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Phyllanthus emblica L. fruit extract (PFE) was introduced to improve ZVI/H2O2 technology, and the efficiency and mechanism of PFE promoting ZVI/H2O2 technology were explored. With the introduction of PFE, the Norfloxacin (NOR) removal rate and kobs of the process were improved by 41.17% and 5.08 times, respectively. In the ZVI/H2O2/PFE process, the degradation of NOR by the attack of ROS is the main pathway for decontamination and is dominated by the heterogeneous reaction on the catalyst surface. PFE contains 13.92 g/L titratable acid and has good complexing ability and antioxidant ability. The mechanism of PFE promoting ZVI/H2O2 technology was based on lowering the pH, complemented by chelation and antioxidant capacity. With the introduction of PFE, the utilization rate of the reagent was significantly increased (7.56 times for ZVI and 3.21 times for H2O2), the applicable pH range was widened (6–9) and the iron sludge was reduced (32.80%). Meanwhile, the concept of UPR is proposed for the first time. The result is the key role to the selection of green promoters in the ZVI/H2O2 process depends on the abundance of titratable acid, followed by a certain chelating ability and antioxidant capacity. [ABSTRACT FROM AUTHOR]

A three‐dimensional Cu‐MOF (XJU‐1) was synthesized based on 5‐((4‐[1H‐1,2,4‐triazol‐1‐yl]benzyl)amino)isophthalic acid ligand (H3L), which showed excellent performance for Fenton‐like degradation of organic dyes (rhodamine B [RhB], methylene blue [MB], methyl orange [MO], methyl violet [MV], congo red [CR], malachite green [MG], xylenol orange [XO]). The results demonstrated that XJU‐1 could efficiently activate H2O2 to achieve 100% removal of RhB and MB with the initial concentration of 10 mg/L under 10 W light‐emitting diode ultraviolet light irradiation within 7 and 6 min, respectively. The possible degradation mechanism was investigated via active species capture experiments, electron spin resonance (ESR) measurement, and the electrochemical analyses. The hydroxyl radical (•OH) was the principal active specie at the whole process, whereas superoxide radical (•O2−), singlet oxygen (1O2) could boost the Fenton‐like reaction for the mineralization of RhB and MB dyes. Possible degradation pathways of RhB and MB were assumed based on the testing results of intermediates. The studies showed that the XJU‐1 still maintained an excellent efficiency for RhB and MB degradation after five cycles. In addition, the iodine capture of XJU‐1 in cyclohexane solution was investigated, the results showed that XJU‐1 had excellent adsorption performance for iodine, and the maximum adsorption capacity was about 368 mg/g. [ABSTRACT FROM AUTHOR]

To reveal the influence of the diversity of precursors on the formation of environmental persistent free radicals (EPFRs), pomelo peel (PP) and its physically divided portion, pomelo cuticle (PC), and white fiber (WF) were used as precursors to prepare six hydrochars: PPH-Fe, PCH-Fe, WFH-Fe, PPH, PCH, and WFH with and without Fe(III) addition during hydrothermal carbonization (HTC). PPH-Fe and WFH-Fe had higher EPFRs content (9.11 × 1018 and 8.25 × 1018 spins·g−1) compared to PPH and WFH (3.33 × 1018 and 2.96 × 1018 spins·g−1), indicating that iron-doping favored EPFRs formation. However, PCH-Fe had lower EPFRs content (2.78 × 1018 spins·g−1) than PCH (7.95 × 1018 spins·g−1), possibly due to excessive iron leading to the consumption of the generated EPFRs. For another reason, the required Fe(III) amount for EPFRs formation might vary among different precursors. PC has a lower concentration of phenolic compounds but 68–97% fatty acids, while WF and PP are rich in cellulose and lignin. In the Fenton-like reaction, oxygen-centered radicals of hydrochar played a significant role in activating H2O2 and efficiently degrading bisphenol A (BPA). Mechanisms of reactive oxygen species (ROS) generation in hydrochar/H2O2 system were proposed. EPFRs on hydrochar activate H2O2 via electron transfer, creating ·OH and 1O2, leading to BPA degradation. More importantly, the embedded EPFRs on the hydrochar's inner surface contributed to the prolonged Fenton-like reactivity of PPH-Fe stored for 45 days. This study demonstrates that by optimizing precursor selection and iron doping, hydrochars can be engineered to maximize their EPFRs content and reactivity, providing a cost-effective solution for the degradation of hazardous pollutants. Article Highlights: Characteristics and mechanisms for the generation and consumption of EPFRs were proposed. To favor g3-type EPFRs formation, the quantity of Fe(III) and aromatic compounds of the biomass should be matched. The g3-type EPFRs on hydrochars played a major role in the Fenton-like reaction. The external EPFRs of hydrochars were consumed easily while the internal EPFRs persisted during long-term storage. [ABSTRACT FROM AUTHOR]

A systematic procedure for the removal of color and chemical oxygen demand (COD) of an aqueous solutions comprising initial mixed binary azo reactive dyes (Corafix Red ME4B and Corazol Black BX), present in any proportions of initial concentrations, has been developed. It utilizes a Fenton-like advanced oxidation process (AOP) involving the activation of mixed binary oxidants as a pretreatment and a hybrid process, consisting of US cavitation and O3 based AOPs, as a post-treatment method. For the red dye, the optimum values of activator concentration, initial oxidant-ratio, initial oxidant-dosage, initial pH of initial H2O2 solution have been determined to be 100 g L−1, 3 wt% mM−1, 18:6 wt% mM−1, and 5 respectively; while, the US cavitation or O3 has been determined to be an optimum post-treatment. Similarly, for the black dye these optimum values and process are identified to be 100 g L−1, 3 wt% mM−1, 30:10 wt% mM−1, 3, and hybrid process respectively. The common optimum values of various parameters of pretreatment and a common optimum post-treatment method have been derived and experimentally demonstrated for the treatment of mixed binary dye solutions. The mechanisms responsible for decolorization and COD removal have been identified via hydroxyl and superoxide radical-trapping experiments [ABSTRACT FROM AUTHOR]

Red mud (RM) is a typical bulk solid waste with Fe/Al/Si/Ca-rich characteristics that has been used to prepare various heterogeneous catalysts such as iron-based catalysts and supported catalysts. Prussian blue analogues (PBA) is a low-cost, environmentally friendly, and active site rich iron-based metal organic framework, but its catalytic properties are adversely affected by their easy aggregation. In this study, nickel-doped RM-based PBA (RM-Ni PBA) was synthesized by acid dissolution-coprecipitation method for the degradation of ciprofloxacin (CIP). The characterization showed that RM-Ni PBA was a material with excellent dispersibility, large specific surface area, and abundant active sites. The degradation results showed that the removal efficiency of CIP in the RM-Ni PBA/H2O2 system was 16.63, 1.78, and 1.81 times that of RM, RM-PB, and Ni PBA, respectively. It was found that 1O2 was the main reactive oxygen species (ROS) dominated the degradation process, and its formation was accompanied by the mutual conversion of Ni(II)/Fe(II) and Ni(III)/Fe(III). Notably, the degradation process maintained a satisfactory efficiency over a wide pH range (3–9) and exhibited strong anti-interference ability against impurities such as Cl−, SO42−, and NO3−. The components and contents of RM-Ni PBA remained relatively stable during the degradation process. In addition, the degradation intermediates of CIP were identified, and possible degradation pathways were proposed. This study is expected to provide theoretical basis and technical guidance for the application of RM-based heterogeneous catalyst in the treatment of antibiotic wastewater. [ABSTRACT FROM AUTHOR]

Oxidative desulfurization (ODS) has emerged as a prominent technique for the removal of sulfur compounds from fuels, aiming to comply with stringent environmental regulations and minimize sulfur dioxide emissions. Herein, Fenton-like deep eutectic solvents (DESs) were synthesized as a catalyst and reaction medium and their application for the ODS process was investigated. The study encompassed the optimization of DES composition, reaction conditions, and the influence of different parameters on the desulfurization efficiency. The experimental findings demonstrated that the Fenton-like DES exhibited outstanding catalytic activity in the oxidative desulfurization of fuel. The optimized conditions involved conducting the reaction at room temperature for 2.5 h, using 200 mg of the prepared DES (HNFM-FeCl4) as both the extraction solvent and catalyst. An oxidant-to-sulfur (O/S) ratio of approximately 3:1 was maintained, with a 30 wt% H2O2 solution utilized as the oxidant. The analysis of the reaction products using GC–MS revealed a remarkable yield of 98% for dibenzothiophene sulfone. The DES provided a suitable medium for the reaction, enhancing the solubility and availability of sulfur compounds. The iron catalyst, in the presence of hydrogen peroxide, facilitated the oxidation of sulfur-containing compounds to their corresponding sulfones, which can be easily separated from the fuel phase. The DES catalysts exhibited stability and recyclability, making them suitable for practical applications in fuel desulfurization processes. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Petroleum Research & Studies is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) 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.)

Environmentally friendly catalysts have come to the forefront due to the cost of chemically produced catalysts and the formation of by-products harmful to the environment. Millions of tons of plant waste are produced every year, some of which is disposed directly. In this study, tomato stem hydrochar (TSCH) was produced from waste tomato stems by the hydrothermal carbonisation (HTC) method, and its use as a catalyst was investigated. The optimisation of Cr(VI) removal from water was carried out using a Fenton-like process with a TSCH catalyst and resulted in 100% of Cr(VI) removal efficiency at 10 mg/L of Cr(VI) concentration, pH 2.00, 0.2 g/L of TSCH catalyst, 10 µL/L of H2O2 and 60 minutes of reaction time. Fenton-like thermodynamic and kinetic data were analyzed, and the results were found to comply with the second-order in Cr(VI) removal. The reusability of the TSCH catalyst in Cr(VI) removal was investigated and it was emphasized that it was reusable for more than 5 uses. In conclusion, TSCH, which is an environmentally friendly, inexpensive and effective catalyst for Cr(VI) treatment in a Fenton-like process, can be used as an alternative catalyst for wastewater treatment in terms of both waste management and economic and environmentally friendly. [ABSTRACT FROM AUTHOR]

The heterogeneous solar-Fenton process is an ecological and promising strategy for removing hazardous pollutants in aqueous media. Therefore, this study aimed to prepare and characterize a heterogeneous solid iron catalyst supported by zeolite Y to degrade tartrazine yellow (TY) food coloring under natural sunlight. The catalyst was produced by wet ion exchange and characterized by several techniques. The catalyst efficiency was evaluated through the degradation of the TY dye in a batch mode with the evaluation of some of the main operational parameters. The presence of iron in zeolite Y was confirmed by XRD, TEM, and EDX techniques and by reducing specific area and pore volume after ion exchange. The FTIR proved the occurrence of an ion exchange process. The oxidative system formed by the Fe-Y catalyst and natural sunlight was highly efficient, with the removal of approximately 98% in 120 min under the experimental conditions: [TY]0 = 10 mg L−1, [H2O2]0 = 200 g L−1, Dosage of Y-Fe = 1.5 g L−1 and pH = 3.0. It was possible to recover the catalyst and use it in five reuse cycles, showing the stability and application potential in heterogeneous solar-Fenton systems with sunlight. The toxicity reduction was evaluated through the COD and TOC parameters and ecotoxicological tests against the bioindicators Artemia salina and Lactuca sativa, showing the efficiency of the proposed process. [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.)

Magnesium spinel ferrite (MgFe2O4) and cerium-doped magnesium spinel ferrite (MgFe2-xCexO4) (x = 0.0, 0.05, 0.1) were synthesized using an inexpensive coprecipitation method. The investigation focused on the influence of cerium on the physicochemical properties and the photocatalytic activity of this material under sunlight irradiation. The various characterization techniques, including X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), environmental scanning electron microscopy (ESEM-EDX), the Brunauer–Emmett–Teller (BET) method, and vibrating sample magnetometer (VSM), were used to determine the structural, morphological, and magnetic properties of the prepared samples. The increase in cerium percentage was found to better agglomerate the sheet-like morphology formed in the pure spinel and increase the average crystallite size, with a decrease in the magnetic properties. The optical band gap measured by UV–visible spectroscopy decreased from 2.21 eV, 2.21 eV, and 2.36 eV, accompanied by a change in the specific surface area of 47.23 m2/g, 57.86 m2/g, and 47.25 m2/g for MgFe2O4, MgFe1.95Ce0.05O4, and MgFe1.90Ce0.1O4, respectively. The maximum photocatalytic degradation of methylene blue under sunlight irradiation was achieved for the MgFe1.95Ce0.05O4 (58.35%) in the absence of hydrogen peroxide, and the maximum degradation for Fenton-like processes was achieved in the presence of MgFe1.90Ce0.1O4 (91.05%) within 180 min. [ABSTRACT FROM AUTHOR]

$\cdot {\rm OH}$ ⋅ O H The wet denitrification technology has a good development prospect due to its simple system and mild reaction conditions, and related research has become a hot topic in the field of flue gas purification. In this work, a novel simultaneous removal technology of NO from flue gas using Fe2+/Cu2+-catalytic H2O2/(NH4)2S2O8 system was developed for the first time. The feasibility of this new flue gas cleaning technology was explored through a series of experiments and performance analyses. The mechanism of oxidation products, free radicals and simultaneous removal of NO was revealed. The effects of the main process parameters on the removal of NO were investigated. Relevant results demonstrated that the removal efficiency of NO was elevated when the concentration of (NH4)2S2O8 or reacting temperature increased, while it was decreased after increasing the raising of Fe2+, Cu2+ and H2O2 concentrations. The main radicals were and· ${\rm SO}_4^-$ S O 4 − , using the electron spin resonance technique in the solution, and played a very important role in NO removal. The main products were carried out by ion chromatography and elemental N material accountancy, and the results showed that it was sulfate and nitrate in the solution, which provided theoretical guidance for the subsequent treatment and resource utilization of the absorption solution. The results of the study provided a theoretical basis for the industrial application of wet denitrification. Highlights A new green process of NO removal by a wet process with Fe2+/Cu2+ activated (NH4)2S2O8 system is proposed in this paper; Elimination mechanisms and paths of NO are elucidated; The synergistic role produced by Cu2+ and Fe2+ is beneficial to the purification of NO; The synergistic role produced by (NH4)2S2O8 and H2O2 increased the concentration of free radicals in the solution; This process jointly considers the enhanced removal of NO and recycling of transition metal ions. [ABSTRACT FROM AUTHOR]

The studies on the origin of versatile oxidation pathways toward targeted pollutants in the single-atom catalysts (SACs)/peroxymonosulfate (PMS) systems were always associated with the coordination structures rather than the perspective of pollutant characteristics, and the analysis of mechanism commonality is lacking. In this work, a variety of single-atom catalysts (M-SACs, M: Fe, Co, and Cu) were fabricated via a pyrolysis process using lignin as the complexation agent and substrate precursor. Sixteen kinds of commonly detected pollutants in various references were selected, and their lnkobs values in M-SACs/PMS systems correlated well (R² = 0.832 to 0.883) with their electrophilic indexes (reflecting the electron accepting/donating ability of the pollutants) as well as the energy gap (R² = 0.801 to 0.840) between the pollutants and M-SACs/PMS complexes. Both the electron transfer process (ETP) and radical pathways can be significantly enhanced in the M-SACs/PMS systems, while radical oxidation was overwhelmed by the ETP oxidation toward the pollutants with lower electrophilic indexes. In contrast, pollutants with higher electrophilic indexes represented the weaker electron-donatingcapacity to the M-SACs/PMS complexes, which resulted in the weaker ETP oxidation accompanied with noticeable radical oxidation. In addition, the ETP oxidation in different M-SACs/PMS systems can be regulated via the energy gaps between the M-SACs/PMS complexes and pollutants. As a result, the Fenton-like activities in the M-SACs/PMS systems could be well modulated by the reaction pathways, which were determined by both electrophilic indexes of pollutants and single-atom sites. This work provided a strategy to establish PMS-based AOP systems with tunable oxidation capacities and pathways for high-efficiency organic decontamination. [ABSTRACT FROM AUTHOR]

A composite of manganese sulfide doped iron oxychloride (MnS-FeOCl) was successfully synthesized for the first time and applied to activate H2O2 to degrade isoniazid under different pH values. The MnS-FeOCl structure was characterized by various analytical methods such as X-ray diffraction (XRD), scanning electron microscopy, energy-dispersive X-ray spectroscopy, Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy, indicating manganese sulfide (MnS) doping greatly changed the physicochemical property of FeOCl. The Fenton-like reaction showed that MnS doping could enhance the Fenton activity of FeOCl in the pH range of 6-9, and 5% MnS-FeOCl composite had the highest activity. Isoniazid (20 mg/L) could be degraded by 89.90% in 5 min at an initial pH of 6.0 by 5% MnS-FeOCl/H2O2. However, the high performance of 5% MnS-FeOCl composite was at the cost of decrease of its stability. The result of XRD analysis indicated that the crystallinity of 5% MnS-FeOCl was poorer than that of pristine FeOCl, thus leading to its decreased stability. It is of great significance for the further study on the modification of FeOCl catalyst in Fenton-like reaction. [ABSTRACT FROM AUTHOR]

Sulfur (S)-doped α-Fe2O3 has been regarded as an excellent catalyst for eliminating organic pollutants in the photo-Fenton-like reaction. Yet, the synthetic complexity and extremely low activity in the dark Fenton-like reaction still need to be solved. In this study, magnetic α-Fe2O3 with sulfide was successfully fabricated via hydrothermal and calcination processes, for the first time, where thiourea acted as both S source and reducing agent, and then, it was applied for activating peroxydisulfate (PDS) to degrade organic contaminants. Important influencing factors were systemically investigated, and the results showed that this catalyst activating PDS was highly effective in the removal of organic pollutants in dark- and photo-Fenton-like reactions. In addition, the catalyst possessed good stability and recyclable ability. The structure of catalyst was analyzed by several characterizations, such as XRD and XPS. The results revealed that sulfide had an important effect on the structure and performance of α-Fe2O3. The detected mechanism indicated that the main reactive oxygen species were altered after switching from darkness to LED illumination. This work offered a promising method to rationally design for S/α-Fe2O3 in the environmental remediation. [ABSTRACT FROM AUTHOR]

Copyright of Acta Scientiarum Naturalium Universitatis Sunyatseni / Zhongshan Daxue Xuebao is the property of Sun-Yat-Sen University 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 combination of semiconductors and transition metal compounds for Fenton‐like application has been widely reported. However, there are still some problems that can be further studied such as the optimization of metal species and in‐depth research of mechanism. In this paper, using melamine and copper acetate as raw materials, a kind of composite of copper oxide and graphitic carbon nitride (CuO/g‐C3N4) is synthesized by a facile hydrothermal method. The synthetic conditions such as type of transition metal salt and ratio of raw material are further optimized. With the presence of H2O2, the CuO/g‐C3N4 composite shows exceptional broad‐spectrum Fenton‐like catalytic performance against the organic dyes in aqueous solution within a wide pH range, and the highest degradation rate of organic dyes can reach 99% within 10 min. After eight times of recycling, the catalytic activity of the composite can still remain more than 85%. More importantly, the CuO/g‐C3N4 composite presented excellent anti‐interference ability toward heavy metal ions and complex pollutants. Finally, the enhanced Fenton‐like catalytic mechanism is illustrated in detail. [ABSTRACT FROM AUTHOR]

The thorny problem of adsorption is the disposing of spent adsorbent. In this manuscript, the exhaust adsorbent of efficient capture Cu(II) over ZSM-5 that supported zero-valent iron (nZVI) was reused as a catalyst for eliminating Rhodamine B (RhB). Batch experiments were used to evaluate the removal performance of Cu2+ and RhB. The results demonstrated that the Cu2+ adsorption process obeyed pseudo-second-order kinetics, and the adsorption performance was dependent on solution pH. The maximum adsorption capacity at the optimal pH 4.0 was 375.9 mg/g; equilibrium was reached rapidly within 35 min. From XPS, the reduction-oxidation between Fe0 and Cu2+ was occurred in the adsorption process, and Fe2+, Fe3+, and Cu0 was formed. In the recycling experiments, RhB was removed by the spent Cu adsorbent, with the removal performance being dependent on the initial Cu concentration, in the order of 5 mg/L > 20 mg/L > 0 mg/L > 100 mg/L > 500 mg/L. RhB removal also improved with increasing H2O2 concentration. More than 99.9% of the RhB was degraded within 8 min using 1.75 mM H2O2, which was a large improvement over the previously used catalyst. The hydroxyl radical was found to be the main free radical responsible for RhB degradation. [ABSTRACT FROM AUTHOR]

The thorny problem of adsorption is the disposing of spent adsorbent. In this manuscript, the exhaust adsorbent of efficient capture Cu(II) over ZSM-5 that supported zero-valent iron (nZVI) was reused as a catalyst for eliminating Rhodamine B (RhB). Batch experiments were used to evaluate the removal performance of Cu2+ and RhB. The results demonstrated that the Cu2+ adsorption process obeyed pseudo-second-order kinetics, and the adsorption performance was dependent on solution pH. The maximum adsorption capacity at the optimal pH 4.0 was 375.9 mg/g; equilibrium was reached rapidly within 35 min. From XPS, the reduction-oxidation between Fe0 and Cu2+ was occurred in the adsorption process, and Fe2+, Fe3+, and Cu0 was formed. In the recycling experiments, RhB was removed by the spent Cu adsorbent, with the removal performance being dependent on the initial Cu concentration, in the order of 5 mg/L > 20 mg/L > 0 mg/L > 100 mg/L > 500 mg/L. RhB removal also improved with increasing H2O2 concentration. More than 99.9% of the RhB was degraded within 8 min using 1.75 mM H2O2, which was a large improvement over the previously used catalyst. The hydroxyl radical was found to be the main free radical responsible for RhB degradation. [ABSTRACT FROM AUTHOR]

Developing a highly efficient Fenton-like catalyst working in a wide pH range is imperative to accomplish its practical wastewater treatment. Herein, FeS2/FeSxOy catalyst was synthesized by hydrothermal-solvothermal vulcanization with thioacetamide as a sulfur source. Characterization results confirmed FeS2/FeSxOy consisted of pyrite, kornelite, and szomolnokite. FeS2/FeSxOy exhibited superior catalytic activity toward H2O2 activation with more than 96% phenol removal within 5 min in pH 3.0 ∼ 8.0 at 30°C. Radical scavenging experiment and EPR analysis revealed both hydroxyl radicals (·OH) and superoxide anion radicals (O2·-) anticipated in phenol elimination, but ·OH played a dominant role. The detailed degradation experiments and density functional theory (DFT) calculation confirmed the vital role of FeS2 in enhancing phenol abatement. This study not only developed a highly active catalyst for H2O2 activation but also theoretically analyzed the FeS2 function in depth, which provided a guide for designing a highly efficient Fenton-like catalyst. [ABSTRACT FROM AUTHOR]

The removal of antibiotics from wastewater to prevent their environmental accumulation is significant for human health and ecosystems. Herein, iron (Fe)-atom-doped anatase TiO2 nanofibers (Fe-TNs) were manufactured for the photocatalytic Fenton-like decomposition of tylosin (TYL) under LED illumination. Compared with the pristine TiO2 nanofibers (TNs), the optimized Fe-TNs exhibited improved visible-light-driven photocatalytic Fenton-like activity with a TYL degradation efficiency of 98.5% within 4 h. The effective TYL degradation could be attributed to the expanded optical light absorption and accelerated separation and migration of photogenerated electrons and holes after the introduction of Fe. The photogenerated electrons were highly conducive to the generation of active SO4•− radicals as they facilitated Fe(III)/Fe(II) cycles, and to oxidizing TYL. Moreover, the holes could be involved in TYL degradation. Thus, a significant enhancement in TYL degradation could be achieved. This research verifies the use of iron-doped anatase nanofibers as an effective method to synthesize novel photocatalytic Fenton-like catalysts through surface engineering for wastewater remediation. [ABSTRACT FROM AUTHOR]

Copyright of Applied Chemical Industry is the property of Shaanxi Research Design Insitute of Petroleum & Chemical 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.)

There have been many studies on the degradation of polyvinyl alcohol (PVA) by the Fenton-like method, but the narrow acid-base (pH) range, poor degradation effect, and time-consuming of the Fenton-like method limit its development. Therefore, to improve the shortcomings of the Fenton-like method, the study aimed to synthesize copper-manganese bimetal oxide loaded catalysts (MnCuO@γ-Al2O3) through the impregnation calcination method, and its potential to activate hydrogen peroxide (H2O2) for the degradation of PVA was evaluated. The X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer Emmett Teller (BET), energy dispersive spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS) characterizations revealed the chemical composition, structure and morphology of the prepared MnCuO@γ-Al2O3, furthermore the synergistic mechanism was proposed. Results indicated that copper and manganese could successfully attach to γ-Al2O3 and reduce the specific surface area of γ-Al2O3, promoting the transformation of multivalent metals and the generation of oxygen vacancies. In addition, comparative experiments demonstrated that the PVA removal efficiency was significantly improved at the catalyst calcination temperature of 500 °C, reaction temperature of 70 °C, H2O2 dosage of 125 mL · L - 1 , and catalyst dosage of 625 mg · L - 1 and more than 96% of PVA was removed within 20 min in neutral conditions. Lastly, four catalyst cycle degradation experiments of PVA were carried out, and the degradation effect could reach more than 96% in a certain time. [ABSTRACT FROM AUTHOR]

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department 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.)

A novel manganese dioxide–hydrogen peroxide (MnO2–H2O2) system was developed for effective Arsenic (As) removal. Under the specified conditions of no external mechanical stirring, a trace H2O2 concentration of 0.015 wt%, and a MnO2 concentration of 25 mg/L, high removal efficiency (88%) of As (100 µg/L) was achieved by the MnO2–H2O2 system within 30 min, which differs from conventional adsorption processes that require external mechanical stirring and conventional arsenite (As (III)) oxidation–adsorption processes that require high quantities of oxidants (such as ozone) and specially synthesized adsorbents/catalysts. The high removal efficiency of As (III) by the MnO2–H2O2 system was attributed to the turbulent conditions precipitated by the extensively generated oxygen (O2) from the catalytic decomposition of H2O2, the efficient adsorption of As on the surface of MnO2, and the effective generation of reactive radicals including hydroxyl and superoxide radicals (•OH and •O2−). Moreover, the MnO2 adsorbents before and after As removal were characterized systematically, and the generated radicals were verified using electron spin resonance (ESR). The results showed that the formation of inner-sphere surface complexes by the surface hydroxyl groups of MnO2 particles and As was responsible for the effective As adsorption process, and the oxidation of As (III) to arsenate (As (V)) was achieved via the generated radicals. The influences of representative environmental factors on As removal performance and the application of the MnO2–H2O2 system in river water and ground water were further studied and tested. In conclusion, the MnO2–H2O2 system offers several advantages, including low cost, ease of operation, and strong environmental adaptability, making it highly promising for practical water treatment applications. [ABSTRACT FROM AUTHOR]

Sulfamethoxazole (SMX) contamination in large quantities of wastewater can cause potential environmental problems. Due to difficulty in degrading SMX by natural processes, it is necessary to develop a novel technology to solve this problem. Advanced oxidation processes (AOPs) have been identified as methods with a high potential to treat recalcitrant organic pollutants. The nanoscale schwertmannite (nano-SWT) was prepared with an indoor-temperature synthesis method facilitated by polyvinylpyrrolidone (PVP). In this study, we performed a reaction of the nano-SWT materials with Fenton-like catalysts for SMX degradation in hydrogen peroxide (H2O2) media. The findings showed that the nano-SWT prepared by addition of 0.1 g·L−1 PVP (nano-SWT-n, n = 0.1) could degrade 92.5% of the SMX within 90 min at indoor temperature, which was due to the nano-SWT providing abundant reaction sites at the solid/solution interfaces. Additionally, SMX could be highly mineralized with 75% TOC removal and H2O2 was efficiently utilized during the nano-SWT/H2O2 process. In addition, after six cycles of Fenton-like degradation, the nano-SWT remained stable and reusable as a Fenton-like catalyst for SMX degradation. The nano-SWT performed well as a catalyst for SMX degradation. Additionally, this work provides a feasible environmental purification approach for the efficient degradation of SMX through the use of nanoscale schwertmannite as a catalyst in heterogeneous Fenton-like systems. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Guangxi Normal University - Natural Science Edition is the property of Gai Kan Bian Wei Hui 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.)

Adsorption and photocatalytic decolourisation of AR14 in aqueous solution was investigated using α-Fe2O3, α-Fe2O3/S and α-Fe2O3/CdS in dark and under UV irradiation, respectively. The synthesis of alpha iron oxide nanoparticles and combining heteroatoms in its matrix were performed by a simple co-precipitation method. Samples were characterised by XRD, Raman and pHPZC. The dye adsorption on the catalysts' surfaces showed a strong dependence on the pH, and the adsorption played the main role in the photocatalytic reaction in acidic medium. The pseudo first order kinetic model was found to be the best fit for the adsorption of AR14 by the three catalysts (R2 > 0.99) and is in good agreement with a chemisorption mechanism. The plot of intra-particle diffusion model showed a three-stage adsorption process which suggests that more than one process affects the AR14 adsorption. α-Fe2O3/S and α-Fe2O3/CdS nanoparticles had significant enhancement on the decolourisation of AR14 compared to the bulk material. A rate removal of 78%, 94% and 98% of the AR14 was recorded at pH = 3 under UV irradiation for α-Fe2O3, α-Fe2O3/S and α-Fe2O3/CdS respectively. The decolourisation was strongly enhanced in the presence of H2O2 leading to Fenton-like process. Added H2O2 competes with AR14 for the powder surface sites and reduces its adsorption on the catalysts' surfaces. The addition of propanol-2 as a radical scavenger confirms that •OH radicals are the main species responsible for the decolourisation of AR14 inα-Fe2O3/H2O2 system. Fenton-like process provides more selective oxidation for AR14 that have a higher affinity for the iron oxide surface and also for the modified iron oxide surface. [ABSTRACT FROM AUTHOR]

Immobilization of photocatalysts on supported materials is the key to achieving the efficiency and stability for wastewater treatment. However, developing high dispersion photocatalysts with high stability and durability is still a great challenge in practical application. Hence, this work reports a facile synthesis for inorganic–organic compound semiconductor nanomaterials using natural cotton substrates and in situ mineralization of β-FeOOH nanorods. In this strategy, abundant hydroxyl groups on cotton fibers as an intermediate bridge anchor Fe3+ for mineralization of β-FeOOH nanorods, forming strong coordination complexes. This resultant fabric, labeled as Cot-FeOOH, has been shown that the mineralized β-FeOOH nanorods covered the cotton fabric perfectly. The Cot-FeOOH displayed efficient photocatalytic activity for antibiotics and dye under visible light irradiation in the presence of hydrogen peroxide (H2O2). Moreover, the stability and durability of Cot-FeOOH were evaluated by multiple recycles and laundering durability tests, demonstrating the satisfactory performance of stability and durability. Our study offers a simple and easy strategy to decorate conventional cotton for versatile applications in environmental remediation. [ABSTRACT FROM AUTHOR]

Copyright of Chemistry & Industry of Forest Products is the property of Chemistry & Industry of Forest Products Editorial Department 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.)

One-dimensional (1D) nanostructures have attracted considerable attention in the field of environmental purification and energy conversion. In this paper, 1D FeV3O8 nanorods with 100 nm diameter and about 1 μm length were synthesized via a facile benign route without any surfactants. The crystal structure morphology and chemical composition of the samples were characterized by powder X-ray diffraction, field-emission scanning electron microscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, Brunauer–Emmett–Teller, and UV–vis and Raman spectroscopy. According to the results, the monoclinic phase of FeV3O8 nanorods is a narrow band gap of 2.38 eV (HOMO, 0.81 eV; LUMO, −1.57 eV). The as-prepared FeV3O8 nanorod has a large specific surface area of 20.006 m2 g–1. It could degrade 100% of Rhodamine B (RhB, 25 mg L–1) and 99% of Methylene blue (MB, 20 mg L–1) within 25 min and still can achieve 98% after four catalytic cycles, which is far better than a commercial TiO2 catalyst (P25). A nucleation–nanoparticle–nanoflower–nanorod growth mechanism (4N mechanism) for the FeV3O8 nanocrystals was proposed. Moreover, on the basis of the radical quenching and electron paramagnetic resonance tests, a possible photo-Fenton degradation mechanism was proposed. •OH was found to be the best active species during the degradation reactions. Results from this work show that the FeV3O8 catalyst exhibited an excellent photocatalytic performance and durability toward the degradation of multiple organic pollutants in a neutral system. [ABSTRACT FROM AUTHOR]

Copyright of Applied Chemical Industry is the property of Shaanxi Research Design Insitute of Petroleum & Chemical 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.)

Landfill leachates are highly contaminated liquid waste, and their treatment and detoxification are a challenging task. The current system of ecotoxicological risk assessment is complex and time-consuming. It is of fundamental importance to develop simpler and faster tools for the evaluation of the treated liquid waste and for an easier preliminary screening of the most active catalytic formulation/reaction conditions of the Fenton-like process. Here, several analytical techniques have been used for the assessment of the reduction of toxicity of the landfill leachate after Fenton process over copper-zirconia catalyst (ZrCu). Ultraviolet–visible (UV–vis) spectroscopy and absorbable organic halogens (AOX) analysis have been coupled to achieve further insight into the degradation of contaminants. In addition, for the first time, the qualitative abatement of organic compounds is monitored through proton nuclear magnetic resonance (1H NMR) analysis, providing a new method for evaluating the effectiveness of the treatment. Spectroscopic techniques reveal that the Fenton process induces a significant abatement of the aromatic and halogen compounds (51%) in the landfill leachate with a reduction of the toxicity that has been confirmed by ecotoxicological test with algae. These results validate the investigated tool for a simple rapid preliminary evaluation of the detoxification efficacy. [ABSTRACT FROM AUTHOR]

Copyright of Environmental Science & Technology (10036504) is the property of Editorial Board of Environmental Science & Technology 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.)

Here, we report a simple and efficient strategy for evenly in situ growth of Cu2(OH)3F nanosheets on BiVO4 spheres as a novel photo-Fenton-like catalyst using hydrothermal method. The Cu2(OH)3F/BiVO4 composite catalysts showed great performance for the organic pollutants degradation under visible light irradiation due to the efficient electron transfer and copper species transformation. The synergetic between Cu2(OH)3F and BiVO4 not only promoted the separation of electrons and holes but also enhanced the Cu2+ reduction, thus produced more strong oxidative radicals under a wide pH value range. The activity of Cu2(OH)3F/BiVO4 composite for methylene blue degradation was 6.03 and 5.47 times more than that of pristine Cu2(OH)3F and BiVO4, respectively. The composite catalysts were characterized with various methods and their stability and adaptability were also evaluated. Finally, a possible photo-Fenton-like reaction mechanism was also proposed based on the band structure/position and reaction species. [ABSTRACT FROM AUTHOR]

The preparation methods of iron/carbon composites and the types of iron and its compounds are introduced, including nano-iron, ferroferric oxide, ferric oxide, iron hydroxide, iron-manganese oxide, etc. The characteristics of the composites, such as improving iron leaching rate, improving reproducibility and adjusting pH range, were reviewed, and the relationship between them. Meanwhile, the regeneration method and advantages and disadvantages of the composite material based on the Fenton principle are expounded, and the recycling of the composite material can be realized in the future. Finally, the problems and challenges of the composite material were summarized, and several possible topics for material optimization, environmental impact and cost. [ABSTRACT FROM AUTHOR]

A novel Fenton-like catalyst made of reduced graphene oxide-coated CuFeO2 (rGO-coated CuFeO2) was synthesized by the hydrothermal reaction method to remove terramycin from aqueous solutions. The catalytic degradation performance of rGO-coated CuFeO2 for terramycin was verified with H2O2 activation. The characterization reveals that rGO-coated CuFeO2 has a micro- and mesoporous structure, with groups such as C=C/C−C, CH2−CO, and HO−C=O found on the surface. The Fenton-like catalytic degradation of terramycin by rGO-coated CuFeO2 was in line with the pseudo-second-order kinetic model, and the elevated temperature accelerated the reaction. Terramycin was catalytically degraded by rGO-coated CuFeO2 in two steps: terramycin was first adsorbed by rGO, and then Fenton-like degradation took place on its surface. This research presents new insight into the design and fabrication of Fenton-like catalysts with enhanced performance. [ABSTRACT FROM AUTHOR]

Dichloromethane (DCM), as a low-chlorinated organic compound, is hardly to be degraded through the reductive dechlorination pathway. In this study, the removal of DCM in Fenton-like system, using activated carbon fibres-supported zero-valence Fe/Ni nanoparticles (ACF-Fe/Ni) as catalysts, was investigated and compared with that of a traditional Fenton system (Fe2+/H2O2). The influence of vital parameters, including initial solution pH, DCM concentration, catalyst and H2O2 dosages, temperature and cosolute on the removal of DCM, was systematically studied. The results showed that 94.2% of DCM with an initial concentration of 5 mg/L could be removed in the Fenton-like reaction under the optimum condition: initial pH of 2.0, 0.4 g/L of ACF-Fe/Ni, 10 mM of H2O2 and a temperature of 30°C. In comparison, the removal of DCM in the Fenton-like system was faster than that of the Fenton system and the corresponding activation energies were 39.69 and 33.82 kJ/mol, respectively. The coexistence of solute was adverse to the removal of DCM in both Fenton-like and Fenton systems. Moreover, the active species for DCM removal in the Fenton-like system was confirmed as hydroxyl radical (·OH) via the quenching experiment and electron paramagnetic resonance measurement. The incomplete mineralisation (41.7%) of DCM after reaction indicated that the Fenton-like technology had the potential to realise DCM's non-toxic and harmless conversion and organic intermediates formed needed to take longer time to be decomposed. [ABSTRACT FROM AUTHOR]

This research paper studies the use of an environmentally and not expensive method to degrade Orange G dye (OG) from the aqueous solution, where the extract of ficus leaves has been used to fabricate the green bimetallic iron/copper nanoparticles (G-Fe/Cu-NPs). The fabricated G-Fe/Cu-NPs were characterized utilizing scanning electron microscopy, BET, atomic force microscopy, energy dispersive spectroscopy, Fourier-transform infrared spectroscopy and zeta potential. The rounded and shaped as like spherical nanoparticles were found for G-Fe/Cu-NPs with the size ranged 32-59 nm and the surface area was 4.452 m² /g. Then the resultant nanoparticles were utilized as a Fenton-like oxidation catalyst. The degradation efficiency of OG dye highly depends on H2O2 concentration (1.7-5.28 mM), catalyst dose (0.4- 1.6 g/L), pH (2-7), initial OG concentration (25-75 mg/L), and temperature (20-50 ℃). Batch experiments showed that 94.8 % of 50 mg/L of OG dye was removed within the optimum peroxide concentration, dose, pH and temperature which were 3.52 mM, 1 g/L, 3, and 40℃ respectively along with 30 min contact time. The results of kinetic models showed that OG removal followed the second-order model. Finally, the thermodynamic study of reaction was also examined and concluded to endothermic reaction with 29.725 kJ/mol activation energy. [ABSTRACT FROM AUTHOR]

In the practical application of water treatment, the Fenton reaction usually works at a lower pH. To overcome the above shortcomings, a Fenton-like reaction system with copper sulfate as a catalyst was proposed. In this paper, quinoline was used as the target pollutant and the effects of catalyst dosage, H2O2 dosage, reaction temperature, and initial concentration of quinoline and pH on the removal effect were investigated, and the evolution in pH and hydroxyl radical concentration during reaction, as well as the possible catalytic mechanism and degradation pathway were clarified. The results show that under a catalyst dosage of 0.4 g·L-1, a H2O2 dosage of 196 mmol·L-1, a quinoline concentration of 100 mg·L-1 and a temperature of 75°C, the removal of quinoline and total organic carbon (TOC) reaches 99.5% and 87.2% in 65 min, respectively. Furthermore, the copper sulfate-driven homogeneous Fenton system exhibits a superior adaptability to pH in the range of 3.8 to 8.8. In the degradation of quinoline, ·OH radicals may attack the nitrogen ring and the benzene ring in sequence. The work provides a technical support for the treatment of organic wastewater, and shows promising in practical applications. [ABSTRACT FROM AUTHOR]

High concentrations of antibiotics have been identified in aqueous media, which has diminished the quality of water resources. These compounds are usually highly toxic and have low biodegradability, and there have been reports about their mutagenic or carcinogenic effects. The aim of this study was to apply zero-valent iron-oxide nanoparticles in the presence of hydrogen peroxide and the sonolysis process for the removal of the amoxicillin antibiotic from aqueous media. In this study, zero-valent iron nanoparticles were prepared by an iron chloride reduction method in the presence of sodium borohydride (NaBH4), and the obtained nanoparticles were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and vibrating-sample magnetometry (VSM). Then, using a Fenton-like process, synthetic wastewater containing 100 to 500 mg/L amoxicillin antibiotic was investigated, and the effects of different parameters, such as the frequency (1 and 2 kHz), contact time (15 to 120 min), the concentration of hydrogen peroxide (0.3%, 0.5%, and 6%), the dose of zero-valent iron nanoparticles (0.05, 0.1, 0.5 g/L), and pH (3, 5, 10) were thoroughly studied. A pH of 3, hydrogen peroxide concentration of 3%, ultrasonic-wave frequency of 130 kHz, zero-valent iron nanoparticles of 0.5 g/L, and contaminant concentration of 100 mg/L were obtained as the optimal conditions of the combined US/H2O2/nZVI process. Under the optimal conditions of the combined process of zero-valent iron nanoparticles and hydrogen peroxide in the presence of ultrasonic waves, a 99.7% removal efficiency of amoxicillin was achieved in 120 min. The results show that the combined US/H2O2/nZVI process could be successfully used to remove environmental contaminants, including antibiotics such as amoxicillin, with a high removal percentage. [ABSTRACT FROM AUTHOR]

We designed a photocatalyst and developed sustainable wastewater purification technology, which have significant advantages in effectively solving the global problem of drinking water shortage. In this study, a new nanocomposite was reported and shown to be a catalyst with excellent performance; CuO was coated successively onto functionalized nano γ-Al2O3, and this novel structure could provide abundant active sites. We evaluated the performance of the CuO@γ-Al2O3 nanocomposite catalyst for polyvinyl alcohol (PVA) degradation under visible light irradiation. Under optimized conditions (calcination temperature, 450 °C; mass ratio of γ-Al2O3:Cu(NO3)2·3H2O, 1:15; pH value, 7; catalyst dosage, 2.6 g/L; reaction temperature, 20 °C; and H2O2 dosage, 0.2 g/mL), the CuO@γ-Al2O3 nanocomposite catalyst presented an excellent PVA removal rate of 99.21%. After ten consecutive degradation experiments, the catalyst could still maintain a PVA removal rate of 97.58%, thus demonstrating excellent reusability. This study provides an efficient and easy-to-prepare photocatalyst and proposes a mechanism for the synergistic effect of the photocatalytic reaction and the Fenton-like reaction. [ABSTRACT FROM AUTHOR]

Disinfection is an essential and significant process for water treatment to protect the environment and human beings from pathogenic infections. In this study, disinfection through the generation of hydroxyl (Fenton process (FP)) and sulfate (Fenton-like process (FLP)) radicals was validated and optimized. The optimization was carried out in synthetic water through an experimental design methodology using the bacteria Escherichia coli as a model microorganism. Different variables were evaluated in both processes: precursor concentration (peroxymonosulfate (PMS) and H2O2), catalyst concentration (Fe+2), and pH in the Fenton process. After that, the optimized conditions (FP: 132.36 mM H2O2, 0.56 mM Fe+2 and 3.26 pH; FLP: 3.82 mM PMS and 0.40 mM Fe+2) were applied to real matrices from wastewater treatment plants. The obtained results suggest that both processes are promising for disinfection due to the high oxidant power of hydroxyl and sulfate radicals. [ABSTRACT FROM AUTHOR]

In this work, using molasses wastewater as a partial acidifying agent and bagasse pith as a pore-enlarging agent, a new low-cost Fenton-like catalyst (ACRMbp) used for degradation of sulfamethoxazole was prepared through a simple process of acidification and calcination using red mud (RM) as the main material. The optimum preparation conditions of ACRMbp were acquired, and the optimum preparation conditions of ACRMbp were as follows: mass ratio of bagasse pith to RM (mbp:mRM) 0.033:1, particle size of bagasse pith 0.10–0.20 mm, calcination temperature 773 K, and calcination time 2 h. The ACRMbp catalyst was characterized by XRD, SEM, EDS, and BET. According to the results of characterizations, it was found that the iron phase of ACRMbp had completely transformed into α-Fe2O3 after the process of acidification and calcination, and the addition of bagasse pith significantly improved the surface area of the prepared ACRMbp. Furthermore, under the reaction conditions of catalyst dosage of 2 g/L, initial pH 3 and reaction time 90 min, the ACRMbp has showed the highest catalytic activity. ACRMbp had significantly higher activity than red mud, and exhibited a remarkable settleability. Besides, ACRMbp retained good recyclability and stability during use. Kinetic studies showed the degradation process could be described with the first-order model. Overall, the prepared ACRMbp was an effective and excellent catalyst in the Fenton-like process. [ABSTRACT FROM AUTHOR]

In this study, a series of CuO@γ-Al2O3 particles were prepared using a facile impregnation–spray drying–calcination method. Fenton-like degradation of polyvinyl alcohol (PVA) over a wide pH range was investigated by focusing on the Cu2+/Cu+ redox cycle during the reaction. CuO@γ-Al2O3 with a suitable amount of CuO demonstrated high activity and stability for PVA mineralization. The reaction mechanism and degradation pathway of the CuO@γ-Al2O3/H2O2 system for PVA degradation were also discussed. Electron spin resistance tests demonstrated that ·OH, O2·−, and 1O2 were the main contributors to PVA degradation. The CuO@γ-Al2O3/H2O2 system achieved an effective removal rate of PVA (92.65%) at the calcination temperature of 450 °C, γ-Al2O3:Cu(NO3)2·3H2O mass ratio of 1:15, initial pH of 7, catalyst dosage of 2.5 g/L, reaction temperature of 70 °C, and H2O2 dosage of 10.5 g/L. Degradation tests of rhodamine-B and reactive red X-3B showed that the CuO@γ-Al2O3/H2O2 system has a certain applicability. These results provide new insights into the development of Cu metal oxides for the oxidative treatment of organic pollutants. [ABSTRACT FROM AUTHOR]

Membrane Fenton-like process with cobalt–copper spinel catalyst is proposed to degrade nitrogenous organic hazardous in wastewater. Cu-auxiliary cobalt oxide (CuxCo3–xO4) was synthesized with the dispersion co-precipitation method. As-prepared CuCo2O4 performed as the best catalyst for Fenton degradation on nitrogen-containing organic compound as methylene blue (C16H18N3ClS) in water and N,N-dimethylacetamide [CH3CON(CH3)2] in industrial wastewater. Lattice substation of Cu2+ to Co2+ ion increased the oxygen vacancies and catalytic activity. The catalyst stability was improved owing to hybrid polarization confinement (total metal elution less than 0.8 mg/L). Methylene blue in water (C0 = 100 mg/L) was completely decolorized in 50 min using 0.6 g/L CuCo2O4 and 0.09 M H2O2 at intrinsic pH 6.7. Degradation reaction rate constant was increased by two folds as k = 0.076 min−1 catalyzed by CuCo2O4 over k = 0.039 min−1 by Co3O4. DMAc-contaminant wastewater of high CODs 19,080 mg/L was treated using 2.4 g/L CuCo2O4 and 2.4 M H2O2 at intrinsic pH = 7.6. Removal rate of DMAc was enhanced from 81 to 99% in the ceramic membrane reactor when H2O2 was activated, and self-sweeping effect was suppressed. As a result, Total Organic Nitrogen (2900 mg/L) in the wastewater was mineralized by 99.9% with a fast transformation to inorganic NO3− ion. Biodegradability of the resistant organic wastewater was remarkably improved, and BOD/COD was increased by 18 folds. [ABSTRACT FROM AUTHOR]

Landfill leachates are a mixture of high concentration organic and inorganic contaminants and need to be appropriately treated due to their toxicity and severe adverse effects on the environment. Here, we studied the treatment of landfill leachate through a heterogeneous Fenton-like oxidation process using a zirconia supported copper catalyst (Cu/ZrO2). Reaction conditions such as pH, amount of catalyst, oxidant dose, temperature, and reaction time were investigated and their effects on pollutant abatement discussed. AOS (average oxidation state) and COS (carbon oxidation state) parameters were used for the evaluation of the degree of oxidation of the process, obtaining some insight into the formation of oxidized intermediates (partial oxidation) and the total oxidation (mineralization) of the leachate during the reaction. A two-step oxidation process enhanced the overall performance of the reaction with an abatement of organic compounds of 92% confirming the promising activity of a copper-based catalyst for the treatment of liquid waste. Higher catalytic activity was achieved when the following reaction conditions were applied: 70 °C, pH 5, 200 mg/L of catalyst, 30 mL/L of H2O2 dose, and 150 min. In addition, durability of the catalyst under optimized reaction conditions was verified by repeated reaction cycles. [ABSTRACT FROM AUTHOR]

Ozone-based and Fenton/Fenton-like-based processes were used to mineralize sulfamethoxazole (SMX). The oxidants were ozone (O3), hydrogen peroxide (H2O2) and persulfate (PS); Fe(II), Cu(II) and Fe(III) were used as metal activators of the oxidants. The effects of Fe(II) concentration in UV/oxidant/Fe(II) systems on SMX mineralization were evaluated. The mineralization rate of SMX was consistent with pseudo-first order kinetics. The results in this study suggested that hydroxyl radicals were responsible for the mineralization of SMX in UV/O3-based and UV/H2O2-based systems; moreover, sulfate radicals were the main reactive species in UV/PS-based systems. Fe(II) was a better activator than Cu(II) and Fe(III) in UV/oxidant/Mn+ systems. With the addition of 0.5 mM Fe(II), the SMX mineralization rate constants in UV/O3/Fe(II), UV/H2O2/Fe(II) and UV/PS/Fe(II) were 0.04089 ± 0.00754, 0.19486 ± 0.06356 and 0.05715 ± 0.03212 min−1. UV/H2O2/Fe(II) exhibited the highest mineralization rate and it was also the most energy-efficient system for SMX mineralization. [ABSTRACT FROM AUTHOR]

In this study, chitosan-based Co–Ni-Fe layered double hydroxide (C-LDH) and Co–Ni-Fe layered double hydroxide (LDH) were prepared by low saturation co-precipitation method. The chitosan-based Co–Ni-Fe layered metal oxide (C-LDO) and Co–Ni-Fe layered metal oxide (LDO)were prepared by the method of low saturation coprecipitation and roasting. Through the investigation of the material's degradation performance of 2,4-DCP, the adsorption, oxidation and catalytic oxidation performance of the material were studied. Interpretation of SEM, XRD, FTIR, BET and other characterization results showed that the hydrotalcite material was successfully prepared, and chitosan was introduced into the hydrotalcite material. Under the best conditions, the adsorption efficiency of the four materials (LDH, C-LDH, LDO, C-LDO) on 2,4-DCP (100 mg L−1) was 13.48%, 25.72%, 18.22% and 35.45%, respectively, the oxidation efficiency was 72.88%, 71.88%, 83.20% and 79.45%, and the efficiency was 99.14%, 97.17%, 74.32% and 71.77% by heterogeneous Fenton-like catalytic oxidation. By modifying the material, the oxidation and catalytic oxidation performance of the material is significantly improved, and the applicable conditions of the material are also broadened. Five cycles of experiments show that the material has excellent reusability. [ABSTRACT FROM AUTHOR]

Featured Application: Heterogeneous electro-Fenton-like processes based on catalyst and electrocatalyst using transition metals for 2-phenylphenol degradation. The hunt for efficient and environmentally friendly degradation processes has positioned the heterogeneous advanced oxidation processes as an alternative more interesting and economical rather than homogenous processes. Hence, the current study lies in investigating the efficiency of different heterogeneous catalysts using transition metals in order to prevent the generation of iron sludge and to extend the catalogue of possible catalysts to be used in advanced oxidation processes. In this study, nickel and zinc were tested and the ability for radical-generation degradation capacity of both ions as homogeneous was evaluated in the electro-Fenton-like degradation of 2-phenylphenol. In both cases, the degradation profiles followed a first-order kinetic model with the highest degradation rate for nickel (1 mM) with 2-phenylphenol removal level of 90.12% and a total organic reduction near 70% in 2 h. To synthesise the heterogeneous nickel catalyst, this transition metal was fixed on perlite by hydrothermal treatment and in a biochar or carbon nanofibers by adsorption. From the removal results using the three synthesized catalysts, it is concluded that the best catalysts were obtained by inclusion of nickel on biochar or nanofibers achieving in both with removal around 80% before 1 h. Thus, to synthetize a nickel electrocatalyst, nickel doped nanofibers were included on carbon felt. To do this, the amount of carbon black, nickel nanofibers and polytetrafluoroethylene to add on the carbon felt was optimized by Taguchi design. The obtained results revealed that under the optimised conditions, a near-complete removal was achieved after 2 h with high stability of the nickel electrocatalyst that open the applicability of this heterogeneous system to operate in flow systems. [ABSTRACT FROM AUTHOR]