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hydroxyl radical production by abiotic oxidation of pyrite under estuarine conditions:The effects of aging,seawater anions and illumination

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Journal of Environmental Sciences 2024年第1期135卷 715-727页

作者： Ruixue Liu Yinshun Dai Yucheng Feng Shiwen Sun Xiaodong Zhang Chunjiang An Shan Zhao Shandong Key Laboratory of Water Pollution Control and Resource Reuse School of Environmental Science and EngineeringShandong UniversityQingdao 266237China Department of Building Civil and Environmental EngineeringConcordia UniversityMontrealQC H3G 1M8Canada

Pyrite is widely distributed in estuarine sediments as an inexpensive natural Fenton-like reagent,however,the mechanism on the hydroxyl radical(HO^(·))production by pyrite under estuarine environmental conditions is still poorly understood.The batch experiments were performed to investigate the effects of estuarine conditions including aging(in air,in water),seawater anions(Cl^(-),Br^(-)and HCO_(3)^(-))and light on the HO^(·)production by pyrite oxidation.The one-electron transfer dominated the process from O_(2) to HO^(·)induced by oxidation of pyrite.The Fe(oxyhydr)oxide coatings on the surface of pyrite aged in air and water consumed hydrogen peroxide while mediating the electron transfer,and the combined effect of the two resulted in a suppression of HO^(·)production in the early stage of aging and a promotion of HO^(·)production in the later stage of aging.Corrosion of the surface oxide layers by aggressive anions was the main reason for the inhibition of HO^(·)production by Cl^(-)and Br^(-),and the generation of Cl^(·)and Br^(·)may also play a role in the scavenging of HO^(·).HCO_(3)^(-)increased the average rate of HO^(·)production through surface-CO_(2) complexes formed by adsorption on the surface of pyrite.The significant enhancement of HO^(·)production under light was attributed to the formation of photoelectrons induced by photochemical reactions on pyrite and its surface oxide layers.These findings provide new insights into the environmental chemical behavior of pyrite in the estuary and enrich the understanding of natural remediation of estuarine environments.

关键词： hydroxyl radical Pyrite oxidation Aging Anions Irradiation

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Enhanced hepatic metabolic perturbation of polystyrene nanoplastics by UV irradiation-induced hydroxyl radical generation

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Journal of Environmental Sciences 2024年第8期142卷 259-268页

作者： Shiyu He Jingran Wang Lihong Zhou Zhen Mao Xiaodan Zhang Jin Cai Peili Huang School of Public Health and Beijing Key Laboratory of Environmental Toxicology Capital Medical UniversityBeijing 100069China

The environmental behavior of and risks associated with nanoplastics(NPs)have attracted considerable attention.However,compared to pristine NPs,environmental factors such as ultraviolet(UV)irradiation that lead to changes in the toxicity of NPs have rarely been studied.We evaluated the changes in morphology and physicochemical properties of polystyrene(PS)NPs before and after UV irradiation,and compared their hepatotoxicity in mice.The results showed that UV irradiation caused particle size reduction and increased the carbonyl index(CI)and negative charge on the particle surface.UV-aged PS NPs(aPS NPs)could induce the generation of hydroxyl radicals(·OH),but also further promoted the generation of·OH in the Fenton reaction system.Hepatic pathological damage was more severe in mice exposed to aPS NPs,accompanied by a large number of vacuoles and hepatocyte balloon-like changes and more marked perturbations in blood glucose and serum lipoprotein,alanine aminotransferase and aspartate aminotransferase levels.In addition,exposure to PS NPs and aPS NPs,especially aPS NPs,triggered oxidative stress and significantly damaged the antioxidant capacity of mice liver.Compared with PS NPs,exposure to aPS NPs increased the number of altered metabolites in hepatic and corresponding metabolic pathways,especially glutathione metabolism.Our research suggests that UV irradiation can disrupt the redox balance in organisms by promoting the production of·OH,enhancing PS NPs-induced liver damage and metabolic disorders.This study will help us understand the health risks of NPs and to avoid underestimation of the risks of NPs in nature.

关键词： Polystyrene nanoplastics Ultraviolet-aged nanoplastics Metabolic pathway Metabolomics hydroxyl radical

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hydroxyl radical-involved cancer therapy via Fenton reactions

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Frontiers of Chemical Science and Engineering 2022年第3期16卷 345-363页

作者： Mengying Liu Yun Xu Yanjun Zhao Zheng Wang Dunyun Shi School of Pharmaceutical Science&Technology Tianjin UniversityTianjin300072China Central Lab Shenzhen Second People’s Hospital/the First Affiliated Hospital of Shenzhen UniversityShenzhen518035China Institute of Hematology Shenzhen Second People’s Hospital/the First Affiliated Hospital of Shenzhen UniversityShenzhen518035China

The tumor microenvironment features over-expressed hydrogen peroxide(H_(2)O_(2)).Thus,versatile therapeutic strategies based on H_(2)O_(2) as a reaction substrate to generate hydroxyl radical(•OH)have been used as a prospective therapeutic method to boost anticancer efficiency.However,the limited Fenton catalysts and insufficient endogenous H_(2)O_(2) content in tumor sites greatly hinder•OH production,failing to achieve the desired therapeutic effect.Therefore,supplying Fenton catalysts and elevating H_(2)O_(2) levels into cancer cells are effective strategies to improve•OH generation.These therapeutic strategies are systematically discussed in this review.Furthermore,the challenges and future developments of hydroxyl radical-involved cancer therapy are discussed to improve therapeutic efficacy.

关键词： hydroxyl radical Fenton catalyst hydrogen peroxide cancer therapy

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Decomposition mechanisms of nuclear-grade cationic exchange resin by advanced oxidation processes:Statistical molecular fragmentation model and DFT calculations

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Journal of Environmental Sciences 2024年第1期135卷 433-448页

作者： Xiang Meng Pierre Désesquelles Lejin Xu Department of Nuclear Engineering and Technology School of Energy and Power EngineeringHuazhong University of Science&TechnologyWuhan 430074China CNRS Laboratoire de Physique des Gaz et des PlasmasUniversitéParis-SaclayOrsay 91405France State Key Laboratory of Coal Combustion School of Energy and Power EngineeringHuazhong University of Science and TechnologyWuhan 430074China

The treatment and disposal of radioactive waste are presently facing great challenges.Spent ion exchange resins have become a focus of attention due to their high production and serious environmental risks.In this paper,a simplified model of cationic exchange resin is proposed,and the degradation processes of cationic resin monomer initiated by hydroxyl radicals(·OH)are clarified by combining statistical molecular fragmentation(SMF)model and density functional theory(DFT)calculations.The prediction of active sites indicates that the S-O bonds and the C-S bond of the sulfonic group are more likely to react during the degradation.The meta-position of the sulfonic group on the benzene ring is the most active site,and the benzene ring without the sulfonic group has a certain reactivity.The C11-C14 and C17-C20 bonds,on the carbon skeleton,are the most easily broken.It is also found that dihydroxy addition and elimination reactions play a major role in the process of desulfonation,carbon skeleton cleavage and benzene ring separation.The decomposition mechanisms found through the combination of physical models and chemical calculations,provide theoretical guidance for the treatment of complex polycyclic aromatic hydrocarbons.

关键词： Cationic exchange resin Statistical molecular fragmentation model Density functional theory hydroxyl radical Decomposition mechanism

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Molecular mechanism for the unusual enhancement of the second-step chemiluminescence production from the carcinogenic tetrabromohydroquinone and H2O_(2)

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Journal of Environmental Sciences 2024年第7期141卷 330-342页

作者： Zi-Han Wang Chun-Hua Huang Zhi-Sheng Liu Li Mao Ben-Zhan Zhu State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China College of Environment and Resources University of Chinese Academy of SciencesBeijing 100049China

We have found recently that two-step intrinsic hydroxyl radical(·OH)-dependent chemiluminescence(CL)could be produced by carcinogenic tetrahaloquinone and H_(2)O_(2).However,the first-step CL was too fast to clearly detect the stepwise generation of·OH and CL,and to distinguish the exact dividing point between the first-step and second-step CL.Here we found that,extremely clear two-step intrinsic CL could be produced by the relative slow reaction of tetrabromohydroquinone(TBHQ)with H_(2)O_(2),which was directly dependent on the two-step·OH generation.Interestingly,the second-step,but not the first-step CL production of TBHQ/H_(2)O_(2)(CRET donor)was markedly enhanced by fluorescein(a typical xanthene dye,CRET acceptor)through a unique chemiluminescence resonance energy transfer(CRET)process.The novel CRET system of TBHQ/H_(2)O_(2)/fluorescein was successfully applied for the sensitive detection of TBHQ with the detection limit as low as 2.5μmol/L.These findings will help to develop more sensitive and highly efficient CL or CRET systems and specific CL sensor to detect the carcinogenic haloquinones,which may have broad environmental applications.

关键词： Two-step chemiluminescence Bromohydroquinone Hydrogen peroxide hydroxyl radical CRET

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hydroxyl radical formation upon dark oxidation of reduced iron minerals: Effects of iron species and environmental factors

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Chinese Chemical Letters 2019年第12期30卷 2241-2244页

作者： Ailing Zhu Yingying Guo Guangliang Liu Maoyong Song Yong Liang Yong Cai Yongguang Yin Institute of Environment and Health Jianghan UniversityWuhan 430056China State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China Laboratory of Environmental Nanotechnology and Health Effect Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China Department of Chemistry and Biochemistry Florida International UniversityMiamiFL 33199United States

Dark formation of hydroxyl radical upon oxidation of reduced iron minerals plays an important role in the degradation and transformation of organic and inorganic pollutants.Herein,we compared the hydroxyl radical formation from various reduced iron minerals at different redox conditions.·OH production was generally observed from the oxidation of reduced iron minerals,following the order:mackinawite(FeS)>reduced nontronite(iron-bearing smectite clay)> pyrite(FeS2)> side rite(FeCO3).Structural Fe^2+ and dissolved O2 play critical roles in ·OH production from reduced iron minerals.·OH production increases with decreasing pH,and Cl^-has little effect on this process.More importantly,dissolved organic matter significantly enhances ·OH production,especially under O2 purging,highlighting the importance of this process in ambient environments.This sunlight-independent pathway in which ’OH forms during oxidation of reduced iron minerals is helpful for understanding the degradation and transformation of various inorganic and organic pollutants in the redox-fluctuation environments.

关键词： Reduced iron minerals hydroxyl radical Dark oxidation Mackinawite Dissolved organic matter

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Effect of substituents in hydroxyl radical-mediated degradation of azo pyridone dyes: Theoretical approaches on the reaction mechanism

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Journal of Environmental Sciences 2020年第12期32卷 14-21页

作者： J.Dostanic M.Hus D.Loncarevic Institute of Chemistry Technology and MetallurgyUniversity of Belgrade(National Institute)Department of Catalysis and Chemical EngineeringNjegoševa 12BelgradeRepublic of Serbia Department of Catalysis and Chemical Reaction Engineering National Institute of ChemistryHajdrihova 19LjubljanaSlovenia

Understanding the degradation behavior of azo dyes in photocatalytic wastewater treatment is of fundamental and practical importance for their application in textile-processing and other coloration industries. In this study, quantum chemistry, as density functional theory, was used to elucidate different degradation pathways of azo pyridone dyes in a hydroxyl radical(HO ·)-initiated photocatalytic system. A series of substituted azo pyridone dyes were synthesized by changing the substituent group in the para position of the benzene moiety, ranging from strong electron-donating to strong electron-withdrawing groups. The effect of dye molecular structure on the photocatalytic degradation reaction mechanism was analyzed and quantification of substituent effects on the thermodynamic and kinetics parameters was performed. Potential energy surface analysis revealed the most susceptible reaction site for the HO ·attack. The calculated reaction barriers are found to be strongly affected by the nature of substituent group with a good correlation using Hammett σp constants and experimentally determined reaction rates. The stability of pre-reaction complexes and transition state complexes were analyzed applying the distortion-interaction model. The increased stability of the transition state complexes with the distancing from the substituent group has been established.

关键词： Quantum chemical calculation Density functional theory Azo dye Reaction mechanism Photocatalytic degradation hydroxyl radical Hammett equation Substituent effect

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Determination of atmospheric hydroxyl radical by HPLC coupled with electrochemical detection

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Journal of Environmental Sciences 2008年第1期20卷 28-32页

作者： LIU Bin WANG Hui-xiang College of Environmental Sciences Peking University Beijing 100871 China

The hydroxyl radical （·OH） plays a central role in the oxidation and removal of many atmospheric compounds. Measurement of atmospheric ·OH is very difficult because of its high reactivity and low atmospheric abundance. In this article, a simple and highly sensitive method, high performance liquid chromatography coupled with coulometric detection （HPLC-CD）, was developed to determine ·OH indirectly by determining its reaction products with salicylic acid （SAL）, 2,3-dihydroxybenzoic acid （2,3-DHBA）, and 2,5-dihydroxybenzoic acid （2,5-DHBA）. Under the optimum conditions for its determination, 2,3-DHBA and 2,5-DHBA could be well separated and the detection limits for 2,3-DHBA were 3 ×10^-10 mol/L and for 2,5-DHBA were 1.5 ×10^-10 mol/L, which were lower than most previous reports. This method was also applied to measure atmospheric hydroxyl radical levels and demonstrated the feasibility in clean and polluted air.

关键词： electrochemical detection HPLC hydroxyl radical troposphere

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Theoretical Studies on the Reaction Mechanism of 1-Chloroethane with hydroxyl radical

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Chinese Journal of Structural Chemistry 2007年第6期26卷 695-702页

作者：王丙星王利 State Key Laboratory of Molecular Reaction Dynamics Dalian Institute of Chemical Physics Chinese Academy of Sciences Graduate School of the Chinese Academy of Sciences Beijing 100039 China

The reaction mechanism of 1-chloroethane with hydroxyl radical has been investigated by using density functional theory （DFT） B3LYP/6-31G （d, p） method. All bond dissociation enthalpies were computed at the same theoretical level. It was found that hydrogen abstraction pathway is the most favorable. There are two hydrogen abstraction pathways with activation barriers of 0.630 and 4.988 kJ/mol, respectively, while chlorine abstraction pathway was not found. It was observed that activation energies have a more reasonable correlation with the reaction enthalpy changes （ΔHr） than with bond dissociation enthalpies （BDE）.

关键词： bond dissociation enthalpies B3LYP 1-chloroethane hydroxyl radical reaction mechanism

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Numerical analysis of quantitative measurement of hydroxyl radical concentration using laser-induced fluorescence in flame

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Chinese Physics B 2016年第6期25卷 157-164页

作者：陈爽苏铁郑尧邦陈力刘亭序李仁兵杨富荣 Science and Technology on Scramjet Laboratory China Aerodynamics Research and Development Center Hypervelocity Aerodynamics Institute Mianyang 621000 China China Aerodynamics Research and Development Center Mianyang 621000 China

The aim of the present work is to quantitatively measure the hydroxyl radical concentration by using LIF（laserinduced fluorescence） in flame.The detailed physical models of spectral absorption lineshape broadening,collisional transition and quenching at elevated pressure are built.The fine energy level structure of the OH molecule is illustrated to understand the process with laser-induced fluorescence emission and others in the case without radiation,which include collisional quenching,rotational energy transfer（RET）,and vibrational energy transfer（VET）.Based on these,some numerical results are achieved by simulations in order to evaluate the fluorescence yield at elevated pressure.These results are useful for understanding the real physical processes in OH-LIF technique and finding a way to calibrate the signal for quantitative measurement of OH concentration in a practical combustor.

关键词： laser-induced fluorescence hydroxyl radical quenching quantitative measurement

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