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In the absence of any hazardous substances, colloidal gold nanoparticles (AuNPs) were synthesized through the reduction and stabilization of corresponding metal cations by a simple Eucommia ulmoides bark extract (EUBE). Employing these AuNPs as catalysts, at least ten distinct azo compounds were catalyzed and analyzed. The findings reveal outstanding catalytic performance across a diverse range of azo dyes, regardless of structural complexity, the count of azo bonds, the presence of various functional groups in the side chains, differences in molecular weight, degrees of water solubility, ionic characteristics of the dyes, and the particular class of dyes, whether reactive or acidic. Regardless of these varieties, azo dyes achieved over 90% degradation within 16 min, following a first-order pseudo-kinetic reaction. This report systematically explains the mechanics of AuNPs synthesis using EUBE and the step-by-step azo dye degradation. It signifies an advancement in azo-contaminated wastewater treatment, transcending the varied types and structural complexities of azo compounds.

Green synthesis assisted by plant extracts is a recent research focus in diverse branches of chemistry. Through simple synthesis, different nanoparticles (NPs) can be produced that include oxides of zinc, copper, magnesium, or silver using various types of plant extracts. A remarkable attribute of plant aqueous extracts is their capability to act as reducing and capping agents. This study assessed the antioxidant and catalytic properties of phytosynthesized zinc oxide (ZnO) NPs using the fresh aqueous extract of pomegranate (Punica granatum) peel. Scanning electron microscopy indicated that the produced NPs had an average size of 49.52 nm with a spherical shape. X-ray diffraction confirmed the hexagonal phase of ZnO NPs and that their average crystallite size was 41.23 nm according to the Scherrer equation. Analysis of the ultraviolet–visible spectrum was performed to confirm the formation of ZnO NPs, and Fourier transform-infrared analysis illustrated the presence of diverse phytochemicals in the plant extract and ZnO NPs. The 2,2-diphenyl-1-picrylhydrazyl assay was used to determine the radical scavenging activity of these NPs. The novel ZnO phyto-nanocatalyst mediated by extracts from plant waste material, exhibited a well-defined reduction of methylene blue dye. Within 20 min, the catalytic degradation of methylene blue was completed, demonstrating that ZnO NPs have excellent catalytic properties.

The development of appropriate and effective periodate (PI) activation technology is currently a popular research area. This study presents a novel efficient photocatalytic activation approach of PI for pollutant degradation based on carbon nitride (g-C3N4) and visible light (Vis). The results show that the system can remove 92.3% of acid orange 7 (AO7) within 60 min under the g-C3N4/PI/Vis reaction system. The degradation rate constant (kobs) reached 4.08 × 10−2 min−1, which is 4.21, 5.16 times, and 51.3 times higher than that of the g-C3N4/Vis system (9.7 × 10−3 min−1), PI/Vis system (7.9 × 10−3 min−1) and the g-C3N4/PI system (7.96 × 10−4 min−1), respectively. Clearly, the addition of PI significantly enhances the degradation efficiency of AO7 in the system. Additionally, under the same reaction conditions, the presence of PI showed excellent oxidation capacity in the photoactivation process compared with other common oxidants, such as peroxymonosulfate, peroxydisulfate, and H2O2. Moreover, the g-C3N4/PI/Vis system showed excellent removal of AO7 across a wide range of pH levels and in the presence of various anions. Electron paramagnetic resonance (EPR) and quenching experiments suggested that the superoxide anions (•O2−) and singlet oxygen (1O2) dominated in the oxidation of pollutants in the g-C3N4/PI/Vis system. In addition, the catalyst showed relative stability during cyclic testing, although a slight reduction in degradation efficiency was observed. In brief, the g-C3N4/PI/Vis system is highly efficient and environmentally friendly, with significant application potential in wastewater treatment.

The health of living things and the ecosystem of the planet have both been negatively impacted by antibiotic residue in the water environment. There has been a lot of interest in the catalyst made of metal-carbon compounds from MOFs as a potential solution for activating peroxymonosulfate (PMS) to produce reactive oxygen species to catalyze the degradation of residual antibiotics. In this study, zeolitic imidazolate frameworks (ZIF-67) on bamboo fiber bundles (BFB) were pyrolyzed to produce magnetic Co/CoO nanoparticles with porous polyhedrons mounted on bamboo charcoal fiber bundles (BCFB)(BCFB@PCo/CoO). Specific surface area of obtained BCFB@PCo/CoO with abundant active sites arrives at 302.41 m2/g. The catalytic degradation efficiency of Tetracycline hydrochloride (TCH), a target contaminant, could reach up to 99.94% within 15 minutes (PMS = 0.4g/L, Cat. = 0.2g/L). The effects of potential factors, including PMS dosage, interference ions, and temperature, on catalytic degradation efficiencies were investigated. Magnetic recovery and antimicrobial properties of the BCFB@PCo/CoO were also evaluated and the possible degradation pathways were explored. Catalytic mechanism explorations of BCFB@PCo/CoO/PMS system reveal MOF-derived magnetic Co/CoO nanoparticles embedded in BCFB promote the synergistic interaction of both radicals and non-radical pathways for catalytic degradation of TCH. The novel BCFB@PCo/CoO provides an alternative to deal with wastewater containing antibiotics. HIGHLIGHTS A novel BCFB@PCo/CoO catalyst was prepared via in-situ growth and pyrolysis of ZIF-67-coated bamboo fiber bundles.; The BCFB@PCo/CoO composite exhibits a high catalytic activity (99.94% for 30mg/L TCH within 15 min) and stability.; The synergistic interaction of both radicals and nonradical pathways for the catalytic degradation of TCH.;

A new combined system of ultrasound (US)/ H2O2/KI was presented in this study for the degradation of amoxicillin (AMX). Various parameters that influencing the degradation efficiency, such as ultrasonic power, pH value of the solution, concentrations of H2O2 and KI, initial concentration of AMX were investigated. The maximum degradation efficiency of 84.1% in 60 min was obtained under the optimal conditions when the ultrasonic power was 195 W, the solution pH was 3.2, the concentrations of H2O2 and KI were 120 and 2.4 mmol/L, respectively. Results also showed US/H2O2/KI system possessed better degradation efficiency compared with that by using the systems of US alone, H2O2, US/H2O2, US/KI and H2O2/KI. The degradation reaction of AMX should be a very complex process, and the corresponding degradation pathways may change at different concentrations or under different reaction conditions. The results indicate that the combined system of US/ H2O2/KI has great potential applications for the treatment of wastewater containing antibiotics with high concentrations. [ABSTRACT FROM AUTHOR]

Adsorption and advanced oxidation technology are important means to remove organic pollutants, and the combination of adsorption and catalytic degradation to construct a multi-field coupled system can realize valid adsorption and degradation of organic contaminants. In this paper, CuBi 2 O 4 supported by a nonmetallic element-modified graphene hydrogel composite structure CuBi 2 O 4 /X-rGH (X = N, P, S, B) was synthesized and applied to the efficient removal of organic pollutants. We found that the doping of nonmetallic elements enhances the graphene conjugated large π-bond system, which not only improves the adsorption performance of pollutants but also increases the graphene conductivity and builds more carrier transport channels, which is beneficial to the photocatalytic Fenton synergistic degradation activity. Among them, CuBi 2 O 4 /P-rGH could achieve 90 % degradation of phenol (50 ppm) after 20 min of turning on the light, which was nearly 2 times more than the degradation activity of CuBi 2 O 4 /rGH. Electron paramagnetic resonance (EPR) and quenching experiments proved that ·OH was the main active species in the synergistic degradation process, and the mechanism of adsorption of nonmetallic modified graphene hydrogel hybrid catalysts and in situ photocatalytic Fenton degradation of pollutants was proposed. [ABSTRACT FROM AUTHOR]

Metal organic frameworks (MOFs) are multi-dimensional network of crystalline material held together by bonding of metal atoms and organic ligands. Owing to unique structural, chemical, and physical properties, MOFs has been used for enzyme immobilization to be employed in different catalytic process, including catalytic degradation of antibiotics. Immobilization process other than providing large surface provides enzyme with enhanced stability, catalytic activity, reusability, and selectivity. There are various approaches of enzyme immobilization over MOFs including physical adsorption, chemical bonding, diffusion and in situ encapsulation. In situ encapsulation is one the best approach that provides extra stability from unfolding and denaturation in harsh industrial conditions. Presence of antibiotic in environment is highly damaging for human in particular and ecosystem in general. Different methods such as ozonation, oxidation, chlorination and catalysis are available for degradation or removal of antibiotics from environment, however these are associated with several issues. Contrary to these, enzyme immobilized MOFs are novel system to be used in catalytic degradation of antibiotics. Enzyme@MOFs are more stable, reusable and more efficient owing to additional support of MOFs to natural enzymes in well-established process of photocatalysis for degradation of antibiotics aimed at environmental remediation. Prime focus of this review is to present catalytic degradation of antibiotics by enzyme@MOFs while outlining their synthetics approaches, characterization, and mechanism of degradation. Furthermore, this review highlights the significance of enzyme@MOFs system for antibiotics degradation in particular and environmental remediation in general. Current challenges and future perspective of research in this field are also outlined along with concluding comments. [ABSTRACT FROM AUTHOR]

The present study focuses on synthesis of gold nanoparticles, quantification of total phenolic content (TPC), and total flavonoids content (TPC), antimicrobial potential, and catalytic activity of Chenopodium botrys and Chenopodium ambrosioides. Gold nanoparticles (AuNPs) due to unique surface texture are considered as promising alternative to synthetic antimicrobial and catalytic agents. TPC quantification revealed that ethanol and methanol extracts of C. botrys are rich with TPC (263.9 and 261.6 mg gallic acid equivalent per gram, mg GAE/g) whereas for C. ambrosioides, ethyl acetate extract exhibited higher content of TPC (273.2 mg GAE/g). Regarding TFC, ethyl acetate extracts of both species exhibited significant content (201.4 mg quercetin equivalent (QE)/g for C. botrys and 223.5 mg (QE)/g for C. ambrosioides). AuNPs synthesized with aqueous and ethanol extracts were respectively optimal in the concentration of 1:5 and 1:10 (extract:salt solution) under sunlight. The extracts and synthesized AuNPs were potential DPPH inhibitors with IC50 values of 0.610–0.250 mg/mL. Moreover, the AuNPs significantly inhibited the microbial strains including S. aureus, E. coli, Candida albicans, and Aspergillus flavus with inhibition zones of 8.0–20.0 mm. In catalytic degradation of synthetic dyes (Congo red, methylene blue, methyl orange, Rhodamine B) and nitrophenols (ortho- and para-nitrophenols) in model water, AuNPs exhibited potential catalytic properties in the tested dyes and nitrophenols degradation (60–90%). From the results, it can be concluded that the species in question have promising therapeutic properties, and offers a safe, simple and cost-effective approach to wastewater treatment. [ABSTRACT FROM AUTHOR]

Copyright of Inorganic Chemicals Industry is the property of Editorial Office of Inorganic Chemicals Industry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Display omitted] • Nolanites (FVO) with adjustable concentrations of oxygen vacancies (Vo) were successfully synthesized. • FVO–180 achieved an efficient degradation of bisphenol A dominated by a nonradical process via the electron transfer regime. • The roles of light and V O in electron transfer processes were unveiled in a photo-assisted persulfate activation system. • New insights into the mechanism of photo-assisted persulfate activation by FVO were proposed. The utilization of photo–assisted persulfate activation for the removal of organic contaminants in water has garnered significant research interest in recent times. However, there remains a lack of clarity regarding specific contributions of light irradiation and catalyst structure in this process. Herein, a photo–assisted peroxymonosulfate (PMS) activation system is designed for the highly efficient degradation of organic contaminants on oxygen vacancy–enriched nolanites (Vo–FVO). Results suggest that the degradation of bisphenol A (BPA) in this system is a nonradical–dominated process via an electron transfer regime, in which V O improves the local electron density and thus facilitates the electron shuttling between BPA and PMS. During BPA degradation, PMS adsorbed at the surface of FVO–180 withdraws electrons near V O and forms FVO–PMS* complexes. Upon light irradiation, photoelectrons effectively restore the electron density around V O , thereby enabling a sustainable electron transfer for the highly efficient degradation of BPA. Overall, this work provides new insights into the mechanism of persulfate activation based on defects engineering in nolanite minerals. [ABSTRACT FROM AUTHOR]

Access to clean water is limited by the increasing amount of persistent organic pollutants (POPs), since current methods fail to remove POPs completely. Therefore, new treatment technologies of surface water and wastewater are needed. In this study, two treatment methods are combined in one step, i.e., membrane filtration and thermocatalytic chemical oxidation of POPs. A perovskite‐type catalyst with formula Sr0.85Ce0.15FeO3‐δ (SCF) is incorporated into an alumina membrane using a simple two‐step heat treatment to minimize any chemical reaction of the catalytic active perovskite with alumina. First, a sintering process under inert atmosphere, then, a heat‐treatment under oxidative conditions to oxidize the iron species in the perovskite structure. The well‐known thermocatalytic properties of SCF make the membrane thermocatalytic and thus able to degrade pollutants under dark conditions without addition of oxidants. The SCF content in the membrane is varied between 0 and 15 wt% to explore the change in membrane properties. Results demonstrate that the thermocatalytic membranes have great potential for continuous membrane filtration and simultaneous degradation of POPs. When considering methyl orange, up to 100% removal is obtained at room temperature, whereas up to 93% of bisphenol A is removed at temperatures approaching 60 °C. [ABSTRACT FROM AUTHOR]

The degradation of refractory pollutants via the activation of peroxydisulfate (PDS) by Co-based nanostructures as catalysts has been gaining significant attention. However, most cobalt-based catalysts suffer from severe aggregation and metal ion leakage, resulting in a loss of activity and potential environmental threats. In this study, exfoliated montmorillonite (EMMT) loaded Co–CoAl 2 O 4 composites were elaborately constructed through a facile coprecipitation-reduction method. The effects of the calcination temperature, the EMMT addition content, the pH of the precursor, and the reduction temperature on the microstructure of the Co–CoAl 2 O 4 /EMMT composites were investigated, and the optimum synthesis conditions were determined. In the optimal sample, well-crystallized CoAl 2 O 4 nanoparticles were uniformly deposited onto the EMMT nanosheets with a considerably large specific surface area, while ultrafine metallic Co nanoparticles were homogeneously immobilized on the CoAl 2 O 4 surface. This sample exhibited a superior activity (90% within 70 min) and reusability during methyl orange (MO) degradation. In the catalytic reaction, the superior adsorption property of EMMT facilitated the rapid transfer of MO molecules to the catalytically active sites. Moreover, CoAl 2 O 4 acted as a transition layer which provided a cobalt source for the subsequent reduction process and regulated the growth of metallic Co nanoparticles, which increased the number of active sites for catalysis. Simultaneously, the metallic Co can not only activate PDS by being an electron donor, but also initiate the formation of Co-based redox pairs. This study offers new insights into the synthesis of efficient and cost-effective supported Co-based catalysts. [ABSTRACT FROM AUTHOR]

Green synthesis assisted by plant extracts is a recent research focus in diverse branches of chemistry. Through simple synthesis, different nanoparticles (NPs) can be produced that include oxides of zinc, copper, magnesium, or silver using various types of plant extracts. A remarkable attribute of plant aqueous extracts is their capability to act as reducing and capping agents. This study assessed the antioxidant and catalytic properties of phytosynthesized zinc oxide (ZnO) NPs using the fresh aqueous extract of pomegranate (Punica granatum) peel. Scanning electron microscopy indicated that the produced NPs had an average size of 49.52 nm with a spherical shape. X-ray diffraction confirmed the hexagonal phase of ZnO NPs and that their average crystallite size was 41.23 nm according to the Scherrer equation. Analysis of the ultraviolet-visible spectrum was performed to confirm the formation of ZnO NPs, and Fourier transform-infrared analysis illustrated the presence of diverse phytochemicals in the plant extract and ZnO NPs. The 2,2-diphenyl-1-picrylhydrazyl assay was used to determine the radical scavenging activity of these NPs. The novel ZnO phyto-nanocatalyst mediated by extracts from plant waste material, exhibited a well-defined reduction of methylene blue dye. Within 20 min, the catalytic degradation of methylene blue was completed, demonstrating that ZnO NPs have excellent catalytic properties. [ABSTRACT FROM AUTHOR]

Mismanagement of plastic waste results in its ubiquitous presence in the environment. Despite being durable and persistent materials, plastics are reduced by weathering phenomena into debris with a particle size down to nanometers. The fate and ecotoxicological effects of these solid micropollutants are not fully understood yet, but they are raising increasing concerns for the environment and people's health. Even if different current technologies have the potential to remove plastic particles, the efficiency of these processes is modest, especially for nanoparticles. Metal-organic frameworks (MOFs) are crystalline nano-porous materials with unique properties, have unique properties, such as strong coordination bonds, large and robustus porous structures, high accessible surface areas and adsorption capacity, which make them suitable adsorbent materials for micropollutants. This review examines the preliminary results reported in literature indicating that MOFs are promising adsorbents for the removal of plastic particles from water, especially when MOFs are integrated in porous composite materials or membranes, where they are able to assure high removal efficiency, superior water flux and antifouling properties, even in the presence of other dissolved co-pollutants. Moreover, a recent trend for the alternative preparation of MOFs starting from plastic waste, especially polyethylene terephthalate, as a sustainable source of organic linkers is also reviewed, as it represents a promising route for mitigating the impact of the costs deriving from the widescale MOFs production and application. This connubial between MOFs and plastic has the potential to contribute at implementing a more effective waste management and the circular economy principles in the polymer life cycle. [ABSTRACT FROM AUTHOR]

Nanomaterials have been used in catalytic degradation of organic pollutants also act as catalysts in for many years. Due to excellent catalytic performances of metal-based nanoparticles, these materials have been used extensively in various hybrid catalyst synthesis. The main subject of this study, heterogeneous catalysis is a low cost and multi-purpose process for many pollutants. Catalytic degradation of organic pollutants such as; 2-nitrophenol, quinolin yellow and rhodamine B was investigated by using Ni, Co, Pd nanoparticles modified SiO2 based nanomaterials. The co-doping effect on the prepared nanomaterials has been investigated with different characterization methods in terms of structural and morphological features: scanning electron microscopy, UV/vis absorption spectroscopy, energy-dispersive X-ray spectroscopy and foruier-transform infrared spectroscopy. The highest catalytic reduction efficiencies (97.6% and 97.5%) for 2-nitrophenol and rhodamine B was obtained by Pd-PEG-AP@SiO2 respectively. The synthesized Co-PEG-AP@SiO2 illustrated higher catalytic reduction efficiency for quinolin yellow (70.1%) at the end of 60s. The prepared M-PEG-AP@SiO2 nanomaterial (M: Pd,Co,Ni) can be able to utilized degradation of organic contaminants effectively. [ABSTRACT FROM AUTHOR]

Water pollution caused by dyeing wastewater discharge, organic chemical reagent leakage and frequent oil spill incidents has aroused widespread international concern. Various methods have been proposed to remove single pollutant from wastewater. However, it is still a challenging task to develop advanced materials that can simultaneously and effectively remove various pollutants from wastewater. In this study, we successfully fabricated a novel multifunctional Pd-decorated alginate/nanofibrillated cellulose (Pd@ALG/NFC) aerogel through a facile and green in-situ reduction, followed by solution-aerogel conversion strategy. The as-prepared Pd@ALG/NFC aerogel exhibited superior catalytic activity toward methylene blue (MB) with a high degradation efficiency above 99% and excellent underwater superoleophobicity with OCA > 150° for various oils. It enabled rapid degradation of MB and efficient separation of different kinds of organic pollutants and oils from water by gravity, with an efficiency exceeding 98.3% and a water flux above 120.5 L·m− 2·min− 1. Moreover, the aerogel is compressible, shape stable and recyclable. These features make the hybrid aerogel a promising candidate for multi-pollutants wastewater treatment. [ABSTRACT FROM AUTHOR]

This paper describes a noval catalyst, cobalt-loaded activated carbon (Co/AC), and a bench-scale experiment involving the preparation of Co/AC and the activated carbon (AC) with a sort of raw material, beer-yeast. Researches on enhancing the electric-Fenton degradation of methylene blue (MB) in wastewater were thereby carried out using Co/AC with AC as a control subject, which highlighted the coupling effect of adsorption and catalytic degradation of MB. As a result, it was showed that in the independent adsorption reaction, the processes of adsorption kinetics and isotherm during MB degradation with Co/AC well fitted the pseudo-second-order model and Langmuir equation, respectively, and the theoretical saturated adsorption capacity was 232.48 mg/g, lower than that with AC (399.79 mg/g); while during the electric-Fenton reaction, the efficiencies of removing MB and TOC in the presence of Co/AC were respectively 99.05% and 88.57%, being higher than those with AC (95.95% of MB and 68.87% of TOC) and with catalyst FeSO4(35.53% of MB and 32.37% of TOC). Summarily, the excellent catalytic activity of Co/AC could be attributed to its ability for boosting the generation of • OH; and the coupling process of adsorption/catalytic degradation of MB was in compliance with the Langmuir-first-order-kinetic equation that had been constructed. [ABSTRACT FROM AUTHOR]

Copyright of Industrial Water Treatment is the property of CNOOC Tianjin Chemical Research & Design Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The CoO-Co3O4/C and CoO-Co3O4/N-C composites were synthesized from β-cyclodextrin (CD)-cobalt acetate and β-CD-Zeolitic imidazolate framework-67 (ZIF-67) via adduct and coordination interactions, respectively. The transformation of the composition and structure of their precursors as well as the composites were studied. The two composites were employed as catalysts for the oxidative degradation of Bisphenol A in the presence of potassium persulfate. The catalytic results confirmed that the CoO-Co3O4/C and CoO-Co3O4/N-C composites demonstrated about 5.2 and 3.7-fold higher degradation rates than that of Co3O4 obtained by cobalt acetate, respectively, and also displayed a robust reusability, which could be due to the unique oxidation-reduction property between CoO and Co3O4 and the small particle size of cobalt oxides with carbonaceous species. The possible degradation mechanism was also investigated by controlled experiments. This work provided new development for the synthesis of functional materials by the assistance of supramolecules as well as their potential applications in the environmental catalysis. Highlights: β-CD–Co(Ac)2 adduct and β-CD-ZIF-67 were synthesized. CoO-Co3O4/C and CoO-Co3O4/N-C composites were obtained by calcination. Efficient catalytic abilities for Bisphenol A degradation were achieved. [ABSTRACT FROM AUTHOR]

BACKGROUND: Nowadays, the large amount of organic textile dyes being regularly consumed also releases hazardous residues into water sources. Nanotechnology can solve part of this problem by using nanoparticles as adsorbents and catalysts for the removal of dyes from water. The present study explored the facile and green synthesis of ZnFe2O4 nanoparticles using Chrysanthemum spp. flower‐mediated extract (ZFOB) as a reducing and capping agent for the removal of cationic malachite green (MG). ZFOB nanoparticles were characterized by various techniques, such as X‐ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy. RESULTS: The average particle size and Brunauer‐Emmett‐Teller (BET) surface area of ZFOB were found to be 60–80 nm and 10.9 m2/g, respectively. The pore size distribution indicated a characteristic of meso‐macropores of the biosynthesized ZFOB nanoparticles. The MG adsorption of the green ZFOB nanoparticles was investigated under batch mode through the effect of various parameters, including contact time (0–60 min), initial concentration (5–100 mg/L), pH (4.0–10.0), and adsorbent dosage (0.25–1.0 g/L). The adsorption process followed the Elovich kinetic model, (Radj.2) = 0.9992, while the adsorption behavior can be described by Koble‐Corrigan, (Radj.2) = 0.9915. Meanwhile, the maximum adsorption capacity was 121.2 mg/g from the Langmuir model at a contact time of 30 min, dosage of 0.5 g/L, and pH 7. Green ZFOB nanoparticles showed a good photocatalytic activity (80.4%) under solar light irradiation and they were able to be recycled up to four times while retaining their high stability. CONCLUSION: ZnFe2O4 nanoparticles biosynthesized using Chrysanthemum spp. flower extract can be a good adsorbent and photocatalyst for the removal of MG dye. © 2022 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Abstract Access to clean water is limited by the increasing amount of persistent organic pollutants (POPs), since current methods fail to remove POPs completely. Therefore, new treatment technologies of surface water and wastewater are needed. In this study, two treatment methods are combined in one step, i.e., membrane filtration and thermocatalytic chemical oxidation of POPs. A perovskite‐type catalyst with formula Sr0.85Ce0.15FeO3‐δ (SCF) is incorporated into an alumina membrane using a simple two‐step heat treatment to minimize any chemical reaction of the catalytic active perovskite with alumina. First, a sintering process under inert atmosphere, then, a heat‐treatment under oxidative conditions to oxidize the iron species in the perovskite structure. The well‐known thermocatalytic properties of SCF make the membrane thermocatalytic and thus able to degrade pollutants under dark conditions without addition of oxidants. The SCF content in the membrane is varied between 0 and 15 wt% to explore the change in membrane properties. Results demonstrate that the thermocatalytic membranes have great potential for continuous membrane filtration and simultaneous degradation of POPs. When considering methyl orange, up to 100% removal is obtained at room temperature, whereas up to 93% of bisphenol A is removed at temperatures approaching 60 °C.

ABSTRACTMismanagement of plastic waste results in its ubiquitous presence in the environment. Despite being durable and persistent materials, plastics are reduced by weathering phenomena into debris with a particle size down to nanometers. The fate and ecotoxicological effects of these solid micropollutants are not fully understood yet, but they are raising increasing concerns for the environment and people’s health. Even if different current technologies have the potential to remove plastic particles, the efficiency of these processes is modest, especially for nanoparticles. Metal-organic frameworks (MOFs) are crystalline nano-porous materials with unique properties, have unique properties, such as strong coordination bonds, large and robustus porous structures, high accessible surface areas and adsorption capacity, which make them suitable adsorbent materials for micropollutants. This review examines the preliminary results reported in literature indicating that MOFs are promising adsorbents for the removal of plastic particles from water, especially when MOFs are integrated in porous composite materials or membranes, where they are able to assure high removal efficiency, superior water flux and antifouling properties, even in the presence of other dissolved co-pollutants. Moreover, a recent trend for the alternative preparation of MOFs starting from plastic waste, especially polyethylene terephthalate, as a sustainable source of organic linkers is also reviewed, as it represents a promising route for mitigating the impact of the costs deriving from the widescale MOFs production and application. This connubial between MOFs and plastic has the potential to contribute at implementing a more effective waste management and the circular economy principles in the polymer life cycle.

Highly efficient and reusable protective materials for chemical warfare agents (CWAs) are in high demand. Here, we used a surface modification technique to develop a material that provides chemical protection. Using an electrospun polyacrylonitrile (PAN) nanofiber membrane as the substrate, we modified the surface of the nanofiber with dopamine hydrochloride, which self-polymerized to form a polydopamine (PDA) surface layer, onto which we loaded metal–organic framework (MOF-808) particles. The presence of PDA on the surface of the PAN nanofibers significantly increased the breaking strength (2-fold increase) and elongation (9-fold increase) of the nanofiber membrane. Moreover, the PDA functionalities formed coordination sites to trigger the in situ growth of MOF-808 particles on the surface of the nanofiber membrane, thereby considerably increasing the growth rate and loading capacity. The surface of the nanofiber membrane was completely covered with MOF-808 particles following solvothermal treatment for 16 h. The MOF-808/PAN/PDA composite membrane could rapidly degrade 99.9% of dimethyl-4-nitrophenyl phosphate to p-nitrophenol within 8 min. After the membrane was used several times, the conversion rate stabilized at 95.9%, indicating that the MOF-808/PAN/PDA composite membrane has significant potential for application as protective clothing for CWAs. [ABSTRACT FROM AUTHOR]

Copyright of Industrial Water Treatment is the property of CNOOC Tianjin Chemical Research & Design Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The construction of novel efficient catalysts for the treatment of organic pollutants in the aqueous environment is essential. The lamellar-like Cu-Al layered double hydroxides (CuAl-LDHs) with various mole ratios were synthesized by a simple route of co-precipitation, and the corresponding degradation characteristic was tested for the removal of tetracycline (TC) using PMS activation. The degradation efficiency of TC over CuAl-LDHs increased up to 93% within 10 min for the Cu/Al mole ratio of 3:1 and almost not changed at a higher mole ratio. For further calcining the optimal catalyst at 300 ℃, the degradation efficiency of TC was found to be increased to 96%. Sulfuric radicals and singlet oxygen were analyzed to be the main reason for the change in degradation characteristics, which was proved by radical quenching experiments and electron paramagnetic resonance technique. The parameters including PMS concentration, catalyst dosage, and reaction temperature on the TC degradation as well as the degradation mechanism for PMS activation were elaborated. The best proportion of CuAl-LDHs owned splendid stability and catalytic activity after reusing, which showed enormous potential in practical application. [ABSTRACT FROM AUTHOR]

Wood has a rich three-dimensional pore structure and many bottom-up nanochannels. However, the structure of wood itself has limited ability to adsorb dyes, so the effective combination of the unique structure of wood and Pd NPs was studied to achieve efficient degradation of dyes. First, the three-dimensional structure of natural wood is optimized by combining the complex pore structure of wood with Pd NPs to improve the contact process between the dye and Pd NPs. Then, Pd (II) ion can be well reduced to Pd NPs by wood lignin. In addition, Pd NPs can be fixed by hydroxyl groups on cellulose in wood. The flow state inside Pd NPs/wood film and the contact area between catalyst and dye were discussed in detail by hydrodynamic simulation, which filled the gap. It provides reference for composite structure. When Pd NPs/wood membrane was used to treat methylene blue (MB), the degradation efficiency was up to 96.7%, which was 90% higher than that of natural wood. Its TOF value was 1.82 molMB molPd−1min−1, which was higher than that in the previous literature. Therefore, the novelty of this study is that the mechanism of catalytic degradation of MB by Pd nanoparticles/wood composites is reported for the first time. The internal flow mode and contact condition of the new material are understood, which has a good application prospect. [ABSTRACT FROM AUTHOR]

[Display omitted] Non-desirable solar energy absorption and poor charge transfer efficiency are two problems that limit the peroxymonosulfate (PMS) photocatalytic techniques. Herein, a metal-free boron-doped graphdiyne quantum dot (BGDs) modified hollow tubular g-C 3 N 4 photocatalyst (BGD/TCN) was synthesized to activate PMS and achieved effective space separation of carriers for degradation of bisphenol A. With 0.5 mM PMS, the degradation rate of bisphenol A (20 ppm) was 0.0634 min−1, 3.7-fold higher than that of TCN itself. The roles of BGDs in the distribution of electrons and photocatalytic property were well identified by experiments and density functional theory (DFT) calculations. The possible degradation intermediate products of bisphenol A were monitored by mass spectrometer and demonstrated to be nontoxic using ecological structure activity relationship modeling (ECOSAR). Finally, this newly-designed material was successfully applied in actual water bodies, which further renders its promising prospect for actual water remediation. [ABSTRACT FROM AUTHOR]

In this paper, a cobalt-doped carbon-based compound was prepared from anhydrous glucose and cobalt nitrate hexahydrate by a combination of hydrothermal method and in situ loading, and applied as an activator of potassium monopersulfate (PMS) for catalytic degradation of tetracycline in water. The prepared cobalt-doped carbon-based compounds were characterized by XRD, SEM, TEM, XPS, etc. The reason why the degradation effect of tetracycline by this catalyst was significantly higher than that of a single hydrothermal carbon was analyzed from the aspects of crystal structure, microstructure, and surface chemical elements. In addition, the effects of catalyst dosage, PMS dosage, and solution pH on the catalytic degradation of tetracycline were investigated. The experimental results show that, under the optimal reaction conditions, the cobalt-doped carbon-based compounds catalyze the degradation of tetracycline for 60 min, the degradation rate of tetracycline reaches 95. 84% (k =0. 051 36 min-1). The degradation mechanism was also investigated, and the analysis results show that Co0 and Co2+ in the cobalt-doped carbon-based material are involved in the activation of potassium monopersulfate to produce ·O-2, SO-4, O2,·OH, and thus the materials have the ability to catalyze the degradation of tetracycline with high efficiency, which is promising for the treatment of antibiotic wastewater. [ABSTRACT FROM AUTHOR]

The use of the nano zero-valent iron (nZVI) nanoparticle-based advanced oxidation systems in conjunction with an activator such as peroxymonosulfate (PMS) to generate hydroxyl and sulfate radicals for the degradation of organic pollutants has been extensively used in recent studies. In this study, a nZVI-modified polyethersulfone (PES) membrane (nZVI@PES) was produced successfully by attaching the nZVI catalytic nanoparticles on the surface of a commercial microporous polymeric membrane material using a simple and easy filter press coating method. The presence of nZVI nanoparticles on the nZVI@PES membrane was confirmed by XRD, SEM, and EDS analyses. The nZVI@PES membrane was applied in the dead-end filtration system in the presence of the PMS activator to treat the reactive black 5 (RB5) dye solution. The effect of catalyst loading, RB5 dye concentration, PMS dosage, and pH level on the nZVI@PES membrane/PMS system was investigated. Quenching experiments were carried out to identify the reactive species responsible, and reusability tests were conducted on the membrane. The highest decolorization efficiency (96.8%) was obtained at 20 mg/L RB5 dye solution, initial pH of 3, the nZVI loading of 5 mg/cm2, and the PMS dosage of 300 mg/L at the end of a reaction time of 30 min. The formation of HO•, SO 4 ∙ - , O 2 ∙ - and, 1O2 was confirmed by quenching experiments. The results indicate that the nZVI@PES membrane/PMS system could successfully treat wastewater contaminated with an organic dye. [ABSTRACT FROM AUTHOR]

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Nanoparticle synthesis from plant resources has recently gained significant impact due to its low cost, simple equipment requirements, and ease of availability. In this work, DR‐AgNPs were synthesized using bark extract of Delonix regia (D. regia) plant under microwave irradiation. The formation of DR‐AgNPs has been confirmed with UV–Vis, XRD, FTIR, FESEM, HRTEM, EDS, DLS, and zeta potential analysis. Catalytic and antioxidant activities were tested on synthesized spherical nanoparticles with a size range of 10–48 nm. The effects of pH and catalyst dosage on the methylene blue (MB) dye degradation were carried out. It was observed from the treatment results that 95% MB dye degradation efficiency was achieved within 4 min with a degradation rate constant of 0.772 min−1. The synthesized nanoparticles showed a strong antioxidant property when analyzed by a 2,2‐Diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging assay. The calculated IC50 value for DR‐AgNPs was 37.1 ± 0.12 μg mL−1. Therefore, DR‐AgNPs are excellent in both catalytic and antioxidant activities when compared to previously reported works. Highlights: Green synthesis of silver nanoparticles (DR‐AgNPs) using Delonix regia bark extract.The catalytic activity of DR‐AgNPs is remarkable against Methylene Blue.DR‐AgNPs also have a strong DPPH radical antioxidant effect.Short degradation time, high degradation rate constant, and a good scavenging activity are key features of this study compared to previously reported works. [ABSTRACT FROM AUTHOR]

• Dissolved carbonates enhanced catalytic activity and stability of CuS for PMS activation. • CO 3 2− as electron transfer medium increased CO 3 •−/1O 2 evolution and Cu2+/Cu+ cycling. • CO 3 •−/1O 2 is high reactivity for electron-rich phenolic compounds. • The CO 3 2−-induced enhancement was linearly correlated with electronic effect of phenol substituents. This study investigated the enhancement effects of dissolved carbonates on the peroxymonosulfate-based advanced oxidation process with CuS as a catalyst. It was found that the added CO 3 2− increased both the catalytic activity and the stability of the catalyst. Under optimized reaction conditions in the presence of CO 3 2−, the degradation removal of 4-methylphenol (4-MP) within 2 min reached 100%, and this was maintained in consecutive multi-cycle experiments. The degradation rate constant of 4-MP was 2.159 min−1, being 685% greater than that in the absence of CO 3 2− (0.315 min−1). The comparison of dominated active species and 4-MP degradation pathways in both CO 3 2−-free and CO 3 2−-containing systems suggested that more CO 3 •−/1O 2 was produced in the case of CO 3 2−deducing an electron transfer medium, which tending to react with electron-rich moieties. Meanwhile, Characterization by X-ray photoelectron spectroscopic and cyclic voltammetry measurement verified CO 3 2− enabled the effective reduction of Cu2+ to Cu+. By investigating the degradation of 11 phenolics with different substituents, the dependence of degradation kinetic rate constant of the phenolics on their chemical structures indicated that there was a good linear relationship between the Hammett constants σ p of the aromatic phenolics and the logarithm of k in the CO 3 2−-containing system. This work provides a new strategy for efficient removal of electron-rich moieties under the driving of carbonate being widely present in actual water bodies. [Display omitted] [ABSTRACT FROM AUTHOR]

In order to obtain more efficient catalytic materials for degrading the air pollutant - formaldehyde, Nano-Mn3O4 and bentonite / Nano-Mn3O4 composite catalysts (BMC) for formaldehyde degradation were prepared by sol gel method, using manganese sulfate, bentonite, citric acid and ammonia as reactants. Field emission-scanning electron microscope, Transmission electron microscope, X-ray Diffraction, Nitrogen adsorption experiments and laser particle size analyzing instrument have been employed to characterize the Mn3O4 and BMC nanoparticles, respectively. The mechanism and effect of formaldehyde degradation of these substances are also discussed. The results show that BMC catalytic material has a better ability to degrade formaldehyde in air than Mn3O4 at the room temperature, which is resulted by the strong adsorption capacity of bentonite providing a reaction site and molecular collision site for oxidative decomposition of formaldehyde. And the synthesized catalytic materials have the advantages of low cost, easy regeneration and recycling. [ABSTRACT FROM AUTHOR]

Fe-containing sludge can be converted to functional biochar as a promising resource recycle pathway. However, activating properties of Fe sludge-based biochar are always limited by low specific surface area and weak carbon center for persistent free radical(PFRs). In the current study, waste expandable polystyrene particles were simultaneously used to improve the biochar catalytic performance. The co-prepared biochar achieved a high micromesoporous ratio(98.4%) with specific surface area (345.3 m²/g), improved by 20.1% and 105.2% than unimproved biochar. The improved micromesoporous properties performed better iron active sites and oxygen-containing functional groups for PFRs functioning in wastewater. The co-prepared biochar showed an efficient catalytic degradation through persulfate activating multiple free radicals of 1O 2 , O 2 ˙ˉ, ˙OH and SO 4 ˙ˉ, which removed 95.4% sulfamethoxazole with mineralizing ratio of 74% within 60 min. The recycling of waste iron sludge and waste polystyrene foam material can achieve functional biochar to apply in deep treatment of refractory organic wastewater. [Display omitted] [ABSTRACT FROM AUTHOR]

In this work, a simple green method was followed to prepare ZrO2/ZnO/AC nanocomposite with the aid of plant extract as a capping and stabilizing agent for the nanoparticles. The prepared nanocomposite was characterized with different techniques such as Fourier transform infrared (FTIR), ultraviolet–visible spectroscopy (UV-Vis), dynamic light scattering (DLS), X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), scanning electron microscope (SEM), thermal gravimetric analysis (TGA), and nitrogen adsorption for surface area. The successful formation of ZrO2/ZnO and loading it on the surface of activated carbon (AC) was confirmed by XRD, UV-Vis, EDS, and SEM images. Different degradation tests were performed under different conditions including the mass of the catalyst, pH, the concentration of dye solution and H2O2 used, and the catalyst. Blank tests ensured the necessity of both catalyst and H2O2 for the degradation to start. ZrO2/ZnO/AC was the best compared to ZrO2/ZnO, and AC with a degradation of 68% compared to 3% and 36%, respectively. The performance of ZrO2/ZnO was almost negligible confirming the importance of combining nanoparticles with suitable support. Furthermore, the highest degradation efficiency using ZrO2/ZnO/AC was achieved at a pH of 2 with degradation of 80% compared to 67% at a pH of 10, since the surface will be positively charged leading to a higher reaching rate of MO anions to the surface. Also, the highest performance was achieved when 0.8% of H2O2 was used with degradation of 91%. Despite the lower degradation in this work compared to what has been reported in the literature, it is still very promising since it was achieved under a stagnant and dark environment, which makes it a promising candidate for treating huge bodies of wastewater stored in dark places or containers. [ABSTRACT FROM AUTHOR]

Contamination of dyes such as methyl red in the aquatic environment causes numerous problems. Therefore, it is necessary to develop a novel catalyst that can quickly, accurately, and effectively eliminate dye contaminants. In this study, we report the successful preparation of a new candidate electrode, the rGOps-TiO2 composite, via a hydrothermal method. Additionally, the electrodes were characterized using X-ray diffraction, spectroscopic techniques such as FTIR, and microscopic techniques such as SEM-EDX to ensure the synthesis of the prepared electrode material. The photocurrent response indicated that the rGOps-TiO2 electrode exhibited higher visible light absorption compared to the undoped rGOps. The degradation efficiency of methyl red reached 90.04% in the UV irradiation-assisted photoelectrocatalytic process, which was significantly different from the efficiency achieved under visible light irradiation, which was 94.78%. Therefore, the photoelectrocatalytic (PEC) technique based on rGOps-TiO2 showed much higher degradation efficiency for methyl red compared to the photocatalytic (PC) technique. This suggests that PEC holds promise for the treatment of dye wastewater in aquatic environments. [ABSTRACT FROM AUTHOR]

In recent years, electrocatalytic degradation of pollutants based on nanogenerators has gradually emerged. Compared with the huge energy consumption of traditional electrocatalysis, this method can effectively use displacement current to induce charge transfer and complete catalysis, so it can directly use the existing water flow energy and other energy sources in nature. This work will explain the basic principles, methods, and measurement methods of preparing nanogenerators from waste plastics, as well as the classification of electrocatalytic principles and methods relative to nanogenerators, which provides important support for the research in this emerging field. At the same time, the analysis based on this knowledge will also lay the foundation for future design. [ABSTRACT FROM AUTHOR]

In this work, a layered silicate Na-magadiite was hydrothermally synthesized and used as a starting material to prepare Ag- exchanged magadiites through intercalation reaction with 0.5 M, 1 M and 1.5 M silver nitrate solutions. The obtained Ag-exchanged magadiite samples are then reduced with sodium tetrahydridoborate (NaBH4) to obtain AgNPs-magadiite composites materials with different silver contents. All samples obtained are characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), UV–visible spectroscopy, Scanning electron microscopy (SEM), Energy dispersive X-ray analysis (EDX) and thermal (TG) analysis. The results show that the exchange with silver is total and leads to a disorganization of the layered magadiite structure which is recovered again once Ag-magadiite samples are reduced with sodium tetrahydridoborate (NaBH4). Therefore, these analysis methods confirm also the formation of silver nanoparticles (AgNPs) with an average size of about 24 nm in AgNPs-magadiite materials after reduction reactions. Formed by agglomeration of reduced Ag° species which occurs outside the layered structure, these AgNPs species are dispersed in the magadiite solid matrix and are not part of its internal structure. Used as catalysts in the photodegradation of Congo red and Methylene blue dyes in aqueous solutions, the AgNPs-magadiite materials obtained lead to the complete reduction of these pollutants into nontoxic organic compounds. [ABSTRACT FROM AUTHOR]

Bimetallic Ni-Cu catalysts supported on halloysite nanotubes with different metal contents (Hal-Ni80Cu20, Hal-Ni70Cu30, Hal-Ni42Cu58) were prepared and employed in the catalytic degradation of chitosan (CS). The relationship between catalytic performances of the catalysts with the different metal contents were studied. The highest catalytic activity was reported for Hal-Ni42Cu58 due to the higher proportion of the active Cu2+ in the catalytic degradation. Furthermore in Hal-Ni42Cu58, CuO persisted dominantly with Ni(OH)2 as compared to Hal-Ni80Cu20 where Cu(OH)2 was also available. Overall, the bimetallic-supported Hal catalysts displayed better catalytic activities than monometallic supported catalysts due to the synergistic effect between the metals.

Article Highlights The hybrid MVPA/Kaolin material presents a novel catalyst for degradation of dyes in water. The characterization of the material yields useful insight into its functioning as a catalyst. MVPA/Kaolin has shown significant catalytic activity with durability and recyclability.

Off-stoichiometric copper-chromium delafossite featuring giant catalytic degradation of ozone is demonstrated for the very first time. This leads to the reversible low-temperature detection of ozone onto resistive thin-film devices to values as low as 50 ppb. The selectivity when compared with molecular oxygen is also evidenced. Near-Atmospheric Pressure X-Ray Photoelectron Spectroscopy led to the understanding of the ozone - Cu0·66Cr1·33O2 surface reaction. The partial oxidation of copper into Cu2+ dependence on the ozone concentration is for the first time revealed. The apparition of a new peak associated with chemisorbed oxygen proves that the specific sub-stochiometric copper sites of the delafossite phase are driving the efficient and selective catalytic decomposition of ozone into monoatomic oxygen at the neat surface of thin films. The sensing response in ambient air is not limited by ozone decomposition but by the number of available adsorption sites. This work discloses pioneering results for the sensing networks integration of competitive ozone sensors based on Cu0·66Cr1·33O2.