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Air filtration materials (AFMs) have gradually become a research hotspot on account of the increasing attention paid to the global air quality problem. However, most AFMs cannot balance the contradiction between high filtration efficiency and low pressure drop. Electrospinning nanofibers have a large surface area to volume ratio, an adjustable porous structure, and a simple preparation process that make them an appropriate candidate for filtration materials. Therefore, electrospun nanofibers have attracted increased attention in air filtration applications. In this paper, first, the preparation methods of high-performance electrospun air filtration membranes (EAFMs) and the typical surface structures and filtration principles of electrospun fibers for air filtration are reviewed. Second, the research progress of EAFMs with multistructures, including nanoprotrusion, wrinkled, porous, branched, hollow, core-shell, ribbon, beaded, nets structure, and the application of these nanofibers in air filtration are summarized. Finally, challenges with the fabrication of EAFMs, limitations of their use, and trends for future developments are presented.

With increasing water pollution and human health problems caused by oily wastewater, the fabrication of oil-water separation materials has become an urgent task. However, most of the reported materials have a single function and poor performance. In this paper, a multifunctional zinc oxide/polyaniline/polyacrylonitrile (ZnO/PANI/PAN) nanofibrous membrane with needle-like ZnO nanorods was prepared by in situ synthesis of PANI and a hydrothermal reaction on a highly stable self-standing PAN blow-spinning fibrous membrane. Due to the electronic synergistic effect of ZnO and PANI, the fibrous membrane exhibits excellent antibacterial activity and visible-light degradation ability of organic dyes. Moreover, the micro-/nanosized pores of the ZnO/PANI/PAN fibrous membranes also guarantee its excellent emulsion separation performance, including an ultrahigh surfactant-free emulsion permeate flux (∼8597.40 L/(m2 h)), ultrahigh surfactant-stabilized emulsion permeate flux (∼2253.50 L/(m2 h)), and excellent separation efficiency (above 99%). Furthermore, the composite membrane maintains stable underwater superoleophobicity and hydrophilicity under adverse conditions, shows good biological safety, and is harmless to the water environment. These excellent properties endow the ZnO/PANI/PAN nanofibrous membranes with great potential in treating oily wastewater.

Considering the complexity of toxic ingredients in practical polluted water, the development of energy- and labor-saving and environmentally friendly multifunctional materials to decontaminate wastewater is of great necessity. Herein, a multifunctional branched poly(ethylenimine) (bPEI) and poly(acrylic acid) (PAA)/tungsten oxide/polyacrylonitrile (PP/WO

The aim of this study is to prepare a fibrous membrane scaffold that possesses a frogspawn structure for high-efficiency oil-water separation. Polyamic acid was first electrospun onto a rotating wheel-collector to obtain the fibrous membrane. Subsequently, post-processing by immersion in a polydimethylsiloxane solution and a silica nanoparticles suspension, followed by a thermal treatment generated a frogspawn-structured fibrous membrane. The obtained membrane achieved superhydrophobicity and superoleophilicity, with the water contact angle as high as 155.75° and the oil contact angle lower than 10°. The separation efficiencies of the membrane were higher than 99.55% and the permeate flux was maintained at greater than 4400 L/m2∙h after 20 separation cycles. Additionally, the wettability studies suggested the membrane exhibits high stability because it can resist damages due to high temperature (150 °C), acid/basic conditions and organic/inorganic solvents. These findings indicated that this composite membrane has great potential for use in gravity-driven oil-water separation and can extend the range of its application for treatments of oil spills incident, oily wastewater and spent liquor.

p-Arsanilic acid (p-ASA) is widely used as feed additives in animal production, and its transformation in environment media may cause arsenic contamination of soils and waters. It is essential to find a technology to effectively treat p-ASA, and meanwhile greatly decrease the mobility of the arsenic. Herein, we propose a disilicate-assisted Fe/Al electrolysis (D-FeAl-E) process for the degradation of p-ASA and the subsequent immobilization of inorganic arsenic. The results showed that, in the first stage of D-FeAl-E, namely the iron anode electrolysis process with disilicate, p-ASA was degraded by 92% under a near-neutral condition. The efficient degradation of p-ASA could be attributed to the disilicate-coordinated electrolytic ferrous ions, which activated dioxygen to produce more reactive oxygen species (e.g., O2−, H2O2 and OH in this study) to attack p-ASA molecules. Following the first stage, the produced inorganic arsenic and other intermediates can be further removed in the second stage of D-FeAl-E process (the Al anode electrolysis), via the coagulation effect initiated by the electrogenerated hydroxylated aluminum species. Electrogenerated Al(III) ions hydrolyzed into positively charged monomeric/oligomeric Al species, which could result in the dissociation of disilicate-Fe(III) complexes, and the formation of hydroxides and oxo-bridging polynuclear entities for arsenic immobilization. Leaching stability tests suggested that the D-FeAl-E process was superior to the conventional electrocoagulation method with respect to the stability of the generated arsenic-containing solid sludge. The D-FeAl-E process is free of the use of chemical oxidants and coagulants, but it provides both oxidation and coagulation effects for the abatement of p-ASA during the two-stage electrolytic process. Therefore, it is expected to be engineered as efficient and compact electrochemical technology capable of providing both oxidation and coagulation effect for decontamination.

The Fe−Si−Zr alloys have attracted considerable interests in recent decades. It is important to study this ternary phase diagram for experimental design. In this paper, the Fe−Si−Zr ternary system is investigated by combining the experiments and thermodynamic calculations. Liquidus surface projection of the Fe−Si−Zr system is characterised using X-ray powder diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive spectrometer (EDS) and differential thermal analysis (DTA). The liquidus projection of this ternary system is constructed by identifying primary crystallization phases and invariant reaction temperatures in the as-cast alloys. Eleven different primary solidification regions are observed. Based on the experimental results of this work and the data from the previous work in the literature, the thermodynamic calculation of the Fe−Si−Zr system is performed using CALPHAD (CALculation of PHAse Diagrams) technique. A set of self-consistent thermodynamic parameters of the Fe−Si−Zr system is obtained. The calculated results are in good agreement with the experimental data. This study provides a set of reliable thermodynamic parameters to the Fe-based thermodynamic database, and a cost-effective tool to design experiments and manufacturing processes.

The degradation efficiency of fulvic acid (FA) was investigated in the catalytic wet oxidation process (CWPO) by zero-valent copper chitosan activated carbon ball (ZVC/CTS-ACB). Characterization of ZVC/CTS-ACB shows that zero-valent copper was loaded successfully on the chitosan activated carbon. Plackett–Buiman (PB) design and response surface methodology (RSM) were employed to determine the influence factors and the optimum processing parameters. The model was well fitted to the actual data and the correlation coefficients of R2 and R2-adj were 0.9359 and 0.9039, respectively. Under the obtained optimum conditions for FA degradation: temperature = 94 °C and pH 3.8, the average FA removal by three replicate experiments was 93.02%, which has a high consistency to the RSM optimal target response of 93.86%. The comparison of catalytic performance showed that the addition of catalyst ZVC/CTS-ACS could increase the removal rate of FA, color number (CN) and TOC by 93.6%, 83.5% and 81.9% respectively. The high TOC removal rate indicated the good performance of the catalyst to FA mineralization. Additionally, the ICP analysis of copper ion leaching was only 0.08 mg/l after 5 repeated recycles of the catalyst, demonstrating the high stability of ZVC/CTS-ACB that is beneficial for the actual application.

Wastewater pollution has always been one of the most severe worldwide environmental problems. In addition, in light of the frequent oil spills that have occurred in recent years, the treatment of oily wastewater is particularly important. In this work, a novel zeolitic imidazolate framework-8@thiolated graphene (ZIF-8@GSH) composites-based polyimide (PI) nanofibrous membrane was developed via a facile electrospinning and in situ hydrothermal synthesis approaches for effective purification of oily wastewater. The membrane showed superhydrophobicity/superoleophilicity and high separation efficiency (>99.9%) for a wide range of oil/water mixtures and water-in-oil emulsions. Besides, the membrane demonstrated excellent photocatalytic dye degradation, antibacterial, self-cleaning, and mechanochemical durable abilities, showing high potential in oily wastewater treatment and water remediation.

Air particulate pollution from ever-increasing industrialization poses an enormous threat to public health. Thus, the development of a green air filter with high efficiency and performance is of urgent necessity. In this study, we introduce a new effective air filtration membrane that can be used for outdoor protection. The air filter's composite nanofibre materials were prepared from polyvinyl alcohol (PVA)-sodium lignosulfonate (LS) via a "green" electrospinning method and thermal crosslinking. The addition of LS helped increase the PM2.5 removal efficiency compared to that of a pure PVA nanofibre membrane. The pressure drops of the electrospun PVA-LS membranes exceeded those of the pristine PVA air filter. The remarkable air filtration performance was maintained even after 10 cycles of circulation filtration. In addition, the PVA-LS composite nanofibre membrane exhibited excellent mechanical properties and transparency due to the introduction of LS. This study provides new insight into the design and development of high-performance and high-visibility green filter media, which include personal protection and building screens.

Sb2S3 and CuSbS2 have been proposed as alternative earth-abundant absorber materials for thin-film solar cells. However, no thermodynamic study of the S−Sb binary system and the Cu−S−Sb ternary system were investigated. In this paper, The S−Sb system and the Cu−S−Sb system are calculated utilizing the so-called CALPHAD (CALculation of PHAse Diagrams) technique. Using TEM-EDS and XRD, Cu0.9Sb1S2 is experimentally confirmed at the Cu1Sb1S2 and Sb2S3 two-phases region in the isothermal section at 673 K of the Cu−S−Sb ternary system. Given the asymmetric shape and miscibility gap of the liquidus in the S−Sb phase diagram, the associate solution model for the liquid phase is adopted. The solution phases (liquid, bcc, fcc) are treated with the Redlich–Kister equation. The compounds S3Sb2, Cu3SbS3, Cu12Sb4S13, CuSbS2, and Cu3SbS4 are described as a stoichiometric compound. A set of self-consistent thermodynamic parameters of the S−Sb binary system and the Cu−S−Sb ternary system are obtained. The calculated results are in good agreement with the experimental data. This study provides a set of reliable thermodynamic parameters to the Cu−Sb−S thermodynamic database, and a cost-effective tool to design material synthesis experiments and manufacturing processes.

In this study Cu-Fe bimetallic aerogel-like carbon based on sodium alginate (SA) was prepared as catalytic particle electrode by freeze-drying and carbonization process. The characterization indicates that Cu and Fe were loaded on the surface and inside SA-based biomass carbon (SAC) in the form of a zero-valent copper-iron alloy to form a Cu-Fe/Sodium alginate Carbon (Cu-Fe/SAC) particle electrode. After using a three-dimensional Electro-Fenton (3D-EF) system with the prepared particle electrode, the optimal experimental operating parameters for removal of fulvic acid (FA) were obtained as follows: voltage 2.5 V, pH 5.4, and catalyst dosage 4 g/L. A removal efficiency from 82.9% to 74.4% for FA was achieved in a wide pH range of 3–7. Comparison experimental results indicate that the 3D-EF system with bimetallic Cu-Fe/SAC as the catalytic particle electrode (CPE) has higher FA degradation rate and mineralization efficiency than two-dimensional Electro-Fenton (2D-EF) system, even higher than the 3D-EF system with Cu/SAC or Fe/SAC. Hydroxyl radicals (·OH) trapping experiments showed that the main contribution to FA degradation and mineralization in the 3D-EF system would be the ·OH radical produced by a heterogeneous Fenton-like reaction. The comparison and trapping experiment results indicate that the possible mechanism of the 3D-EF with Cu-Fe/SAC as CPE for FA degradation may involve adsorption, anode oxidation, heterogeneous and homogeneous Fenton-like reactions.

The phase equilibria and thermodynamic properties of the Al–Ge–Ni system are useful for understanding the diffusion process during the transient liquid phase (TLP) bonding. In this work, the thermodynamic description of the Al–Ge–Ni system over the whole composition and temperature ranges was performed by means of the CALPHAD (CALculation of PHAse Diagrams) method. The enthalpies of mixing of the liquid phase, three isothermal sections at 973, 823, and 673 K and nine vertical sections at 10, 20, 35, 55, 60, 70, 75, and 80 at% Ni and at a constant Al:Ni ratio of 1:3 were taken into account in the present optimization work. A set of self-consistent thermodynamic parameters of the Al–Ge–Ni system was first obtained. The liquidus projection and reaction scheme were constructed according to the thermodynamic parameters obtained in this work. The phase equilibria and thermodynamic properties calculated by the present thermodynamic description show satisfactory agreement with the available experimental information.

Sodium disilicate (SD), an inorganic and environmentally friendly ligand, is introduced into the conventional iron electrolysis system to achieve an oxidizing Fenton process to degrade organic pollutants. Electrolytic ferrous ions, which are complexed by the disilicate ions, can chemically reduce dioxygen molecules via consecutive reduction steps, producing H2O2 for the Fenton-oxidation of organics. At the near-neutral pH (from 6 to 8), the disilicate-Fe(II) complexes possess strong reducing capabilities; therefore, a near-neutral pH rather than an acid condition is preferable for the disilicate-assisted iron electrolysis (DAIE) process. Following the DAIE process, the different complexing capacities of disilicate for ferrous/ferric ions and calcium ions can be used to break the disilicate-iron complexes. The addition of CaO or CaCl2 can precipitate ferrous/ferric ions, disilicates and possibly heavy metals in the wastewater. Compared to previously reported organic and phosphorus ligands, SD is a low-cost inorganic agent that does not lead to secondary pollution, and would not compete with the target organic pollutants for •OH; therefore, it would greatly expand the application fields of the O2 activation process. The combination of DAIE and CaO treatments is envisioned to be a versatile and affordable method for treating wastewater with complicated pollutants (e.g., mixtures of biorefractory organics and heavy metals).

The present study demonstrates the effectiveness of a novel oxidant system, namely the combined use of peroxymonosulfate (PMS) and permanganate (CUPP), for the degradation of benzene and trichloroethylene (TCE) in simulated groundwater. The CUPP process exhibited favorable oxidizing capability because the in-situ generated colloidal and amorphous MnO 2 linked the two oxidants. Compared with the separate use of permanganate or peroxymonosulfate, the CUPP process showed much better efficiency for the removal of refractory benzene. According to the electron paramagnetic resonance analysis and PMS-activating experiments, both colloidal and amorphous MnO 2 (AM-MnO 2 ) triggered the radical-mediated oxidation, but the AM-MnO 2 -activated PMS showed an adsorption-dependent oxidizing capability. For the CUPP process, higher temperatures promoted the initial degradation rate of benzene, but did not change its final removal efficiency. The degradation of benzene was mostly associated with the activated PMS, and the intermediates also competed with TCE for KMnO 4 . The KMnO 4 component played a more important role than PMS for the removal of TCE. For an aqueous mixture of 0.3 mM benzene and TCE, the combination of 2.4 mM PMS and 1.8 mM KMnO 4 was optimal, achieving removal efficiencies higher than 85% for both pollutants. Regarding the degradation of benzene, chloride ions had a concentration-dependent effect, and bicarbonate ions and dihydrogen phosphate showed different levels of retarding effect. The CUPP is envisaged to be used as a remedial reagent for the in-situ chemical oxidation of groundwater contaminants.

Dissolved silicate, as a ubiquitous inorganic component in natural waters, is reported to depress the reactivity of zero-valent iron (ZVI) for reductive reactions under anoxic conditions, but it is unclear if the same inhibitory effect occurs for a ZVI/O

The isothermal sections at 1073 and 1273 K, and liquidus surface projection of the Ti–V–Zr system were investigated using X-ray powder diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive spectrometer (EDS) and differential thermal analysis (DTA). Combined with experimental results in the present work and literature, the Ti–V–Zr system was optimized by the means of the CALPHAD (CALculation of PHAse Diagram) method. The solution phases, liquid, hcp (Ti, Zr) and bcc (Ti, V, Zr), were modeled with the substitutional solution model, and the compound V 2 Zr was treated as (Ti, V, Zr) 2 (Ti, V, Zr) based on its thermodynamic model in the V–Zr system and the experimental solid solubility of Ti in the Ti–V–Zr system. A set of self-consistent thermodynamic parameters of the Ti–V–Zr system was obtained.

HMG-CoA reductase inhibitors were widely used as lipid-lowing agents through effectively blocking the rate-limiting step of cholesterol biosynthesis. 8 analogs of Rosuvastatin were firstly prepared with different distance and functional group between the O5-hydroxyl group and terminal COOH group in the hydrophilic side-chain. In primary and secondary screening of the inhibitory activities against human HMG-CoA reductase, gem-difluoromethylenated derivatives exhibited more than 50% inhibition rate. Then 4 compounds with gem-difluoro group were further synthesized and evaluated in vitro, three compounds among them exhibited low single digital nmol/L IC50 values against HMG-CoA reductase. Molecular docking also well explained the observed special contribution of the gem-difluoro group.

The V–Zr system was investigated by experiments and thermodynamic modeling. In experiments, 10 crucial alloys were selected, and the microstructure, crystal structure and phase transformation temperatures of the alloys were obtained using scanning electron microscopy (SEM) with energy dispersive spectrometer (EDS), X-ray powder diffraction (XRD) and differential thermal analysis (DTA). A thermodynamic modeling of the V–Zr system was then performed by considering the reviewed literature data and incorporating the present experimental results. The solution phases, liquid, hcp (Zr) and bcc(V, Zr), were modeled with the substitutional solution model, and the compound V 2 Zr was treated as (V, Zr) 2 (V, Zr) by means of two-sublattice model. A set of self-consistent thermodynamic parameters of the V–Zr system was obtained.

This work proposes an anti-corrosive nanofibrous membrane by combining one-pot solvothermal reduction method and electrospinning technology as a solution to the ever-increasing water pollution issues. Such membrane is made of aromatic polymer-polyimide and further modified by reduced graphene oxide, which maintained the original performance under different external environment and multi-cycled test, and achieved high separation efficiency (99.19%) and flux (2040.04 L m-2h−1) at the same time. The purification process is suitable for various contaminants and different combinations. Additionally, the inherent purification mechanism was fully explored in this study. The practicability of the membrane can be tested for the contaminated water purification, the recycle of poisonous and harmful substances, pre-process of precision extraction and so on.

Efficient electrogeneration of hydrogen peroxide (H2O2) is critical for treatment of refractory pollutants by the electro-Fenton process. An effective strategy is developed by combining a flow-through reactor with a poly- tetrafluoroethylene (PTFE)-modified graphite felt cathode. In this design, anodic oxygen is directly used for efficient H2O2 generation at the modified cathode. Experimental results show that the modified cathode with the optimum PTFE content can produce 29.6 mg/L of H2O2, which is 16 times higher than the unmodified graphite felt cathode for a flow rate of 3 mL/min. Maximum H2O2 production, up to 30.7 mg/L, was obtained under the following conditions: 120 mA, 3 mL/min, initial pH 13, no external aeration.

The feasibility of using polymer‑carbon composite material (PCCM) substrate, instead of titanium substrate, for the preparation of PbO2 electrode was explored. The preparation procedure was optimized to maximize the performance of the PbO2 anodes. Our investigation shows that introducing α-PbO2 interlayer could significantly enhance the bonding of the surface β-PbO2 with the substrate. The addition of fluoride ions in the electrodeposition electrolyte could refine the grain size of the β-PbO2, resulting in a dense and smooth surface to enhance the service life of the composite anode. Therefore, the electrode PCCM\α\F−-β-PbO2, which had a α-PbO2 interlayer and a fluoride doped β-PbO2 surface layer, showed the longest accelerating life. The results of experiments also showed that the current density and deposition time significantly affected the surface morphologies of the PbO2 composite electrode. The optimal condition for the deposition of F−-β-PbO2 surface layer was 1 h of operation at 10 mA/cm2 current density, and this condition allowed to offer the electrode with a compact surface to prevent the penetration of caustic electrolyte and an appropriate thickness to avoid the strong internal stress. It was also found that the PCCM\α\F−-β-PbO2 exhibited the same electrocatalytic activity as that of the Ti-substrate counterpart electrode for the electrochemical oxidation of 2,4-dichlorophenol. This study indicates that the PCCM substrate can be used as an alternative substrate for the preparation of affordable PbO2 anode for non-heavy duty applications.

The unique characteristics of H2O2 render it a versatile and green agent for environmental remediation applications. As an essential component of a classic Fenton or Fenton-like reaction, H2O2 can effectively decompose aqueous refractory contaminants via the large amounts of reactive oxygen species produced. There is increasing interest in developing decentralized H2O2 production methods that can greatly reduce the risks and costs of H2O2 storage, transportation, and use for oxidative reactions. The on-site activation of molecular oxygen is an ideal way to produce H2O2 for decontamination since oxygen is safe and readily available. Understanding the behaviors of O2 activation by different reductants is essential in optimizing the selectivity of H2O2 production, removal efficiency, and the functioning of a specific catalyst. In this review, the on-site generation of H2O2, including zero-valent metals, ferrous iron species, catalytic H2 reduction, and the photocatalytic activation route are critically reviewed and discussed from the fundamental aspects to their environmental applications. We hope that this review not only deepens understanding of the on-site generation of H2O2 by O2 activation, but also give pointers to further studies in this important field.

As oily wastewater issues continue to grow, the treatment of oily wastewater has become urgent an emergency. However, present solutions are restricted by the limited performance of materials. An UV-resist and transparent coating consisting of PDMS and ZnO decorated on a highly stable and self-standing polyimide is reported in this work as a potential solution. The obtained fibrous membranes not only allow high-efficiency (higher than 99%) oily wastewater separation but also show superior UV-resistant activity. Moreover, the superoleophilicity and hydrophobicity of the composite membrane were confirmed to be stable under harsh conditions, and the transparent coating layer has the potential to be applied in other fields. The design of the UV-resistant, transparent and superoleophilic nanofibrous membrane is very practical, and will be quite promising for reducing oily environmental contaminations from waters.

BACKGROUND Electrolysis with an iron anode is a novel way to provide ferrous activators for chemical oxidation. The objective of this study is to evaluate the performance of peroxymonosulfate (PMS) for chlorophenol destruction when compared with H2O2 and persulfate (PS), and to see whether the electrolysis mode facilitates the buildup of conditions that favor the activation of PMS and removal of chlorophenols. RESULTS Ferrous species can effectively activate the PMS over a wide pH range. In comparison with H2O2 and PS, PMS is less sensitive to the solution's pH and possesses stronger oxidation capability at alkaline pHs. The optimal molar ratio of PMS to Fe(II) activator is 1:1 for the destruction of 2,4-dichlorophenol (2,4-DCP). The column experiments show that an acidic zone developed downstream from the anode is favorable to maintain ferrous ions and subsequent activation of PMS. The reactivity of the PMS can be manipulated by varying the electrical currents, and the process demonstrates effectiveness for treating organic contaminants. 2,4-DCP contaminated groundwater shows decreased biotoxicity after the chemical oxidation process without considering the residual PMS. CONCLUSIONS Iron electrolysis-assisted peroxymonosulfate chemical oxidation can effectively treat the 2,4-dichlorophenol and mixtures of organic contaminants. This process can be engineered as an in situ chemical oxidation method for groundwater remediation. © 2015 Society of Chemical Industry