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Pan W, He S, Xue Q, Liu X, Fu J, Xiao K, Zhang A. First-principles study on the heterogeneous formation of environmentally persistent free radicals (EPFRs) over α-Fe 2O 3(0001) surface: Effect of oxygen vacancy. J Environ Sci (China) 2024; 142:279-289. [PMID: 38527893 DOI: 10.1016/j.jes.2023.07.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 07/13/2023] [Accepted: 07/19/2023] [Indexed: 03/27/2024]
Abstract
Metal oxides with oxygen vacancies have a significant impact on catalytic activity for the transformation of organic pollutants in waste-to-energy (WtE) incineration processes. This study aims to investigate the influence of hematite surface oxygen point defects on the formation of environmentally persistent free radicals (EPFRs) from phenolic compounds based on the first-principles calculations. Two oxygen-deficient conditions were considered: oxygen vacancies at the top surface and on the subsurface. Our simulations indicate that the adsorption strength of phenol on the α-Fe2O3(0001) surface is enhanced by the presence of oxygen vacancies. However, the presence of oxygen vacancies has a negative impact on the dissociation of the phenol molecule, particularly for the surface with a defective point at the top layer. Thermo-kinetic parameters were established over a temperature range of 300-1000 K, and lower reaction rate constants were observed for the scission of phenolic O-H bonds over the oxygen-deficient surfaces compared to the pristine surface. The negative effects caused by the oxygen-deficient conditions could be attributed to the local reduction of FeIII to FeII, which lower the oxidizing ability of surface reaction sites. The findings of this study provide us a promising approach to regulate the formation of EPFRs.
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Affiliation(s)
- Wenxiao Pan
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Shuming He
- School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310012, China
| | - Qiao Xue
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| | - Xian Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Jianjie Fu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310012, China
| | - Kang Xiao
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China; Beijing Yanshan Earth Critical Zone National Research Station, University of Chinese Academy of Sciences, Beijing 101408, China
| | - Aiqian Zhang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310012, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China.
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2
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Wang X, Hadizadeh MH, Wang W, Hu Y, Zhou Y, Xu F, Sun Y, Wang W. DFT and AIMD insights into heterogeneous dissociation of 2-chlorothiophenol on CuO(111) surface: Impact of H 2O and OH. CHEMOSPHERE 2024; 359:142228. [PMID: 38705407 DOI: 10.1016/j.chemosphere.2024.142228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2024] [Revised: 04/29/2024] [Accepted: 05/01/2024] [Indexed: 05/07/2024]
Abstract
Copper oxides are vital catalysts in facilitating the formation of polychlorinated thianthrenes/dibenzothiophenes (PCTA/DTs) through heterogeneous reactions in high-temperature industrial processes. Chlorothiophenols (CTPs) are the most crucial precursors for PCTA/DT formation. The initial step in this process is the metal-catalyzed production of chlorothiophenoxy radicals (CTPRs) from CTPs via dissociation reactions. This work combines density functional theory (DFT) calculations with ab initio molecular dynamics (AIMD) simulations to explore the formation mechanism of the adsorbed 2-CTPR from 2-CTP, with the assistance of CuO(111). Our study demonstrates that flat adsorption configurations of 2-CTP on the CuO(111) surface are more stable than vertical configurations. The CuO(111) surface acts as a strong catalyst, facilitating the dissociation of 2-CTP into the adsorbed 2-CTPR. Surface oxygen vacancies enhance the adsorption of 2-CTP on the CuO(111) surface, while moderately suppressing the dissociation of 2-CTP. More importantly, water molecules and surface hydroxyl groups actively promote the dissociation of 2-CTP. Specifically, water directly participates in the reaction through "water bridge", enabling a barrier-free process. This research provides molecular-level insights into the heterogeneous generation of dioxins with the catalysis of metal oxides in fly ash from static and dynamic aspects, providing novel approaches for reducing dioxin emissions and establishing dioxin control strategies.
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Affiliation(s)
- Xiaotong Wang
- Environment Research Institute, Shandong University, Qingdao, 266237, China
| | - Mohammad Hassan Hadizadeh
- Environment Research Institute, Shandong University, Qingdao, 266237, China; International Center for Quantum Design of Functional Materials (ICQD), Hefei National Laboratory for Physical Sciences at the Microscale, and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, 230026, China
| | - Wei Wang
- Environment Research Institute, Shandong University, Qingdao, 266237, China
| | - Yongxia Hu
- Environment Research Institute, Shandong University, Qingdao, 266237, China
| | - Ying Zhou
- Environment Research Institute, Shandong University, Qingdao, 266237, China
| | - Fei Xu
- Environment Research Institute, Shandong University, Qingdao, 266237, China; Shenzhen Research Institute of Shandong University, Shenzhen, 518057, China.
| | - Yanhui Sun
- College of Environment and Safety Engineering, Qingdao University of Science & Technology, Qingdao, 266042, China
| | - Wenxing Wang
- Environment Research Institute, Shandong University, Qingdao, 266237, China
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3
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Zhang K, Wang L, Qin M, Mulder J, Hou D. Mercury reduction by black carbon under dark conditions. WATER RESEARCH 2023; 242:120241. [PMID: 37392509 DOI: 10.1016/j.watres.2023.120241] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 06/12/2023] [Accepted: 06/16/2023] [Indexed: 07/03/2023]
Abstract
An accurate depiction of mercury (Hg) reduction is important to predict Hg biogeochemistry in both aquatic and soil systems. Although the photoreduction of Hg is well documented, reduction in the dark is poorly known and is thus the focus of this work. Black carbon (BC), an important constituent of organic matter in environments, can reduce Hg2+ in dark and oxygen-deficient conditions. Fast removal of Hg2+ in BC/Hg2+ solution was observed, with 4.99-86.88 L mg-1h-1 of the reaction rate constant, which could be ascribed to the combined actions of adsorption and reduction. Meanwhile, slow Hg reduction was obtained, compared to Hg removal, with 0.06-2.16 L mg-1h-1 of the reaction rate constant. Thus, in the initial stage, Hg2+ removal was mainly triggered by adsorption, rather than reduction. Afterward, the adsorbed Hg2+ on black carbon was converted into Hg0. Dissolved black carbon and aromatic CH on particulate black carbon were dominant triggers of Hg reduction for black carbon. During Hg reduction, the intastable intermediate, formed in the complex between aromatic CH and Hg2+, behaved as persistent free radicals, which could be detected by in situ electron paramagnetic resonance. Subsequently, the intastable intermediate was mainly converted into CO on black carbon and Hg0. Corresponding results of the present study highlight the important role of black carbon in the Hg biogeochemical cycle.
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Affiliation(s)
- Kaikai Zhang
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Liuwei Wang
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Muhan Qin
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Jan Mulder
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, P.O. Box 5003, 1432 Ås, Norway
| | - Deyi Hou
- School of Environment, Tsinghua University, Beijing 100084, China.
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4
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Qiu Y, Zhang T, Zhang P. Fate and environmental behaviors of microplastics through the lens of free radical. JOURNAL OF HAZARDOUS MATERIALS 2023; 453:131401. [PMID: 37086675 DOI: 10.1016/j.jhazmat.2023.131401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 04/04/2023] [Accepted: 04/11/2023] [Indexed: 05/03/2023]
Abstract
Microplastics (MPs), as plastics with a size of less than 5 mm, are ubiquitously present in the environment and become an increasing environmental concern. The fate and environmental behavior of MPs are significantly influenced by the presence of free radicals. Free radicals can cause surface breakage, chemical release, change in crystallinity and hydrophilicity, and aggregation of MPs. On the other hand, the generation of free radicals with a high concentration and oxidation potential can effectively degrade MPs. There is a limited review article to bridge the fate and environmental behaviors of MP with free radicals and their reactions. This paper reviews the sources, types, detection methods, generation mechanisms, and influencing factors of free radicals affecting the environmental processes of MPs, the environmental effects of MPs controlled by free radicals, and the degradation strategies of MPs based on free radical-associated technologies. Moreover, this review elaborates on the limitations of the current research and provides ideas for future research on the interactions between MPs and free radicals to better explain their environmental impacts and control their risks. This article aims to keep the reader abreast of the latest development in the fate and environmental behaviors of MP with free radicals and their reactions and to bridge free radical chemistry with MP control methodology.
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Affiliation(s)
- Ye Qiu
- College of Environmental Science and Engineering, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, 38 Tongyan Rd., Tianjin 300350, China; Department of Civil and Environmental Engineering, Faculty of Science and Technology, University of Macau, Taipa, Macao Special Administrative Region of China
| | - Tong Zhang
- College of Environmental Science and Engineering, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, 38 Tongyan Rd., Tianjin 300350, China.
| | - Ping Zhang
- Department of Civil and Environmental Engineering, Faculty of Science and Technology, University of Macau, Taipa, Macao Special Administrative Region of China.
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Yuan Z, Huang Q, Wang Z, Wang H, Luo J, Zhu N, Cao X, Lou Z. Medium-Low Temperature Conditions Induce the Formation of Environmentally Persistent Free Radicals in Microplastics with Conjugated Aromatic-Ring Structures during Sewage Sludge Pyrolysis. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:16209-16220. [PMID: 36165785 DOI: 10.1021/acs.est.2c04453] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Medium-low temperature pyrolysis is an effective method of retaining active components in sludge char. However, we found that incomplete cracking reactions resulted in residues of microplastics (MPs) remaining in the char; moreover, high levels of environmentally persistent free radicals (EPFRs) were detected in these MPs. Here, we investigated the temperature-dependent variations in the char-volatile products derived from sludge and MPs under different pyrolysis scenarios using multiple in situ probe coupling techniques and electron paramagnetic resonance spectroscopy, thereby identifying the sources of EPFRs and elucidating the corresponding formation-conversion mechanisms. The temperature was the key factor in the formation of EPFRs; in particular, in the 350-450 °C range, the abundance of EPFRs increased exponentially. Reactive EPFR readily formed in MPs with conjugated aromatic-ring structures (polyethylene terephthalate and polystyrene) at a temperature above 350 °C; EPFR concentrations were 5-17 times higher than those found in other types of polymers, and these radicals exhibited half-lives of more than 90 days. The EPFR formation mechanism could be summarized as solid-solid/solid-gas interfacial interactions between the polymers and the intermediate products from sludge pyrolysis (at 160-350 °C) and the homolytic cleavage-proton transfer occurring in the polymers themselves under the dual action of thermal induction and acid sites (at 350-450 °C). Based on the understanding of the evolution of EPFRs, temperature regulation and sludge components conditioning may be effective approaches to inhibit the formation of EPFRs in MPs, constituting reliable strategies to diminish the environmental risk associated with the byproducts of sludge pyrolysis.
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Affiliation(s)
- Zhihang Yuan
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Qiujie Huang
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Zhuoqin Wang
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Hui Wang
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Jinming Luo
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Nanwen Zhu
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Xinde Cao
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Ziyang Lou
- Shanghai Engineering Research Center of Solid Waste Treatment and Resource Recovery, School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
- China Institute for Urban Governance, Shanghai Jiao Tong University, Shanghai 200240, China
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6
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Wang Y, Peng A, Ding K, Ren L, Chen Z, Gu C. Dioxin-like compounds formation mediated by Fe 3+-montmorillonite: The substituent effects of halophenols. CHEMOSPHERE 2022; 300:134531. [PMID: 35398469 DOI: 10.1016/j.chemosphere.2022.134531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 03/28/2022] [Accepted: 04/04/2022] [Indexed: 06/14/2023]
Abstract
Toxic dioxin or/and dioxin-like compounds could be naturally formed from the reaction of halophenols on Fe3+-montmorillonite minerals under ambient conditions. Given that the toxicities and productions of dioxin or/and dioxin-like compounds are largely determined by the number, species, and position of the carried halogen atoms, it is necessary to explore the substituent effects on the reaction of halophenols with Fe3+-montmorillonite. Herein, Fe3+-montmorillonite catalyzed polymerizations of six halophenols were examined in a wide range of relative humidity (10%∼80%) using combinations of mass spectrometry identifications and density functional theory calculations. Results show that both the position and species of the substituents substantially impact the reaction rate, product species, and transformation pathways. In general, regardless of humidity ortho-substituted chlorophenols are more reactive than meta-substituted chlorophenols, which is also supported by the density functional theory calculations indicating that the ortho positions are more likely to be attacked. Regarding substituent species, bromophenols are slightly more reactive and also more easily affected by humidities than chlorophenols, which is due to the weaker electron absorbing ability of the bromine atom than the chlorine atom. Hydroxylated polyhalogenated diphenyl ethers are more frequently detected polymerization products, although hydroxylated polyhalogenated biphenyls are greater quantity of products. Overall, this study provides useful information for understanding the natural formation of dioxin or/and dioxin-like compounds mediated by clay minerals and underlying reaction mechanisms.
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Affiliation(s)
- Yi Wang
- College of Environmental Engineering, Nanjing Institute of Technology, Nanjing, Jiangsu, 211167, China
| | - Anping Peng
- School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin, 300384, China.
| | - Keqiang Ding
- College of Environmental Engineering, Nanjing Institute of Technology, Nanjing, Jiangsu, 211167, China
| | - Lingxiao Ren
- College of Environmental Engineering, Nanjing Institute of Technology, Nanjing, Jiangsu, 211167, China
| | - Zeyou Chen
- Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin, 300071, China
| | - Cheng Gu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210093, China
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7
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Ye Y, Li Y, Wang J, Yuan S, Xu X, Zhang X, Zhou J, Wang B, Ma X. Generation of Environmentally Persistent Free Radicals on Metal-Organic Frameworks. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:3265-3275. [PMID: 35245423 DOI: 10.1021/acs.langmuir.1c03491] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Environmentally persistent free radicals (EPFRs) have been recognized as one of the important emerging contaminants with biological toxicity, environmental persistence, and global mobility. Previous studies have identified the catalytic role of surface metal oxides in EPFRs formation and illustrated the metal-dependence of EPFRs by studying on various metal oxide nanoparticles and single crystals. However, there is still lack of an understanding on the formation of EPFRs from the point of view of metal sites. Various factors (e.g., crystalline phases and surface species) of metal oxides are regarded to contribute to the generation of EPFRs, which present profound difficulties for scientists to tease apart the impact of metal type. Herein, a laboratory investigation, in terms of the acidity and oxidation strength of metal cations, was conducted by selecting metal-variable isostructural metal-organic frameworks as material platforms. Specifically, we evaluated EPFRs generation on MIL-100(M) (M = Al, Cr, Fe) from chlorine-substituted phenol vapor and catechol under thermal conditions. It is found that high Lewis acidity of metal sites is crucial for capturing the above two phenolic precursors, activating the O-H bond and promoting EPFRs formation. Radical species with half-life as long as 70 days were generated on MIL-100 rich in 5-fold coordinated Al3+ sites. The unpaired electron spin density donation was further confirmed by using 27Al solid-state nuclear magnetic resonance spectroscopy. Despite their higher oxidation power than Al3+, the exposed Cr3+ and Fe3+ sites show undetectable catalytic activity for the formation of EPFRs, because of their insufficient Lewis acidity. Our results suggest that the surface species rather than Lewis acid sites may be a major contributor to the formation of EPFRs on metal oxides like Fe2O3.
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Affiliation(s)
- Yuqing Ye
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Cluster Science, Ministry of Education, Advanced Technology Research Institute (Jinan), School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Yuan Li
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Cluster Science, Ministry of Education, Advanced Technology Research Institute (Jinan), School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Jie Wang
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Cluster Science, Ministry of Education, Advanced Technology Research Institute (Jinan), School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Shuai Yuan
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Cluster Science, Ministry of Education, Advanced Technology Research Institute (Jinan), School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Xiaojun Xu
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Cluster Science, Ministry of Education, Advanced Technology Research Institute (Jinan), School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Xinning Zhang
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Cluster Science, Ministry of Education, Advanced Technology Research Institute (Jinan), School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Junwen Zhou
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Cluster Science, Ministry of Education, Advanced Technology Research Institute (Jinan), School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Bo Wang
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Cluster Science, Ministry of Education, Advanced Technology Research Institute (Jinan), School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Xiaojie Ma
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, Key Laboratory of Cluster Science, Ministry of Education, Advanced Technology Research Institute (Jinan), School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, People's Republic of China
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Ali L, A Mousa H, Al-Harahsheh M, Al-Zuhair S, Abu-Jdayil B, Al-Marzouqi M, Altarawneh M. Removal of Bromine from the non-metallic fraction in printed circuit board via its Co-pyrolysis with alumina. WASTE MANAGEMENT (NEW YORK, N.Y.) 2022; 137:283-293. [PMID: 34823135 DOI: 10.1016/j.wasman.2021.11.025] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Revised: 11/07/2021] [Accepted: 11/17/2021] [Indexed: 06/13/2023]
Abstract
The effectiveness of a recycling approach of the printed circuit board (PCBs), and, thus, the quality of polymeric constituents, primarily rests on the capacity to eliminate the bromine content (mainly as HBr). HBr is emitted in appreciable quantities during thermal decomposition of PCB-contained brominated flame retardants (BFRs). The highly corrosive, yet relatively reactive HBr, renders recovery of bromine-free hydrocarbons streams from brominated polymers in PCBs very challenging. Via combined experimental and theoretical frameworks, this study explores the potential of deploying alumina (Al2O3) as a debromination agent of Br-containing hydrocarbon fractions in PCBs. A consensus from a wide array of characterization techniques utilized herein (ICP-OES, IC, XRD, FTIR, SEM-EDX, and TGA) clearly demonstrates the transformation of alumina upon its co-pyrolysis with the non-metallic fractions of PCBs, into aluminum bromides and oxy-bromides. ICP-OES measurements disclose the presence of high concentration of Cu in the non-metallic fraction of PCB, along with minor levels of selected valuable metals. Likewise, elemental ionic analysis by IC demonstrates an elevated concentration of bromine in washed alumina-PCBs pyrolysates, especially at 500 °C. The Coats-Redfern model facilitates the derivation of thermo-kinetic parameters underpinning the thermal degradation of alumina-PCB mixtures. Density functional theory calculations (DFT) establish an accessible reaction pathway for the HBr uptake by the alumina surface, thus elucidating chemical reactions governing the observed alumina debromination activity. Findings from this study illustrate the capacity of alumina as a HBr fixation agent during the thermal treatment of e-waste.
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Affiliation(s)
- Labeeb Ali
- United Arab Emirates University, Department of Chemical and Petroleum Engineering, Al-Ain 15551, United Arab Emirates
| | - Hussein A Mousa
- United Arab Emirates University, Department of Chemical and Petroleum Engineering, Al-Ain 15551, United Arab Emirates
| | - Mohammad Al-Harahsheh
- Department of Chemical Engineering, Jordan University of Science and Technology, Irbid 22110, Jordan
| | - Sulaiman Al-Zuhair
- United Arab Emirates University, Department of Chemical and Petroleum Engineering, Al-Ain 15551, United Arab Emirates
| | - Basim Abu-Jdayil
- United Arab Emirates University, Department of Chemical and Petroleum Engineering, Al-Ain 15551, United Arab Emirates
| | - Mohamed Al-Marzouqi
- United Arab Emirates University, Department of Chemical and Petroleum Engineering, Al-Ain 15551, United Arab Emirates
| | - Mohammednoor Altarawneh
- United Arab Emirates University, Department of Chemical and Petroleum Engineering, Al-Ain 15551, United Arab Emirates.
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9
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Guo C, Richmond-Bryant J. A critical review of environmentally persistent free radical (EPFR) solvent extraction methodology and retrieval efficiency. CHEMOSPHERE 2021; 284:131353. [PMID: 34225117 PMCID: PMC8487994 DOI: 10.1016/j.chemosphere.2021.131353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 06/14/2021] [Accepted: 06/26/2021] [Indexed: 05/16/2023]
Abstract
Long-lived environmentally persistent free radical (EPFR) exposures have been shown in toxicology studies to lead to respiratory and cardiovascular effects, which were thought to be due to the persistence of EPFR and their ability to produce reactive oxygen species. To characterize EPFR exposure and resulting health impacts, it is necessary to identify and systematize analysis protocols. Both direct measurement and solvent extraction methods have been applied to analyze environmental samples containing EPFR. The use of different protocols and solvents in EPFR analyses makes it difficult to compare results among studies. In this work, we reviewed EPFR studies that involved solvent extraction and carefully reported the details of the extraction methodology and retrieval recovery. EPFR recovery depends on the structure of the radical species and the solvent. For the limited number of studies available for review, the polar solvents had superior recovery in more studies. Radicals appeared to be more oxygen-centered following extraction for fly ash and particulate matter (PM) samples. Different solvent extraction methods to retrieve EPFR may produce molecular products during the extraction, thus potentially changing the sample toxicity. The number of studies reporting detailed methodologies is limited, and data in these studies were not consistently reported. Thus, inference about the solvent and protocol that leads to the highest EPFR extraction efficiency for certain types of radicals is not currently possible. Based on our review, we proposed reporting criteria to be included for future EPFR studies.
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Affiliation(s)
- Chuqi Guo
- Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, NC, 27695, USA.
| | - Jennifer Richmond-Bryant
- Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, NC, 27695, USA
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10
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Huang M, Han Y, Xiang W, Zhong D, Wang C, Zhou T, Wu X, Mao J. In Situ-Formed Phenoxyl Radical on the CuO Surface Triggers Efficient Persulfate Activation for Phenol Degradation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:15361-15370. [PMID: 34697937 DOI: 10.1021/acs.est.1c03758] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Transition-metal oxide (MxOy)-based persulfate (PDS) activation processes have demonstrated enormous potential for pollutant degradation in water purification. However, the mechanistic insight of PDS activation by a MxOy catalyst concerning the mediate role of the organic substrate remains obscure. Here, we demonstrated that the in situ-formed phenoxyl radical on the CuO surface can trigger efficient persulfate activation for phenol degradation. The formation of the phenoxyl radical was an inner-sphere process, which involved the successive steps of chemisorption through surface hydroxyl group substitution and the subsequent spontaneous electron transfer reaction from adsorbed phenol to CuO. The organic substrate phenol can be oxidized by the PDS molecule and surface-bound SO4•- through the nonradical and free-radical pathways, respectively. Such a unique "half-radical" mechanism resulted in an extraordinarily high PDS utilization efficiency of 188.9%. More importantly, a general rule for phenoxyl radical formation was concluded; it can be formed in the cases of organic substrates with a Hammett constant σ+ lower than -0.02 and metal ion of a 3d subshell between half-filled and fully filled. This study clarifies the mediate role of the organic substrate for interfacial PDS activation on MxOy and also gives new insights into the rational design of a highly efficient MxOy catalyst for selective phenolic/aniline pollutant degradation in wastewater.
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Affiliation(s)
- Mingjie Huang
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
- CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Yi Han
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Wei Xiang
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
- Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Wuhan 430074, China
| | - Delai Zhong
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon 999077, Hong Kong, China
| | - Chen Wang
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
- Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Wuhan 430074, China
| | - Tao Zhou
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Xiaohui Wu
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
- Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Wuhan 430074, China
| | - Juan Mao
- School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
- Key Laboratory of Water and Wastewater Treatment (HUST), MOHURD, Wuhan 430074, China
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11
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Xiang L, Liu S, Ye S, Yang H, Song B, Qin F, Shen M, Tan C, Zeng G, Tan X. Potential hazards of biochar: The negative environmental impacts of biochar applications. JOURNAL OF HAZARDOUS MATERIALS 2021; 420:126611. [PMID: 34271443 DOI: 10.1016/j.jhazmat.2021.126611] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Revised: 07/06/2021] [Accepted: 07/07/2021] [Indexed: 06/13/2023]
Abstract
Biochar has been widely used as an environmentally friendly material for soil improvement and remediation, water pollution control, greenhouse gas emission reduction, and other purposes because of its characteristics such as a large surface area, porous structure, and abundant surface O-containing functional groups. However, some surface properties (i.e., (i) some surface properties (i.e., organic functional groups and inorganic components), (ii) changes in pH), and (iii) chemical reactions (e.g., aromatic C ring oxidation) that occur between biochar and the application environment may result in the release of harmful components. In this study, biochars with a potential risk to the environment were classified according to their harmful components, surface properties, structure, and particle size, and the potential negative environmental effects of these biochars and the mechanisms inducing these negative effects were reviewed. This article presents a comprehensive overview of the negative environmental impacts of biochar on soil, water, and atmospheric environments. It also summarizes various technical methods of environment-related risk detection and evaluation of biochar application, thereby providing a baseline reference and guiding significance for future biochar selection and toxicity detection, evaluation, and avoidance.
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Affiliation(s)
- Ling Xiang
- College of Environmental Science and Engineering, Hunan University, and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China
| | - Shaoheng Liu
- College of Chemistry and Material Engineering, Hunan University of Arts and Science, Changde 415000, Hunan, PR China
| | - Shujing Ye
- College of Environmental Science and Engineering, Hunan University, and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China
| | - Hailan Yang
- College of Environmental Science and Engineering, Hunan University, and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China
| | - Biao Song
- College of Environmental Science and Engineering, Hunan University, and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China
| | - Fanzhi Qin
- College of Environmental Science and Engineering, Hunan University, and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China
| | - Maocai Shen
- College of Environmental Science and Engineering, Hunan University, and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China
| | - Chang Tan
- College of Environmental Science and Engineering, Hunan University, and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China
| | - Guangming Zeng
- College of Environmental Science and Engineering, Hunan University, and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
| | - Xiaofei Tan
- College of Environmental Science and Engineering, Hunan University, and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
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12
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Huang J, Jones A, Waite TD, Chen Y, Huang X, Rosso KM, Kappler A, Mansor M, Tratnyek PG, Zhang H. Fe(II) Redox Chemistry in the Environment. Chem Rev 2021; 121:8161-8233. [PMID: 34143612 DOI: 10.1021/acs.chemrev.0c01286] [Citation(s) in RCA: 147] [Impact Index Per Article: 49.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Iron (Fe) is the fourth most abundant element in the earth's crust and plays important roles in both biological and chemical processes. The redox reactivity of various Fe(II) forms has gained increasing attention over recent decades in the areas of (bio) geochemistry, environmental chemistry and engineering, and material sciences. The goal of this paper is to review these recent advances and the current state of knowledge of Fe(II) redox chemistry in the environment. Specifically, this comprehensive review focuses on the redox reactivity of four types of Fe(II) species including aqueous Fe(II), Fe(II) complexed with ligands, minerals bearing structural Fe(II), and sorbed Fe(II) on mineral oxide surfaces. The formation pathways, factors governing the reactivity, insights into potential mechanisms, reactivity comparison, and characterization techniques are discussed with reference to the most recent breakthroughs in this field where possible. We also cover the roles of these Fe(II) species in environmental applications of zerovalent iron, microbial processes, biogeochemical cycling of carbon and nutrients, and their abiotic oxidation related processes in natural and engineered systems.
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Affiliation(s)
- Jianzhi Huang
- Department of Civil and Environmental Engineering, Case Western Reserve University, 2104 Adelbert Road, Cleveland, Ohio 44106, United States
| | - Adele Jones
- UNSW Water Research Centre, School of Civil and Environmental Engineering, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - T David Waite
- UNSW Water Research Centre, School of Civil and Environmental Engineering, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Yiling Chen
- Institute of Environmental and Ecological Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Xiaopeng Huang
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Kevin M Rosso
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Andreas Kappler
- Geomicrobiology, Center for Applied Geosciences, University of Tuebingen, 72076 Tuebingen, Germany
| | - Muammar Mansor
- Geomicrobiology, Center for Applied Geosciences, University of Tuebingen, 72076 Tuebingen, Germany
| | - Paul G Tratnyek
- School of Public Health, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, Oregon 97239, United States
| | - Huichun Zhang
- Department of Civil and Environmental Engineering, Case Western Reserve University, 2104 Adelbert Road, Cleveland, Ohio 44106, United States
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13
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A review of tobacco abuse and its epidemiological consequences. JOURNAL OF PUBLIC HEALTH-HEIDELBERG 2021; 30:1485-1500. [PMID: 33425659 PMCID: PMC7786188 DOI: 10.1007/s10389-020-01443-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 11/20/2020] [Indexed: 12/12/2022]
Abstract
Aim The economic burden caused by death and disease in the world is credited mainly to tobacco use—currently linked to approximately 8,000,000 deaths per year with approximately 80% of these faralities reported in low and middle income economies. The World Health Organization (WHO) estimates that nearly 7,000,000 deaths are attributed to direct tobacco use, while approximately 1,200,000 non-smokers exposed to second hand cigarette smoke die every year. Accordingly, tobacco use is a major threat to the public health infrastructure; therefore, proper cessation interventions must be put in place to curb tobacco abuse and ease economic and social burdens caused by the tobacco epidemic. Methods A systematic review was conducted to investigate how scientific efforts have been advanced towards harm reduction among smokers and non-smokers. Relevant articles published during the period 2010–2020 in PubMed, Crossref, Google scholar, and Web of Science were used in this study. The articles were selected based on health impacts of cigarette smoking, tobacco cessation and emerging diseases, including Covid−19. Various cessation strategies have been identified although their efficiency is yet to match the desired results. Results A series of carcinogenic chemicals are generated during cigarette smoking resulting in serious health complications such as cancer and mutagenesis. The precursors for tobacco induced diseases are toxic and carcinogenic chemicals of the nitrosamine type, aldehydes, polonium-210 and benzo[a]pyrene, which bio-accumulate in the body system during cigarette smoking to cause disease. Rehabilitation facilities, use of drugs to diminish the desire to smoke, heavy taxation of tobacco products and warning labels on cigarettes are some of the cessation strategies employed towards curbing tobacco abuse. Conclusion The need for further research to develop better methods and research based policies for safe cigarette smoking and workable cessation strategies must be a priority in order to deal with the tobacco epidemic. Campaigns to promote tobacco cessation and abstinence are recommended in this review as a sure measure to mitigate against the deleterious impacts caused by cigarette smoking and tobacco abuse.
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14
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Xing X, Chen Z, Tian Q, Mao Y, Liu W, Shi M, Cheng C, Hu T, Zhu G, Li Y, Zheng H, Zhang J, Kong S, Qi S. Characterization and source identification of PM 2.5-bound polycyclic aromatic hydrocarbons in urban, suburban, and rural ambient air, central China during summer harvest. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2020; 191:110219. [PMID: 31972455 DOI: 10.1016/j.ecoenv.2020.110219] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 01/11/2020] [Accepted: 01/14/2020] [Indexed: 06/10/2023]
Abstract
Characterization and source identification of PM2.5-bound polycyclic aromatic hydrocarbons (PAHs) are conducted in urban Wuhan (WH), suburban Pingdingshan (PDS), and rural Suizhou (SZ) in China during summer harvest. This study analyzes 16 priority PAHs with 38 PM.2.5 samples in June. PAHs had similar physical-chemical properties like polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs), which had been listed as Priority Pollutants. The concentration and detection frequency of OCPs and PCBs were considerably lower than those of PAHs in PM2.5. Results indicate that PDS adjoining the highway has the highest PM2.5-bound PAHs. SZ possesses the lowest concentration of PAHs. Principal component analysis and multivariate linear regression model and molecular diagnostic ratio distinguish the sources. Vehicle emissions and coal combustion are extracted in three sites, while the source of PDS also includes gas combustion. SZ was affected by gas combustion and petroleum. The potential source contribution function and the concentration-weighted trajectory track the potential pollution area. The sampling places might be affected by the local sources and short distance transmission cannot be neglected. The incremental lifetime cancer risks (ILCRs) model evaluates the exposure risk of PAHs. According to the ILCR model, WH and PDS are exposed to harmful PAHs. By contrast, SZ is a substantially safe place.
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Affiliation(s)
- Xinli Xing
- Laboratory of Basin Hydrology and Wetland Eco-restoration, School of Environmental Studies, China University of Geosciences, Wuhan, 430074, China; State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430074, China.
| | - Zhanle Chen
- Laboratory of Basin Hydrology and Wetland Eco-restoration, School of Environmental Studies, China University of Geosciences, Wuhan, 430074, China
| | - Qian Tian
- Laboratory of Basin Hydrology and Wetland Eco-restoration, School of Environmental Studies, China University of Geosciences, Wuhan, 430074, China; School of Environmental Science and Engineering, Hubei Key Laboratory of Mine Environmental Pollution Control and Remediation, Hubei Polytechnic University, Huangshi, 435003, China
| | - Yao Mao
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430074, China
| | - Weijie Liu
- Laboratory of Basin Hydrology and Wetland Eco-restoration, School of Environmental Studies, China University of Geosciences, Wuhan, 430074, China
| | - Mingming Shi
- Laboratory of Basin Hydrology and Wetland Eco-restoration, School of Environmental Studies, China University of Geosciences, Wuhan, 430074, China; State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430074, China
| | - Cheng Cheng
- Laboratory of Basin Hydrology and Wetland Eco-restoration, School of Environmental Studies, China University of Geosciences, Wuhan, 430074, China
| | - Tianpeng Hu
- Laboratory of Basin Hydrology and Wetland Eco-restoration, School of Environmental Studies, China University of Geosciences, Wuhan, 430074, China; School of Environmental Science and Engineering, Hubei Key Laboratory of Mine Environmental Pollution Control and Remediation, Hubei Polytechnic University, Huangshi, 435003, China
| | - Gehao Zhu
- Laboratory of Basin Hydrology and Wetland Eco-restoration, School of Environmental Studies, China University of Geosciences, Wuhan, 430074, China
| | - Ying Li
- Laboratory of Basin Hydrology and Wetland Eco-restoration, School of Environmental Studies, China University of Geosciences, Wuhan, 430074, China
| | - Huang Zheng
- Laboratory of Basin Hydrology and Wetland Eco-restoration, School of Environmental Studies, China University of Geosciences, Wuhan, 430074, China
| | - Jiaquan Zhang
- School of Environmental Science and Engineering, Hubei Key Laboratory of Mine Environmental Pollution Control and Remediation, Hubei Polytechnic University, Huangshi, 435003, China
| | - Shaofei Kong
- Laboratory of Basin Hydrology and Wetland Eco-restoration, School of Environmental Studies, China University of Geosciences, Wuhan, 430074, China
| | - Shihua Qi
- Laboratory of Basin Hydrology and Wetland Eco-restoration, School of Environmental Studies, China University of Geosciences, Wuhan, 430074, China; State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430074, China
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15
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Ahmed OH, Altarawneh M, Al-Harahsheh M, Jiang ZT, Dlugogorski BZ. Formation of phenoxy-type Environmental Persistent Free Radicals (EPFRs) from dissociative adsorption of phenol on Cu/Fe and their partial oxides. CHEMOSPHERE 2020; 240:124921. [PMID: 31726593 DOI: 10.1016/j.chemosphere.2019.124921] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2019] [Revised: 08/16/2019] [Accepted: 09/19/2019] [Indexed: 06/10/2023]
Abstract
The interplay of phenolic molecules with 3d transition metals, such as Fe and Cu, and their oxide surfaces, provide important fingerprints for environmental burdens associated with thermal recycling of e-waste and subsequent generation of notorious dioxins compounds and phenoxy-type Environmental Persistent Free Radicals (EPFRs). DRIFTS and EPR measurements established a strong interaction of the phenol molecule with transition metal oxides via synthesis of phenolic- and catecholic-type EPFRs intermediates. In this contribution, we comparatively examined the dissociative adsorption of a phenol molecule, as the simplest model for phenolic-type compounds, on Cu and Fe surfaces and their partially oxidized configurations through accurate density functional theory (DFT) studies. The underlying aim is to elucidate the specific underpinning mechanism forming phenoxy- or phenolate-type EFPRs. Simulated results show that, the phenol molecule undergoes fission of its hydroxyl's O-H bond via accessible activation energies. These values are lower by 46.5-74.1% when compared with the analogous gas phase value. Physisorbed molecules of phenol incur very low binding energies in the range of -2.1 to -5.5 over clean Cu/Fe and their oxides surfaces. Molecular attributes based on charge transfer and geometrical features are in accord with the very weak interaction in physisorbed states. Thermo-kinetic parameters established over the temperature region of 300 and 1000 K, exhibit a lower activation energy for scission of phenolic's O-H bonds over the oxide surfaces in reference to their pure surfaces (24.7 and 43.0 kcal mol-1vs 38.4 and 47.0 kcal mol-1).
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Affiliation(s)
- Oday H Ahmed
- Murdoch University, Discipline of Chemistry and Physics, College of Science Health, Engineering and Education (SHEE), Murdoch University, 90 South Street, Murdoch, WA 6150, Australia; Department of Physics, College of Education, Al- Iraqia University, Baghdad, Iraq
| | - Mohammednoor Altarawneh
- United Arab Emirates University, Department of Chemical and Petroleum Engineering, Sheikh Khalifa bin Zayed Street, Al-Ain 15551, United Arab Emirates.
| | - Mohammad Al-Harahsheh
- Department of Chemical Engineering, Jordan University of Science and Technology, Irbid, 22110, Jordan
| | - Zhong-Tao Jiang
- Murdoch University, Discipline of Chemistry and Physics, College of Science Health, Engineering and Education (SHEE), Murdoch University, 90 South Street, Murdoch, WA 6150, Australia
| | - Bogdan Z Dlugogorski
- Office of Deputy Vice Chancellor Research & Innovation, Charles Darwin University, Darwin, NT, 0909, Australia
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16
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Odinga ES, Waigi MG, Gudda FO, Wang J, Yang B, Hu X, Li S, Gao Y. Occurrence, formation, environmental fate and risks of environmentally persistent free radicals in biochars. ENVIRONMENT INTERNATIONAL 2020; 134:105172. [PMID: 31739134 DOI: 10.1016/j.envint.2019.105172] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 09/04/2019] [Accepted: 09/08/2019] [Indexed: 05/22/2023]
Abstract
Biochars are used globally in agricultural crop production and environmental remediation. However, environmentally persistent free radicals (EPFRs), which are stable emerging pollutants, are generated as a characteristic feature during biomass pyrolysis. EPFRs can induce the formation of reactive oxygen species, which poses huge agro-environmental and human health risks. Their half-lives and persistence in both biochar residues and in the atmosphere may lead to potentially adverse risks in the environment. This review highlights the comprehensive research into these bioreactive radicals, as well as the bottlenecks of biochar production leading up to the formation and persistence of EPFRs. Additionally, a way forward has been proposed, based on two main recommendations. A global joint initiative to create an all-encompassing regulations policy document that will improve both the technological and the quality control aspects of biochars to reduce EPFR generation at the production level. Furthermore, environmental impact and risk assessment studies should be conducted in the extensive applications of biochars in order to protect the environmental and human health. The highlighted key research directions proposed herein will shape the production, research, and adoption aspects of biochars, which will mitigate the considerable concerns raised on EPFRs.
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Affiliation(s)
- Emmanuel Stephen Odinga
- Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Michael Gatheru Waigi
- Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Fredrick Owino Gudda
- Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Jian Wang
- Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Bing Yang
- Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiaojie Hu
- Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Shunyao Li
- Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Yanzheng Gao
- Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
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17
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Zhao S, Gao P, Miao D, Wu L, Qian Y, Chen S, Sharma VK, Jia H. Formation and Evolution of Solvent-Extracted and Nonextractable Environmentally Persistent Free Radicals in Fly Ash of Municipal Solid Waste Incinerators. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:10120-10130. [PMID: 31403286 DOI: 10.1021/acs.est.9b03453] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Environmentally persistent free radicals (EPFRs) are emerging contaminants occurring in combustion-borne particulates and atmospheric particulate matter, but information on their formation and behavior on fly ash from municipal solid waste (MSW) incinerators is scarce. Here, we have found that MSW-associated fly ash samples contain an EPFR concentration of 3-10 × 1015 spins g-1, a line width (ΔHp-p) of ∼8.6 G, and a g-factor of 2.0032-2.0038. These EPFRs are proposed to be mixtures of carbon-centered and oxygen-centered free radicals. Fractionation of the fly ash-associated EPFRs into solvent-extracted and nonextractable radicals suggests that the solvent-extracted part accounts for ∼45-73% of the total amount of EPFRs. Spin densities of solvent-extracted EPFRs correlate positively with the concentrations of Fe, Cu, Mn, Ti, and Zn, whereas similar correlations are comparatively insignificant for nonextractable EPFRs. Under natural conditions, these two types of EPFRs exhibit different stabilization that solvent-extracted EPFRs are relatively unstable, whereas the nonextractable fraction possesses a long life span. Significant correlations between concentrations of solvent-extracted EPFRs and generation of hydroxyl and superoxide radicals are found. Overall, our results suggest that the fractionated solvent-extracted and nonextractable EPFRs may experience different formation and stabilization processes and health effects.
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Affiliation(s)
- Song Zhao
- College of Natural Resources and Environment; State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau, Institute of Soil and Water Conservation , Northwest A & F University , Yangling 712100 , China
| | - Pin Gao
- College of Environmental Science and Engineering , Donghua University , Shanghai 201620 , China
| | - Duo Miao
- College of Natural Resources and Environment; State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau, Institute of Soil and Water Conservation , Northwest A & F University , Yangling 712100 , China
| | - Lan Wu
- College of Natural Resources and Environment; State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau, Institute of Soil and Water Conservation , Northwest A & F University , Yangling 712100 , China
| | - Yajie Qian
- College of Environmental Science and Engineering , Donghua University , Shanghai 201620 , China
| | - Shanping Chen
- Shanghai Environmental Sanitation Engineering Design Institute Co., Ltd. , Shanghai 200232 , China
| | - Virender K Sharma
- Program for the Environment and Sustainability, Department of Occupational and Environmental Health, School of Public Health , Texas A&M University , College Station , Texas 77843 , United States
| | - Hanzhong Jia
- College of Natural Resources and Environment; State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau, Institute of Soil and Water Conservation , Northwest A & F University , Yangling 712100 , China
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18
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Guan X, Ghimire A, Potter PM, Lomnicki SM. Role of Fe 2O 3 in fly ash surrogate on PCDD/Fs formation from 2-monochlorophenol. CHEMOSPHERE 2019; 226:809-816. [PMID: 30965252 PMCID: PMC6504581 DOI: 10.1016/j.chemosphere.2019.03.175] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 03/19/2019] [Accepted: 03/26/2019] [Indexed: 05/22/2023]
Abstract
The correlation between the content and morphology of Fe2O3 and the yields of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) was studied in this work. Three fly ash surrogates containing 1%, 2.5%, and 4% of Fe2O3 were prepared and their effects on PCDD/Fs formation were investigated and compared to our previously studied 5% iron oxide sample using 2-monochlorophenol precursor model. As the intermediate of PCDD/Fs, environmentally persistent free radical formation propensity was correlated with the PCDD/Fs formation yields for different iron oxide samples. PCDD/Fs yield increases exponentially with the increasing iron content under pyrolytic conditions. On the contrary, low iron oxide content promotes oxidation and lowers yields of PCDD/Fs. Changing iron oxide clusters' morphology (crystallinity and cluster size) affects the mechanism of PCDD/Fs formation - on larger crystallites, a bidentate chemisorption of precursor is preferred leading to lower chlorinated congeners, while smaller clusters promote formation of PCDFs through mixed monodentate-bidentate surface species, resulting in formation of congeners with 1 chlorine more. This study further confirms the propensity of iron oxide to predominantly form PCDFs. The iron content also defines PCDDs:PCDFs ratio.
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Affiliation(s)
- Xia Guan
- Department of Environmental Sciences, Louisiana State University, 1251 Energy Coast & Environment Bldg., Baton Rouge, LA 70803, USA
| | - Ajit Ghimire
- Department of Environmental Sciences, Louisiana State University, 1251 Energy Coast & Environment Bldg., Baton Rouge, LA 70803, USA
| | - Phillip M Potter
- Oak Ridge Institution for Science and Education, U.S. Environmental Protection Agency, 5995 Center Hill Avenue, Cincinnati, OH 45224, USA
| | - Slawomir M Lomnicki
- Department of Environmental Sciences, Louisiana State University, 1251 Energy Coast & Environment Bldg., Baton Rouge, LA 70803, USA.
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19
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Wu X, Wu G, Xie J, Wang Q, Liu G, Liu W, Yang L, Zheng M. Thermochemical formation of multiple unintentional persistent organic pollutants on metallurgical fly ash and their correlations. CHEMOSPHERE 2019; 226:492-501. [PMID: 30953894 DOI: 10.1016/j.chemosphere.2019.03.166] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 03/16/2019] [Accepted: 03/24/2019] [Indexed: 06/09/2023]
Abstract
Metallurgical processes are currently the predominant anthropogenic sources of multiple unintentional persistent organic pollutants (POPs), including polycyclic aromatic hydrocarbons (PAHs), chlorinated and brominated PAHs (Cl-PAHs and Br-PAHs), polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs), and polybrominated diphenyl ether (PBDEs). Understanding the formation of multiple POPs is important for source control. These POPs could be formed through fly ash-mediated heterogeneous reactions. In this study, we comprehensively investigated the thermochemical (150-450 °C) formation of these POPs on fly ash samples collected from a secondary aluminum smelter, secondary lead smelter, and iron ore sintering plant. The maximum concentrations of PCNs and PCBs were 154.5 and 181.3 times those in the original fly ash, respectively. Formation variations of PAHs, Cl-PAHs and Br-PAHs, and PBDEs were different from that of PCBs and PCNs. The PAHs concentration, which was the highest among the POPs in the original fly ash, decreased sharply by 95% at 150 °C. The ∑19Cl-PAHs and ∑19Br-PAHs increased marginally at 250 °C before decreasing slightly at 350 °C. The PBDE concentrations decreased under 250 °C and increased at 350 °C. PCNs, PCBs, and PCDD/Fs showed good correlations, all of which had a negative relationship with the PAHs. There were no significant correlations between PAHs and Cl/Br-PAHs. Low brominated congeners could be formed by destruction of higher brominated congeners because of thermal instability of the PBDEs.
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Affiliation(s)
- Xiaolin Wu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Guanglong Wu
- Foreign Economic Cooperation Office, Ministry of Environmental Protection of China, Beijing, 100035, China
| | - Jiahong Xie
- Foreign Economic Cooperation Office, Ministry of Environmental Protection of China, Beijing, 100035, China
| | - Qingjie Wang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing, 100085, China
| | - Guorui Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Wenbin Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Lili Yang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Minghui Zheng
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
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20
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Wang Y, Peng A, Chen Z, Jin X, Gu C. Transformation of gaseous 2-bromophenol on clay mineral dust and the potential health effect. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 250:686-694. [PMID: 31035151 DOI: 10.1016/j.envpol.2019.04.072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2019] [Revised: 03/22/2019] [Accepted: 04/15/2019] [Indexed: 06/09/2023]
Abstract
Iron-bearing clays are ubiquitously distributed as mineral dusts in the atmosphere. Bromophenols were reported as the major products from thermal decomposition of the widely used brominated flame retardants (BFRs). However, little information is available for the reactivity of iron associated with mineral dusts to interact with the atmospheric bromophenols and the subsequent toxic effects. Herein, three common clay minerals (montmorillonite, illite and kaolinite) were used to simulate mineral dusts, and the reactions with gaseous 2-bromophenol were systematically investigated under environmentally relevant atmospheric conditions. Our results demonstrate that structural Fe(III) in montmorillonite and Fe(III) from iron oxide in illite mediated the dimerization of 2-bromophenol to form hydroxylated polybrominated biphenyl and hydroxylated polybrominated diphenyl ether. The surface reaction is favored to occur at moisture environment, since water molecules formed complex with 2-bromophenol and the reaction intermediates via hydrogen bond to significantly lower the reaction energy and promote the dimerization reaction. More importantly, the formed dioxin-like products on clay mineral dust increased the toxicity of the particles to A549 lung cell by decreasing cell survival and damaging cellular membrane and proteins. The results of this study indicate that not only mineral dust itself but also the associated surface reaction should be fully considered to accurately evaluate the toxic effect of mineral dust on human health.
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Affiliation(s)
- Yi Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu, 210023, PR China
| | - Anping Peng
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu, 210023, PR China
| | - Zeyou Chen
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu, 210023, PR China
| | - Xin Jin
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu, 210023, PR China
| | - Cheng Gu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu, 210023, PR China.
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Pan W, Chang J, Liu X, Xue Q, Fu J, Zhang A. Interfacial formation of environmentally persistent free radicals-A theoretical investigation on pentachlorophenol activation on montmorillonite in PM 2.5. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2019; 169:623-630. [PMID: 30496994 DOI: 10.1016/j.ecoenv.2018.11.041] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 11/10/2018] [Indexed: 06/09/2023]
Abstract
Environmentally persistent free radicals (EPFRs) in atmospheric fine particulate matters (PM2.5) possess high bioactivity and result in severe health problems. The facile transformation of aromatic pollutants into EPFRs on montmorillonite (MMT), an important solid component in PM2.5, is an activation of air pollutants into more toxic chemical species and also attributes to the secondary source of EPFRs in PM2.5. In this study, the interfacial reactions of pentachlorophenol (PCP), a typical EPFR precursor in air pollution, on the Fe(III)-, Ca- and Na-MMT surfaces have been explored by the density functional theory (DFT) calculations using the periodic slab models. The PCP molecule is found to be exothermically adsorbed on the three MMT surfaces. Moreover, significant charge transfer from PCP to Fe takes place and finally leads to the surface-bound phenoxyl radical formation on the Fe(III)-MMT surface since the half-filled 3d orbital of Fe3+ in Fe(III)-MMT could act as electron acceptor allowing the electron transferring from the 2p orbital of the phenolic O in PCP to Fe ion. However, similar charge transfer is not found in the Ca- and Na-MMTs, and the PCP transformation reaction is hindered on the Ca- and Na-MMT surfaces. Namely, the PCP activation to the corresponding EPFRs is impossible on the Ca-MMT and Na-MMT surfaces, while the catalytically active Fe(III)-MMT in PM2.5 can transform the chlorinated phenols into more toxic phenoxy-type EPFRs at ambient temperatures. Accordingly, more attention should be paid on the effect of MMT with catalytical capacity on the toxicity of PM2.5.
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Affiliation(s)
- Wenxiao Pan
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China
| | - Jiamin Chang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100190, PR China
| | - Xian Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100190, PR China
| | - Qiao Xue
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China
| | - Jianjie Fu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China
| | - Aiqian Zhang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100190, PR China; Institute of Environment and Health, Jianghan University, Wuhan 430056, PR China.
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22
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Cui JT, Zhao Y, Hu JC, Ma JB. Direct hydroxylation of benzene to phenol mediated by nanosized vanadium oxide cluster ions at room temperature. J Chem Phys 2018; 149:074308. [PMID: 30134679 DOI: 10.1063/1.5038175] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Gas-phase vanadium oxide cluster cations and anions are prepared by laser ablation. The small cluster ions (<1000 amu) are mass-selected using a quadrupole mass filter and reacted with benzene in a linear ion trap reactor; large clusters (>1000 amu) with no mass selection are reacted with C6H6 in a fast flow reactor. Rich product variety is encountered in these reactions, and the reaction channels for small cationic and anionic systems are different. For large clusters, the reactivity patterns of (V2O5) n+ (n = 6-25) and (V2O5) n O- (n = 6-24) cluster series are very similar to each other, indicating that the charge state has little influence on the oxidation of benzene. In sharp contrast to the dramatic changes of reactivity of small clusters, a weakly size dependent reaction behavior of large (V2O5)6-25+ and (V2O5)6-24O- clusters is observed. Therefore, the charge state and the size are not the major factors influencing the reactivity of nanosized vanadium oxide cluster ions toward C6H6, which is not common in cluster science. In the reactions with benzene, the small and large reactive vanadium oxide cations show similar reactivity of hydroxyl radicals (OH•) toward C6H6 at higher and lower temperatures, respectively; different numbers of vibrational degrees of freedom and the released energy during the formation of adduct complexes can explain this intriguing correlation. The reactions investigated herein might be used as the models of how to realize the partial oxidation of benzene to phenol in a single step, and the observed mechanisms are helpful to understand the corresponding heterogeneous reactions, such as those over vanadium oxide aerosols and vanadium oxide catalysts.
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Affiliation(s)
- Jia-Tong Cui
- The Institute for Chemical Physics, Key Laboratory of Cluster Science, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, 102488 Beijing, People's Republic of China
| | - Yue Zhao
- The Institute for Chemical Physics, Key Laboratory of Cluster Science, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, 102488 Beijing, People's Republic of China
| | - Ji-Chuang Hu
- The Institute for Chemical Physics, Key Laboratory of Cluster Science, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, 102488 Beijing, People's Republic of China
| | - Jia-Bi Ma
- The Institute for Chemical Physics, Key Laboratory of Cluster Science, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, 102488 Beijing, People's Republic of China
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23
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Qin Y, Li G, Gao Y, Zhang L, Ok YS, An T. Persistent free radicals in carbon-based materials on transformation of refractory organic contaminants (ROCs) in water: A critical review. WATER RESEARCH 2018; 137:130-143. [PMID: 29547776 DOI: 10.1016/j.watres.2018.03.012] [Citation(s) in RCA: 121] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 03/02/2018] [Accepted: 03/05/2018] [Indexed: 06/08/2023]
Abstract
With the increased concentrations and kinds of refractory organic contaminants (ROCs) in aquatic environments, many previous reviews systematically summarized the applications of carbon-based materials in the adsorption and catalytic degradation of ROCs for their economically viable and environmentally friendly behavior. Interestingly, recent studies indicated that carbon-based materials in natural environment can also mediate the transformation of ROCs directly or indirectly due to their abundant persistent free radicals (PFRs). Understanding the formation mechanisms of PFRs in carbo-based materials and their interactions with ROCs is essential to develop their further applications in environment remediation. However, there is no comprehensive review so far about the direct and indirect removal of ROCs mediated by PFRs in amorphous, porous and crystalline carbon-based materials. The review aims to evaluate the formation mechanisms of PFRs in carbon-based materials synthesized through pyrolysis and hydrothermal carbonization processes. The influence of synthesis conditions (temperature and time) and carbon sources on the types as well as the concentrations of PFRs in carbon-based materials are also discussed. In particular, the effects of metals on the concentrations and types of PFRs in carbon-based materials are highlighted because they are considered as the catalysts for the formation of PFRs. The formation mechanisms of reactive species and the further transformation mechanisms of ROCs are briefly summarized, and the surface properties of carbon-based materials including surface area, types and number of functional groups, etc. are found to be the key parameters controlling their activities. However, due to diversity and complexity of carbon-based materials, the exact relationships between the activities of carbon-based materials and PFRs are still uncertain. Finally, the existing problems and current challenges for the ROCs transformation with carbon-based materials are also pointed out.
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Affiliation(s)
- Yaxin Qin
- Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
| | - Guiying Li
- Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
| | - Yanpeng Gao
- Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
| | - Lizhi Zhang
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, Institute of Environmental Chemistry, College of Chemistry, Central China Normal University, Wuhan 430079, China
| | - Yong Sik Ok
- Korea Biochar Research Center, O-Jeong Eco-Resilience Institute & Division of Environmental Science and Ecological Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Taicheng An
- Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China.
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24
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Jia H, Zhao S, Shi Y, Zhu L, Wang C, Sharma VK. Transformation of Polycyclic Aromatic Hydrocarbons and Formation of Environmentally Persistent Free Radicals on Modified Montmorillonite: The Role of Surface Metal Ions and Polycyclic Aromatic Hydrocarbon Molecular Properties. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:5725-5733. [PMID: 29658709 DOI: 10.1021/acs.est.8b00425] [Citation(s) in RCA: 103] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
This paper presents the transformation of PAHs (phenanthrene, anthracene, benzo[a]anthracene, pyrene, and benzo[a]pyrene) on montmorillonite clays that are modified by transition-metal ions [Fe(III), Cu(II), Ni(II), Co(II), or Zn(II)] at room temperature (∼23 °C). The decay of these PAHs follows first-order kinetics, and the dependence of the observed rate constants ( kobs, day-1) on the presence of metal ions follows the order Fe(III) > Cu(II) > Ni(II) > Co(II) > Zn(II). The values of kobs show reasonable linear relationships with the oxidation potentials of the PAHs and the redox potentials of the metal ions. Notably, transformation of these PAHs results in the formation of environmentally persistent free radicals (EPFRs), which are of major concern due to their adverse effects on human health. The potential energy surface (PES) calculations using density functional theory were performed to understand the trends in kobs and the plausible mechanisms for radical formation from the PAHs on modified clays. The yields and stability of these EPFRs from anthracene and benzo[a]pyrene on clay surfaces varies with both the parent PAH and the metal ion. The results demonstrated the potential role of metals in the formation and fate of PAH-induced EPFR at co-contaminated sites.
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Affiliation(s)
- Hanzhong Jia
- Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China, Ministry of Agriculture, College of Natural Resources and Environment , Northwest A&F University , Yangling 712100 , China
- Xinjiang Technical Institute of Physics & Chemistry , Chinese Academy of Sciences , Urumqi 830011 , China
| | - Song Zhao
- Xinjiang Technical Institute of Physics & Chemistry , Chinese Academy of Sciences , Urumqi 830011 , China
| | - Yafang Shi
- Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China, Ministry of Agriculture, College of Natural Resources and Environment , Northwest A&F University , Yangling 712100 , China
| | - Lingyan Zhu
- Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China, Ministry of Agriculture, College of Natural Resources and Environment , Northwest A&F University , Yangling 712100 , China
| | - Chuanyi Wang
- Xinjiang Technical Institute of Physics & Chemistry , Chinese Academy of Sciences , Urumqi 830011 , China
| | - Virender K Sharma
- Program for the Environment and Sustainability, Department of Occupational and Environmental Health, School of Public Health , Texas A&M University , College Station , Texas 77843 , United States
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25
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Vejerano EP, Rao G, Khachatryan L, Cormier SA, Lomnicki S. Environmentally Persistent Free Radicals: Insights on a New Class of Pollutants. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:2468-2481. [PMID: 29443514 PMCID: PMC6497067 DOI: 10.1021/acs.est.7b04439] [Citation(s) in RCA: 113] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Environmentally persistent free radicals, EPFRs, exist in significant concentration in atmospheric particulate matter (PM). EPFRs are primarily emitted from combustion and thermal processing of organic materials, in which the organic combustion byproducts interact with transition metal-containing particles to form a free radical-particle pollutant. While the existence of persistent free radicals in combustion has been known for over half-a-century, only recently that their presence in environmental matrices and health effects have started significant research, but still in its infancy. Most of the experimental studies conducted to understand the origin and nature of EPFRs have focused primarily on nanoparticles that are supported on a larger micrometer-sized particle that mimics incidental nanoparticles formed during combustion. Less is known on the extent by which EPFRs may form on engineered nanomaterials (ENMs) during combustion or thermal treatment. In this critical and timely review, we summarize important findings on EPFRs and discuss their potential to form on pristine ENMs as a new research direction. ENMs may form EPFRs that may differ in type and concentration compared to nanoparticles that are supported on larger particles. The lack of basic data and fundamental knowledge about the interaction of combustion byproducts with ENMs under high-temperature and oxidative conditions present an unknown environmental and health burden. Studying the extent of ENMs on catalyzing EPFRs is important to address the hazards of atmospheric PM fully from these emerging environmental contaminants.
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Affiliation(s)
- Eric P. Vejerano
- Center for Environmental Nanoscience and Risk, Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia South Carolina 29208, United States
- Corresponding Author: Phone: (803) 777 6360;
| | - Guiying Rao
- Center for Environmental Nanoscience and Risk, Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia South Carolina 29208, United States
| | - Lavrent Khachatryan
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | - Stephania A. Cormier
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana 70803, United States
- Comparative Biomedical Sciences, Louisiana State University School of Veterinary Medicine, Baton Rouge, Louisiana 70803, United States
| | - Slawo Lomnicki
- Department of Environmental Sciences, Louisiana State University, Baton Rouge, Louisiana 70803, United States
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26
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Ahmed OH, Altarawneh M, Al-Harahsheh M, Jiang ZT, Dlugogorski BZ. Recycling of zincite (ZnO) via uptake of hydrogen halides. Phys Chem Chem Phys 2018; 20:1221-1230. [DOI: 10.1039/c7cp06159e] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We investigate chemical interplay between HCl/HBr and zincite surfaces as a representative model for structures of zinc oxides in EAFD.
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Affiliation(s)
- Oday H. Ahmed
- School of Engineering and Information Technology
- Murdoch University
- Murdoch
- Australia
- Department of Physics
| | | | - Mohammad Al-Harahsheh
- Chemical Engineering Department
- Jordan University of Science and Technology
- Irbid 22110
- Jordan
| | - Zhong-Tao Jiang
- School of Engineering and Information Technology
- Murdoch University
- Murdoch
- Australia
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27
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Ćwieląg-Piasecka I, Witwicki M, Jerzykiewicz M, Jezierska J. Can Carbamates Undergo Radical Oxidation in the Soil Environment? A Case Study on Carbaryl and Carbofuran. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:14124-14134. [PMID: 29171253 DOI: 10.1021/acs.est.7b03386] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Radical oxidation of carbamate insecticides, namely carbaryl and carbofuran, was investigated with spectroscopic (electron paramagnetic resonance [EPR] and UV-vis) and theoretical (density functional theory [DFT] and ab initio orbital-optimized spin-component scaled MP2 [OO-SCS-MP2]) methods. The two carbamates were subjected to reaction with •OH, persistent DPPH• and galvinoxyl radical, as well as indigenous radicals of humic acids. The influence of fulvic acids on carbamate oxidation was also tested. The results obtained with EPR and UV-vis spectroscopy indicate that carbamates can undergo direct reactions with various radical species, oxidizing themselves into radicals in the process. Hence, they are prone to participate in the prolongation step of the radical chain reactions occurring in the soil environment. Theoretical calculations revealed that from the thermodynamic point of view hydrogen atom transfer is the preferred mechanism in the reactions of the two carbamates with the radicals. The activity of carbofuran was determined experimentally (using pseudo-first-order kinetics) and theoretically to be noticeably higher in comparison with carbaryl and comparable with gallic acid. The findings of this study suggest that the radicals present in soil can play an important role in natural remediation mechanisms of carbamates.
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Affiliation(s)
- Irmina Ćwieląg-Piasecka
- Institute of Soil Science and Environmental Protection, Wroclaw University of Environmental and Life Sciences , Grunwaldzka 53 St., Wroclaw, Poland
| | - Maciej Witwicki
- Faculty of Chemistry, Wroclaw University , 14 F. Joliot-Curie St., 50-383 Wroclaw, Poland
| | - Maria Jerzykiewicz
- Faculty of Chemistry, Wroclaw University , 14 F. Joliot-Curie St., 50-383 Wroclaw, Poland
| | - Julia Jezierska
- Faculty of Chemistry, Wroclaw University , 14 F. Joliot-Curie St., 50-383 Wroclaw, Poland
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28
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Shiraiwa M, Ueda K, Pozzer A, Lammel G, Kampf CJ, Fushimi A, Enami S, Arangio AM, Fröhlich-Nowoisky J, Fujitani Y, Furuyama A, Lakey PSJ, Lelieveld J, Lucas K, Morino Y, Pöschl U, Takahama S, Takami A, Tong H, Weber B, Yoshino A, Sato K. Aerosol Health Effects from Molecular to Global Scales. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:13545-13567. [PMID: 29111690 DOI: 10.1021/acs.est.7b04417] [Citation(s) in RCA: 208] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Poor air quality is globally the largest environmental health risk. Epidemiological studies have uncovered clear relationships of gaseous pollutants and particulate matter (PM) with adverse health outcomes, including mortality by cardiovascular and respiratory diseases. Studies of health impacts by aerosols are highly multidisciplinary with a broad range of scales in space and time. We assess recent advances and future challenges regarding aerosol effects on health from molecular to global scales through epidemiological studies, field measurements, health-related properties of PM, and multiphase interactions of oxidants and PM upon respiratory deposition. Global modeling combined with epidemiological exposure-response functions indicates that ambient air pollution causes more than four million premature deaths per year. Epidemiological studies usually refer to PM mass concentrations, but some health effects may relate to specific constituents such as bioaerosols, polycyclic aromatic compounds, and transition metals. Various analytical techniques and cellular and molecular assays are applied to assess the redox activity of PM and the formation of reactive oxygen species. Multiphase chemical interactions of lung antioxidants with atmospheric pollutants are crucial to the mechanistic and molecular understanding of oxidative stress upon respiratory deposition. The role of distinct PM components in health impacts and mortality needs to be clarified by integrated research on various spatiotemporal scales for better evaluation and mitigation of aerosol effects on public health in the Anthropocene.
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Affiliation(s)
- Manabu Shiraiwa
- Department of Chemistry, University of California , Irvine, California 92697, United States
| | - Kayo Ueda
- Kyoto University , Kyoto 606-8501, Japan
| | | | - Gerhard Lammel
- Research Centre for Toxic Compounds in the Environment, Masaryk University , 625 00 Brno, Czech Republic
| | - Christopher J Kampf
- Institute for Organic Chemistry, Johannes Gutenberg University , 55122 Mainz, Germany
| | - Akihiro Fushimi
- National Institute for Environmental Studies , Tsukuba 305-8506, Japan
| | - Shinichi Enami
- National Institute for Environmental Studies , Tsukuba 305-8506, Japan
| | - Andrea M Arangio
- Swiss Federal Institute of Technology in Lausanne (EPFL) , Lausanne 1015, Switzerland
| | | | - Yuji Fujitani
- National Institute for Environmental Studies , Tsukuba 305-8506, Japan
| | - Akiko Furuyama
- National Institute for Environmental Studies , Tsukuba 305-8506, Japan
| | - Pascale S J Lakey
- Department of Chemistry, University of California , Irvine, California 92697, United States
| | | | | | - Yu Morino
- National Institute for Environmental Studies , Tsukuba 305-8506, Japan
| | | | - Satoshi Takahama
- Swiss Federal Institute of Technology in Lausanne (EPFL) , Lausanne 1015, Switzerland
| | - Akinori Takami
- National Institute for Environmental Studies , Tsukuba 305-8506, Japan
| | | | | | - Ayako Yoshino
- National Institute for Environmental Studies , Tsukuba 305-8506, Japan
| | - Kei Sato
- National Institute for Environmental Studies , Tsukuba 305-8506, Japan
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29
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Yang L, Liu G, Zheng M, Jin R, Zhu Q, Zhao Y, Wu X, Xu Y. Highly Elevated Levels and Particle-Size Distributions of Environmentally Persistent Free Radicals in Haze-Associated Atmosphere. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:7936-7944. [PMID: 28613843 DOI: 10.1021/acs.est.7b01929] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Levels and particle-size distributions of environmentally persistent free radicals (EPFRs) in haze-associated atmospheric particulate matter (PM) have not been highlighted, even though they may enter the human body along with PM and adversely affect human health. This study quantified the levels of EPFRs in airborne PM with different aerodynamic diameters (dae) using electron paramagnetic resonance (EPR) spectroscopy. EPR spectra showed a single, unstructured signal from persistent semiquinone radicals. The average concentration of EPFRs in the airborne PM during haze events was 2.18 × 1220 spins/g (range: 3.06 × 1019-6.23 × 1020 spins/g), approximately 2 orders of magnitude higher than that reported previously in the US atmosphere. Particle-size distributions of EPFRs in four different PM fractions (dae > 10 μm, 10 μm < dae < 2.5 μm, 2.5 μm <dae < 1 μm, dae < 1 μm) indicated the highest levels of EPFRs in the PM fraction with dae < 1 μm, with average 1/e lifetime of 59.2 days. A significant occurrence of EPFRs in PM samples collected from coal-burning activities (1.52 × 1022 spins/g), automobile exhaust (3.0 × 1022 spins/g), and biomass burning activities (1.14 × 1022 spins/g) was detected, which may be potential primary sources of EPFRs in airborne PM. The results in this study may help to understand the sources and potential risks of EPFRs in airborne fine particles.
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Affiliation(s)
- Lili Yang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , P.O. Box 2871, Beijing 100085, China
- University of Chinese Academy of Sciences , Beijing 100049, China
| | - Guorui Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , P.O. Box 2871, Beijing 100085, China
- University of Chinese Academy of Sciences , Beijing 100049, China
| | - Minghui Zheng
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , P.O. Box 2871, Beijing 100085, China
- University of Chinese Academy of Sciences , Beijing 100049, China
| | - Rong Jin
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , P.O. Box 2871, Beijing 100085, China
- University of Chinese Academy of Sciences , Beijing 100049, China
| | - Qingqing Zhu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , P.O. Box 2871, Beijing 100085, China
- University of Chinese Academy of Sciences , Beijing 100049, China
| | - Yuyang Zhao
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , P.O. Box 2871, Beijing 100085, China
- University of Chinese Academy of Sciences , Beijing 100049, China
| | - Xiaolin Wu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , P.O. Box 2871, Beijing 100085, China
- University of Chinese Academy of Sciences , Beijing 100049, China
| | - Yang Xu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , P.O. Box 2871, Beijing 100085, China
- University of Chinese Academy of Sciences , Beijing 100049, China
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30
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Jia H, Zhao S, Nulaji G, Tao K, Wang F, Sharma VK, Wang C. Environmentally Persistent Free Radicals in Soils of Past Coking Sites: Distribution and Stabilization. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:6000-6008. [PMID: 28492316 DOI: 10.1021/acs.est.7b00599] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
This study presents the existence of environmentally persistent free radicals (EPFRs) in soils of past coking sites, mainly contaminated by polycyclic aromatic hydrocarbons (PAHs). Measurements of EPFRs were conducted by electron paramagnetic resonance (EPR) technique with numerous soil samples, which were collected from different distances (0-1000 m) and different depths (0-30 cm) of three contaminant sources. EPR signals with ∼3 × 1017 radicals/g of the soil samples were obtained, which are very similar to that generated in PAHs contaminated clays, that is, g = 2.0028-2.0036. Concentrations of PAHs and soil components were determined to understand their role in producing EPFRs. PAHs, clay, and iron predominately contributed to generating EPRFs. Meanwhile, organic matter negatively influenced the production of EPRFs. The effects of environmental factors (moisture and oxic/anoxic) were also studied to probe the persistency of EPFRs under various simulated conditions. The EPFRs are stable under relatively dry and oxic conditions. Under anoxic conditions without O2 and H2O, the spin densities decrease initially, followed by gradual increase before attaining constant values in two months period time. The present work implies that continuous formation of EPFRs induced by PAHs is largely responsible for the presence of relatively stable radicals in soils of coking sites.
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Affiliation(s)
- Hanzhong Jia
- Laboratory of Environmental Sciences and Technology, Xinjiang Technical Institute of Physics & Chemistry, Chinese Academy of Sciences , Urumqi 830011, China
| | - Song Zhao
- Laboratory of Environmental Sciences and Technology, Xinjiang Technical Institute of Physics & Chemistry, Chinese Academy of Sciences , Urumqi 830011, China
| | - Gulimire Nulaji
- Laboratory of Environmental Sciences and Technology, Xinjiang Technical Institute of Physics & Chemistry, Chinese Academy of Sciences , Urumqi 830011, China
| | - Kelin Tao
- Laboratory of Environmental Sciences and Technology, Xinjiang Technical Institute of Physics & Chemistry, Chinese Academy of Sciences , Urumqi 830011, China
| | - Fu Wang
- Laboratory of Environmental Sciences and Technology, Xinjiang Technical Institute of Physics & Chemistry, Chinese Academy of Sciences , Urumqi 830011, China
| | - Virender K Sharma
- Program for the Environment and Sustainability, Department of Occupational and Environmental Health, School of Public Health, Texas A&M University , College Station, Texas 77843, United States
| | - Chuanyi Wang
- Laboratory of Environmental Sciences and Technology, Xinjiang Technical Institute of Physics & Chemistry, Chinese Academy of Sciences , Urumqi 830011, China
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Assaf NW, Altarawneh M, Radny MW, Al-Nu'airat J, Dlugogorski BZ. Formation of environmentally-persistent free radicals (EPFR) on α-Al2O3 clusters. RSC Adv 2017. [DOI: 10.1039/c7ra09527a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
This study explores the role of alumina clusters assume an important role in catalyzing formation of notorious environmental persistent free radicals (EPFRs).
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Affiliation(s)
- Niveen W. Assaf
- School of Engineering and Information Technology
- Murdoch University
- Perth
- Australia
| | | | - Marian W. Radny
- School of Mathematical and Physical Sciences
- The University of Newcastle
- Australia
| | - Jomana Al-Nu'airat
- School of Engineering and Information Technology
- Murdoch University
- Perth
- Australia
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