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The Journal of Physical Chemistry... Jun 2024Atmospheric new particle formation events can be driven by iodine oxides or oxoacids via both neutral and ionic mechanisms. Photolysis of new particles likely plays a...
Atmospheric new particle formation events can be driven by iodine oxides or oxoacids via both neutral and ionic mechanisms. Photolysis of new particles likely plays a significant role in their growth mechanisms, but their spectra and photolysis mechanisms remain difficult to characterize. We recorded ultraviolet (UV) photodissociation spectra of (IO)(IO) clusters, observing loss of an O atom, IO, and (IO) in the atmospherically relevant range of 300-340 nm. With increasing cluster size, the intensity of absorption red shifts and generally increases, suggesting particles photolyze more frequently as they grow. Estimates of the rates indicate that even relatively small clusters are likely to undergo photolysis under high-UV conditions. Vibrational spectra identify the covalent moiety IO as the likely chromophore, not IO. The IO loss pathway competes with particle growth, while the slower O loss pathway likely produces O + (cluster) products that could drive subsequent intraparticle chemistry, particularly with co-adsorbed organic or amine species.
PubMed: 38856106
DOI: 10.1021/acs.jpclett.4c01324 -
Journal of Hazardous Materials Aug 2024Photochemical transformation is an important attenuation process for the non-steroidal anti-inflammatory drug naproxen (NPX) in both engineered and natural waters....
Photochemical transformation is an important attenuation process for the non-steroidal anti-inflammatory drug naproxen (NPX) in both engineered and natural waters. Herein, we investigated the photolysis of NPX in aqueous solution exposed to both ultraviolet (UV, 254 nm) and natural sunlight irradiation. Results show that N purging significantly promoted NPX photolysis under UV irradiation, suggesting the formation of excited triplet state (NPX*) as a critical transient. This inference was supported by benzophenone photosensitization and transient absorption spectra. Sunlight quantum yield of NPX was only one fourteenth of that under UV irradiation, suggesting the wavelength-dependence of NPX photochemistry. NPX* formed upon irradiation of NPX underwent photodecarboxylation leading to the formation of 2-(1-hydroxyethyl)-6-methoxynaphthalene (2HE6MN), 2-(1-hydroperoxyethyl)-6-methoxynaphthalene (2HPE6MN), and 2-acetyl-6-methoxynaphthalene (2A6MN). Notably, the conjugation and spin-orbit coupling effects of carbonyl make 2A6MN a potent triplet sensitizer, therefore promoting the photodegradation of the parent NPX. In hospital wastewater, the photolysis of NPX was influenced because the photoproduct 2A6MN and wastewater components could competitively absorb photons. Bioluminescence inhibition assay demonstrated that photoproducts of NPX exhibited higher toxicity than the parent compound. Results of this study provide new insights into the photochemical behaviors of NPX during UV treatment and in sunlit surface waters.
Topics: Naproxen; Photolysis; Ultraviolet Rays; Sunlight; Water Pollutants, Chemical; Anti-Inflammatory Agents, Non-Steroidal; Benzophenones; Photosensitizing Agents
PubMed: 38852251
DOI: 10.1016/j.jhazmat.2024.134841 -
International Journal of Biological... Jun 2024Lignin-based microcapsules are extremely attractive for their biodegradability and photolysis resistance. However, the water-soluble all-lignin shells were...
Lignin-based microcapsules are extremely attractive for their biodegradability and photolysis resistance. However, the water-soluble all-lignin shells were unsatisfactory in terms of rainfall and foliar retention, and lacked the test of agricultural production practices. Herein, a novel microcapsule based on a flexible skeleton formed by interfacial polymerization and absorbed with lignin particles (LPMCs) was prepared in this study. Further analysis demonstrated that the shell was formed by cross-linking the two materials in layers and showed excellent flexibility and photolysis resistance. The pesticide loaded LPMCs showed about 98.68 % and 73.00 % improvement in scour resistance and photolysis resistance, respectively, as compared to the bare active ingredient. The foliar retention performance of LPMCs was tested in peanut plantations during the rainy season. LPMCs loaded with pyraclostrobin (Pyr) and tebuconazole (Teb) exhibited the best foliar disease control and optimum plant architecture, resulting in an increase in yield of about 5.36 %. LPMCs have a promising application prospect in the efficient pesticide utilization, by controlling its deformation, adhesion and release, an effective strategy for controlling diseases and managing plant growth was developed.
PubMed: 38851616
DOI: 10.1016/j.ijbiomac.2024.132944 -
Chemosphere Jun 2024Temperature-dependent kinetics of OH radical and Cl atom-initiated reaction of an important halogenated alkene, 2,3-Dichloropropene (23DCP), were investigated using...
Temperature-dependent kinetics of OH radical and Cl atom-initiated reaction of an important halogenated alkene, 2,3-Dichloropropene (23DCP), were investigated using absolute and relative methods over 278-363 K. Pulsed laser photolysis - laser induced fluorescence technique and relative rate method using gas chromatography with flame ionization detector were employed for studying the kinetics of 23DCP with OH radical and Cl atom, respectively. The obtained Arrhenius expressions were k(expt)=(4.08 ± 1.63) × 10exp{(1043 ± 124)/T} cm molecule s and k(expt)=(1.54 ± 0.24) × 10exp{(705 ± 48)/T} cm molecule s. Computational calculations were conducted to validate our experimental kinetic results and provide new insights into the importance of a particular pathway among all based on thermodynamic parameters. The addition of OH/Cl to the terminal carbon of the double bond present in 23DCP proved to be the predominant pathway across the selected temperature range for the present study (200-400 K). The degradation mechanism of these reactions was proposed by analyzing the products with the aid of gas chromatography with mass spectrometry. Calculating various atmospheric implication parameters can help to understand how the release of 23DCP may affect the troposphere.
PubMed: 38851505
DOI: 10.1016/j.chemosphere.2024.142566 -
Journal of Environmental Management Jul 2024Defect engineering is regarded as an effective strategy to boost the photo-activity of photocatalysts for organic contaminants removal. In this work, abundant surface...
Defect engineering is regarded as an effective strategy to boost the photo-activity of photocatalysts for organic contaminants removal. In this work, abundant surface oxygen vacancies (Ov) are created on AgIO microsheets (AgIO-O) by a facile and controllable hydrogen chemical reduction approach. The introduction of surface Ov on AgIO broadens the photo-absorption region from ultraviolet to visible light, accelerates the photoinduced charges separation and migration, and also activates the formation of superoxide radicals (•O). The AgIO-O possesses an outstanding degradation rate constant of 0.035 min, for photocatalytic degrading methyl orange (MO) under illumination of natural sunlight with a light intensity is 50 mW/cm, which is 7 and 3.5 times that of the pristine AgIO and C-AgIO (AgIO is calcined in air without generating Ov). In addition, the AgIO-O also exhibit considerable photoactivity for degrading other diverse organic contaminants, including azo dye (rhodamine B (RhB)), antibiotics (sulflsoxazole (SOX), norfloxacin (NOR), chlortetracycline hydrochloride (CTC), tetracycline hydrochloride (TC) and ofloxacin (OFX)), and even the mixture of organic contaminants (MO-RhB and CTC-OFX). After natural sunlight illumination for 50 min, 41.4% of total organic carbon (TOC) for MO-RhB mixed solution can be decreased over AgIO-O. In a broad range of solution pH from 3 to 11 or diverse water bodies of MO solution, AgIO-O exhibits attractive activity for decomposing MO. The MO photo-degradation process and mechanism over AgIO-O under natural sunlight irradiation has been systemically investigated and proposed. The toxicities of MO and its degradation intermediates over AgIO-O are compared using Toxicity Estimation Software (T.E.S.T.). Moreover, the non-toxicity of both AgIO-O catalyst and treated antibiotic solution (CTC-OFX mixture) are confirmed by E. coli DH5a cultivation test, supporting the feasibility of AgIO-O catalyst to treat organic contaminants in real water under natural sunlight illumination.
Topics: Sunlight; Photolysis; Oxygen; Water Pollutants, Chemical; Azo Compounds; Catalysis; Rhodamines
PubMed: 38850920
DOI: 10.1016/j.jenvman.2024.121393 -
ChemSusChem Jun 2024A convenient and sustainable method for synthesizing sulfonyl-containing compounds through a catalyst-free aqueous-phase hydrosulfonylation of alkenes and alkynes with...
A convenient and sustainable method for synthesizing sulfonyl-containing compounds through a catalyst-free aqueous-phase hydrosulfonylation of alkenes and alkynes with sulfonyl chlorides under visible light irradiation is presented. Unactivated alkenes, electron-deficient alkenes, alkyl and aryl alkynes can be hydrosulfonylated with various sulfonyl chlorides at room temperature with excellent yields and geometric selectivities by using tris(trimethylsilyl)silane as a hydrogen atom donor and silyl radical precursor to activate sulfonyl chlorides. Mechanistic studies revealed that the photolysis of tris(trimethylsilyl)silane in aqueous solution to produce silyl radical is crucial for the success of this reaction.
PubMed: 38850152
DOI: 10.1002/cssc.202400650 -
Environmental Geochemistry and Health Jun 2024This study investigates the removal of amoxicillin micropollutants (AM) from hospital wastewater using CoMoO-modified graphitic carbon nitride (CMO/gCN). Consequently,...
This study investigates the removal of amoxicillin micropollutants (AM) from hospital wastewater using CoMoO-modified graphitic carbon nitride (CMO/gCN). Consequently, CMO/gCN exhibits notable improvements in visible light absorption and electron-hole separation rates compared to unmodified gCN. Besides, CMO/gCN significantly enhances the removal efficiency of AM, attaining an impressive 96.5%, far surpassing the performance of gCN at 48.6%. Moreover, CMO/gCN showcases outstanding reusability, with AM degradation performance exceeding 70% even after undergoing six cycles of reuse. The removal mechanism of AM employing CMO/gCN involves various photoreactions of radicals (•OH, •O) and amoxicillin molecules under light assistance. Furthermore, CMO/gCN demonstrates a noteworthy photodegradation efficiency of AM from hospital wastewater, reaching 92.8%, with a near-complete reduction in total organic carbon levels. Detailed discussions on the practical applications of the CMO/gCN photocatalyst for removal of micropollutants from hospital wastewater are provided. These findings underline the considerable potential of CMO/gCN for effectively removing various pollutants in environmental remediation strategies.
Topics: Amoxicillin; Wastewater; Graphite; Water Pollutants, Chemical; Oxidation-Reduction; Photolysis; Hospitals; Nitrogen Compounds; Catalysis; Water Purification
PubMed: 38849667
DOI: 10.1007/s10653-024-01990-9 -
Environmental Geochemistry and Health Jun 2024Pesticide micropollutants like 4-chlorophenol (4CP) and E. coli bacteria represent a substantial hazard, impacting both the environment and human health. This study...
Pesticide micropollutants like 4-chlorophenol (4CP) and E. coli bacteria represent a substantial hazard, impacting both the environment and human health. This study delves into the effectiveness of Ag-doped TiO (Ag@TiO) in removing both 4CP and E. coli. Ag@TiO has demonstrated remarkable effectiveness in removing 4CP under both solar and visible light conditions, earning degradation efficiencies of 91.3% and 72.8%, respectively. Additionally, it demonstrates outstanding photodegradation efficiency for 4CP (98.8%) at an initial concentration of 1 mg L. Moreover, Ag@TiO exhibited substantially higher removal performance for 4CP (81.6%) compared to TiO (27.6%) in wastewater. Analysis of the radicals present during the photodegradation process revealed that ·O primarily drives the decomposition of 4CP, with h and ·OH also playing significant roles in the oxidation reactions of the pollutant. Interestingly, even under dark conditions, Ag@TiO exhibited the capability to eliminate approximately 20% of E. coli, a percentage that increased to over 96% under solar light. In addition, the prospects for environmental and health impacts of utilizing Ag@TiO for pesticide micropollutant removal and bacteria were discussed.
Topics: Titanium; Pesticides; Escherichia coli; Sunlight; Silver; Chlorophenols; Water Pollutants, Chemical; Photolysis; Wastewater
PubMed: 38849639
DOI: 10.1007/s10653-024-02017-z -
Environmental Geochemistry and Health Jun 2024This study reported the synthesis and assessment of zinc oxide/iron oxide (ZnO/FeO) nanocomposite as photocatalysts for the degradation of a mixture of methylene red and...
This study reported the synthesis and assessment of zinc oxide/iron oxide (ZnO/FeO) nanocomposite as photocatalysts for the degradation of a mixture of methylene red and methylene blue dyes. X-ray diffraction analysis confirms that the crystallite of zinc oxide (ZnO) has a hexagonal wurtzite phase and iron oxide (FeO) has a rhombohedral phase. Fourier Transform Infra-Red spectrum confirms the presence of Zn-O vibration stretching at 428, 480 and 543 cm stretching confirming Fe-O bond formation. Scanning Electron Microscope images exhibited a diverse size and shape of the nanocomposites. The ZnO-90%/FeO-10% and ZnO-10%/FeO-90% nanocomposites reveal good photocatalytic activity with reaction rate constants of 1.5 × 10 and 0.66 × 10; and 1.3 × 10 and 0.60 × 10 for methylene blue and methyl red dye respectively. The results revealed that the synthesized ZnO/FeO nanocomposite is the best catalyst for dye degradation and can be used for industrial applications in future.
Topics: Zinc Oxide; Nanocomposites; Methylene Blue; Ferric Compounds; Catalysis; Coloring Agents; X-Ray Diffraction; Microscopy, Electron, Scanning; Azo Compounds; Water Pollutants, Chemical; Photolysis; Spectroscopy, Fourier Transform Infrared
PubMed: 38849635
DOI: 10.1007/s10653-024-02000-8 -
Chemosphere Aug 2024Development of effective adsorbents for the removal of contaminants from wastewater is indispensable due to increasing water scarcity and a lack of pure drinking water,... (Review)
Review
Development of effective adsorbents for the removal of contaminants from wastewater is indispensable due to increasing water scarcity and a lack of pure drinking water, which are prevailing as a result of rapid industrialization and population growth. Recently, the development of new adsorbents and their effective use without generating secondary waste is receiving huge consideration. In order to protect the environment from primary and secondary pollution, the development of adsorbents from wastes and their recycling have become conventional practices aimed at waste management. As a result, significant progress has been made in the synthesis of new porous carbon and metal-organic frameworks as adsorbents, with the objective of using them for the removal of pollutants. While many different kinds of pollutants are produced in the environment, drug pollutants are the most vicious because of their tendency to undergo significant structural changes, producing metabolites and residues with entirely different properties compared to their parent compounds. Chemical reactions involving oxidation, hydrolysis, and photolysis transform drugs. The resulting compounds can have detrimental effects on living beings that are present in soil and water. This review stresses the development of adsorbents with adjustable porosities for the broad removal of primary drug pollutants and their metabolites, which are formed as a result of drug transformations in environmental matrices. This keeps adsorbents from building up in the environment and prevents them from becoming significant pollutants in the future. Additionally, it stops secondary pollution caused by the deterioration of the used adsorbents. Focus on the development of effective adsorbents with flexible porosities allows for the complete removal of coexisting contaminants and makes a substantial contribution to wastewater management. In order to concentrate more on the development of flexible pore adsorbents, it is crucial to comprehend the milestones reached in the research and applications of porous magnetic adsorbents based on metal and carbon, which are discussed here.
Topics: Porosity; Adsorption; Water Pollutants, Chemical; Metal-Organic Frameworks; Carbon; Wastewater; Water Purification; Metals; Pharmaceutical Preparations
PubMed: 38849099
DOI: 10.1016/j.chemosphere.2024.142533