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The Science of the Total Environment Sep 2023Hydrogen peroxide (HO), hydroxyl radicals (OH), hydroperoxyl (HO), and superoxide (O) radicals interacting with aerosol particles significantly affect the atmospheric...
Hydrogen peroxide (HO), hydroxyl radicals (OH), hydroperoxyl (HO), and superoxide (O) radicals interacting with aerosol particles significantly affect the atmospheric pollutant budgets. A multiphase chemical kinetic box model (PKU-MARK), including the multiphase processes of transition metal ions (TMI) and their organic complexes (TMI-OrC), was built to numerically drive HO chemical behaviors in the aerosol particle liquid phase using observational data obtained from a field campaign in rural China. Instead of relying on fixed uptake coefficient values, a thorough simulation of multiphase HO chemistry was performed. In the aerosol liquid phase, light-driven TMI-OrC reactions promote OH, HO/O, and HO recycling and spontaneous regenerations. The in-situ generated aerosol HO would offset gas-phase HO molecular transfer into the aerosol bulk phase and promote the gas-phase level. When combined with the multiphase loss and in-situ aerosol generation involving TMI-OrC mechanism, the HULIS-Mode significantly improves the consistency between modeled and measured gas-phase HO levels. Aerosol liquid phase could be a pivotal potential source of aqueous HO and influence the multiphase budgets. Our work highlights the intricate and significant effects of aerosol TMI and TMI-OrC interactions on the multiphase partitioning of HO when assessing atmospheric oxidant capacity.
Topics: Peroxides; Hydrogen Peroxide; Coordination Complexes; Air Pollutants; Aerosols
PubMed: 37245820
DOI: 10.1016/j.scitotenv.2023.164455 -
International Journal of Molecular... Dec 2023Dinitrosyl iron complexes (DNICs) are important physiological derivatives of nitric oxide. These complexes have a wide range of biological activities, with antioxidant...
Dinitrosyl iron complexes (DNICs) are important physiological derivatives of nitric oxide. These complexes have a wide range of biological activities, with antioxidant and antiradical ones being of particular interest and importance. We studied the interaction between DNICs associated with the dipeptide L-carnosine or serum albumin and prooxidants under conditions mimicking oxidative stress. The ligands of these DNICs were histidine residues of carnosine or His39 and Cys34 in bovine serum albumin. Carnosine-bound DNICs reduced the level of piperazine free radicals in the reaction system containing -butyl hydroperoxide (-BOOH), bivalent iron ions, a nitroxyl anion donor (Angeli's salt), and HEPES buffer. The ability of carnosine DNICs to intercept organic free radicals produced from -BOOH decay could lead to this effect. In addition, carnosine DNICs reacted with the superoxide anion radical (O) formed in the xanthine/xanthine oxidase enzymatic system. They also reduced the oxoferryl form of the heme group formed in the reaction of myoglobin with -BOOH. DNICs associated with serum albumin were found to be rapidly destroyed in a model system containing metmyoglobin and t-BOOH. At the same time, these protein DNICs inhibited the -BOOH-induced oxidative degradation of coenzymes Q and Q in rat myocardial homogenate. The possible mechanisms of the antioxidant and antiradical action of the DNICs studied and their role in the metabolism of reactive oxygen and nitrogen species are discussed.
Topics: Rats; Animals; Antioxidants; Histidine; Carnosine; Nitrogen Oxides; Iron; Nitric Oxide; Free Radicals; Superoxides; Oxygen; Serum Albumin
PubMed: 38139065
DOI: 10.3390/ijms242417236 -
Water Research Aug 2023Dissolved organic matters (DOM) are widely present in different water sources, causing significant effects on water treatment processes. Herein, the molecular...
Dissolved organic matters (DOM) are widely present in different water sources, causing significant effects on water treatment processes. Herein, the molecular transformation behavior of DOM during peroxymonosulfate (PMS) activation by biochar for organic degradation in a secondary effluent were comprehensively analyzed. Evolution of DOM was identified and inhibition mechanisms to organic degradation were elucidated. DOM underwent oxidative decarbonization (e.g., -CHO, -CH, -CH and -CO), dehydrogenation (-2H) and dehydration reactions by OH and SO. N and S containing compounds witnessed deheteroatomisation (e.g., -NH, -NO+H, -SO, -SO, -SH), hydration (+HO) and N/S oxidation reactions. Among DOM, CHO-, CHON-, CHOS-, CHOP- and CHONP-containing molecules showed moderate inhibition while condensed aromatic compounds and aminosugars exhibited strong and moderate inhibition effects on contaminant degradation. The fundamental information could provide references for the rational regulation of ROS composition and DOM conversion process in a PMS system. This in turn offered theoretical guidance to minimize the interference of DOM conversion intermediates on PMS activation and degradation of target pollutants.
Topics: Dissolved Organic Matter; Environmental Pollutants; Peroxides; Organic Chemicals
PubMed: 37290196
DOI: 10.1016/j.watres.2023.120166 -
Water Research Feb 2024Dissolved organic matter (DOM) is a major sink of radicals in advanced oxidation processes (AOPs) and the radical-induced DOM transformation influences the subsequent...
Dissolved organic matter (DOM) is a major sink of radicals in advanced oxidation processes (AOPs) and the radical-induced DOM transformation influences the subsequent water treatment processes or receiving waters. In this study, we quantified and compared DOM transformation by tracking the changes of dissolved organic carbon (DOC), UVA, and electron donating capacity (EDC) as functions of four one-electron oxidants (SO, Cl, Br, and CO) exposures as well as the changes of functional groups and molecule distribution. SO had the highest DOC reduction while Cl had the highest EDC reduction, which could be due to their preferential reaction pathways of decarboxylation and converting phenols to quinones, respectively. Br and CO induced less changes in DOC, UVA, and EDC than SO and Cl. Additionally, DOM enriched with high aromatic contents tended to have higher DOC, UVA, and EDC reductions. Decreases in hydroxyl and carboxyl groups and increases in carbonyl groups were observed in these four types of radicals treated DOM using Fourier transform infrared spectroscopy. High resolution mass spectrometry using FTICR-MS showed that one-electron oxidants preferred to attack unsaturated carbon skeletons and transformed into molecules featuring high saturation and low aromaticity. Moreover, SO was inclined to decrease oxidation state of carbon and O/C of DOM due to its strong decarboxylation capacity. This study highlights the distinct DOM transformation by four one-electron oxidants and provides comprehensive insights into the reactions of one-electron oxidants with DOM.
Topics: Oxidants; Dissolved Organic Matter; Antioxidants; Electrons; Carbon
PubMed: 38101043
DOI: 10.1016/j.watres.2023.121011 -
Environmental Research Aug 2023Graphitic carbon nitride (g-CN)-based materials are attracting attention for their unique properties, such as low-cost, chemical stability, facile synthesis, adjustable... (Review)
Review
Graphitic carbon nitride (g-CN)-based materials are attracting attention for their unique properties, such as low-cost, chemical stability, facile synthesis, adjustable electronic structure, and optical properties. These facilitate the use of g-CN to design better photocatalytic and sensing materials. Environmental pollution by hazardous gases and volatile organic compounds (VOCs) can be monitored and controlled using eco-friendly g-CN- photocatalysts. Firstly, this review introduces the structure, optical and electronic properties of CN and CN assisted materials, followed by various synthesis strategies. In continuation, binary and ternary nanocomposites of CN with metal oxides, sulfides, noble metals, and graphene are elaborated. g-CN/metal oxide composites exhibited better charge separation that leads to enhancement in photocatalytic properties. g-CN/noble metal composites possess higher photocatalytic activities due to the surface plasmon effects of metals. Ternary composites by the presence of dual heterojunctions improve properties of g-CN for enhanced photocatalytic application. In the later part, we have summarised the application of g-CN and its assisted materials for sensing toxic gases and VOCs and decontaminating NOx and VOCs by photocatalysis. Composites of g-CN with metal and metal oxide give comparatively better results. This review is expected to bring a new sketch for developing g-CN-based photocatalysts and sensors with practical applications.
Topics: Graphite; Volatile Organic Compounds; Gases; Oxides
PubMed: 37209982
DOI: 10.1016/j.envres.2023.116149 -
Chemosphere Sep 2023Tetracycline (TC) and Oxytetracycline (OTC) are common antibiotics increasingly detected in the environment, posing a potential risk to human and aquatic lives. Although...
Non-thermal plasma activated peroxide and percarbonate for tetracycline and oxytetracycline degradation: Synergistic performance, degradation pathways, and toxicity evaluation.
Tetracycline (TC) and Oxytetracycline (OTC) are common antibiotics increasingly detected in the environment, posing a potential risk to human and aquatic lives. Although conventional methods such as adsorption and photocatalysis are used for the degradation of TC and OTC, they are inefficient in removal efficiency, energy yield, and toxic byproduct generation. Herein, a falling-film dielectric barrier discharge (DBD) reactor coupled with environmentally friendly oxidants (hydrogen peroxide (HPO), sodium percarbonate (SPC), and HPO + SPC) was applied, and the treatment efficiency of TC and OTC was investigated. Experimental results showed that moderate addition of the HPO and SPC exhibited a synergistic effect (SF > 2), significantly improving the antibiotic removal ratio, total organic removal ratio (TOC), and energy yield by more than 50%, 52%, and 180%, respectively. After 10 min of DBD treatment, the introduction of 0.2 mM SPC led to a 100% antibiotic removal ratio and a TOC removal of 53.4% and 61.2% for 200 mg/L TC and 200 mg/L OTC, respectively. Also, 1 mM HPO dosage led to 100% antibiotic removal ratios after 10 min of DBD treatment and a TOC removal of 62.4% and 71.9% for 200 mg/L TC and 200 mg/L OTC, respectively. However, the DBD + HPO + SPC treatment method had a detrimental effect on the performance of the DBD reactor. After 10 min of DBD plasma discharge, the removal ratios for TC and OTC were 80.8% and 84.1%, respectively, when 0.5 mM HPO + 0.5 mM SPC was added. Moreover, principal component and hierarchical cluster analysis confirmed the differences between the treatment methods. Furthermore, the concentration of oxidant-induced in-situ generated ozone and hydrogen peroxide were quantitatively determined, and their indispensable roles during the degradation process were established via radical scavenger tests. Finally, the synergetic antibiotic degradation mechanisms and pathways were proposed, and the toxicities of the intermediate byproducts were evaluated.
Topics: Humans; Oxytetracycline; Peroxides; Hydrogen Peroxide; Water Pollutants, Chemical; Anti-Bacterial Agents; Tetracycline; Heterocyclic Compounds; Oxidants
PubMed: 37330069
DOI: 10.1016/j.chemosphere.2023.139246 -
Chemosphere Nov 2023To achieve excellent activation efficiency of peroxymonosulfate (PMS), this work prepared a biochar-supported CuO (CuO@BC) catalyst, and the CuO@BC/PMS system was...
To achieve excellent activation efficiency of peroxymonosulfate (PMS), this work prepared a biochar-supported CuO (CuO@BC) catalyst, and the CuO@BC/PMS system was proposed to remove the organic matter in natural surface water and reduce the fouling of ultrafiltration membrane. The successful synthesis of CuO@BC was demonstrated through characterization of its microscopic morphology and chemical composition by various techniques. The prepared heterogeneous catalyst showed a strong catalytic effect on PMS, which significantly removed natural organic matter through the production of active substances (OH, SO, O and O) from water. With respective degradation rates of 39.4% and 59.4%, the concentrations of DOC and UV dropped to 1.702 mg/L and 0.026 cm, respectively. Additionally, the CuO@BC/PMS oxidation displayed potent oxidation capabilities for contaminants and fluorescent organics with various molecular weights. The system effectively decreased the amount of organic matter that caused reversible and irreversible fouling of polyethersulfone membranes in natural water by 85.8% and 56.3%, respectively. The main fouling mechanisms changed as well, with standard and complete blocking dominating the entire filtration process. The results demonstrated the capacity of the CuO@BC/PMS system to remove contaminants in natural water and mitigate membrane fouling.
Topics: Membranes; Water
PubMed: 37660795
DOI: 10.1016/j.chemosphere.2023.140044 -
Microbial Ecology Aug 2023Research on niche specialization in the microbial communities of ammonia oxidizers is important for assessing the consequences of vegetation shift on nitrogen (N)...
Research on niche specialization in the microbial communities of ammonia oxidizers is important for assessing the consequences of vegetation shift on nitrogen (N) cycling. In this study, soils were sampled from three tree stands (needleleaf, mixed, and evergreen broadleaf) from the Hannam experimental forest in South Korea in spring (May 2019), summer (August 2019), autumn (November 2019), and winter (January 2020). Quantitative polymerase chain reaction (qPCR) and high-throughput sequencing were used to measure the abundance and community structure of various nitrifiers: ammonia-oxidizing archaea and bacteria (AOA and AOB, respectively) as well as complete ammonia oxidizers (comammox). Nitrification rates and total ammonia oxidizer abundance were significantly higher in needleleaf forest soil than those in other forest stands, and they were lowest in evergreen broadleaf forest soil. Comammox clade B was most abundant in needleleaf and evergreen broadleaf forest soils, while AOA were significantly more abundant in mixed forest soil. The abundances of comammox clade B and AOA were negatively correlated with dissolved organic carbon. Phylogenetic analysis showed that NT-alpha and NS-gamma-2.3.2 were the most abundant AOA lineages in all the samples. The seasonal of AOA, AOB, and comammox varied with the sites, suggesting the need to examine the combinations of environmental factors when considering the effects of seasonal changes in the environment. Overall, the results suggest that potential vegetation shifts in forest ecosystems might affect nitrification activities by regulating the abundance and community structure of ammonia oxidizers.
Topics: Soil; Nitrification; Ecosystem; Ammonia; Phylogeny; Oxidation-Reduction; Soil Microbiology; Archaea; Forests
PubMed: 36151339
DOI: 10.1007/s00248-022-02110-9 -
Chemosphere Dec 2023Due to its complex and, often, highly contaminated nature, treating industrial wastewater poses a significant environmental problem. Many of the persistent pollutants... (Review)
Review
Due to its complex and, often, highly contaminated nature, treating industrial wastewater poses a significant environmental problem. Many of the persistent pollutants found in industrial effluents cannot be effectively removed by conventional treatment procedures. Advanced Oxidation Processes (AOPs) have emerged as a promising solution, offering versatile and effective means of pollutant removal and mineralization. This comprehensive review explores the application of various AOP strategies in industrial wastewater treatment, focusing on their mechanisms and effectiveness. Ozonation (O): Ozonation, leveraging ozone (O), represents a well-established AOP for industrial waste water treatment. Ozone's formidable oxidative potential enables the breakdown of a broad spectrum of organic and inorganic contaminants. This paper provides an in-depth examination of ozone reactions, practical applications, and considerations involved in implementing ozonation. UV/Hydrogen Peroxide (UV/HO): The combination of ultraviolet (UV) light and hydrogen peroxide (HO) has gained prominence as an AOP due to its ability to generate hydroxyl radicals (ȮH), highly efficient in pollutant degradation. The review explores factors influencing the efficiency of UV/HO processes, including HO dosage and UV radiation intensity. Fenton and Photo-Fenton Processes: Fenton's reagent and Photo-Fenton processes employ iron ions and hydrogen peroxide to generate hydroxyl radicals for pollutant oxidation. The paper delves into the mechanisms, catalyst selection, and the role of photoactivation in enhancing degradation rates within the context of industrial wastewater treatment. Electrochemical Advanced Oxidation Processes (EAOPs): EAOPs encompass a range of techniques, such as electro-Fenton and anodic oxidation, which employ electrode reactions to produce ȮH radicals. This review explores the electrochemical principles, electrode materials, and operational parameters critical for optimizing EAOPs in industrial wastewater treatment. TiO Photocatalysis (UV/TiO): Titanium dioxide (TiO) photocatalysis, driven by UV light, is examined for its potential in industrial wastewater treatment. The review investigates TiO catalyst properties, reaction mechanisms, and the influence of parameters like catalyst loading and UV intensity on pollutant removal. Sonolysis (Ultrasonic Irradiation): High-frequency ultrasound-induced sonolysis represents a unique AOP, generating ȮH radicals during the formation and collapse of cavitation bubbles. This paper delves into the physics of cavitation, sonolytic reactions, and optimization strategies for industrial wastewater treatment. This review offers a critical assessment of the applicability, advantages, and limitations of these AOP strategies in addressing the diverse challenges posed by industrial wastewater. It emphasizes the importance of selecting AOPs tailored to the specific characteristics of industrial effluents and outlines potential directions for future research and practical implementation. The integrated use of these AOPs, when appropriately adapted, holds the potential to achieve sustainable and efficient treatment of industrial wastewater, contributing significantly to environmental preservation and regulatory compliance.
Topics: Wastewater; Hydrogen Peroxide; Ultraviolet Rays; Oxidation-Reduction; Water Purification; Ozone; Environmental Pollutants; Water Pollutants, Chemical
PubMed: 37866496
DOI: 10.1016/j.chemosphere.2023.140473 -
Journal of Chromatographic Science Oct 2023Dasatinib is an aminopyrimidine used as an inhibitor of multiple tyrosine kinases in two different formulations an immediate-release tablet and a powder for oral...
Dasatinib is an aminopyrimidine used as an inhibitor of multiple tyrosine kinases in two different formulations an immediate-release tablet and a powder for oral suspension. It shows a very low pH-dependent solubility in aqueous solutions and higher solubility in organic solvents. The solubility plays an essential role in analytical methodology to establish the purity, potency, safety and efficacy of any drug product as a diluent. Also, extraction of active drug substance with a suitable diluent from matrix composition is crucial for any analytical method development. However, a diluent optimization study during the method development of related substances for the drug product reveals that the Piperazine ring presented in Dasatinib is susceptible to oxidation and forms an N-oxide impurity. The impurity formation is due to the micro oxidic properties of the solvent used as a diluent which is inducing an oxidation reaction. Therefore, a comprehensive investigative study was conducted to optimize the diluent by limiting N-Oxide generation.
Topics: Dasatinib; Chemistry, Pharmaceutical; Oxides; Solubility; Drug Compounding; Excipients; Solvents
PubMed: 36222064
DOI: 10.1093/chromsci/bmac081