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The growing demand for low-cost and functional snacks in many developing nations called for interest in the use of locally grown crops as substitutes for costly imported wheat flour. The amino acid composition, antioxidant and anti-inflammatory properties of the cookies from whole wheat, sweet potato, rice bran and peanut (56.25:18.75:5:20; 37.50:37.50:5:20; 18.75:56.25:5:20% as WPRG 1, WPRG 2, WPRG 3) composite flour blends, respectively, were obtained in this study. The 100% whole wheat and 100% refined flours served as control 1 and 2, respectively. The level of hydrophobic and aromatic amino acids was significantly (p < 0.05) high in WPRG 2 (~ 30 and ~ 10%), respectively when compared to others. However, the branched chain amino acids and Fischer ratio was significantly (p < 0.05) high in WPRG 1 (11.40% and 1.29), respectively, which could have contributed to their improved bioactivities. Notably, the composite cookie samples WPRG 1, 2 and 3 had higher hydroxyl (73.86 − 84.16%), DPPH (76.52 − 84.60%) radical scavenging as well as ferric reducing antioxidant (0.64–0.87 mmolFe2+/mg) properties than the control samples WWF and CWF, respectively. On the contrary, the metal chelating activities of the cookies WPRG 1–3 were not significantly (p > 0.05) different from control samples WWF and CWF. The improved amino acid profile and enhanced antioxidant properties of the composite cookies might have effectively influenced their anti-inflammatory properties (IC50; < 26 μg/ml) when compared to the control samples (IC50; ~ 40 μg/ml), respectively. Hence, the cookies that comprised of antioxidants and anti-inflammatory potentials needed in human health, were acceptable by the consumers. [ABSTRACT FROM AUTHOR]

Batch heterogeneous catalytic ozonation experiments were performed using commercial and synthesized nanoparticles as catalysts in aqueous ozone. The transferred ozone dose (TOD) ranged from 0 to 150 μM, and nanoparticles were added in concentrations between 0 and 1.5 g L−1, with all experiments conducted at 20 °C and a total volume of 240 mL. A Ce-doped TiO2 catalyst (1% molar ratio of Ce/Ti) was synthesized via the sol–gel method. Response surface methodology (RSM) was applied to identify the most significant factors affecting the removal of selected pharmaceuticals, with TOD emerging as the most critical variable. Higher TOD resulted in greater removal efficiencies. Furthermore, it was found that the commercially available metal oxides α-Al2O3, Mn2O3, TiO2, and CeO2, as well as the synthesized CeTiOx, did not increase the catalytic activity of ozone during the degradation of ibuprofen (IBF) and para-chlorobenzoic acid (pCBA). Carbamazepine (CBZ) and diclofenac (DCF) are compounds susceptible to ozone oxidation, thus their complete degradation at 150 μM transferred ozone dose was attained. The limited catalytic effect was attributed to the rapid consumption of ozone within the first minute of reaction, as well as the saturation of catalyst active sites by water molecules, which inhibited effective ozone adsorption and subsequent hydroxyl radical generation (●OH). [ABSTRACT FROM AUTHOR]

Layered double hydroxides (LDH) exhibit macromolecular behavior due to their layered structure, providing unique properties that make them suitable for various applications. Their crystal structure allows for intercalation of various species, demonstrating excellent thermal stability and mechanical strength. Synthesis methods, such as co-precipitation, ion exchange, and hydrothermal techniques, enable the preparation of well-defined LDH macromolecules with tailored characteristics. These materials find applications in catalysis, drug delivery systems, environmental remediation processes, and energy storage devices. Our research described here an LDH material based on nickel, copper, and aluminum was synthesized, characterized and used as a catalyst for the oxidation of Acetaminophen (Ac) using H2O2. Our materials were created using the co-precipitation process at a constant pH. Fourier Transform infrared spectroscopy (FTIR), Raman spectroscopy (RAMAN), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Energy-Dispersive X-ray Spectroscopy (EDS) were used to characterize the synthesized material. The material was crystalline and devoid of contaminants, according to the characterization. The CuNiAl-CO3 material was used to catalyze the elimination of the Ac (1 g.L−1) from an aqueous solution. The amount of the LDH, the molar ratio (oxidant/pollutant), the temperature, and the pH were among the experimental factors that were modified to get superior results. The kinetic analysis revealed that using 3 g L−1 of LDH with a molar ratio (oxidant/pollutant) of 2.5 for 3 h at room temperature and without modification of the pH of the solution resulted in a complete degradation of the Ac, and that our LDH performed best in acidic conditions. [ABSTRACT FROM AUTHOR]

The Baeyer–Villiger (B–V) oxidation of ketones to the corresponding lactones/esters is a classic and essential reaction in the chemical industry. However, this oxidation process has not yet been achieved in ambient conditions with the aid of oxygen and heterogeneous photocatalysts. In this study, we developed an organic photocatalytic system using covalent triazine/heptazine‐based frameworks (CTF‐TB/CHF‐TB) to enable the B–V oxidation reaction under mild conditions through a cascade reaction pathway. Experimental data and theoretical calculations showed that heptazine/triazine units can “chelate” and decompose the in situ generated H2O2 into hydroxyl radicals (⋅OH). Compared to conventional methods that primarily involve metal‐activated benzaldehyde at elevated temperatures (e.g., 60 °C), the ⋅OH generated in our study can readily cleave the C−H bond of benzaldehyde, forming an active intermediate that drives subsequent sequential processes: O2→H2O2→⋅OH→Ph‐CO⋅→Ph‐COOO⋅. By employing this photocatalytic process, a yield of 91 % and a selectivity of over 99 % were obtained in the oxidation of cyclohexanone to caprolactone at room temperature. This performance is comparable to the state‐of‐the‐art catalysts, and our CHF‐TB catalyst demonstrates impressive reusability, maintaining a high yield after 5 consecutive runs. This work presents a straightforward approach for C−H cleavage by organocatalysts to produce ϵ‐caprolactone in a mild manner by B–V oxidation. [ABSTRACT FROM AUTHOR]

Heterogeneous Advanced Oxidation Processes (H-AOPs) are considered a new process for removing emerging pollutants. In this case, the high reactivity of hydroxyl radicals is used to degrade persistent organic pollutants. This review explores the state-of-the-art catalyst for hydroxyl radical generation in AOPs. As a parasite reaction, chloride ions appear in alkaline conditions and compete with the active sites. The theoretical foundation of catalyst performance is explored, focusing on the fundamental principles that govern the efficiency and mechanism of hydroxyl or chloride radical production. The synthesis and electronic modification sections explore the modifications of catalysts. It discusses key methodologies for catalyst preparation, with a particular emphasis on electronic modification that enhances both activity and stability. Finally, laboratory and pilot applications highlight the effectiveness of novel or modified catalysts in different scenarios. These last findings provide insights into the future directions for research and application, aiming to draw attention to the gap between laboratory studies and real-world implementations. [ABSTRACT FROM AUTHOR]

Polychlorinated naphthalenes (PCNs) are a new type of persistent organic pollutant (POP) characterized by persistence, bioaccumulation, dioxin-like toxicity, and long-range atmospheric transport. Focusing on one type of PCN, monochlorinated naphthalenes (CN-1, CN-2), this study aimed to examine their photodegradation in the environment. In this work, CN-1 and CN-2 were employed as the model pollutants to investigate their photodegradation process under UV-C irradiation. Factors like the pH, initial concentrations of CN-1, and inorganic anions were investigated. Next, the roles of hydroxyl radicals (•OH), superoxide anion radicals (O2•−), and singlet oxygen (1O2) in the photodegradation process were discussed and proposed via theory computation. The results show that the photodegradation of CN-1 and CN-2 follows pseudo-first-order kinetics. Acidic conditions promote the photodegradation of CN-1, while the effects of pH on the photodegradation of CN-2 are not remarkable. Cl−, NO3−, and SO32− accelerate the photodegradation of CN-1, whereas the effect of SO42− and CO32− is not significant. Additionally, the contributions of •OH and O2•− to the photodegradation of CN-1 are 20.47% and 38.80%, while, for CN-2, the contribution is 16.40% and 16.80%, respectively. Moreover, the contribution of 1O2 is 15.7%. Based on DFT calculations, C4 and C6 of the CN-1 benzene ring are prioritized attack sites for •OH, while C2 and C9 of CN-2 are prioritized attack sites. [ABSTRACT FROM AUTHOR]

This study focuses on synthesizing a catalyst that can quickly degrade micropollutants in water with minimal ozone exposure. While ozone is an effective oxidizing agent, it can harm the environment at higher concentrations if released in gaseous form. Thus, due to their efficiency and non-toxicity, researchers prefer to use hydroxyl radicals as oxidizing agents. In this study, Fe magnetite nanoparticles (FeNPs) have been synthesized to generate hydroxyl radicals for ozonation. The stability and effectiveness of the FeNPs as an ozonation catalyst were tested under different pH levels and ozone doses. Promising results have been obtained showing complete degradation of the model pharmaceutical compound within 10 min for the catalytic ozonation process. The parameters have been optimized for the holistic picture of the process, and their significance on the % degradation has been evaluated thoroughly. The energy requirement of the process has been evaluated to compare the proposed work with the available AOPs. It was found that the heterogenous catalytic ozonation process projects a much lower energy requirement as compared to many other AOPs. [ABSTRACT FROM AUTHOR]

The Fenton reaction is known for generating highly reactive hydroxyl radicals that are applied to accelerate the polishing removal rate of chemically inert SiC substrates. However, previous research primarily focuses on the polishing removal rate acceleration on the C surfaces of SiC substrates, and very limited studies have been conducted to investigate whether the hydroxyl radicals produced by the Fenton reaction serve as the primary agents of oxidative activity. Furthermore, the oxidation ability of hydroxyl radicals on the C surface and its relationship with their concentration are still not well-established. Therefore, more extensive research is needed to gain comprehensive understanding on the role of hydroxyl radicals in the oxidative activity on the C surface and their concentration-dependent effects. In this study, the polishing results of alumina, cerium oxide, and silica containing polishing slurries with and without Fenton reaction were compared and analyzed. The material removal rate (MRR) of the C surfaces of SiC substrates was significantly improved after the introduction of the Fenton reaction in alumina-containing slurry at pH 4, resulting in a smoother surface. Low-field nuclear magnetism, atomic force microscopy (AFM), ultraviolet spectrophotometry, and X-ray photoelectron spectroscopy (XPS) were employed to gain insights on inter-particle interactions and oxidation mechanisms of C face of SiC in presence of Fenton reaction. The results revealed that while hydroxyl radicals demonstrated potent oxidation ability, they alone were incapable of oxidizing C face of SiC. [ABSTRACT FROM AUTHOR]

The study investigates the effect of different parameters for the removal of SO2 and NOx through a wet process concurrently. Two separate processes have been compared for the removal of flue gases, that is, Ozone/UV and H2O2/UV. The research aims to develop a comparative study for the removal of SO2 and NOx simultaneously using Ozone/H2O2 and UV light and find the energy consumption (also known as EEO) for each process. Combining UV with O3 and H2O2 play a crucial role in generating hydroxyl radicals. Different combinations of Ozone/H2O2, flue gas, and UV intensity were studied at different pH and temperatures of the solution to achieve maximum removal of the flue gases. For, the ozonation process it was observed that the removal% of flue gases increases with increasing UV intensity, and at higher UV intensity (250 W), the removal% for NOx is 92% and SO2 is 95% simultaneously at optimum temperature 308 K. For H2O2/UV process (250 W UV intensity), removal% for NOx is 95% and SO2 is 100% at 313 K, 0.3 LPM flow rate of flue gases. The EEO values obtained for both processes were less than 1 for 95% NOx/SO2 removal efficiency. [ABSTRACT FROM AUTHOR]

A Fe2+-EGTA(ethylene glycol-bis (β-aminoethyl ether)-N,N,N′,N′-tetraacetic acid)-H2O2 system emits photons, and quenching this chemiluminescence can be used for determination of anti-hydroxyl radical (•OH) activity of various compounds. The generation of •OH and light emission due to oxidative damage to EGTA may depend on the buffer and pH of the reaction milieu. In this study, we evaluated the effect of pH from 6.0 to 7.4 (that may occur in human cells) stabilized with 10 mM phosphate buffer (main intracellular buffer) on a chemiluminescence signal and the ratio of this signal to noise (light emission from medium alone). The highest signal (4698 ± 583 RLU) and signal-to-noise ratio (9.7 ± 1.5) were noted for pH 6.6. Lower and higher pH caused suppression of these variables to 2696 ± 292 RLU, 4.0 ± 0.8 at pH 6.2 and to 3946 ± 558 RLU, 5.0 ± 1.5 at pH 7.4, respectively. The following processes may explain these observations: enhancement and inhibition of •OH production in lower and higher pH; formation of insoluble Fe(OH)3 at neutral and alkaline environments; augmentation of •OH production by phosphates at weakly acidic and neutral environments; and decreased regeneration of Fe2+-EGTA in an acidic environment. Fe2+-EGTA-H2O2 system in 10 mM phosphate buffer pH 6.6 seems optimal for the determination of anti-•OH activity. [ABSTRACT FROM AUTHOR]

The lack of vertical observation of reactive nitrogen oxides in agricultural areas has posed a significant challenge in fully understanding their sources and impacts on atmospheric oxidation. Ground-based multi-axis differential optical absorption spectroscopy (MAX-DOAS) observations were conducted in the agricultural regions of the North China Plain (NCP) during the summer of 2019 to measure the vertical distributions of aerosols, nitrogen dioxide (NO2), and nitrous acid (HONO). This study aimed at revealing the spatiotemporal distribution, sources, and environmental effects of reactive nitrogen oxides in the NCP agricultural areas. Our findings indicated that the vertical profiles of aerosols and NO2 exhibited a near-Gaussian distribution, with distinct peak times occurring between 8:00–10:00 and 16:00–18:00. HONO reached its maximum concentration near the surface around 8:00 in the morning and decreased exponentially with altitude. After sunrise, the concentration of HONO rapidly decreased due to photolysis. Additionally, the potential source contribution function (PSCF) was used to evaluate the potential sources of air pollutants. The results indicated that the main potential pollution sources of aerosols were located in the southern part of the Hebei, Shanxi, Shandong, and Jiangsu provinces, while the potential pollution sources of NO2 were concentrated in the Beijing–Tianjin–Hebei region. At altitudes exceeding 500 m, the heterogeneous reactions of NO2 on aerosol surfaces were identified as one of the important contributors to the formation of HONO. Furthermore, we discussed the production rate of hydroxyl radicals (OH) from HONO photolysis. It was found that the production rate of OH from HONO photolysis decreased with altitude, with peaks occurring in the morning and late afternoon. This pattern was consistent with the variations in HONO concentration, indicating that HONO was the main contributor to OH production in the agricultural regions of the NCP. This study provides a new perspective on the sources of active nitrogen in agricultural regions and their contribution to atmospheric oxidation capacity from a vertical perspective. [ABSTRACT FROM AUTHOR]

Herein, this study has examined the influence of Zn2+ sources during a biogenic-mediated pathway to synthesize ZnO nanoparticles with highly desirable solar-responsive catalytic properties. Salts of nitrate, acetate and chloride have been utilized. The ZnO powders underwent characterization using diverse analytical tools, including XRD, FTIR, Raman, BET, SEM, TEM with EDS/elemental mapping and UV-vis absorption/emission spectroscopic analyses. Accordingly, precursors have proved to affect crystallinity, morphology, surface characteristics, optical properties and the photocatalytic degradation of methylene blue (MB) model pollutant. It was observed that ZnO derived from zinc acetate precursor (Z-AC NPs) exhibits very fast photocatalytic degradation of MB at pH 11 with superior kinetic estimates of 0.314 min−1 and t1/2 = 2.2 min over many of recent reports. In contrast, the chloride precursor is not recommended along with the employed biogenic route. The intriguing findings could be directly correlated to the decreased crystal size, augmented surface area, the hexagonal morphology of the crystals, high potency in absorbing visible photons, high efficacy in separating photogenerated charge carriers and producing high amounts of •OH radicals. Further testing of Z-AC NPs in photocatalytic remediation of water samples from Dumat Aljandal Lake in Aljouf, Saudi Arabia, contaminated with MB and pyronine Y (PY) dyestuffs, showed high dye photodegradation. Therefore, this work could lead to an extremely fast avenue for decontaminating wastewater from hazmat dyestuff. [ABSTRACT FROM AUTHOR]

Since 2,4,6-trinitrotoluene (TNT) is one of the most used explosives for military purposes or different industries such as mining and construction, it is highly probable to cause environmental pollution. Exposure to TNT can cause serious health problems in humans; therefore, its degradation is important. Two advanced oxidation processes (AOPs) were thoroughly investigated for TNT degradation in the presence of 0.04 M Fe(II)-EDTA complex at circumneutral pH (pH 6). In order to produce two different powerful oxidative radicals, namely, •OH and •SO4−, 100 mM H2O2 and K2S2O8 were used, respectively. Interferences of different radical scavengers possibly present in water and soil were also tested in detail. In order to determine TNT concentrations before and after AOP degradation, an existing colorimetric method was modified, depending on the formation of Meisenheimer anion of TNT. The optimal degradation conditions were experimentally determined and analyzed using face-centered composite design (FCCD) program. Both approaches showed that the most important parameters were the concentrations of Fe-EDTA and oxidant for TNT decomposition. The optimal degradation percentages were determined as 84 and 88%, respectively, in the presence of K2S2O8 and H2O2. The persulfate-aided process was much less affected by •OH scavenger solvents such as t-butanol and DMSO. The novel persulfate-driven process was advantageously not affected from catalase (the H2O2 annihilator enzyme) which may exist in soil to eventually obstruct the H2O2 treatment of TNT wastes. This work establishes a comprehensive persulfate process for the first time and improves the existing process with H2O2 in the Fe(II)-EDTA degradation of TNT. [ABSTRACT FROM AUTHOR]

Abstract The growing demand for low-cost and functional snacks in many developing nations called for interest in the use of locally grown crops as substitutes for costly imported wheat flour. The amino acid composition, antioxidant and anti-inflammatory properties of the cookies from whole wheat, sweet potato, rice bran and peanut (56.25:18.75:5:20; 37.50:37.50:5:20; 18.75:56.25:5:20% as WPRG 1, WPRG 2, WPRG 3) composite flour blends, respectively, were obtained in this study. The 100% whole wheat and 100% refined flours served as control 1 and 2, respectively. The level of hydrophobic and aromatic amino acids was significantly (p 0.05) different from control samples WWF and CWF. The improved amino acid profile and enhanced antioxidant properties of the composite cookies might have effectively influenced their anti-inflammatory properties (IC50;

The oxidative potential (OP) of particulate matter has been widely suggested as a key metric for describing atmospheric particle toxicity. Secondary organic aerosol (SOA) and redox-active transition metals, such as iron and copper, are key drivers of particle OP. However, their relative contributions to OP, as well as the influence of metal-organic interactions and particulate chemistry on OP, remains uncertain. In this work, we simultaneously deploy two novel online instruments for the first time, providing robust quantification of particle OP. We utilize online AA (OPAA) and 2,7-dichlorofluoroscein (ROSDCFH) methods to investigate the influence of Fe(II) and Cu(II) on the OP of secondary organic aerosol (SOA). In addition, we quantify the OH production (OPOH) from these particle mixtures. We observe a range of synergistic and antagonistic interactions when Fe(II) and Cu(II) are mixed with representative biogenic (β-pinene) and anthropogenic (naphthalene) SOA. A newly developed kinetic model revealed key reactions among SOA components, transition metals, and ascorbate, influencing OPAA. Model predictions agree well with OPAA measurements, highlighting metal-ascorbate and -naphthoquinone-ascorbate reactions as important drivers of OPAA. The simultaneous application of multiple OP assays and a kinetic model provides new insights into the influence of metal and SOA interactions on particle OP.

Herein, this study has examined the influence of Zn2+ sources during a biogenic-mediated pathway to synthesize ZnO nanoparticles with highly desirable solar-responsive catalytic properties. Salts of nitrate, acetate and chloride have been utilized. The ZnO powders underwent characterization using diverse analytical tools, including XRD, FTIR, Raman, BET, SEM, TEM with EDS/elemental mapping and UV-vis absorption/emission spectroscopic analyses. Accordingly, precursors have proved to affect crystallinity, morphology, surface characteristics, optical properties and the photocatalytic degradation of methylene blue (MB) model pollutant. It was observed that ZnO derived from zinc acetate precursor (Z-AC NPs) exhibits very fast photocatalytic degradation of MB at pH 11 with superior kinetic estimates of 0.314 min−1 and t1/2 = 2.2 min over many of recent reports. In contrast, the chloride precursor is not recommended along with the employed biogenic route. The intriguing findings could be directly correlated to the decreased crystal size, augmented surface area, the hexagonal morphology of the crystals, high potency in absorbing visible photons, high efficacy in separating photogenerated charge carriers and producing high amounts of •OH radicals. Further testing of Z-AC NPs in photocatalytic remediation of water samples from Dumat Aljandal Lake in Aljouf, Saudi Arabia, contaminated with MB and pyronine Y (PY) dyestuffs, showed high dye photodegradation. Therefore, this work could lead to an extremely fast avenue for decontaminating wastewater from hazmat dyestuff.

Abstract Ultra-high dose rate (UHDR) irradiation has been shown to have a sparing effect on healthy tissue, an effect known as ‘FLASH’. This effect has been studied across several radiation modalities, including photons, protons and clinical energy electrons, however, very little data is available for the effect of FLASH with Very High Energy Electrons (VHEE). pBR322 plasmid DNA was used as a biological model to measure DNA damage in response to Very High Energy Electron (VHEE) irradiation at conventional (0.08 Gy/s), intermediate (96 Gy/s) and ultra-high dose rates (UHDR, (2 × 109 Gy/s) at the CERN Linear Electron Accelerator (CLEAR) user facility. UHDRs were used to determine if the biological FLASH effect could be measured in the plasmid model, within a hydroxyl scavenging environment. Two different concentrations of the hydroxyl radical scavenger Tris were used in the plasmid environment to alter the proportions of indirect damage, and to replicate a cellular scavenging capacity. Indirect damage refers to the interaction of ionising radiation with molecules and species to generate reactive species which can then attack DNA. UHDR irradiated plasmid was shown to have significantly reduced amounts of damage in comparison to conventionally irradiated, where single strand breaks (SSBs) was used as the biological endpoint. This was the case for both hydroxyl scavenging capacities. A reduced electron energy within the VHEE range was also determined to increase the DNA damage to pBR322 plasmid. Results indicate that the pBR322 plasmid model can be successfully used to explore and test the effect of UHDR regimes on DNA damage. This is the first study to report FLASH sparing with VHEE, with induced damage to pBR322 plasmid DNA as the biological endpoint. UHDR irradiated plasmid had reduced amounts of DNA single-strand breaks (SSBs) in comparison with conventional dose rates. The magnitude of the FLASH sparing was a 27% reduction in SSB frequency in a 10 mM Tris environment and a 16% reduction in a 100 mM Tris environment.

The photochemistry of Fe(III)-Iminodiacetic acid complex (Fe(III)-IDA) was studied under UVA and UV/Vis irradiation. The synthesis was realised via molar ratio method modified by reaction of IDA as ligand with Fe(III) as metal. The interaction of Fe(III) with IDA was characterised using Fourier-transform infrared (FTIR) and spectroscopy UV–visible. The results confirmed the stability of the complex at pH > 5; with constant of stability (Log β = 10.02) and stoichiometry Fe(III): IDA = 1:1. In addition, the redox potential was calculated at 521 mV, which is significantly lower than E° for the Fe(III)/Fe(II) couple. The photolysis of this complex in the presence of UVA light and UV/Vis light at different pHs was carried out. This photolysis was followed by several assay Fe(II) and •OH. The results show that the Fe(III)-IDA complex present a photo-reactivities under either light source and the phenomenon is faster when the UV/Vis was used. The initial conversion rate (r0) decreased with increasing of initial pH. The formation of hydroxyl radicals via the Fenton reaction was improved at pH = 2.12 for both irradiation sources used. Reduction of total organic carbon was also studied using the total organic carbon (TOC). The feasibility of amino iron complexes to improve the Fenton process under irradiation was confirmed. Additionally, our research also evidenced the optimal conditions for the formation of hydroxyl radicals; which are the key factor in remove pharmaceuticals pollutants in aqueous media. Based on the results obtained, the Fe(III)-IDA complex could be efficiently photolysis under UV/Vis light. [ABSTRACT FROM AUTHOR]

The removal of persistent organic micropollutants (OMPs) from secondary effluent in wastewater treatment plants is critical for meeting water reuse standards. Traditional treatment methods often fail to adequately degrade these contaminants. This study explored the efficacy of a hybrid ozonation membrane filtration (HOMF) process using CeO2 and CeTiOx-doped ceramic crossflow ultrafiltration ceramic membranes for the degradation of OMPs. Hollow ceramic membranes (CM) with a 300 kDa molecular weight cut-off (MWCO) were modified to serve as substrates for catalytic nanosized metal oxides in a crossflow and inside-out operational configuration. Three types of depositions were tested: a single layer of CeO2, a single layer of CeTiOx, and a combined layer of CeO2 + CeTiOx. These catalytic nanoparticles were distributed uniformly using a solution-based method supported by vacuum infiltration to ensure high-throughput deposition. The results demonstrated successful infiltration of the metal oxides, although the yield permeability and transmembrane flow varied, following this order: pristine > CeTiOx > CeO2 > CeO2 + CeTiOx. Four OMPs were examined: two easily degraded by ozone (carbamazepine and diclofenac) and two recalcitrant (ibuprofen and pCBA). The highest OMP degradation was observed in demineralized water, particularly with the CeO2 + CeTiOx modification, suggesting O3 decomposition to hydroxyl radicals. The increased resistance in the modified membranes contributed to the adsorption phenomena. The degradation efficiency decreased in secondary effluent due to competition with the organic and inorganic load, highlighting the challenges in complex water matrices. [ABSTRACT FROM AUTHOR]

Solar Fenton is an important and extensively used advanced oxidation process (AOP) to degrade pharmaceutical pollutants. The objective of this study was to evaluate the performance of simultaneous degradation of the mixed pollutants (amoxicillin, acetaminophen, and ciprofloxacin) for an aqueous solution using the solar Fenton process. Operating parameters such as pH, iron doses, H2O2 doses, pollutant concentrations, and time were studied. From the experimental results, the ideal conditions were obtained for the removal of mixed pollutants such as pH 3, Fe2+ 0.04 mM, H2O2 4 mM, the concentration of the mixed pollutants 5 mg/L, solar radiation 400 W/m2, and time 10 min, respectively. The pseudo-first-order kinetics were utilized to investigate the degradation efficacy of the mixed pollutants. The result of the study indicates that the degradation efficiency was > 99% for the mixed pollutants. A maximum of 63% mineralization was observed, and hydroxyl radical scavenger effects were studied. The best optimal conditions were applied to assess the spiked wastewater (municipal wastewater (MWW) and hospital wastewater (HWW)). The highest elimination rates for AMX, ACET, and CIP were observed as 65%, 89%, and 85% for MWW and 76%, 92%, and 80% for HWW, respectively. The degraded by-products were detected by LC–ESI–MS in the water matrix (aqueous solution and spiked wastewater), and ECOSAR analysis was performed for the transformed products. The study concluded that the solar Fenton technique is promising and effective for the removal of mixed pollutants from the water matrix. [ABSTRACT FROM AUTHOR]

This paper studies the dynamics of the development of laser breakdown plasma in aqueous colloids of dysprosium nanoparticles by analyzing the time patterns of plasma images obtained using a high-speed streak camera. In addition, the distribution of plasma flashes in space and their luminosity were studied, and the amplitude of acoustic signals and the rate of generation of new chemical products were studied depending on the concentration of dysprosium nanoparticles in the colloid. Laser breakdown was initiated by pulsed radiation from a nanosecond Nd:YAG laser. It is shown that the size of the plasma flash, the speed of motion of the plasma–liquid interface, and the lifetime of the plasma flash decrease with an increasing concentration of nanoparticles in the colloid. In this case, the time delay between the beginning of the laser pulse and the moment the plasma flash reaches its maximum intensity increases with increasing concentrations of nanoparticles. Varying the laser fluence in the range from 67 J/cm2 to 134 J/cm2 does not lead to noticeable changes in these parameters, due to the transition of the breakdown plasma to the critical regime. For dysprosium nanoparticles during laser breakdown of colloids, a decrease in the yield of hydrogen peroxide and an increase in the rate of formation of hydroxyl radicals per water molecule, characteristic of nanoparticles of rare earth metals, are observed, which may be due to the participation of nanoparticles and hydrogen peroxide in reactions similar to the Fenton and Haber–Weiss reactions. [ABSTRACT FROM AUTHOR]

After biochemical treatment，coking wastewater still has a large number of refractory components，and direct discharge will lead to natural water pollution. The classical Fenton reaction has problems such as the generation of iron-containing sludge and the narrow pH application range，which is limited in practical applications. Natural pyrite was used as a heterogeneous Fenton reaction catalyst to treat the biochemical effluent of coking wastewater，and phenol in the wastewater was used as a model pollutant to explore its oxidation mechanism. The results indicated that the process could effectively remove COD from wastewater under relatively broad initial pH conditions. The removal rate of COD in wastewater was proportional to the amount of pyrite added，and the removal rate of COD increased slightly under the condition of high concentration of H2O2，but the increase rate slowed down. There were two catalytic conditions in the system，homogeneous and heterogeneous. After adding ·OH scavenger，the degradation efficiency of the system significantly decreased，indicating that the main free radical in the system was ·OH. Phenol was the main organic pollutant in coking wastewater，and the intermediate products of phenol degradation by Fenton-like using pyrite were detected，and phenol was first oxidized to p-phenol，then quickly converted to p-benzoquinone，and finally oxidized to small molecule acids.

This study investigated the applicability of industrial waste. The high affinity of Fe-based products is widely used for industrial effluents because of their capability to oxidize contaminants. Waste foundry dust (WFD) is an Fe oxide that has been investigated as a potential reactive material that causes the generation of reactive oxidants. We aimed to investigate the physicochemical properties of WFD and the feasibility in the Fenton oxidation process. The WFD was used as a catalyst for removing Congo red (CR), to evaluate the generation of •OH and dissolution of Fe during the oxidation process. The linkage of •OH generation by WFD with eluted Fe(II) through the Fe dissolution was found. The Fenton oxidation reaction, CR degradation was affected by H2O2 concentration, initial pH, WFD dosage, initial CR concentration, and coexisting anions. The CR degradation efficiency increased with an increase in H2O2 concentration and WFD dosage. In addition, chloride and sulfate in solution promoted CR degradation, whereas carbonate had a negative effect on the Fenton oxidation process. The elution of Fe promotes CR degradation, over three reuse cycles, the degradation performance of the CR decreased from 100 to 81.1%. For the Fenton oxidation process, •OH generation is linked to Fe redox cycling, the surface passivation and Fe complexes interrupted the release of reactive oxidants, which resulted in the degradation of the CR decreased. This study proposed that WFD can serve as catalysts for the removal of CR. [ABSTRACT FROM AUTHOR]

The reactions of acetylcholine halides with H2O2 were studied at room temperature in initially deionized water, i.e., at pH ∼7. Acetylcholine (ACh), which catalyzes the decomposition of hydroperoxides and H2O2 into radicals in an organic medium, virtually does not affect the decomposition of H2O2 in aqueous solutions. In the case of AChI, hydrogen peroxide oxidizes the iodide anion to form diiodine and hydroxyl radical HO•, which was identified using the 5,5-dimethylpyrrolidine N-oxide spin trap. The rate constant of this reaction was estimated from the initial sections of the kinetic curves for the consumption of 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPOL): k1 = (2.0±0.1)•10−3 L mol−1 s−1. A nontrivial combination of radical reactions and redox disproportionation reactions occurs in the AChI—H2O2—TEMPOL system in initially deionized water. In this medium, H2O2, iodine compounds, TEMPOL, and the formed hydroperoxide radicals HO2• have a dual ability to act as oxidants or reducing agents, which results in quasi-stationary concentrations of I2 and TEMPOL being established in the process. The I− oxidation by peroxides in acid medium, known in iodometric titration, generates hydroxide radicals when conducted in neutral solutions (pH ∼7) and can compete with the Fenton reaction in systems in which the presence of metal ions is excluded. [ABSTRACT FROM AUTHOR]

The development of catalysts for treating hazardous organic effluents contained in wastewater via the light-induced advanced oxidation processes (AOPs) has been at the forefront of recent research. The heterogeneous photo-Fenton process is one of the most effective AOPs used in the abatement of wastewater pollutants. However, there is a frequent requirement for acidic pH and ultraviolet (UV) irradiation, both of which hinder its industrial viability. Thus, there is a demand for a stable solar light-activated photo-Fenton catalyst capable of operating under near-neutral pH. This is the first demonstration of the mesoporous FeNbO4 used for solar-driven photocatalytic reaction under an oxidative environment at near neutral pH. The present work reports the preparation of pure-phase mesoporous FeNbO4 with a high specific surface area through a wet chemical technique. The cationic surfactant tetradecyl trimethylammonium bromide (TTAB) has been employed as the structure-directing agent in the present synthesis that produces a mesoporous structure with a surface area of 97 m2/g, an average pore diameter of ~ 6.5 nm and an average pore volume of 0.139 cm3/g. The synthesized mesoporous FeNbO4 has been characterized by thermo-gravimetric analysis (TGA), Fourier Transform Infrared Spectrophotometer (FTIR), X-ray diffractometer (XRD), Branauer-Emmett-Teller analysis (BET), transmission electron microscope (TEM), and UV-vis spectroscopy. Our synthesized material exhibits high activity towards the degradation of organic dyes in the presence of H2O2 under natural sunlight irradiation in an optimized catalytic scheme. The complete degradation of the mixture of dyes was achieved by direct sunlight irradiation at near natural pH (5.7) in the presence of a catalyst (3 g/L) and 50 mM H2O2 for 1 h. The present article also reports the measurement of its point zero surface charge and the role of reactive species in the degradation of organic dyes. The synthesized material has been found to be a promising, stable, and recyclable photo-Fenton catalyst for the removal of organic pollutants from wastewater under solar light irradiation and near neutral pH. [ABSTRACT FROM AUTHOR]

Nitrogen oxide (NOx) pollutants have a significant impact on both the environment and human health. Photocatalytic NOx removal offers a sustainable and eco-friendly approach to combatting these pollutants by harnessing renewable solar energy. Photocatalysis demonstrates remarkable efficiency in removing NOx at sub-scale levels of parts per billion (ppb). The effectiveness of these catalysts depends on various factors, including solar light utilization efficiency, charge separation performance, reactive species adsorption, and catalytic reaction pathway selectivity. Moreover, achieving high stability and efficient photocatalytic activity necessitates a multifaceted materials design strategy. This strategy encompasses techniques such as ion doping, defects engineering, morphology control, heterojunction construction, and metal decoration on metal- or metal oxide-based photocatalysts. To optimize photocatalytic processes, adjustments to band structures, optimization of surface physiochemical states, and implementation of built-in electric field approaches are imperative. By addressing these challenges, researchers aim to develop efficient and stable photocatalysts, thus contributing to the advancement of environmentally friendly NOx removal technologies. This review highlights recent advancements in photocatalytic NOx removal, with a focus on materials design strategies, intrinsic properties, fundamental developmental aspects, and performance validation. This review also presents research gaps, emphasizing the need to understand the comprehensive mechanistic photocatalytic process, favored conditions for generating desired reactive species, the role of water concentration, temperature effects, inhibiting strategies for photocatalyst-deactivating species, and the formation of toxic NO2. [ABSTRACT FROM AUTHOR]

Advanced oxidation processes (AOPs) using hydroxyl radicals (•OH) as oxidizing agents are a promising technology. Herein, a feasible strategy is developed to initially construct carbazole‐based D‐π‐A type conjugated polymer (PBNCZ) via the oxidative coupling. Additionally, introducing ─COO− through Cyano hydrolysis extends its conjugated structure and improves the energy band structure, which greatly facilitates the generation of •OH as well as the enrichment of pollutants. Detailed experiments and theoretical calculations have proved that the introduction of ─COO− enhances the adsorption of O2 and bisphenol A (BPA), optimizing the reaction path of •OH. Thus, it completely decomposes 10 ppm of BPA within just 10 min, exceeding all previously organic photocatalysts. Meanwhile, the efficiency of photocatalytic H2O2 production by PBNCZ‐COO− reaches 1719.03 µmol h−1 g−1 under visible light. This multifunctional material with high adsorption capacity, photodegradation efficiency, and photocatalytic H2O2 production activity provides a solid foundation for the preparation of organic photocatalysts. [ABSTRACT FROM AUTHOR]

Advanced oxidation processes (AOPs) using hydroxyl radicals (•OH) as oxidizing agents are a promising technology. Herein, a feasible strategy is developed to initially construct carbazole‐based D‐π‐A type conjugated polymer (PBNCZ) via the oxidative coupling. Additionally, introducing ─COO− through Cyano hydrolysis extends its conjugated structure and improves the energy band structure, which greatly facilitates the generation of •OH as well as the enrichment of pollutants. Detailed experiments and theoretical calculations have proved that the introduction of ─COO− enhances the adsorption of O2 and bisphenol A (BPA), optimizing the reaction path of •OH. Thus, it completely decomposes 10 ppm of BPA within just 10 min, exceeding all previously organic photocatalysts. Meanwhile, the efficiency of photocatalytic H2O2 production by PBNCZ‐COO− reaches 1719.03 µmol h−1 g−1 under visible light. This multifunctional material with high adsorption capacity, photodegradation efficiency, and photocatalytic H2O2 production activity provides a solid foundation for the preparation of organic photocatalysts. [ABSTRACT FROM AUTHOR]

The lifetime of hydroxyl radicals (⋅OH) in the fuel cell catalyst layer remains uncertain, which hampers the comprehension of radical‐induced degradation mechanisms and the development of longevity strategies for proton‐exchange membrane fuel cells (PEMFCs). In this study, we have precisely determined that the lifetime of ⋅OH radicals can extend up to several seconds in realistic fuel cell catalyst layers. This finding reveals that ⋅OH radicals are capable of carrying out long‐range attacks spanning at least a few centimeters during PEMFCs operation. Such insights hold great potential for enhancing our understanding of radical‐mediated fuel cell degradation processes and promoting the development of durable fuel cell devices. [ABSTRACT FROM AUTHOR]

Here, we have studied the purification of water from phenol and tetracycline by oxidation with ozone and hydroxyl radicals generated in a corona electric discharge. Liquid circulation has been used to process large volumes. It has been established that tetracycline decomposes from a concentration of 11 mg/L to (1.7 ± 0.3) × 10−3 mg/L at a dose of 140 J/50 mL. Phenol decomposes more slowly, the oxidation rate decreases at low residual concentrations. The phenol concentration decreases from 13 mg/L to (27 ± 5) × 10−3 mg/L at a dose of 5 × 104 J/50 mL. The reasons for the strong decrease in the rate of phenol oxidation at low concentrations in the case of oxidation by hydroxyl radicals are analyzed. [ABSTRACT FROM AUTHOR]

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Skeletal materials belonging to the defect pyrochlore family have been the subject of considerable interest due to their remarkable properties. In this work, a highly efficient, stable and visible light active composite photocatalytic system consisting of defect pyrochlore of composition KMn0·33Te1·67O6 (KMnTeO) and g-C3N4 (g-CN) has been successfully prepared by simple physical mixing of pre-prepared KMnTeO and g-CN components synthesized in solid state and thermal treatment of low-cost melamine, respectively. Structural, morphological and optical properties of as-prepared catalysts were deduced from powder X-ray Diffraction (XRD), Fourier Transform Infrared (FT-IR), Raman, Field Emission Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy (FESEM-EDX), Transmission Electron Microscopy-High Resolution Transmission Electron Microscopy (TEM-HRTEM), Ultraviolet–Visible Diffuse Reflectance Spectroscopy (UV–Vis DRS), X-ray Photoelectron Spectroscopy (XPS) and Photoluminescence (PL) measurements. The lattice parameter “a” of parent KMnTeO was obtained from Rietveld refinement of its powder XRD pattern. The FT-IR and Raman spectra of KMnTeO gave characteristic bands belonging to the defect pyrochlore structure. The photocatalytic activities of KMnTeO and composite KMnTeO-g-CN were evaluated by the degradation of methylene blue (MB). Scavenger experiments were carried out to identify the reactive species responsible for the degradation of MB. Furthermore, the reusability and stability of the photocatalysts were explored. The probable photocatalytic mechanism for MB degradation over the composite KMnTeO-g-CN was surmised according to the scavenger experiments. The work provides a new approach for the development of novel defect pyrochlore based composite photocatalysts to treat industrial wastewater containing organic pollutants.

Anchoring noble metal sites through photo-reduction is an effective way to modulate charge distribution on photocatalytic interfaces, thereby enhancing photocatalytic performance. The irradiation field on the exposed surfaces of photocatalysts has an important influence on the morphology and distribution of noble metal sites. However, non-uniform light field derived from the scattering effects of particle-form photocatalysts hinders the well-distributed photo-deposition of noble metal sites. To address this challenge, we proposed a photo-deposition method utilizing the optical fiber coated with photocatalysts. TiO2 nanorod (NR) array was coated on the optical fiber to achieve a well-distributed irradiation filed across the NR array. This resulted in a concentration of the irradiation field primarily within the NR array, maintaining uniformly distributed light intensities throughout. Palladium (Pd) sites dominated by nanoclusters were well distributed on TiO2 NR array utilizing a photo-reduction method. These Pd sites functioned as electron acceptors, facilitating the effective separation and transfer of photo-generated carriers. Consequently, an highly active photocatalytic reaction interface was constructed, demonstrating the accumulation of a substantial concentration of holes and their efficient conversion into hydroxyl radicals (·OH). Notably, hydroxyl radicals with a concentration of 62.6 μM could be generated within 14.4 min. The construction of this efficient photocatalytic interface offers an optimal platform for accelerating photocatalytic reactions and enhancing photocatalytic efficiency.

Background: Leachate, containing challenging-to-degrade organic substances and persistent toxins, poses significant environmental concerns. Advanced oxidation processes (AOPs) have emerged as a promising solution for effective leachate treatment. This research provides a comprehensive review of the impact of various AOPs in leachate treatment. Methods: This systematic review was conducted, encompassing commonly used AOPs such as ozone, peroxone, O3/catalyst, Fenton, photo-Fenton, UV/TiO2, photolytic persulfate, O3/UV, and O3/H2O2/ UV. Extensive searches were performed using reputable databases, including EBSCO, PubMed, Web of Science, and Google Scholar. Specific keywords and inclusion/exclusion criteria were applied. Data regarding leachate treatment parameters were meticulously summarized and analyzed using descriptive statistical methods. Results: The efficiency of AOPs in removing leachate organic matter varied, with chemical oxygen demand (COD) removal ranging from 41% to 83% in treatment systems. The order of effectiveness was found to be: O3/UV/H2O2 > photo-Fenton > UV/TiO2 > Fenton > persulfate (PS) > O3/UV > O3/H2O2 > O3/ catalyst > ozonation (O3). The highest COD removal efficiency of 83.75% was achieved using the O3/UV/ H2O2 AOP approach. The removal efficiency of color also varied, ranging from 32% to 100%, depending on the leachate’s characteristics, concentration, and specific treatment process utilized. Conclusion: AOPs, particularly the hybrid approach using O3/UV/H2O2, significantly enhance waste leachate treatment by effectively degrading persistent organic compounds through the generation of hydroxyl radicals. Further research is required to optimize AOPs and improve their efficiency in waste leachate treatment.

The concentration of hydrogen peroxide and hydroxyl radicals in dependence of the intensity (strength) of water drop impact on a solid surface has been measured. The intensity was varied by changing the fall height from 1 to 4 m and the tilt angle of the surface onto which drops fell. It is shown that the content of hydrogen peroxide and hydroxyl radicals in solution increases after the drop impact on the solid surface. Apparently, the main mechanism of the observed effects is the generation of singlet oxygen and its further reduction. [ABSTRACT FROM AUTHOR]

Batch heterogeneous catalytic ozonation experiments were performed using commercial and synthesized nanoparticles as catalysts in aqueous ozone. The transferred ozone dose (TOD) ranged from 0 to 150 μM, and nanoparticles were added in concentrations between 0 and 1.5 g L−1, with all experiments conducted at 20 °C and a total volume of 240 mL. A Ce-doped TiO2 catalyst (1% molar ratio of Ce/Ti) was synthesized via the sol–gel method. Response surface methodology (RSM) was applied to identify the most significant factors affecting the removal of selected pharmaceuticals, with TOD emerging as the most critical variable. Higher TOD resulted in greater removal efficiencies. Furthermore, it was found that the commercially available metal oxides α-Al2O3, Mn2O3, TiO2, and CeO2, as well as the synthesized CeTiOx, did not increase the catalytic activity of ozone during the degradation of ibuprofen (IBF) and para-chlorobenzoic acid (pCBA). Carbamazepine (CBZ) and diclofenac (DCF) are compounds susceptible to ozone oxidation, thus their complete degradation at 150 μM transferred ozone dose was attained. The limited catalytic effect was attributed to the rapid consumption of ozone within the first minute of reaction, as well as the saturation of catalyst active sites by water molecules, which inhibited effective ozone adsorption and subsequent hydroxyl radical generation (●OH).

Polychlorinated naphthalenes (PCNs) are a new type of persistent organic pollutant (POP) characterized by persistence, bioaccumulation, dioxin-like toxicity, and long-range atmospheric transport. Focusing on one type of PCN, monochlorinated naphthalenes (CN-1, CN-2), this study aimed to examine their photodegradation in the environment. In this work, CN-1 and CN-2 were employed as the model pollutants to investigate their photodegradation process under UV-C irradiation. Factors like the pH, initial concentrations of CN-1, and inorganic anions were investigated. Next, the roles of hydroxyl radicals (•OH), superoxide anion radicals (O2•−), and singlet oxygen (1O2) in the photodegradation process were discussed and proposed via theory computation. The results show that the photodegradation of CN-1 and CN-2 follows pseudo-first-order kinetics. Acidic conditions promote the photodegradation of CN-1, while the effects of pH on the photodegradation of CN-2 are not remarkable. Cl−, NO3−, and SO32− accelerate the photodegradation of CN-1, whereas the effect of SO42− and CO32− is not significant. Additionally, the contributions of •OH and O2•− to the photodegradation of CN-1 are 20.47% and 38.80%, while, for CN-2, the contribution is 16.40% and 16.80%, respectively. Moreover, the contribution of 1O2 is 15.7%. Based on DFT calculations, C4 and C6 of the CN-1 benzene ring are prioritized attack sites for •OH, while C2 and C9 of CN-2 are prioritized attack sites.

Ag-loaded ZnO nanocomposite film photocatalysts were constructed by physical vapor deposition and thermal oxidation. The relationship between the surface morphology, optical properties, photoelectric properties, and photocatalytic activity of nanocomposite films were mainly investigated. The surface morphology of nanocomposite films exhibits a thickness dependence of the Zn layer, which can be acknowledged by the SEM image. Furthermore, under the surface plasmon resonance (SPR) effect of Ag particles, the nanocomposite films not only demonstrate a sensitivity to visible light but accelerate the photoelectron transfer efficiency at the interface between Ag particles and ZnO films. Photocatalytic experiments demonstrate that the photocatalytic activity of nanocomposite films is significantly enhanced in the photodegradation experiment of methyl orange (MO) or methylene blue (MB) pigments in comparison with pure ZnO films. It is relevant to note that hydroxyl radicals (•OH) contribute notably in photocatalytic degradation. The present work proposes a simple approach to preparing an efficient and recyclable nanoscale photocatalyst for the visible-light-induced purification to pigments in wastewater. [ABSTRACT FROM AUTHOR]

In conventional wastewater treatment plants, micropollutants mix with the aquatic environment because they cannot be removed entirely due to their nonbiodegradable structure. Advanced oxidation processes can be considered an alternative solution to this problem. In this study, five different pharmaceutical and personal care products, carbamazepine, diclofenac, ibuprofen, paracetamol, and triclosan, which are commonly found in aquatic environments, were selected as target pollutants. The removal of these target pollutants was investigated using advanced oxidation methods such as the Fenton and UV processes (UV, UV/H2O2, and UV/TiO2). The feasibility of processes in terms of cost was investigated. In the study, both initial and final pharmaceutical concentrations were measured using liquid chromatography mass spectrometry/mass spectrometry to accurately calculate removal efficiency. It has been determined that processes other than the UV process have removal efficiency >99.9%. The UV process showed removal efficiency of 40% for carbamazepine, 90% for diclofenac, 85% for ibuprofen, 86% for paracetamol and 85% for triclosan. Among the processes with high removal efficiency, the Fenton process has been integrated into wastewater treatment plants and has been shown to be the most suitable system in terms of both performance and cost in solving the micropollutant problem. [ABSTRACT FROM AUTHOR]

Type‐I photosensitizers (PSs) can efficiently generate reactive oxygen species (ROS) in the hypoxia condition of tumors, which show less oxygen dependence and are considered better candidates for photodynamic therapy (PDT). However, relatively few efficient type‐I organic PSs simultaneously generating two or more type‐I ROS under irradiation are reported. Herein, new alternate donor (D)‐acceptor (A) type molecules containing ladder‐type core (DA′D) fused with an electron‐deficient benzothiadiazole core are reported, which show symmetrical A‐DA′D‐A (QY1) and asymmetrical A‐DA′D‐A′′ (QY2) configurations, respectively. As these ROSs possess complementary properties of strong oxidizing ability (•OH) and long radical lifetime (O2•−), in vitro and in vivo experiments demonstrate that QY1 and QY2 show excellent PDT effects for tumor cells under normoxia or hypoxia, and can achieve remarkable tumor growth inhibition (TGI) rate of 90% for the QY2. More importantly, the generation of •OH in these PSs is revealed by experiments both in aqueous and in vitro, including the well‐known transformation of O2•− and direct electron transition from water to excited triplet PS. It thus provides a comprehensive understanding of the O2 dependence property of •OH radical and deep insights into the mechanism of type‐I PS. [ABSTRACT FROM AUTHOR]

Radiotherapy is one of the basic treatments for cancer, involving the damage of cancer cells caused by reactive oxygen species generated upon ionizing radiation. As radiation and oxidative damage also affect normal cells, modern treatments include the application of effective radioprotectors in order to minimize side effects. In this study, pulse radiolysis was used for the kinetic evaluation of antiradical properties of three water-soluble metallofullerenols (MFs), Sc3N@C80(OH)18, Lu3N@C80(OH)18, and Gd@C82(OH)22, as potential candidates for radioprotectors. The rate constants for their reactions with hydroxyl radicals (HO•) are 2.24 × 109, 4.32 × 109, and 1.11 × 1010 M–1 s–1, respectively. The ability of MFs to trap HO• is well correlated with their protecting effect against hemolysis of human erythrocytes (red blood cells, RBC) induced by radiolysis under anaerobic conditions, suggesting that MFs effectively scavenge HO• radicals before they attack the biomembranes. This correlation is no longer valid for aerobic conditions, when HO• attacks the membrane lipids and the process turns into peroxidation mediated by lipidperoxyl radicals, but all three MFs exhibited much better radioprotection than vitamin C or Trolox (water-soluble analogue of tocopherol). The high polarity (bioavailability) of MFs and their ability to effectively trap radicals make them potential good inhibitors of oxidative damage caused as a side effect of radiotherapy. [ABSTRACT FROM AUTHOR]

Among pollution remediation technologies, advanced oxidation processes (AOPs) are genuinely efficient since they are based on the production of strong, non-selective oxidants, mainly hydroxyl radicals (·OH), by a set of physicochemical methods. The biological counterparts of AOPs, which may be referred to as advanced bio-oxidation processes (ABOPs), have begun to be investigated since the mechanisms of induction of ·OH production in fungi are known. To contribute to the development of ABOPs, advanced oxidation of a wide number of dyes by the white-rot fungus Pleurotus eryngii, via a quinone redox cycling (QRC) process based on Fenton's reagent formation, has been described for the first time. The fungus was incubated with 2,6-dimethoxy-1,4-benzoquinone (DBQ) and Fe3+-oxalate, with and without Mn2+, leading to different ·OH production rates, around twice higher with Mn2+. Thanks to this process, the degradative capacity of the fungus increased, not only oxidising dyes it was not otherwise able to, but also increasing the decolorization rate of 20 dyes by more than 7 times in Mn2+ incubations. In terms of process efficacy, it is noteworthy that with Mn2+ the degradation of the dyes reached values of 90–100% in 2–4 h, which are like those described in some AOPs based on the Fenton reaction. [ABSTRACT FROM AUTHOR]

As a set of persistent organic pollutants (POPs) that cause serious harm to human and animal health, polycyclic aromatic hydrocarbons (PAHs) degradation has attracted attentions of many scholars. Ozonation is one of the promising techniques for removing PAHs from various aqueous solutions because of its molecular structures, rapid reaction with ozone (O3), and oxidation by-products of PAHs produced during ozonation are more biodegradable than initial PAHs. However, its application is constrained by the high cost of ozone production, and organic matter in water is only partially oxidized. In recent years, to improve the efficiency of the ozonation process and optimize economic efficiency, several methods of O3-based advanced oxidation processes (AOPs) (i.e. O3/UV, O3/H2O2, O3/H2O2/UV, O3/Fenton, O3/Catalyst) have been studied. These AOPs generate more HO• than molecular ozone. This review summarized recent developments relating to the degradation of PAHs via O3-based AOPs and their exciting mechanisms. Compared different processes characteristics in terms, such as radical species, operational conditions, by-products and their toxicity, and cost. We considered that O3/photocatalyst seems to be a better choice for PAHs degradation. Finally, the challenges and future trends of PAH degradation have prospected. [ABSTRACT FROM AUTHOR]

[Display omitted] Cobalt-based catalysts are one of the preferred materials for effective activation of hydrogen peroxide, and metal element doping and active site dispersion are effective methods to enhance their catalytic activity. In this work, manganese-doped cobalt silicate@diatomite composites with enhanced photo-Fenton-like oxidation performance were prepared and used for degradation of methyl orange (MO) dyes. Experiments showed that manganese doping increased the specific surface area of the samples and decreased the band gap energy of the materials. Moreover, the samples doped with manganese elements had better photo-Fenton-like properties. The degradation of methyl orange by Co0.25MnSi@DE/H 2 O 2 -UV reached more than 95%. In addition, density-functional theory (DFT) calculations showed that the Mn-doped samples were more prone to activate H 2 O 2 than non-manganese-doped samples, and the synergistic effect from using a bimetallic catalyst increased the photo-Fenton oxidation activity in the system. ESR spectroscopy and bursting tests indicated that the possible degradation mechanism consisted of hydroxyl radicals and superoxide radicals generated by the synergistic effect of cobalt ions and manganese under UV radiation. This study thus presents a feasible idea for the preparation of cobalt-based photo-Fenton catalysts that also provides a basis for understanding the catalytic mechanism analysis of other types of bimetallic catalysts. [ABSTRACT FROM AUTHOR]