reaching equilibrium within 20 min. Thermodynamics of the adsorption process revealed that it was endothermic and spontaneous in nature due to the positive ΔH0 of 48 kJ/mol and negative ΔG0 values of -4.5 kJ/mol at 293 K. Wastewater treatment revealed 98% removal of mercury indicating the selective nature of HCPA. Finally, HCPA exhibited excellent performance and regeneration up to three cycles, demonstrating its great potential as an adsorbent for environmental remediation applications.

Poly(dimethyldiallylammonium chloride)-modified magnetic bentonite for removal of polystyrene nanoplastics

Nanoplastics (NPs) can contaminate water sources and living organisms, posing significant challenges for removal due to their small size and complex surface properties. There is a need to develop efficient technologies for the removal of NPs. In this study, bentonite was magnetically modified and loaded with Poly(dimethyldiallylammonium chloride) (PDMDAC) to enhance the adsorption for NPs, and improve separation and recovery efficiency. The synthesized PDMDAC-modified magnetic bentonite (PDMMB) had a high specific surface area of 49.386 m2/g and a maximum adsorption capacity of 250.50 mg/g for polystyrene nanoplastics (PS-NPs). The incorporation of PDMDAC increased the surface charge of magnetic bentonite from −39.50 mV to +37.7 mV, generating strong electrostatic attraction to the negatively charged PS-NPs (-64.3 mV). The PDMMB exhibited a saturation magnetization of 17.619 emu/g and an S-type hysteresis curve, indicating strong superparamagnetism that facilitating magnetic separation and recovery. Characterization analysis revealed that the adsorption was driven by electrostatic attraction and the Fe-O functional group. Kinetics and adsorption model analyses indicated that the adsorption mechanism involved electrostatic attraction, complexation, and single/multilayer adsorption, the adsorption process was exothermic and thermodynamically favorable. The adsorption rate remained at 86.41 % after 5 adsorption-desorption cycles. PDMMB exhibited high removal efficiency over a wide range of pH (3−10), ionic strength (0.01–0.5 mol/L), and in the presence of various anion types, indicating its potential for flexible application. The high efficiency, easy operation and excellent regeneration of PDMMB demonstrate its potential for effective removal of NPs from wastewater.

Enhancing long-segmental tracheal restoration: A self-repairing hydrogel loaded with chondrocytokines for sutureless anastomosis and cartilage regeneration

Artificial tracheal substitutes encounter significant challenges during long-segmental tracheal defects (LSTD) reconstruction, notably early postoperative anastomotic stenosis and tracheal chondromalacia. Mitigating early anastomotic stenosis by creating a compliant sutureless substitute is pivotal. Enhancing its chondrogenic capacity is equally critical for sustained healthy tracheal cartilage regeneration. This study proposes a self-healing hydrogel for sutureless tracheal anastomosis to mitigate anastomotic stenosis, enriched with kartogenin (KGN) and transforming growth factor-β1 (TGFβ1) to bolster chondrogenic properties. Initially, two precursor solutions were prepared: 1) aldehyde-modified hyaluronic acid with sulfonation and β-cyclodextrin-CHO loaded with KGN; 2) hydrazide-grafted gelatin loaded with TGFβ1. Coextrusion of these solutions resulted in a gelated G + TGFβ1/sH-CD + KGN hydrogel, characterized by a robust covalent bonding network of acylhydrazones between hydrazide and aldehyde groups, imparting excellent self-healing properties. The G + TGFβ1/sH-CD + KGN hydrogels, showcasing favorable cytocompatibility, excellent injectability, and rapid gelation, were loaded with bone marrow stem cells. These were customized into O-shaped rings and assembled into a malleable tracheal substitute using our established ring-to-tube method. This resultant compliant substitute facilitated sutureless anastomosis of LSTD in a rabbit model, attributed to the Schiff base reaction between the hydrogel's carbonyl group and the tissue's amino group. Notably, the tracheal substitute reduced early postoperative anastomotic stenosis, maintained tracheal patency, alleviated sputum blockage, promoted reepithelization, and increased the survival rate of the experimental rabbits. The sustained release of chondrocytokines resulted in excellent tracheal cartilage regeneration. Employing chondrocytokines-loaded hydrogels with self-healing properties represents a significant advancement in sutureless tracheal anastomosis and tracheal cartilage regeneration, holding promising potential in inhibiting early postoperative anastomotic stenosis and tracheal chondromalacia when treating LSTD.

Post-synthetic modification of zirconium-based metal-organic frameworks for enhanced simultaneous adsorption of heavy metal ions and organic dyes

Heavy metal and dye pollution pose a serious threat to human health and ecology, and there is an urgent need to develop novel adsorbent materials for wastewater treatment. In this study, a novel functionalized zirconium-based MOF UiO-66-Gd was prepared by a post-synthetic modification strategy and used for the simultaneous removal of Pb2+, Cu2+ and methylene blue (MB) from wastewater. UiO-66-Gd retained the crystalline structure and morphological features before modification. The specific surface area reached 574.94 m2/g, which can provide abundant active sites for adsorption. The effects of several factors on the adsorptive performance of UiO-66-Gd were investigated by batch adsorption experiments. The adsorption of Pb2+ by UiO-66-Gd reached the adsorption equilibrium in only 5 min. The theoretical maximum adsorption capacities for Pb2+, Cu2+ and MB were 833.33, 354.61 and 564.91 mg/g, respectively. In addition, UiO-66-Gd has excellent anti-interference and regeneration properties with potential for practical applications. Competition adsorption experiments showed that UiO-66-Gd had the greatest affinity for Pb2+. The adsorption of UiO-66-Gd on Pb2+ and Cu2+ was mainly through electrostatic interactions and chelation, and on MB mainly through electrostatic interactions, π-π interactions and hydrogen bonding. Overall, UiO-66-Gd has great potential for application in the removal of Pb2+, Cu2+ and MB.

Enhanced adsorption of tylosin by ordered multistage porous carbon and efficient in-situ regeneration of saturated adsorbents by activated persulfate oxidation: Performance, mechanism and multiple cycles

In this study, a novel ordered multistage porous carbon (OMPC) with a micro-mesoporous structure was prepared and used for the removal of tylosin (TYL). The porous material, carbonized at 900 °C (OMPC-900), exhibited micro-mesoporous structures with pore sizes of 0.71 nm and 3.63 nm, while had a specific surface area of 1300.02 m2 g−1. OMPC-900 demonstrated a maximum adsorption capacity of 341.28 mg g−1 for TYL in water by electrostatic attraction, hydrogen bonding, π-π interactions, and pore-filling mechanisms, which is 6.41 times higher than that of activated carbon. The TYL-saturated adsorbents could be efficiently regenerated by in-situ oxidation through the activation of persulfate (PDS), achieving a regeneration rate of 94.17%, significantly higher than that of activated carbon (55.22%). The excellent regeneration performance may be attributed to the presence of -C=O and graphitic carbon in the adsorbent, which promotes the production of free radicals (•OH, SO4•- and •O2−) and non-free radicals. Among these, the non-radical pathways (1O2 and electron transfer) played a key role in the degradation of TYL loaded on the adsorbent. OMPC-900 maintained stable regenerative adsorption performance of 80.85% after five in-situ regeneration, and the normalized adsorption capacity per unit surface area increased from 0.21 to 0.39 mg m−2, which may be due to that the increase in oxygen-carbon ratio and surface defects improved the adsorption sites activity of the regenerated adsorbent. In comparison to conventional pyrolysis and organic solvent elution, oxidative regeneration through the activation of PDS is a more efficient and sustainable method.

Arsenic removal from contaminated water using adsorptive electrospun nanofibrous membrane of polyacrylonitrile/organoclay

AbstractAdsorptive nanofiber electrospun membranes (ANEMs) show promise for heavy metal removal, particularly in dilute solutions. Nanofibrous polyacrylonitrile (PAN) membranes incorporating Cloisite 20A (C20) organoclay were fabricated via electrospinning for As(V) removal. The impact of C20 on structural properties and As(V) removal efficiency of the nanofiber membranes was investigated. The results indicated that the PAN‐C20 membranes morphology was uniform, with fiber diameters mostly falling within the 100–300 nm range. Incorporation of C20, especially in an exfoliated structure, led to increased hydrophilicity, mechanical strength, and roughness of the membranes. Batch adsorption results revealed that the adding C20 up to 1.5 wt.% significantly enhanced adsorption capacity due to the higher concentration and proper C20 dispersion. Dynamic filtration showed that the PAN‐C20(1.0) membrane achieved over 90% As(V) removal efficiency for 960 min and demonstrated excellent regeneration ability.Highlights Cloisite 20A organoclay was incorporated into PAN by electrospinning to prepare adsorptive membrane. Adsorptive membranes were used for As(V) removal from water. Type of Cloisite 20A dispersion in PAN in dynamic filtration was more important than in static adsorption PAN‐C20‐1.0 with exfoliated structure showed higher removal efficiency than PAN‐C20‐1.0 with intercalated structure. PAN‐C20‐1.0 membrane was usable for multiple adsorption–desorption cycles.

Eco-friendly thiol-functionalized magnetic oxygenous carbon nitride nanocomposites for effective elimination of heavy metals

The increased pollution of water resources by toxic heavy metals poses a huge threat to the aqueous ecosystem. Since the low concentrations of heavy metals are often highly toxic but difficult to remove, novel efficient adsorbents still need to be explored. Herein, the superparamagnetic thiol-functionalized oxygenous carbon nitride nanocomposite (CNO/Fe3O4-SH) with multifunctional groups such as –NH2, –OH, –SH, and –COOH was fabricated by a simple and eco-friendly method. The maximum adsorption capacities of Pb2+, As3+, and Cd2+ ions on CNO/Fe3O4-SH at pH = 6 were 80.79, 71.78 and 66.19 mg/g, respectively, when their equilibrium concentrations were 20 mg/L. Under the equilibrium concentration below 0.01 mg/L, the adsorption capacities of these heavy metals over CNO/Fe3O4-SH were much higher than those of other adsorbents. The competitive adsorption investigations showed that the adsorption order in polymetallic solutions was Pb2+ > As3+ > Cd2+. Adsorption kinetics and isotherms studies indicated that the adsorption of Pb2+, As3+ and Cd2+ by CNO/Fe3O4-SH was attributed to monolayer adsorption and the adsorption process was controlled by chemical adsorption. The thermodynamic experiments showed that the adsorption processes were spontaneous and endothermic. After six adsorption/desorption cycles, CNO/Fe3O4-SH maintained its original morphology and adsorption ability, indicating its excellent regeneration performance, which had significant potential application in the decontamination of trace heavy metal ions in water.

Interpreting the removal behaviours of aniline and 3,4-diaminotoluene on aromatic carbon-rich magnetic polymer: Statistical modelling, DFT quantitative calculations and new perspectives

The widespread presence of harmful and stubborn amine organic contaminants in aquatic environments motivated the exploration of efficient technologies for alleviating their serious environmental crisis. Herein, the recyclable magnetic Schiff base polymer (Fe3O4-TENE) with satisfactory and promising capacity in treating aniline and 3,4-diaminotoluene as representative amine organic contaminants was fabricated via a simple in-situ polymerization method, which combined the magnetic separability advantage of magnetic oxides with the abundant aromatic carbon content properties of Schiff base polymer. Multiple characterization methods verified the effectiveness of the in-situ polycondensation coating reaction and analyzed the physicochemical properties of Fe3O4-TENE. The Fe3O4-TENE possessed abundant homogeneous reaction sites and excellent regeneration performance, multiple diffusion driving forces and micro-mechanisms co-participated in the removal reaction. The adsorption pathway, underlying reaction mechanism and the most probable bonding system were identified based on the statistical modelling and DFT quantitative calculations. Especially, the visible electrostatic potential molecular and molecular orbitals verified the π-π interaction and electrostatic forces greatly contributed to the removal reaction. The Driving forces – Challenges – Breakthrough – Application framework was proposed for comprehensively assessing the possible environmental application of Fe3O4-TENE. Overall, this work not only provides important insights into the utilization of magnetic polymer composite to alleviate ecological and environmental risks caused by amine organic pollutants, but also contributes to an in-depth excavation of the bonding types and removal mechanisms from both micro and macro perspectives.

3D hydrophobic wood membrane with micro-nano baffle structure for multifunctional air purification filters: “Kill three eagles with one arrow”

Air pollution has presented an imminent threat to the world. Multifunctional filters with high filtration efficiency, low pressure drop, moisture resistance, antibacterial properties, and renewability are urgently needed to be developed. In this study, multifunctional wood filters are innovatively designed with a baffle structure combining macroscopic structural design and microscopic in-situ synthesis of silver nanoparticles (Ag NPs). The filter has excellent particle removal efficiency (PM0.3, 98.5 %), exceptional volatile organic compounds (VOCs) adsorption efficiency (98.4 % for formaldehyde and 91.7 % for xylene), high sterilization efficiency (99.99 %) and excellent regeneration ability (performance recovery to 98 % of the initial). Furthermore, personal protective masks were assembled by the prepared filters, whose process of replacing element is as simple as replacement of electric mosquito incense tablets. This innovative filter holds promise for applications such as daily protection, sudden accidents and prevention and control of respiratory infectious diseases. We envision that the functionally modified Ag NPs wood filters with a multilayer structure offer a comprehensive solution for more effective air purification in polluted environment.

Facile and scalable synthesis of long-life porous MgO-nanofiber functionalized biochar adsorbent from magnesite for phosphate recycling

The recycling of phosphate from wastewater using regenerable and highly efficient MgO-modified biochar for Mg-P fertilizer application is of great interest. However, the practical application of MgO-modified biochar for the removal and recycling of phosphate is hindered by its short-recycled service-life. Herein, a facile yet scalable method is proposed to fabricate porous MgO nanofiber-functionalized biochar (PMgNF-BC) with enhanced phosphate adsorption and regeneration performances from wastewater using waste biomass and magnesite. The as-prepared PMgNF-BC exhibited the maximum phosphate adsorption capacities of 594.53, 661.57, and 725.43 mg/g at 298.15 K, 308.15 K and 318.15 K, respectively. More importantly, PMgNF-BC demonstrated excellent regeneration performance with the removal efficiency of 84.2 % after eight regeneration cycles. Furthermore, the regenerated PMgNF-BC exhibited the well-preserved fiber shape of MgO on BC, enabling splendid regeneration performance. This work validates PMgNF-BC as a sustainable adsorbent for recycling phosphorus from wastewater, addressing the urgent need for synthesizing biochar with high regeneration performance.

Efficient ammoximation and regeneration of degraded hydroxyoxime CP150 over TS-1 molecular sieve/H2O2 system and reuse for solvent extraction of Cu(II)

The regeneration of failed hydroxyoxime extractants in the copper hydrometallurgy industry is crucial. However, the existing regeneration system has limitations in terms of operability, yield, and environmental friendliness, which restricts its industrial application. This paper presents a clean one-pot ammoximation regeneration system for the in-situ preparation of hydroxylamine for the oximation of aldehydes, catalyzed by TS-1 with NH3 and H2O2. It was tailored based on the characteristics of the degraded organic phase produced by long-term operation at the copper solvent extraction site. The developed system demonstrates an excellent regeneration conversion efficiency (>90%) for the degraded copper-extracted organic phase. Following regeneration, the copper extraction efficiency of the organic phase reaches the same level as the fresh organic phase and maintains good copper extraction stability even after multiple extraction cycles. Moreover, the phase separation performance was improved through optimization. This regeneration system meets the demand for environmentally friendly and resourceful utilization of degraded waste organic phases in copper extraction systems.