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Ekhator OC, Orish FC, Nnadi EO, Ogaji DS, Isuman S, Orisakwe OE. Impact of black soot emissions on public health in Niger Delta, Nigeria: understanding the severity of the problem. Inhal Toxicol 2024; 36:314-326. [PMID: 38145546 DOI: 10.1080/08958378.2023.2297698] [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: 04/24/2023] [Accepted: 12/16/2023] [Indexed: 12/27/2023]
Abstract
Rivers State, Niger Delta, Nigeria often referred to as the 'treasure bed of the nation' is the seat of crude oil production activities with the accompanying environmental degradation. The severity of the environmental pollution and contaminated air quality took a new turn for the worse in November 2016, when the residents of Port Harcourt city, Rivers State, a major oil producing State experienced for the first time, aerosol deposition of plumes of black soot. This systematic review paper is aimed at quantifying the severity of this public health challenge. Using appropriate search words, the following databases SCOPUS, PUBMED, Google Scholar, and AJOL were searched from 1990 to 2022 to enable comparative analyses of data before and after the emergence of black soot deposition. Air-related morbidities and mortalities such as cerebrospinal meningitis (CSM), chronic bronchitis, measles, pertussis, hemoptysis, cough, pulmonary tuberculosis, pneumonia, and upper respiratory tract infection (URTI), pneumonia, eye irritation, conjunctivitis, traumatic skin outgrowth, cancers, cardiovascular diseases, and child deformities were compared with levels of air pollutants and particulate matter. The results showed that Port Harcourt city's ambient air quality data were above the standard National Ambient Air Quality data and that of other regulatory agencies having higher levels of both inorganic and organic pollutants. There were significant relationships between air pollutants concentration with morbidities. These correlations were significant in the period covering 2016-2022. Consequently, it is concluded that the black soot emissions in Port Harcourt city, Nigeria has worsened the public health situation in the city.
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Affiliation(s)
| | | | - Ernest O Nnadi
- School of Energy, Construction & Environment (ECE), Coventry University, Coventry, UK
| | - Daprim Samuel Ogaji
- African Centre of Excellence for Public Health and Toxicological Research (ACE-PUTOR), University of Port Harcourt, Port Harcourt, Nigeria
| | - Success Isuman
- Department of Science Laboratory Technology, University of Benin, Benin City, Nigeria
| | - Orish Ebere Orisakwe
- African Centre of Excellence for Public Health and Toxicological Research (ACE-PUTOR), University of Port Harcourt, Port Harcourt, Nigeria
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2
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Wang X, Wei J, Zeng Y, Qian Y. Diesel soot combustion in air-NO environment: Evolution of functional groups on soot surfaces. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 918:170579. [PMID: 38336061 DOI: 10.1016/j.scitotenv.2024.170579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 01/24/2024] [Accepted: 01/28/2024] [Indexed: 02/12/2024]
Abstract
It is inevitable for NO to be involved in the soot combustion in diesel particulate filters (DPFs), so giving full play to the NO oxidation activity is one of the most effective means to improve the DPF regeneration performance. In this work, based on the results of programmed temperature oxidation (TPO) experiments, Fourier transfer inference spectroscopy, and X-ray photoelectron spectroscopy, the evolution of surface functional groups was seriously analyzed to explore the soot oxidation mechanism. The results revealed that with the presence of NO in the air atmosphere, the concentration of -ONO2 groups showed an increasing trend in the early oxidation stage of 0-20 % oxidation degree (OD) and then slowly decreased during 20-80 % OD, while the variations in CH functional group concentration were directly related to the concentration NO in the air atmosphere. COO functional group is easy to decompose, and NO promotes COO's generation and decomposition. The sp3/sp2 hybrid ratio is strongly correlated with CO (carbon‑oxygen double bond), but the content of CO is also affected by the desorption of COO functional groups. It is worth noting that when the soot oxidation degree is at 50 %-80 % OD, CO groups are converted to CO functional groups.
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Affiliation(s)
- Xin Wang
- School of Automotive and Transportation Engineering, Hefei University of Technology, No. 93 Tunxi Road, Hefei 230009, China
| | - Jiangjun Wei
- School of Automotive and Transportation Engineering, Hefei University of Technology, No. 93 Tunxi Road, Hefei 230009, China.
| | - Yang Zeng
- School of Automotive and Transportation Engineering, Hefei University of Technology, No. 93 Tunxi Road, Hefei 230009, China
| | - Yejian Qian
- School of Automotive and Transportation Engineering, Hefei University of Technology, No. 93 Tunxi Road, Hefei 230009, China.
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3
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Huang H, Ni Z, Wang W, Chen H. Effects of thermal aging atmospheres on oxidation activity, element composition and microstructure of diesel soot particles. RSC Adv 2023; 13:29975-29985. [PMID: 37842675 PMCID: PMC10570905 DOI: 10.1039/d3ra05340g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2023] [Accepted: 09/25/2023] [Indexed: 10/17/2023] Open
Abstract
As an emission control device for diesel engines, DPF plays an important role in reducing particulate matter emissions. The research work on soot thermal aging will help optimize DPF regeneration strategies, improve regeneration efficiency, and promote the progress of engine emission control technology. In order to explore the influence of thermal aging under different atmospheres on particle physicochemical characteristics from diesel engines, the oxidation activity of soot particles after different thermal aging were evaluated by thermogravimetric analysis (TGA) and pyrolysis kinetics calculation, and the distribution of functional groups and elemental composition on the soot surface were investigated by FT-IR and XPS analysis. Additionally, the microstructure and graphitization degree of basic carbon with O2/NO2 aging were analyzed by HRTEM technology. The results show that the ignition temperature and activation energy of soot significantly increase after thermal aging, and their lowest values are 569 °C and 165.29 kJ mol-1 in O2/NO2/N2 atmosphere, respectively. The branching degree and content of hydrocarbon functional groups on the soot surface decrease after thermal aging, and the relative content of hydrocarbon functional groups with NO2 participating in thermal aging is the highest. The content of O element on the soot surface decreases after thermal aging, and the maximum O/C molar ratio of soot particles after thermal aging in O2/NO2/N2 atmosphere is 0.15. After thermal aging, the hybridization degree of carbon atoms and the content of -C-OH and -C[double bond, length as m-dash]O functional groups on the soot surface decrease. The content of -C-OH functional group decreases to 0.21% and 0.53% respectively after the addition of O2 and NO2 in the thermal aging atmosphere, while the content of -C[double bond, length as m-dash]O functional group increases to 4.98% and 5.98% respectively. In addition, the layer spacing and microcrystalline curvature of basic carbon particles decrease after thermal aging, however, the microcrystalline size and the graphitization degree increase.
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Affiliation(s)
- He Huang
- School of Traffic Engineering, Nanjing Vocational University of Industry Technology Nanjing 210046 China +86-025-85864356
| | - Zifei Ni
- School of Traffic Engineering, Nanjing Vocational University of Industry Technology Nanjing 210046 China +86-025-85864356
| | - Wenkai Wang
- School of Traffic Engineering, Nanjing Vocational University of Industry Technology Nanjing 210046 China +86-025-85864356
| | - Heng Chen
- School of Traffic Engineering, Nanjing Vocational University of Industry Technology Nanjing 210046 China +86-025-85864356
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4
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Liu Y, Wu S, Fan C, Wang X, Liu F, Chen H. Variations in surface functional groups, carbon chemical state and graphitization degree during thermal deactivation of diesel soot particles. J Environ Sci (China) 2023; 124:678-687. [PMID: 36182173 DOI: 10.1016/j.jes.2022.01.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 12/28/2021] [Accepted: 01/08/2022] [Indexed: 06/16/2023]
Abstract
The thermal deactivation of diesel soot particles exerts a significant influence on the control strategy for the regeneration of diesel particulate filters (DPFs). This work focused on the changes in the surface functional groups, carbon chemical state, and graphitization degree during thermal treatment in an inert gas environment at intermediate temperatures of 600°C, 800°C, and 1000°C and explore the chemical species that were desorbed from the diesel soot surface during thermal treatment using a thermogravimetric analyser coupled with a gas-chromatograph mass spectrometer (TGA-GC/MS). The surface functional groups and carbon chemical state were characterized using Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The graphitization degree was evaluated by means of Raman spectroscopy (RS). The concentrations of aliphatic C-H, C-OH, C=O, and O-C=O groups are reduced for diesel soot and carbon black when increasing the thermal treatment temperature, while the sp2/sp3 hybridized ratio and graphitization degree enhance. These results provide comprehensive evidence of the decreased reactivity of soot samples. Among oxygenated functional groups, the percentage reduction during thermal treatment is the largest for the O-C=O groups owing to its worst thermodynamic stability. TGA-GC/MS results show that the aliphatic and aromatic chains and oxygenated species would be desorbed from the soot surface during 1000°C thermal treatment of diesel soot.
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Affiliation(s)
- Ye Liu
- Institute for Transport Studies, University of Leeds, Leeds LS2 9JT, UK
| | - Sijin Wu
- Institute for Transport Studies, University of Leeds, Leeds LS2 9JT, UK
| | - Chenyang Fan
- Vehicle & Transportation Engineering Institute, Henan University of Science and Technology, Luoyang 471003, China.
| | - Xin Wang
- Vehicle & Transportation Engineering Institute, Henan University of Science and Technology, Luoyang 471003, China
| | - Fangjie Liu
- Vehicle & Transportation Engineering Institute, Henan University of Science and Technology, Luoyang 471003, China
| | - Haibo Chen
- Institute for Transport Studies, University of Leeds, Leeds LS2 9JT, UK
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5
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Xu Y, Wang H, Chang X, Fuentes A, Demarco R, Chen D. Optical Properties of Polycyclic Aromatic Hydrocarbon Clusters with Oxygenated Substitutions: A Theoretical Analysis. J Phys Chem A 2022; 126:5776-5783. [PMID: 35984739 DOI: 10.1021/acs.jpca.2c02907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The introduction of functional groups at high coverage levels can have significant impacts on the band structures of polycyclic aromatic hydrocarbon (PAH) clusters. The HOMO-LUMO gaps are highly sensitive to the type and distribution of functional groups. An in-house method is proposed to build PAH (naphthalene, pyrene, coronene, and ovalene) clusters with surface functionalization of -OH, -COOH and -CHO groups using the DFT method. The -CHO groups are found to reduce the gap value the most, but exceptions exist due to the spatial distribution of functional groups. Considering the impact of -CHO groups only, we can approximate that the impact of functional groups lies in the range of 0.14-0.89 eV. Applying further analysis on the possible energy number of energy transitions of substituted PAH clusters, it is shown that PAH clusters with oxygenated functions still behave like an indirect band gap material. The coupling effect of PAH stacking and PAH size is also addressed. A simple expression is proposed to estimate the bandgap of a mixed system using the HOMO and LUMO energy of the two components. Further attempts are made to interpret recent experiments from the impact of PAH stacking, PAH size, and functional groups.
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Affiliation(s)
- Yabei Xu
- State Key Lab of Explosion Science and Technology, Beijing Institute of Technology, No. 5 Zhong Guan Cun Nan Da Street, Beijing 100081, China
| | - Hongyu Wang
- State Key Lab of Explosion Science and Technology, Beijing Institute of Technology, No. 5 Zhong Guan Cun Nan Da Street, Beijing 100081, China
| | - Xiaoya Chang
- State Key Lab of Explosion Science and Technology, Beijing Institute of Technology, No. 5 Zhong Guan Cun Nan Da Street, Beijing 100081, China
| | - Andres Fuentes
- Departamento de Industrias, Universidad Técnica Federico Santa María, Avenada España 1680, Casilla 110-V, 2340000 Valparaíso, Chile
| | - Rodrigo Demarco
- Departamento de Industrias, Universidad Técnica Federico Santa María, Avenada España 1680, Casilla 110-V, 2340000 Valparaíso, Chile
| | - Dongping Chen
- State Key Lab of Explosion Science and Technology, Beijing Institute of Technology, No. 5 Zhong Guan Cun Nan Da Street, Beijing 100081, China
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6
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Li M, Li J, Zhu Y, Chen J, Andreae MO, Pöschl U, Su H, Kulmala M, Chen C, Cheng Y, Zhao J. Highly oxygenated organic molecules with high unsaturation formed upon photochemical aging of soot. Chem 2022. [DOI: 10.1016/j.chempr.2022.06.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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7
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He G, Ma J, Chu B, Hu R, Li H, Gao M, Liu Y, Wang Y, Ma Q, Xie P, Zhang G, Zeng XC, Francisco JS, He H. Generation and Release of OH Radicals from the Reaction of H
2
O with O
2
over Soot. Angew Chem Int Ed Engl 2022; 61:e202201638. [DOI: 10.1002/anie.202201638] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Indexed: 11/08/2022]
Affiliation(s)
- Guangzhi He
- State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-environmental Sciences Chinese Academy of Sciences Beijing 100085 China
| | - Jinzhu Ma
- State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-environmental Sciences Chinese Academy of Sciences Beijing 100085 China
- Center for Excellence in Regional Atmospheric Environment Institute of Urban Environment Chinese Academy of Sciences Xiamen 361021 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Biwu Chu
- State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-environmental Sciences Chinese Academy of Sciences Beijing 100085 China
- Center for Excellence in Regional Atmospheric Environment Institute of Urban Environment Chinese Academy of Sciences Xiamen 361021 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Renzhi Hu
- State Key Laboratory of Environmental Optics and Technology Anhui Institute of Optics and Fine Mechanics Chinese Academy of Sciences Hefei 230031 China
| | - Hao Li
- State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-environmental Sciences Chinese Academy of Sciences Beijing 100085 China
| | - Meng Gao
- State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-environmental Sciences Chinese Academy of Sciences Beijing 100085 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Yuan Liu
- State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-environmental Sciences Chinese Academy of Sciences Beijing 100085 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Yonghong Wang
- State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-environmental Sciences Chinese Academy of Sciences Beijing 100085 China
| | - Qingxin Ma
- State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-environmental Sciences Chinese Academy of Sciences Beijing 100085 China
- Center for Excellence in Regional Atmospheric Environment Institute of Urban Environment Chinese Academy of Sciences Xiamen 361021 China
- University of Chinese Academy of Sciences Beijing 100049 China
| | - Pinhua Xie
- Center for Excellence in Regional Atmospheric Environment Institute of Urban Environment Chinese Academy of Sciences Xiamen 361021 China
- University of Chinese Academy of Sciences Beijing 100049 China
- State Key Laboratory of Environmental Optics and Technology Anhui Institute of Optics and Fine Mechanics Chinese Academy of Sciences Hefei 230031 China
| | - Guoxian Zhang
- State Key Laboratory of Environmental Optics and Technology Anhui Institute of Optics and Fine Mechanics Chinese Academy of Sciences Hefei 230031 China
| | - Xiao Cheng Zeng
- Department of Chemistry University of Nebraska-Lincoln Lincoln NE 68588 USA
| | - Joseph S. Francisco
- Department of Earth and Environmental Science and Department of Chemistry University of Pennsylvania Philadelphia PA 19104 USA
| | - Hong He
- State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-environmental Sciences Chinese Academy of Sciences Beijing 100085 China
- Center for Excellence in Regional Atmospheric Environment Institute of Urban Environment Chinese Academy of Sciences Xiamen 361021 China
- University of Chinese Academy of Sciences Beijing 100049 China
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8
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Do VT, Tran NG, Chun DM. Fabrication of robust superhydrophobic micro-nano hierarchical surface structure using compression molding with carbon soot nanoparticles and thermoplastic polymer. POLYMER 2022. [DOI: 10.1016/j.polymer.2022.124893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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9
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He G, Ma J, Chu B, Hu R, Li H, Gao M, Liu Y, Wang Y, Ma Q, Xie P, Zhang G, Zeng XC, Francisco JS, He H. Generation and release of OH radicals from the reaction of H2O with O2 over soot. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202201638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Guangzhi He
- Chinese Academy of Sciences Research Center for Eco-Environmental Sciences CHINA
| | - Jinzhu Ma
- Chinese Academy of Sciences Research Center for Eco-Environmental Sciences CHINA
| | - Biwu Chu
- Chinese Academy of Sciences Research Center for Eco-Environmental Sciences CHINA
| | - Renzhi Hu
- Chinese Academy of Sciences Anhui Institute of Optics and Fine Mechanics CHINA
| | - Hao Li
- Chinese Academy of Sciences Research Center for Eco-Environmental Sciences CHINA
| | - Meng Gao
- Chinese Academy of Sciences Research Center for Eco-Environmental Sciences CHINA
| | - Yuan Liu
- Chinese Academy of Sciences Research Center for Eco-Environmental Sciences CHINA
| | - Yonghong Wang
- Chinese Academy of Sciences Research Center for Eco-Environmental Sciences CHINA
| | - Qingxin Ma
- Chinese Academy of Sciences Research Center for Eco-Environmental Sciences CHINA
| | - Pinhua Xie
- Chinese Academy of Sciences Anhui Institute of Optics and Fine Mechanics CHINA
| | - Guoxian Zhang
- Chinese Academy of Sciences State Key Laboratory of Environmental Optics and Technology CHINA
| | - Xiao Cheng Zeng
- UNL: University of Nebraska-Lincoln Department of Chemistry UNITED STATES
| | - Joseph S. Francisco
- University of Pennsylvania Department of Earth and Environmental Science and Department of Chemistry 251 Hayden Hall240 South 33rd Street 19104-6316 Philadelphia UNITED STATES
| | - Hong He
- Chinese Academy of Sciences Research Center for Eco-Environmental Sciences CHINA
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10
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Le YTH, Youn JS, Moon HG, Chen XY, Kim DI, Cho HW, Lee KH, Jeon KJ. Relationship between Cytotoxicity and Surface Oxidation of Artificial Black Carbon. NANOMATERIALS 2021; 11:nano11061455. [PMID: 34072737 PMCID: PMC8229741 DOI: 10.3390/nano11061455] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 05/11/2021] [Accepted: 05/28/2021] [Indexed: 12/15/2022]
Abstract
The lacking of laboratory black carbon (BC) samples have long challenged the corresponding toxicological research; furthermore, the toxicity tests of engineered carbon nanoparticles were unable to reflect atmospheric BC. As a simplified approach, we have synthesized artificial BC (aBC) for the purpose of representing atmospheric BC. Surface chemical properties of aBC were controlled by thermal treatment, without transforming its physical characteristics; thus, we were able to examine the toxicological effects on A549 human lung cells arising from aBC with varying oxidation surface properties. X-ray photoelectron spectroscopy, as well as Raman and Fourier transform infrared spectroscopy, verified the presence of increased amounts of oxygenated functional groups on the surface of thermally-treated aBC, indicating aBC oxidization at elevated temperatures; aBC with increased oxygen functional group content displayed increased toxicity to A549 cells, specifically by decreasing cell viability to 45% and elevating reactive oxygen species levels up to 294% for samples treated at 800 °C.
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Affiliation(s)
- Yen Thi-Hoang Le
- Department of Environmental Engineering, Inha University, Incheon 22212, Korea; (Y.T.-H.L.); (H.-W.C.)
- Program in Environmental and Polymer Engineering, Inha University, Incheon 22212, Korea
| | - Jong-Sang Youn
- Department of Energy and Environmental Engineering, The Catholic University of Korea, 43 Jibong-ro, Bucheon-si 14662, Korea;
| | - Hi-Gyu Moon
- Jeonbuk Department of Inhalation Research, Korea Institute of Toxicology, Jeongeup 53212, Korea; (H.-G.M.); (X.-Y.C.); (D.-I.K.)
| | - Xin-Yu Chen
- Jeonbuk Department of Inhalation Research, Korea Institute of Toxicology, Jeongeup 53212, Korea; (H.-G.M.); (X.-Y.C.); (D.-I.K.)
- Department of Human and Environmental Toxicology, University of Science & Technology, Daejeon 34113, Korea
| | - Dong-Im Kim
- Jeonbuk Department of Inhalation Research, Korea Institute of Toxicology, Jeongeup 53212, Korea; (H.-G.M.); (X.-Y.C.); (D.-I.K.)
| | - Hyun-Wook Cho
- Department of Environmental Engineering, Inha University, Incheon 22212, Korea; (Y.T.-H.L.); (H.-W.C.)
| | - Kyu-Hong Lee
- Jeonbuk Department of Inhalation Research, Korea Institute of Toxicology, Jeongeup 53212, Korea; (H.-G.M.); (X.-Y.C.); (D.-I.K.)
- Department of Human and Environmental Toxicology, University of Science & Technology, Daejeon 34113, Korea
- Correspondence: (K.-H.L.); (K.-J.J.)
| | - Ki-Joon Jeon
- Department of Environmental Engineering, Inha University, Incheon 22212, Korea; (Y.T.-H.L.); (H.-W.C.)
- Program in Environmental and Polymer Engineering, Inha University, Incheon 22212, Korea
- Correspondence: (K.-H.L.); (K.-J.J.)
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11
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Michelsen HA, Colket MB, Bengtsson PE, D'Anna A, Desgroux P, Haynes BS, Miller JH, Nathan GJ, Pitsch H, Wang H. A Review of Terminology Used to Describe Soot Formation and Evolution under Combustion and Pyrolytic Conditions. ACS NANO 2020; 14:12470-12490. [PMID: 32986401 DOI: 10.1021/acsnano.0c06226] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
This review presents a glossary and review of terminology used to describe the chemical and physical processes involved in soot formation and evolution and is intended to aid in communication within the field and across disciplines. There are large gaps in our understanding of soot formation and evolution and inconsistencies in the language used to describe the associated mechanisms. These inconsistencies lead to confusion within the field and hinder progress in addressing the gaps in our understanding. This review provides a list of definitions of terms and presents a description of their historical usage. It also addresses the inconsistencies in the use of terminology in order to dispel confusion and facilitate the advancement of our understanding of soot chemistry and particle characteristics. The intended audience includes senior and junior members of the soot, black carbon, brown carbon, and carbon black scientific communities, researchers new to the field, and scientists and engineers in associated fields with an interest in carbonaceous material production via high-temperature hydrocarbon chemistry.
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Affiliation(s)
- Hope A Michelsen
- Rady Department of Mechanical Engineering and Environmental Engineering Program, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Meredith B Colket
- United Technologies Research Center, Avon, Connecticut 06001, United States
| | | | - Andrea D'Anna
- Dipartimento di Ingegneria Chimica dei Materiali e della Produzione Industriale, Università degli Studi di Napoli Federico II, 80125 Napoli, Italy
| | - Pascale Desgroux
- UMR-8522-PC2A-Physicochimie des Processus de Combustion et de l'Atmosphère, Université Lille, CNRS, F-59000 Lille, France
| | - Brian S Haynes
- School of Chemical and Biomolecular Engineering, University of Sydney, Sydney, New South Wales 2006, Australia
| | - J Houston Miller
- Department of Chemistry, George Washington University, Washington, D.C. 20052, United States
| | - Graham J Nathan
- School of Mechanical Engineering, University of Adelaide, SA 5005 Adelaide, Australia
| | - Heinz Pitsch
- Institute for Combustion Technology, RWTH Aachen University, 52056 Aachen, Germany
| | - Hai Wang
- Department of Mechanical Engineering, Stanford University, Stanford, California 94305, United States
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12
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Baldelli A, Trivanovic U, Sipkens TA, Rogak SN. On determining soot maturity: A review of the role of microscopy- and spectroscopy-based techniques. CHEMOSPHERE 2020; 252:126532. [PMID: 32229356 DOI: 10.1016/j.chemosphere.2020.126532] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 03/13/2020] [Accepted: 03/16/2020] [Indexed: 05/23/2023]
Abstract
Incomplete combustion is the main source of airborne soot, which has negative impacts on public health and the environment. Understanding the morphological and chemical evolution of soot is important for assessing and mitigating the impact of soot emissions. Morphological and chemical structures of soot are commonly studied using microscopy or spectroscopy, and the best technique depends on the parameter of interest and the stage of soot formation considered (i.e., maturity). For the earliest stages of soot formation, particles exhibit simple morphology yet complex and reactive chemical composition, which is best studied by spectroscopic techniques sensitive to the large number of soot precursor species. The only microscope that can offer some morphological information at this stage is the scanning probe microscopy, which can image single polycyclic aromatic hydrocarbons, the precursors of soot. A broader range of types of spectrometers and microscopes can be used by increasing the soot maturity. Mature soot is primarily carbon, and exhibits complex fractal-like morphology best studied with electron microscopy and techniques sensitive to thin oxide or organic coatings. Each characterization technique can target different morphological and chemical properties of soot, from the early to the late stage of its formation. Thus, a guideline for the selection of the appropriate technique can facilitates studies on environmental samples involving the presence of soot.
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Affiliation(s)
- Alberto Baldelli
- Department of Mechanical Engineering, University of British Columbia, 6250 Applied Science Ln #2054, Vancouver, BC, V6T 1Z4, Canada.
| | - Una Trivanovic
- Department of Mechanical Engineering, University of British Columbia, 6250 Applied Science Ln #2054, Vancouver, BC, V6T 1Z4, Canada
| | - Timothy A Sipkens
- Department of Mechanical Engineering, University of British Columbia, 6250 Applied Science Ln #2054, Vancouver, BC, V6T 1Z4, Canada
| | - Steven N Rogak
- Department of Mechanical Engineering, University of British Columbia, 6250 Applied Science Ln #2054, Vancouver, BC, V6T 1Z4, Canada
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13
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McNulty D, Landgraf V, Trabesinger S. Simplifying the synthesis of carbon inverse opals. RSC Adv 2020; 10:24108-24114. [PMID: 35517340 PMCID: PMC9055082 DOI: 10.1039/d0ra03693e] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 06/15/2020] [Indexed: 11/21/2022] Open
Abstract
Carbon inverse opals (IOs) were prepared via a facile synthesis approach using a sucrose-based precursor and polystyrene (PS) spheres as a sacrificial template. During IO preparation, polymer spheres are typically removed by dispersion in organic solvents, such as toluene or tetrahydrofuran. In this study, carbon IOs are prepared with and without removal of PS spheres by toluene to determine the influence of template removal prior to high-temperature treatment on the morphology and chemistry of the resulting carbons. Properties of samples are compared through a systematic investigation by electron microscopy, Fourier-transform infrared spectroscopy and Raman spectroscopy. We demonstrate that a commonly used processing step—polymer sphere template chemical removal—does not make any significant difference to the IO morphology. A correlation of Raman spectroscopy with SEM imaging and TGA analysis indicates that carbon IOs prepared without the solvent-treatment step are more ordered than samples prepared with this processing step. The key finding of this report is the simplified IO synthesis procedure, which can be adapted to the preparation of IOs of other materials besides carbon. A simplified synthesis method to prepare carbon inverse opals is presented, which is applicable to other inverse opal materials.![]()
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Affiliation(s)
- David McNulty
- Battery Electrodes and Cells, Electrochemistry Laboratory, Paul Scherrer Institute Forschungsstrasse 111 5232 Villigen PSI Switzerland +41 56 310 57 75
| | - Victor Landgraf
- Battery Electrodes and Cells, Electrochemistry Laboratory, Paul Scherrer Institute Forschungsstrasse 111 5232 Villigen PSI Switzerland +41 56 310 57 75
| | - Sigita Trabesinger
- Battery Electrodes and Cells, Electrochemistry Laboratory, Paul Scherrer Institute Forschungsstrasse 111 5232 Villigen PSI Switzerland +41 56 310 57 75
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14
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He G, He H. Water Promotes the Oxidation of SO 2 by O 2 over Carbonaceous Aerosols. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:7070-7077. [PMID: 32338880 DOI: 10.1021/acs.est.0c00021] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Severe haze episodes typically occur with concurrent high relative humidity. Here, the vital role of water in promoting the oxidation of SO2 by O2 on carbonaceous soot surfaces was identified at the atomic level by first-principles calculations. Water molecules can dissociate into surface hydroxyl groups through a self-catalyzed process under ambient conditions. The surface hydroxyl groups, acting as facilitators, can significantly accelerate the conversion of SO2 to SO3 (precursor of particulate sulfate) over soot aerosols by reducing the reaction barriers. Specifically, the hydroxyl groups activate the reactants and stabilize the transition states and products through hydrogen-bonding interactions, making the reactions both thermodynamically and kinetically more favorable at room temperature. The findings indicate that atmospheric humidity plays an important role in enhancing the atmospheric oxidation capacity, thus exacerbating SO2 oxidation and severe haze development. Also, this study unravels a mechanism of surface hydroxyl-assisted O2 and H2O dissociation over metal-free carbocatalysts under normal conditions.
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Affiliation(s)
- Guangzhi He
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, People's Republic of China
| | - Hong He
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, People's Republic of China
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, Fujian 361021, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
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15
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Dong H, Zhang Y, Du Q, Li D, Feng D, Gao J, Wu S, Luan J. Roles of Ion-Exchangeable Sodium in the Conversion Process of Tar to Soot during Rapid Pyrolysis of Two Brown Coals in a Drop-Tube Reactor. ACS OMEGA 2020; 5:9078-9092. [PMID: 32363260 PMCID: PMC7191602 DOI: 10.1021/acsomega.9b03441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 04/09/2020] [Indexed: 06/11/2023]
Abstract
In this work, two series of brown coals (including acid-washed coal and ion-exchangeable Na-loaded coal) were pyrolyzed in a drop-tube reactor. The experimental results revealed that soot and tar yields of Na-loaded coals were significantly lower than that of acid-washed coals. Gasified Na can reduce the formation of big soot agglomerates. During coal primary pyrolysis, ion-exchangeable Na can reduce the amount and aromaticity of primary tar. Na released with volatiles can catalyze the cracking of aliphatic and aromatic compounds, inhibit the polymerization between aromatic rings, and promote the combination of soot/tar with oxygen-containing substances, resulting in the decrease of graphite crystallite size and the increase of amorphous carbon content. Na can also reduce the organization degree of soot by forming intercalation compounds.
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Affiliation(s)
- Heming Dong
- School
of Energy Science and Engineering, Harbin
Institute of Technology, 92, Xidazhi Street, Harbin, Heilongjiang 150001, China
| | - Yu Zhang
- School
of Energy Science and Engineering, Harbin
Institute of Technology, 92, Xidazhi Street, Harbin, Heilongjiang 150001, China
| | - Qian Du
- School
of Energy Science and Engineering, Harbin
Institute of Technology, 92, Xidazhi Street, Harbin, Heilongjiang 150001, China
| | - Dun Li
- School
of Energy Science and Engineering, Harbin
Institute of Technology, 92, Xidazhi Street, Harbin, Heilongjiang 150001, China
| | - Dongdong Feng
- School
of Energy Science and Engineering, Harbin
Institute of Technology, 92, Xidazhi Street, Harbin, Heilongjiang 150001, China
| | - Jianmin Gao
- School
of Energy Science and Engineering, Harbin
Institute of Technology, 92, Xidazhi Street, Harbin, Heilongjiang 150001, China
| | - Shaohua Wu
- School
of Energy Science and Engineering, Harbin
Institute of Technology, 92, Xidazhi Street, Harbin, Heilongjiang 150001, China
| | - Jiyi Luan
- School
of Mechanical Engineering, Jiamusi University, 258, Xuefu Street, Jiamusi, Heilongjiang 154007, China
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16
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Functional Factors of Biomass Burning Contribution to Spring Aerosol Composition in a Megacity: Combined FTIR-PCA Analyses. ATMOSPHERE 2020. [DOI: 10.3390/atmos11040319] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Whether the spring season brings additional pollution to the urban environment remains questionable for a megacity. Aerosol sampling and characterization was performed in the urban background of the Moscow megacity in spring 2017, in a period of a significant impact of mass advection from surrounding fire regions. Parametrization of Angstrom absorption exponent (AAE) on low and high values provides periods dominated by fossil fuel (FF) combustion and affected by biomass burning (BB), respectively. The period identification is supported by air mass transportation from the south of Russia through the regions where a number of fires were observed. Functionalities in entire aerosol composition, assigned to classes of organic, ionic compounds, and dust, are inferred by diffusion refection infrared Fourier transmission (FTIR) spectroscopy. Functional markers of urban transport emissions relate to modern engine technology and driving cycles. Regional BB functionalities indicate the fire impacts to the spring aerosol composition. The development of the advanced source apportionment for a megacity is performed by means of combined ambient FTIR data and statistical PCA analysis. PCA of FTIR spectral data differentiate daily aerosol chemistry by low and high AAE values, related to FF- and BB-affected spectral features. PC loadings of 58%, 21%, and 11% of variability reveal the functional factors of transport, biomass burning, biogenic, dust, and secondary aerosol spring source impacts.
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17
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Zhang T, Yang W, Han C, Yang H, Xue X. Heterogeneous reaction of ozone with syringic acid: Uptake of O 3 and changes in the composition and optical property of syringic acid. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 257:113632. [PMID: 31785942 DOI: 10.1016/j.envpol.2019.113632] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 11/08/2019] [Accepted: 11/13/2019] [Indexed: 06/10/2023]
Abstract
Syringic acid, which is a typical methoxyphenol emitted from wood combustion, can provide heterogeneous reaction sites for gaseous active components, influencing the concentrations of trace gases and the compositions of syringic acid. The heterogeneous uptake of O3 on syringic acid was investigated using a flow tube reactor under ambient pressure. The initial uptake coefficient (γi) and the steady-state uptake coefficient (γss) of O3 linearly increased with syringic acid mass (0-0.16 μg cm-2) and temperature (278-328 K), while they decreased with increasing the O3 concentration and the O2 content. The γi was independent of relative humidity (20%-70%), whereas γss decreased with relative humidity (7%-70%). The compositional changes of syringic acid by the ozonization were analyzed by the Fourier transform infrared spectrometer (FT-IR) and the gas chromatography-mass spectrometry (GC-MS), confirming the generation of 2,6-dimethoxy-1,4-benzoquinone. In addition, compared to that of fresh syringic acid, the mass absorption efficiency of syringic acid aged by O3 exhibited an increase in the range of 290-320 nm.
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Affiliation(s)
- Tingting Zhang
- School of Metallurgy, Northeastern University, Shenyang, 110819, China
| | - Wangjin Yang
- School of Metallurgy, Northeastern University, Shenyang, 110819, China
| | - Chong Han
- School of Metallurgy, Northeastern University, Shenyang, 110819, China.
| | - He Yang
- School of Metallurgy, Northeastern University, Shenyang, 110819, China
| | - Xiangxin Xue
- School of Metallurgy, Northeastern University, Shenyang, 110819, China
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18
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Zhang Y, Liu P, Li Y, Zhan R, Huang Z, Lin H. Study on fluorescence spectroscopy of PAHs with different molecular structures using laser-induced fluorescence (LIF) measurement and TD-DFT calculation. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2020; 224:117450. [PMID: 31422341 DOI: 10.1016/j.saa.2019.117450] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 08/02/2019] [Accepted: 08/03/2019] [Indexed: 06/10/2023]
Abstract
Laser-induced fluorescence (LIF) is an effective technique for non-intrusive and on-line measurement of PAHs in sooting flames but it is still need further investigation due to the complexity of PAH fluorescence characteristics. Therefore, in-depth investigations on the fluorescence spectroscopy of PAHs with different molecular structures are relevant. In this study, we investigated the fluorescence spectrum characteristics of 13 gas-phase PAHs using LIF measurement and time-dependent density functional theory (TD-DFT) calculation. The experimental results showed that the fluorescence emission wavelengths increased with more aromatic (benzenoid) rings, but this relationship no longer existed when the PAH molecules contain the five-membered ring structures. The TD-DFT calculation showed that the fluorescence emission wavelength ranges of PAHs with different molecular structures were dominantly determined by the electronic structures of highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) and their energy gaps. It was found that the saturated aliphatic branched chains (methyl and ethyl) only slightly influenced the LIF spectra, while the unsaturated aliphatic branched chains (ethenyl and ethynyl) caused remarkable redshifts. The TD-DFT results indicated that the aliphatic branched chains changed the electric structures of HOMO and LUMO of the core aromatic rings, and then influence the fluorescence emission wavelength ranges.
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Affiliation(s)
- Yiran Zhang
- Key Laboratory for Power Machinery and Engineering of Ministry of Education, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Peng Liu
- King Abdullah University of Science and Technology (KAUST), Clean Combustion Research Center, Thuwal 23955-6900, Saudi Arabia
| | - Youping Li
- Key Laboratory for Power Machinery and Engineering of Ministry of Education, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Reggie Zhan
- Key Laboratory for Power Machinery and Engineering of Ministry of Education, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Zhen Huang
- Key Laboratory for Power Machinery and Engineering of Ministry of Education, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - He Lin
- Key Laboratory for Power Machinery and Engineering of Ministry of Education, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
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19
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Easter J, Bohac S, Hoard J, Boehman A. Influence of Ash-Soot Interactions on the Reactivity of Soot from a Gasoline Direct Injection Engine. AEROSOL SCIENCE AND TECHNOLOGY : THE JOURNAL OF THE AMERICAN ASSOCIATION FOR AEROSOL RESEARCH 2020; 54:1373-1385. [PMID: 33268913 PMCID: PMC7707118 DOI: 10.1080/02786826.2020.1788208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 06/07/2020] [Accepted: 06/08/2020] [Indexed: 06/12/2023]
Abstract
Gasoline particulate filters (GPF) are being utilized in certain markets on gasoline direct injection (GDI) vehicles to reduce tailpipe particulate emissions as required by particle number regulations. GPF filtration efficiency is dependent on soot build-up within the filter. Since soot oxidizes within the GPF during normal vehicle operation, an understanding of soot reactivity is important for optimizing aftertreatment architecture and engine calibration. Past work has indicated that gasoline soot reactivity may depend on levels of metallic ash species. In this work, carbonaceous particulate matter from a GDI engine are evaluated from engine operation at a consistent speed and load but with different levels of fuel injection pressures and timings to vary the relative ash to soot ratio. Soot reactivity is found to vary significantly with the ratio of ash to soot present. Interestingly, the more reactive soots possess a unique oxidation profile by which a conventional Arrhenius type expression cannot be used to quantify reactivity. To understand the mechanisms driving such distinct oxidation differences, soot samples are analyzed after being partially oxidized. Particulate characteristics are evaluated by x-ray photoelectron spectroscopy (XPS), Raman spectroscopy, high-resolution transmission electron microscopy (HR-TEM), and scanning transmission electron microscopy with energy dispersive spectroscopy (STEM + EDS). A mechanism is proposed that may explain further why ash affects gasoline soot reactivity to the extent seen in this and other work.
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Affiliation(s)
- Jordan Easter
- Mechanical Engineering, University of Michigan, Ann Arbor, Mi, USA
| | - Stanislav Bohac
- United States Environmental Protection Agency, Ann Arbor, Mi, USA
| | - John Hoard
- Mechanical Engineering, University of Michigan, Ann Arbor, Mi, USA
| | - Andre Boehman
- Mechanical Engineering, University of Michigan, Ann Arbor, Mi, USA
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20
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Effect of noble metal addition to alkali-exchanged cryptomelane on the simultaneous soot and VOC combustion activity. CATAL COMMUN 2019. [DOI: 10.1016/j.catcom.2019.105807] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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21
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Impacts of Organic Structures and Inherent Minerals of Coal on Soot Formation during Pyrolysis. ENERGIES 2019. [DOI: 10.3390/en12234410] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The pyrolysis of four pairs of raw and acid-washed coals under N2 atmosphere was carried out in a drop tube reactor at 1250 °C. The results show that both organic structures and metal elements have an important influence on the formation of soot. The total area of aromatic and aliphatic hydrogen absorption bands is positively correlated with soot yield. Aromatic compounds have a greater contribution to soot and tar formation. The absorption band area of oxygen structures in coal FTIR spectra is negatively correlated with the soot conversion rate of tar. During pyrolysis, metal substances in coal can catalyze the dehydrogenation and deoxygenation of tar, reduce the content and stability of the aliphatic compound, and catalyze aromatic ring rupturing. More importantly, gasified metals can inhibit the polymerization reaction of aromatic compounds.
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22
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Li M, Bao F, Zhang Y, Sheng H, Chen C, Zhao J. Photochemical Aging of Soot in the Aqueous Phase: Release of Dissolved Black Carbon and the Formation of 1O 2. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:12311-12319. [PMID: 31545023 DOI: 10.1021/acs.est.9b02773] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The photochemical aging of soot in the aqueous phase could have an important influence on water environments such as fog water and wet aerosols in the atmosphere, as well as lakes and oceans. In this study, we systematically investigated the photochemistry of soot in the aqueous phase. Soot releases dissolved black carbon into the aqueous phase during photoreactions, which is attributed to the phototransformation of the nonpolar unsaturated C-H species in soot to polar carbonyl-containing species. More importantly, we found that soot suspensions, particularly those of the dissolved part of soot, were effective photosensitizers for the generation of singlet oxygen (1O2). The 1O2 apparent quantum yield of the dissolved part reached 33 ± 2% under 377 nm irradiation, which is an order of magnitude higher than those of most types of well-studied dissolved organic matter in water. As a result, soot could impact the environmental fate of coexisting organic contaminants, such as the photodegradation of bisphenol A. This study will not only give insight into the photochemistry of soot in the liquid phase but also reveal the significant implications of soot photoaging in the aqueous phase by the release and degradation of organic matter.
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Affiliation(s)
- Meng Li
- Key Laboratory of Photochemistry, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry , Chinese Academy of Sciences , Beijing 100190 , P. R. China
- University of Chinese Academy of Sciences , Beijing 100049 , P. R. China
| | - Fengxia Bao
- Key Laboratory of Photochemistry, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry , Chinese Academy of Sciences , Beijing 100190 , P. R. China
- University of Chinese Academy of Sciences , Beijing 100049 , P. R. China
| | - Yue Zhang
- Key Laboratory of Photochemistry, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry , Chinese Academy of Sciences , Beijing 100190 , P. R. China
- University of Chinese Academy of Sciences , Beijing 100049 , P. R. China
| | - Hua Sheng
- Key Laboratory of Photochemistry, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry , Chinese Academy of Sciences , Beijing 100190 , P. R. China
- University of Chinese Academy of Sciences , Beijing 100049 , P. R. China
| | - Chuncheng Chen
- Key Laboratory of Photochemistry, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry , Chinese Academy of Sciences , Beijing 100190 , P. R. China
- University of Chinese Academy of Sciences , Beijing 100049 , P. R. China
| | - Jincai Zhao
- Key Laboratory of Photochemistry, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry , Chinese Academy of Sciences , Beijing 100190 , P. R. China
- University of Chinese Academy of Sciences , Beijing 100049 , P. R. China
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23
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Jiang H, Xie Y, Ge Y, He H, Liu Y. Effects of ultrasonic treatment on dithiothreitol (DTT) assay measurements for carbon materials. J Environ Sci (China) 2019; 84:51-58. [PMID: 31284916 DOI: 10.1016/j.jes.2019.04.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 04/16/2019] [Accepted: 04/16/2019] [Indexed: 06/09/2023]
Abstract
The dithiothreitol (DTT) assay is the most commonly used method to quantify the oxidative potential of fine particles. However, the reported DTT decay rates of carbon black (CB) materials vary greatly among different researchers. This might have resulted from either the intrinsic toxicity of CB or the unsuitability of the DTT assay protocol for CB particles. In the current study, the protocol of the DTT assay for CB materials has been carefully evaluated. It was found that the dispersion degree of CB particles in water has a great influence on the DTT decay rate of CB materials. For CB particles (special black 4A (SB4A) and Printex U) and single-walled carbon nanotube tube (SWCNT), the DTT decay rate after sonication for 10 min became 4.2, 4.6 and 1.7 times higher than that without sonication. The rate continued to grow as a function of ultrasound time up to 30 min of sonication. Although the concentration of soluble transition metals and surface oxygen-containing species such as carbonyls increased slightly with sonication, they had no significant effects on the measured DTT activity, while the increase in the dispersion degree of aggregates was found to play a vital role in the observed enhancement of the DTT decay rates for different CB materials. Based on our results, 30 min of sonication is recommended for sample dispersion when measuring the DTT decay rate of CB materials.
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Affiliation(s)
- Haotian Jiang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yun Xie
- University of Chinese Academy of Sciences, Beijing 100049, China; Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Yanli Ge
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Hong He
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China; Center for Excellence in Urban Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Yongchun Liu
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; Aerosol and Haze Laboratory, Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
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24
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Jiang H, Liu Y, Xie Y, Liu J, Chen T, Ma Q, He H. Oxidation Potential Reduction of Carbon Nanomaterials during Atmospheric-Relevant Aging: Role of Surface Coating. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:10454-10461. [PMID: 31403290 DOI: 10.1021/acs.est.9b02062] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Carbon nanomaterials from various sources are the important component of PM2.5 and have many adverse effects on human health. They are prone to interact with other pollutants and subsequently age, defined here as changes in chemical properties. In this work, we investigated the aging process of various carbon nanoparticle samples such as Special Black 4A, Printex U, single-walled carbon nanotubes, and hexane flame soot by ambient air and studied the evolution of their oxidation potential. We found that coatings of inorganic and organic species dominated the aging process of carbonaceous particles by ambient air. The amounts of disordered carbon and C-H functional groups of aged carbonaceous particles decreased during the aging process; meanwhile, the contents of sulfate and nitrate showed significant increases. In addition, the oxidation potential measured by the dithiothreitol assay remarkably declined as a function of aging time with ambient air evidently because of heterogeneous reactions between SO2 and NO2, as well as the coating with organic vapors. This work is important for understanding the oxidation potential changes of carbonaceous particles during atmospheric transport.
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Affiliation(s)
- Haotian Jiang
- University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Yongchun Liu
- Aerosol and Haze Laboratory, Advanced Innovation Center for Soft Matter Science and Engineering , Beijing University of Chemical Technology , Beijing 100029 , China
| | - Yun Xie
- University of Chinese Academy of Sciences , Beijing 100049 , China
| | | | - Tianzeng Chen
- University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Qingxin Ma
- University of Chinese Academy of Sciences , Beijing 100049 , China
- Center for Excellence in Urban Atmospheric Environment, Institute of Urban Environment , Chinese Academy of Sciences , Xiamen 361021 , China
| | - Hong He
- University of Chinese Academy of Sciences , Beijing 100049 , China
- Center for Excellence in Urban Atmospheric Environment, Institute of Urban Environment , Chinese Academy of Sciences , Xiamen 361021 , China
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25
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Amine cured double Schiff base epoxy as efficient anticorrosive coating materials for protection of mild steel in 3.5% NaCl medium. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.01.066] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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26
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Hernández-Rojas J, Calvo F. Coarse-grained modeling of the nucleation of polycyclic aromatic hydrocarbons into soot precursors. Phys Chem Chem Phys 2019; 21:5123-5132. [PMID: 30766988 DOI: 10.1039/c8cp07724j] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The aggregation and physical growth of polycyclic aromatic hydrocarbon (PAH) molecules was simulated using a coarse-grained (CG) approach based on the Paramonov-Yaliraki (PY) potential and a stochastic Monte Carlo framework, following earlier efforts in which the structure [Phys. Chem. Chem. Phys., 2016, 18, 13736] and equilibrium thermodynamics [Phys. Chem. Chem. Phys., 2017, 19, 1884] were investigated and critically compared to the predictions of all-atom models. Homomolecular and heteromolecular assemblies of pyrene, coronene, and circumcoronene were considered at various temperatures and compositions, and the distributions of aggregation products were characterized. Under the simulated conditions, and in agreement with earlier studies, the clusters are rather small and, in the case of pyrene-rich systems, only formed below 1000 K. The clusters obtained by spontaneous aggregation of isolated molecules are statistically analysed. For the selected sizes of tetramers and octamers, broad distributions of isomers are obtained with a clear entropic stabilization. In heteronuclear assemblies, our results suggest a minor spontaneous segregation towards pure and equi concentrations at variance with purely statistical expectations.
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Affiliation(s)
- J Hernández-Rojas
- Departamento de Física and IUdEA, Universidad de La Laguna, 38205, La Laguna, Tenerife, Spain.
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27
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Shalini Devi K, Jain A, Huang ST, Kumar AS. Metal and heteroatoms-free carbon soot obtained from atmospheric combustion of naphthalene for sensitive dissolved oxygen reduction reaction and sensing in neutral media. Electrochim Acta 2019. [DOI: 10.1016/j.electacta.2018.11.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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28
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Adamson BD, Skeen SA, Ahmed M, Hansen N. Detection of Aliphatically Bridged Multi-Core Polycyclic Aromatic Hydrocarbons in Sooting Flames with Atmospheric-Sampling High-Resolution Tandem Mass Spectrometry. J Phys Chem A 2018; 122:9338-9349. [PMID: 30415549 DOI: 10.1021/acs.jpca.8b08947] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This paper provides experimental evidence for the chemical structures of aliphatically substituted and bridged polycyclic aromatic hydrocarbon (PAH) species in gas-physe combustion environments. The identification of these single- and multicore aromatic species, which have been hypothesized to be important in PAH growth and soot nucleation, was made possible through a combination of sampling gaseous constituents from an atmospheric pressure inverse coflow diffusion flame of ethylene and high-resolution tandem mass spectrometry (MS-MS). In these experiments, the flame-sampled components were ionized using a continuous VUV lamp at 10.0 eV and the ions were subsequently fragmented through collisions with Ar atoms in a collision-induced dissociation (CID) process. The resulting fragment ions, which were separated using a reflectron time-of-flight mass spectrometer, were used to extract structural information about the sampled aromatic compounds. The high-resolution mass spectra revealed the presence of alkylated single-core aromatic compounds and the fragment ions that were observed correspond to the loss of saturated and unsaturated units containing up to a total of 6 carbon atoms. Furthermore, the aromatic structures that form the foundational building blocks of the larger PAHs were identified to be smaller single-ring and pericondensed aromatic species with repetitive structural features. For demonstrative purposes, details are provided for the CID of molecular ions at masses 202 and 434. Insights into the role of the aliphatically substituted and bridged aromatics in the reaction network of PAH growth chemistry were obtained from spatially resolved measurements of the flame. The experimental results are consistent with a growth mechanism in which alkylated aromatics are oxidized to form pericondensed ring structures or react and recombine with other aromatics to form larger, potentially three-dimensional, aliphatically bridged multicore aromatic hydrocarbons.
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Affiliation(s)
- B D Adamson
- Combustion Research Facility , Sandia National Laboratories , Livermore , California 94551 , United States
| | - S A Skeen
- Combustion Research Facility , Sandia National Laboratories , Livermore , California 94551 , United States
| | - M Ahmed
- Chemical Sciences Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
| | - N Hansen
- Combustion Research Facility , Sandia National Laboratories , Livermore , California 94551 , United States
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29
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Tóth Á, Hoffer A, Pósfai M, Ajtai T, Kónya Z, Blazsó M, Czégény Z, Kiss G, Bozóki Z, Gelencsér A. Chemical characterization of laboratory-generated tar ball particles. ATMOSPHERIC CHEMISTRY AND PHYSICS 2018. [DOI: 10.5194/acp-18-10407-2018] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Abstract. The chemical properties of laboratory-generated tar ball (Lab-TB) particles
produced from dry distillate (wood tars) of three different wood species in
the laboratory were investigated by analytical techniques that had never been
used before for their characterization. The elemental compositions of
laboratory-generated tar balls (Lab-TBs) from three tree species were very
similar to one another and to those characteristic of atmospheric tar balls
(TBs) collected from the savanna fire during the SAFARI 2000 sampling
campaign. The O ∕ C and H ∕ C molar ratios of the generated Lab-TBs
were at the upper limit characteristic of soot particles. The Fourier
transform infrared spectroscopy (FT-IR) spectra of the generated Lab-TBs were
very similar to one another as well and also showed some similarity with
those of atmospheric humic-like substances (HULIS). The FT-IR measurements
indicated that Lab-TBs have a higher proportion of aromatic structure than
HULIS and the oxygen atoms of Lab-TBs are mainly found in hydroxyl and keto
functional groups. Whereas Raman activity was detected in the starting
materials of the Lab-TBs (wood tars) in the range of 1000–1800 cm−1,
the Raman spectra of TBs were dominated by two pronounced bands with
intensity maxima near 1580 (G band) and 1350 cm−1 (D band), indicating
the presence of sp2-hybridized carbon structures and disorder in them,
respectively. In the Py-GC-MS chromatograms of the Lab-TBs mostly aromatic
compounds (aromatic hydrocarbons, oxygenated aromatics and heterocyclic
aromatics) were identified in accordance with the results of Raman and FT-IR
spectroscopy. According to organic carbon ∕ elemental carbon
(OC ∕ EC) analysis using EUSAAR_2 thermal protocol, 22 % of the
total carbon content of Lab-TBs was identified as EC, contrary to
expectations based on the current understanding that negligible if any EC is
present in this sub-fraction of the brown carbon family. Our results suggest
that spherical atmospheric TBs with high C ∕ O molar ratios are closer to
BC in many of their properties than to weakly absorbing HULIS.
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Abstract
Soot, which consists of organic carbon (OC) and elemental carbon (EC), is a significant component of the total aerosol mass in the atmosphere. Photochemical oxidation is an important aging pathway for soot. It is commonly believed that OC is photoactive but EC, albeit its strong light absorption, is photochemically inert. Here, by taking advantage of the different light absorption properties of OC and EC, we provide direct experimental evidence that EC also plays an important role in the photochemical aging of soot by initiating the oxidation of OC, even under red light irradiation. We show that nascent soot, in addition to undergoing photochemical oxidation under blue light with a wavelength of 440 nm, undergoes similar oxidation under red light irradiation of λ = 648 nm (L648). However, separated OC (extracted from soot by n-hexane) and EC exhibit little reactivity under L648 These observations indicate that EC plays a pivotal role in photoaging of soot by adsorbing light to initiate the oxidation of OC. Comparison of in situ IR spectra and photoelectrochemical behaviors suggests that EC-initiated photooxidation of OC proceeds through an electron transfer pathway, which is distinct from the photoaging induced by light absorption of OC. Since the absorption spectra of EC have a much larger overlap with the solar spectra than those of OC, our results provide insight into the chemical mechanism leading to rapid soot aging by organic species observed from atmospheric field measurements.
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Affiliation(s)
- Guangzhi He
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, People’s Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
| | - Jinzhu Ma
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, People’s Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, People’s Republic of China
| | - Hong He
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, People’s Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, People’s Republic of China
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32
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Vlasova M, Parra Parra A, Márquez Aguilar PA, Trujillo Estrada A, González Molina V, Kakazey M, Tomila T, Gómez-Vidales V. Closed cycle of recycling of waste activated sludge. WASTE MANAGEMENT (NEW YORK, N.Y.) 2018; 71:320-333. [PMID: 29113837 DOI: 10.1016/j.wasman.2017.10.051] [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: 03/06/2017] [Revised: 10/24/2017] [Accepted: 10/31/2017] [Indexed: 06/07/2023]
Abstract
The recycling of waste activated sludge (WAS) formed in the process of biological purification of sewage is an urgent ecological problem. In the present work, two ways of recycling of WAS containing from 8 to 30% free water, namely, the synthesis of a carbon-containing component and synthesis of porous building ceramics (bricks) with the use of WAS and waste carbonizate, have been considered. For the preparation of a carbon adsorbent, the carbonization of WAS has been carried out in an argon atmosphere. For the synthesis of ceramics, clay-cullet-tezontle-WAS mixtures with different contents of the components have been used. Sintering has been performed in air. It has been established that, in treatment of WAS at 600 °C for 30 min, better adsorption properties are obtained due to the presence of free carbon bonds. The efficiency of water purification from dyes (methylene blue) depends on the standard conditions: the methylene blue concentration, cabonizate-to-solution ratio, and exposure time of the carbonizate in solution. The use of wet WAS makes it possible to exclude the addition of water from the traditional scheme of preparation of a plastic semiproduct, i.e., realize a water-saving technology. The introduction of low-melting cullet, basalt, and WAS powders into red clay makes enables us to reduce substantially the sintering time of porous bricks (down to 8 h) and vary their strength properties.
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Affiliation(s)
- Marina Vlasova
- Center of Investigation in Engineering and Applied Sciences of the Autonomous University of the State of Morelos (CIICAp-UAEMor), Av. Universidad, 1001 Cuernavaca, Mexico.
| | - Abigail Parra Parra
- Center of Investigation in Engineering and Applied Sciences of the Autonomous University of the State of Morelos (CIICAp-UAEMor), Av. Universidad, 1001 Cuernavaca, Mexico
| | - Pedro Antonio Márquez Aguilar
- Center of Investigation in Engineering and Applied Sciences of the Autonomous University of the State of Morelos (CIICAp-UAEMor), Av. Universidad, 1001 Cuernavaca, Mexico
| | - Ariadna Trujillo Estrada
- Center of Investigation in Engineering and Applied Sciences of the Autonomous University of the State of Morelos (CIICAp-UAEMor), Av. Universidad, 1001 Cuernavaca, Mexico
| | - Veronica González Molina
- Center of Investigation in Engineering and Applied Sciences of the Autonomous University of the State of Morelos (CIICAp-UAEMor), Av. Universidad, 1001 Cuernavaca, Mexico
| | - Mykola Kakazey
- Center of Investigation in Engineering and Applied Sciences of the Autonomous University of the State of Morelos (CIICAp-UAEMor), Av. Universidad, 1001 Cuernavaca, Mexico
| | - Tamara Tomila
- Institute for Problems of Materials Science, National Academy of Sciences of Ukraine,3, Krzhyzhanovsky St., Kiev 252680, Ukraine
| | - Virginia Gómez-Vidales
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior C.U., 04510 Cd. México, Mexico
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33
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Zhang M, Tan X, Zhang T, Han Z, Jiang H. The deactivation of a ZnO doped ZrO2–SiO2catalyst in the conversion of ethanol/acetaldehyde to 1,3-butadiene. RSC Adv 2018; 8:34069-34077. [PMID: 35548838 PMCID: PMC9086731 DOI: 10.1039/c8ra06757k] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2018] [Accepted: 09/27/2018] [Indexed: 12/31/2022] Open
Abstract
A deactivation study on the ethanol/acetaldehyde conversion to 1,3-butadiene over a ZnO promoted ZrO2–SiO2 catalyst prepared by a sol–gel method was performed. The samples were characterized by N2 adsorption–desorption isotherms, scanning electron microscopy (SEM), NH3 temperature programmed desorption (NH3-TPD), X-ray powder diffraction characterization (XRD), thermogravimetric analyses (TGA), Fourier transform infrared resonance (FT-IR), 13C magic-angle spinning nuclear magnetic resonance (13C NMR) and X-ray photoelectron spectroscopy (XPS). The pore structure characteristics and surface acidity of Zn0.5–Zr–Si catalysts were largely decreased with time-on-stream and no crystal structure was formed in the used catalyst, indicating that the deactivation was caused by carbon deposition. Two main types of carbon deposition were formed, namely low-temperature carbon deposition with the oxidation temperature of around 400 °C and high-temperature carbon deposition with the oxidation temperature of 526 °C. The carbon species were mainly composed of graphitized carbon, amorphous carbon, carbon in C–O bonds and carbonyls. The deactivated catalyst could be regenerated by a simple oxidation process in air. Adding a certain amount of water into the feed had a positive effect on reducing the carbon deposition. Deactivation study on the ethanol/acetaldehyde conversion to 1,3-butadiene over a ZnO–ZrO2–SiO2 catalyst.![]()
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Affiliation(s)
- Minhua Zhang
- Key Laboratory for Green Chemical Technology of Ministry of Education
- R&D Center for Petrochemical Technology
- Tianjin University
- Tianjin 300072
- China
| | - Xuechao Tan
- Key Laboratory for Green Chemical Technology of Ministry of Education
- R&D Center for Petrochemical Technology
- Tianjin University
- Tianjin 300072
- China
| | - Tong Zhang
- Key Laboratory for Green Chemical Technology of Ministry of Education
- R&D Center for Petrochemical Technology
- Tianjin University
- Tianjin 300072
- China
| | - Zheng Han
- Key Laboratory for Green Chemical Technology of Ministry of Education
- R&D Center for Petrochemical Technology
- Tianjin University
- Tianjin 300072
- China
| | - Haoxi Jiang
- Key Laboratory for Green Chemical Technology of Ministry of Education
- R&D Center for Petrochemical Technology
- Tianjin University
- Tianjin 300072
- China
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34
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Han C, Liu Y, He H. Heterogeneous reaction of NO 2 with soot at different relative humidity. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:21248-21255. [PMID: 28735474 DOI: 10.1007/s11356-017-9766-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 07/12/2017] [Indexed: 06/07/2023]
Abstract
The influences of relative humidity (RH) on the heterogeneous reaction of NO2 with soot were investigated by a coated wall flow tube reactor at ambient pressure. The initial uptake coefficient (γ initial) of NO2 showed a significant decrease with increasing RH from 7 to 70%. The γ initial on "fuel-rich" and "fuel-lean" soot at RH = 7% was (2.59 ± 0.20) × 10-5 and (5.92 ± 0.34) × 10-6, respectively, and it decreased to (5.49 ± 0.83) × 10-6 and (7.16 ± 0.73) × 10-7 at RH = 70%, respectively. Nevertheless, the HONO yields were almost independent of RH, with average values of (72 ± 3)% for the fuel-rich soot and (60 ± 2)% for the fuel-lean soot. The Langmuir-Hinshelwood mechanism was used to demonstrate the negative role of RH in the heterogeneous uptake of NO2 on soot. The species containing nitrogen formed on soot can undergo hydrolysis to produce carboxylic species or alcohols at high RH, accompanied by the release of little gas-phase HONO and NO.
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Affiliation(s)
- Chong Han
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
- School of Metallurgy, Northeastern University, Shenyang, 110819, China
| | - Yongchun Liu
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
- Center for Excellence in Urban Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China
| | - Hong He
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
- Center for Excellence in Urban Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China.
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35
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Migahed MA, Abdul-Rahiem AM, Zaki EG. Inhibition of Acid Corrosion of Carbon Steel Using Amine Surfactants Based on Cellulose. ACTA ACUST UNITED AC 2017. [DOI: 10.1007/s40735-017-0104-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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36
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Niranjan R, Thakur AK. The Toxicological Mechanisms of Environmental Soot (Black Carbon) and Carbon Black: Focus on Oxidative Stress and Inflammatory Pathways. Front Immunol 2017; 8:763. [PMID: 28713383 PMCID: PMC5492873 DOI: 10.3389/fimmu.2017.00763] [Citation(s) in RCA: 125] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 06/16/2017] [Indexed: 12/29/2022] Open
Abstract
The environmental soot and carbon blacks (CBs) cause many diseases in humans, but their underlying mechanisms of toxicity are still poorly understood. Both are formed after the incomplete combustion of hydrocarbons but differ in their constituents and percent carbon contents. For the first time, “Sir Percival Pott” described soot as a carcinogen, which was subsequently confirmed by many others. The existing data suggest three main types of diseases due to soot and CB exposures: cancer, respiratory diseases, and cardiovascular dysfunctions. Experimental models revealed the involvement of oxidative stress, DNA methylation, formation of DNA adducts, and Aryl hydrocarbon receptor activation as the key mechanisms of soot- and CB-induced cancers. Metals including Si, Fe, Mn, Ti, and Co in soot also contribute in the reactive oxygen species (ROS)-mediated DNA damage. Mechanistically, ROS-induced DNA damage is further enhanced by eosinophils and neutrophils via halide (Cl− and Br−) dependent DNA adducts formation. The activation of pulmonary dendritic cells, T helper type 2 cells, and mast cells is crucial mediators in the pathology of soot- or CB-induced respiratory disease. Polyunsaturated fatty acids (PUFAs) were also found to modulate T cells functions in respiratory diseases. Particularly, telomerase reverse transcriptase was found to play the critical role in soot- and CB-induced cardiovascular dysfunctions. In this review, we propose integrated mechanisms of soot- and CB-induced toxicity emphasizing the role of inflammatory mediators and oxidative stress. We also suggest use of antioxidants and PUFAs as protective strategies against soot- and CB-induced disorders.
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Affiliation(s)
- Rituraj Niranjan
- Department of Biological Sciences and Bioengineering (BSBE), Indian Institute of Technology Kanpur, Kanpur, India
| | - Ashwani Kumar Thakur
- Department of Biological Sciences and Bioengineering (BSBE), Indian Institute of Technology Kanpur, Kanpur, India
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37
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Tapia A, Salgado MS, Martín MP, Rodríguez-Fernández J, Rossi MJ, Cabañas B. Chemical characterization of diesel and hydrotreated vegetable oil (HVO) soot after reactive gas probing using diffuse reflectance FTIR spectroscopy (DRIFTS). ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:7534-7543. [PMID: 28116624 DOI: 10.1007/s11356-017-8436-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 01/09/2017] [Indexed: 06/06/2023]
Abstract
A chemical characterization of diesel and hydrotreated vegetable oil (HVO) soot has been developed using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) before and after the reaction with different probe gases. Samples were generated under combustion conditions corresponding to an urban operation mode of a diesel engine and were reacted with probe gas-phase molecules in a Knudsen flow reactor. Specifically, NH2OH, O3 and NO2 were used as reactants (probes) and selected according to their reactivities towards specific functional groups on the sample surface. Samples of previously ground soot were diluted with KBr and were introduced in a DRIFTS accessory. A comparison between unreacted and reacted soot samples was made in order to establish chemical changes on the soot surface upon reaction. It was concluded that the interface of diesel and HVO soot before reaction mainly consists polycyclic aromatic hydrocarbons, nitro and carbonyl compounds, as well as ether functionalities. The main difference between both soot samples was observed in the band of the C=O groups that in diesel soot was observed at 1719 cm-1 but not in HVO soot. After reaction with probe gases, it was found that nitro compounds remain on the soot surface, that the degree of unsaturation decreases for reacted samples, and that new spectral bands such as hydroxyl groups are observed.
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Affiliation(s)
- A Tapia
- Departamento de Química Física, Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla La Mancha, Avda. Camilo José Cela s/n, 13071, Ciudad Real, Spain
| | - M S Salgado
- Departamento de Química Física, Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla La Mancha, Avda. Camilo José Cela s/n, 13071, Ciudad Real, Spain.
| | - M P Martín
- Departamento de Química Física, Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla La Mancha, Avda. Camilo José Cela s/n, 13071, Ciudad Real, Spain
| | - J Rodríguez-Fernández
- Grupo de Combustibles y Motores, Escuela Técnica Superior de Ingenieros Industriales, Universidad de Castilla La Mancha, Avda. Camilo José Cela 10, 13071, Ciudad Real, Spain
| | - M J Rossi
- Labor für Atmosphärenchemie (LAC), Paul Scherrer Institute (PSI), OBBA006, 5232, Villigen PSI, Switzerland
| | - B Cabañas
- Departamento de Química Física, Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla La Mancha, Avda. Camilo José Cela s/n, 13071, Ciudad Real, Spain
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38
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Hu C, Li W, Lin Q, Zheng X, Pan H, Huang Q. Impact of ferrocene on the nanostructure and functional groups of soot in a propane/oxygen diffusion flame. RSC Adv 2017. [DOI: 10.1039/c6ra26096a] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Ferrocene influences soot oxidation activity by changing its nanostructure and functional groups on the surface. Reactions between oxygen and ferrocene reduce the oxygen-containing functional groups on the soot.
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Affiliation(s)
- Chao Hu
- Department of Thermal Science and Energy Engineering
- University of Science and Technology of China
- Hefei 230026
- People's Republic of China
| | - Wenzhi Li
- Department of Thermal Science and Energy Engineering
- University of Science and Technology of China
- Hefei 230026
- People's Republic of China
| | - Qizhao Lin
- Department of Thermal Science and Energy Engineering
- University of Science and Technology of China
- Hefei 230026
- People's Republic of China
| | - Xusheng Zheng
- National Synchrotron Radiation Laboratory
- University of Science and Technology of China
- Hefei 230026
- People's Republic of China
| | - Haibin Pan
- National Synchrotron Radiation Laboratory
- University of Science and Technology of China
- Hefei 230026
- People's Republic of China
| | - Qifu Huang
- Department of Thermal Science and Energy Engineering
- University of Science and Technology of China
- Hefei 230026
- People's Republic of China
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39
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Zeng X, Liu S, Shi Z, Liu G, Xu B. Synthesis of α-Fluoroketones by Insertion of HF into a Gold Carbene. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201603914] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Xiaojun Zeng
- College of Chemistry, Chemical Engineering and Biotechnology; Donghua University; 2999 North Renmin Lu Shanghai 201620 China
| | - Shiwen Liu
- College of Chemistry, Chemical Engineering and Biotechnology; Donghua University; 2999 North Renmin Lu Shanghai 201620 China
| | - Zhenyu Shi
- College of Chemistry, Chemical Engineering and Biotechnology; Donghua University; 2999 North Renmin Lu Shanghai 201620 China
| | - Guangchang Liu
- College of Chemistry, Chemical Engineering and Biotechnology; Donghua University; 2999 North Renmin Lu Shanghai 201620 China
| | - Bo Xu
- College of Chemistry, Chemical Engineering and Biotechnology; Donghua University; 2999 North Renmin Lu Shanghai 201620 China
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40
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Zeng X, Liu S, Shi Z, Liu G, Xu B. Synthesis of α-Fluoroketones by Insertion of HF into a Gold Carbene. Angew Chem Int Ed Engl 2016; 55:10032-6. [DOI: 10.1002/anie.201603914] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 06/12/2016] [Indexed: 11/11/2022]
Affiliation(s)
- Xiaojun Zeng
- College of Chemistry, Chemical Engineering and Biotechnology; Donghua University; 2999 North Renmin Lu Shanghai 201620 China
| | - Shiwen Liu
- College of Chemistry, Chemical Engineering and Biotechnology; Donghua University; 2999 North Renmin Lu Shanghai 201620 China
| | - Zhenyu Shi
- College of Chemistry, Chemical Engineering and Biotechnology; Donghua University; 2999 North Renmin Lu Shanghai 201620 China
| | - Guangchang Liu
- College of Chemistry, Chemical Engineering and Biotechnology; Donghua University; 2999 North Renmin Lu Shanghai 201620 China
| | - Bo Xu
- College of Chemistry, Chemical Engineering and Biotechnology; Donghua University; 2999 North Renmin Lu Shanghai 201620 China
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41
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Formation and emission of large furans and oxygenated hydrocarbons from flames. Proc Natl Acad Sci U S A 2016; 113:8374-9. [PMID: 27410045 DOI: 10.1073/pnas.1604772113] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Many oxygenated hydrocarbon species formed during combustion, such as furans, are highly toxic and detrimental to human health and the environment. These species may also increase the hygroscopicity of soot and strongly influence the effects of soot on regional and global climate. However, large furans and associated oxygenated species have not previously been observed in flames, and their formation mechanism and interplay with polycyclic aromatic hydrocarbons (PAHs) are poorly understood. We report on a synergistic computational and experimental effort that elucidates the formation of oxygen-embedded compounds, such as furans and other oxygenated hydrocarbons, during the combustion of hydrocarbon fuels. We used ab initio and probabilistic computational techniques to identify low-barrier reaction mechanisms for the formation of large furans and other oxygenated hydrocarbons. We used vacuum-UV photoionization aerosol mass spectrometry and X-ray photoelectron spectroscopy to confirm these predictions. We show that furans are produced in the high-temperature regions of hydrocarbon flames, where they remarkably survive and become the main functional group of oxygenates that incorporate into incipient soot. In controlled flame studies, we discovered ∼100 oxygenated species previously unaccounted for. We found that large alcohols and enols act as precursors to furans, leading to incorporation of oxygen into the carbon skeletons of PAHs. Our results depart dramatically from the crude chemistry of carbon- and oxygen-containing molecules previously considered in hydrocarbon formation and oxidation models and spearhead the emerging understanding of the oxidation chemistry that is critical, for example, to control emissions of toxic and carcinogenic combustion by-products, which also greatly affect global warming.
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42
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Tapia A, Salgado MS, Martín MP, Lapuerta M, Rodríguez-Fernández J, Rossi MJ, Cabañas B. Molecular Characterization of the Gas-Particle Interface of Soot Sampled from a Diesel Engine Using a Titration Method. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:2946-2955. [PMID: 26886850 DOI: 10.1021/acs.est.5b05531] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Surface functional groups of two different types of combustion aerosols, a conventional diesel (EN 590) and a hydrotreated vegetable oil (HVO) soot, have been investigated using heterogeneous chemistry (i.e., gas-particle surface reactions). A commercial sample of amorphous carbon (Printex XE2-B) was analyzed as a reference substrate. A Knudsen flow reactor was used to carry out the experiments under molecular flow conditions. The selected gases for the titration experiments were: N(CH3)3 for the identification of acidic sites, NH2OH for the presence of carbonyl groups, CF3COOH and HCl for basic sites of different strength, and O3 and NO2 for reducing groups. Reactivity with N(CH3)3 indicates a lower density of acidic functionalities for Printex XE2-B in relation to diesel and HVO soot. Results for NH2OH experiments indicates that commercial amorphous carbon exhibits a lower abundance of available carbonyl groups at the interface compared to the results from diesel and HVO soot, the latter being the one with the largest abundance of carbonyl functions. Reactions with acids indicate the presence of weak basic oxides on the particle surface that preferentially interact with the strong acid CF3COOH. Finally, reactions with O3 and NO2 reveal that diesel and especially HVO have a significantly higher reactivity with both oxidizers compared to that of Printex XE2-B because they have more reducing sites by roughly a factor of 10 and 30, respectively. The kinetics of titration reactions have also been investigated.
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Affiliation(s)
- A Tapia
- Departamento de Química Física, Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla La Mancha , Avda. Camilo José Cela s/n, 13071 Ciudad Real, Spain
| | - M S Salgado
- Departamento de Química Física, Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla La Mancha , Avda. Camilo José Cela s/n, 13071 Ciudad Real, Spain
| | - María Pilar Martín
- Departamento de Química Física, Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla La Mancha , Avda. Camilo José Cela s/n, 13071 Ciudad Real, Spain
| | - M Lapuerta
- Grupo de Combustibles y Motores, Escuela Técnica Superior de Ingenieros Industriales, Universidad de Castilla la Mancha , Avda. Camilo José Cela 10, 13071 Ciudad Real, Spain
| | - J Rodríguez-Fernández
- Grupo de Combustibles y Motores, Escuela Técnica Superior de Ingenieros Industriales, Universidad de Castilla la Mancha , Avda. Camilo José Cela 10, 13071 Ciudad Real, Spain
| | - M J Rossi
- Labor für Atmosphärenchemie (LAC), Paul Scherrer Institute (PSI) , OBBA006, CH-5232 Villigen PSI, Switzerland
| | - B Cabañas
- Departamento de Química Física, Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla La Mancha , Avda. Camilo José Cela s/n, 13071 Ciudad Real, Spain
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43
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Omidvarborna H, Kumar A, Kim DS. Variation of diesel soot characteristics by different types and blends of biodiesel in a laboratory combustion chamber. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 544:450-459. [PMID: 26657390 DOI: 10.1016/j.scitotenv.2015.11.076] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 10/25/2015] [Accepted: 11/15/2015] [Indexed: 06/05/2023]
Abstract
Very little information is available on the physical and chemical properties of soot particles produced in the combustion of different types and blends of biodiesel fuels. A variety of feedstock can be used to produce biodiesel, and it is necessary to better understand the effects of feedstock-specific characteristics on soot particle emissions. Characteristics of soot particles, collected from a laboratory combustion chamber, are investigated from the blends of ultra-low sulfur diesel (ULSD) and biodiesel with various proportions. Biodiesel samples were derived from three different feedstocks, soybean methyl ester (SME), tallow oil (TO), and waste cooking oil (WCO). Experimental results showed a significant reduction in soot particle emissions when using biodiesel compared with ULSD. For the pure biodiesel, no soot particles were observed from the combustion regardless of their feedstock origins. The overall morphology of soot particles showed that the average diameter of ULSD soot particles is greater than the average soot particles from the biodiesel blends. Transmission electron microscopy (TEM) images of oxidized soot particles are presented to investigate how the addition of biodiesel fuels may affect structures of soot particles. In addition, inductively coupled plasma mass spectrometry (ICP-MS), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA) were conducted for characterization of soot particles. Unsaturated methyl esters and high oxygen content of biodiesel are thought to be the major factors that help reduce the formation of soot particles in a laboratory combustion chamber.
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Affiliation(s)
- Hamid Omidvarborna
- Department of Civil Engineering, The University of Toledo, Toledo, OH, USA
| | - Ashok Kumar
- Department of Civil Engineering, The University of Toledo, Toledo, OH, USA
| | - Dong-Shik Kim
- Department of Chemical and Environmental Engineering, The University of Toledo, Toledo, OH, USA.
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Han C, Liu Y, He H. The photoenhanced aging process of soot by the heterogeneous ozonization reaction. Phys Chem Chem Phys 2016; 18:24401-7. [DOI: 10.1039/c6cp03938c] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Light can dramatically enhance the heterogeneous aging process of soot by O3, leading to the formation of various oxygen-containing species.
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Affiliation(s)
- Chong Han
- Research Center for Eco-Environmental Sciences
- Chinese Academy of Sciences
- Beijing
- China
- School of Metallurgy
| | - Yongchun Liu
- Research Center for Eco-Environmental Sciences
- Chinese Academy of Sciences
- Beijing
- China
- Center for Excellence in Urban Atmospheric Environment
| | - Hong He
- Research Center for Eco-Environmental Sciences
- Chinese Academy of Sciences
- Beijing
- China
- Center for Excellence in Urban Atmospheric Environment
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45
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He G, He H. DFT studies on the heterogeneous oxidation of SO2 by oxygen functional groups on graphene. Phys Chem Chem Phys 2016; 18:31691-31697. [DOI: 10.1039/c6cp06665h] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Conversion of SO2 to SO3 on oxygen-functionalized graphene under ambient conditions.
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Affiliation(s)
- Guangzhi He
- State Key Joint Laboratory of Environment Simulation and Pollution Control
- Research Center for Eco-Environmental Sciences
- Chinese Academy of Sciences
- Beijing 100085
- China
| | - Hong He
- State Key Joint Laboratory of Environment Simulation and Pollution Control
- Research Center for Eco-Environmental Sciences
- Chinese Academy of Sciences
- Beijing 100085
- China
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46
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Saffaripour M, Chan TW, Liu F, Thomson KA, Smallwood GJ, Kubsh J, Brezny R. Effect of Drive Cycle and Gasoline Particulate Filter on the Size and Morphology of Soot Particles Emitted from a Gasoline-Direct-Injection Vehicle. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:11950-11958. [PMID: 26340691 DOI: 10.1021/acs.est.5b02185] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The size and morphology of particulate matter emitted from a light-duty gasoline-direct-injection (GDI) vehicle, over the FTP-75 and US06 transient drive cycles, have been characterized by transmission-electron-microscope (TEM) image analysis. To investigate the impact of gasoline particulate filters on particulate-matter emission, the results for the stock-GDI vehicle, that is, the vehicle in its original configuration, have been compared to the results for the same vehicle equipped with a catalyzed gasoline particulate filter (GPF). The stock-GDI vehicle emits graphitized fractal-like aggregates over all driving conditions. The mean projected area-equivalent diameter of these aggregates is in the 78.4-88.4 nm range and the mean diameter of primary particles varies between 24.6 and 26.6 nm. Post-GPF particles emitted over the US06 cycle appear to have an amorphous structure, and a large number of nucleation-mode particles, depicted as low-contrast ultrafine droplets, are observed in TEM images. This indicates the emission of a substantial amount of semivolatile material during the US06 cycle, most likely generated by the incomplete combustion of accumulated soot in the GPF during regeneration. The size of primary particles and soot aggregates does not vary significantly by implementing the GPF over the FTP-75 cycle; however, particles emitted by the GPF-equipped vehicle over the US06 cycle are about 20% larger than those emitted by the stock-GDI vehicle. This may be attributed to condensation of large amounts of organic material on soot aggregates. High-contrast spots, most likely solid nonvolatile cores, are observed within many of the nucleation-mode particles emitted over the US06 cycle by the GPF-equipped vehicle. These cores are either generated inside the engine or depict incipient soot particles which are partially carbonized in the exhaust line. The effect of drive cycle and the GPF on the fractal parameters of particles, such as fractal dimension and fractal prefactor, is insignificant.
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Affiliation(s)
| | - Tak W Chan
- Environment Canada, Ottawa, Ontario K1A 0H3, Canada
| | - Fengshan Liu
- National Research Council Canada, Ottawa, Ontario K1A 0R6, Canada
| | - Kevin A Thomson
- National Research Council Canada, Ottawa, Ontario K1A 0R6, Canada
| | | | - Joseph Kubsh
- Manufacturers of Emission Controls Association, Arlington, Virginia 22201, United States
| | - Rasto Brezny
- Manufacturers of Emission Controls Association, Arlington, Virginia 22201, United States
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47
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Saha SK, Dutta A, Ghosh P, Sukul D, Banerjee P. Adsorption and corrosion inhibition effect of Schiff base molecules on the mild steel surface in 1 M HCl medium: a combined experimental and theoretical approach. Phys Chem Chem Phys 2015; 17:5679-90. [PMID: 25623363 DOI: 10.1039/c4cp05614k] [Citation(s) in RCA: 195] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Corrosion inhibition performance of 2-(2-hydroxybenzylideneamino)phenol (L(1)), 2-(5-chloro-2-hydroxybenzylideneamino)phenol (L(2)) and 2-(2-hydroxy-5-nitrobenzylideneamino)phenol (L(3)) on the corrosion behaviour of mild steel surface in a 1 M hydrochloric acid (HCl) solution is investigated by sophisticated analytical methods like potentiodynamic polarization, electrochemical impedance spectroscopy and weight loss measurements. Polarization studies showed that all the compounds are mixed type (cathodic and anodic) inhibitors and the inhibition efficiency (η%) increased with increasing inhibitor concentration. The inhibition actions of these Schiff base molecules are discussed in view of blocking the electrode surface by means of adsorption of the inhibitor molecule obeying the Langmuir adsorption isotherm. Scanning electron microscopy (SEM) studies of the metal surfaces confirmed the existence of an adsorbed film. Density functional theory (DFT) and molecular dynamics (MD) simulation have been used to determine the relationship between molecular configuration and their inhibition efficiencies. The order of inhibition performance obtained from experimental results is successfully verified by DFT and MD simulation.
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Affiliation(s)
- Sourav Kr Saha
- Surface Engineering & Tribology Group, CSIR-Central Mechanical Engineering Research Institute, Mahatma Gandhi Avenue, Durgapur 713209, West Bengal, India.
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48
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Tapia A, Salgado MS, Martín MP, Sánchez-Valdepeñas J, Rossi MJ, Cabañas B. The use of heterogeneous chemistry for the characterization of functional groups at the gas/particle interface of soot from a diesel engine at a particular running condition. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2015; 22:4863-4872. [PMID: 24807246 DOI: 10.1007/s11356-014-2976-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Accepted: 04/23/2014] [Indexed: 06/03/2023]
Abstract
Two gases, O3 and NO2, were selected to probe the surface of a diesel fuel combustion aerosol sample, diesel soot, and amorphous carbon nanoparticles (PRINTEX XE2-B) using heterogeneous (i.e., gas-surface reactions). The gas uptake to saturation of the probes was measured under molecular flow conditions using a Knudsen flow reactor in order to quantify and characterize surface functional groups. Specifically, O3 and NO2 are used for the titration of oxidizable groups. Diesel soot samples interacted with the probe gases to various extents which points to the coexistence of different functional groups on the same aerosol surface such as reduced groups. The carbonaceous particles displayed significant differences: PRINTEX XE2-B amorphous carbon had a significantly lower surface functional group density of both total and strongly reducing groups despite its significantly larger internal surface area, compared to diesel soot. The uptake kinetics of the gas-phase probe molecules (uptake probabilities) were also measured in order to obtain further information on the reactivity of emitted soot aerosols in order to enable the potential prediction of health effects.
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Affiliation(s)
- A Tapia
- Departamento de Química Física Facultad de Ciencias Químicas, Universidad de Castilla La Mancha, Avda Camilo José Cela 10, 13071, Ciudad Real, Spain
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49
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Liu Y, Liggio J, Li SM, Breznan D, Vincent R, Thomson EM, Kumarathasan P, Das D, Abbatt J, Antiñolo M, Russell L. Chemical and toxicological evolution of carbon nanotubes during atmospherically relevant aging processes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:2806-14. [PMID: 25607982 DOI: 10.1021/es505298d] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
The toxicity of carbon nanotubes (CNTs) has received significant attention due to their usage in a wide range of commercial applications. While numerous studies exist on their impacts in water and soil ecosystems, there is a lack of information on the exposure to CNTs from the atmosphere. The transformation of CNTs in the atmosphere, resulting in their functionalization, may significantly alter their toxicity. In the current study, the chemical modification of single wall carbon nanotubes (SWCNTs) via ozone and OH radical oxidation is investigated through studies that simulate a range of expected tropospheric particulate matter (PM) lifetimes, in order to link their chemical evolution to toxicological changes. The results indicate that the oxidation favors carboxylic acid functionalization, but significantly less than other studies performed under nonatmospheric conditions. Despite evidence of functionalization, neither O3 nor OH radical oxidation resulted in a change in redox activity (potentially giving rise to oxidative stress) or in cytotoxic end points. Conversely, both the redox activity and cytotoxicity of SWCNTs significantly decreased when exposed to ambient urban air, likely due to the adsorption of organic carbon vapors. These results suggest that the effect of gas-particle partitioning of organics in the atmosphere on the toxicity of SWCNTs should be investigated further.
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Affiliation(s)
- Yongchun Liu
- Atmospheric Science and Technology Directorate, Science and Technology Branch, Environment Canada , 4905 Dufferin Street, Toronto, Ontario M3H 5T4, Canada
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50
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Mueller L, Jakobi G, Orasche J, Karg E, Sklorz M, Abbaszade G, Weggler B, Jing L, Schnelle-Kreis J, Zimmermann R. Online determination of polycyclic aromatic hydrocarbon formation from a flame soot generator. Anal Bioanal Chem 2015; 407:5911-22. [PMID: 25711989 DOI: 10.1007/s00216-015-8549-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2014] [Revised: 01/20/2015] [Accepted: 02/09/2015] [Indexed: 11/29/2022]
Abstract
In this study, we produced a class of diffusion flame soot particles with varying chemical and physical properties by using the mini-Combustion Aerosol STandard (CAST) and applying varying oxidant gas flow rates under constant propane, quenching, and dilution gas supply. We varied the soot properties by using the following fuel-to-air equivalence ratios (Φ): 1.13, 1.09, 1.04, 1.00, 0.96, and 0.89. Within this Φ range, we observed drastic changes in the physical and chemical properties of the soot. Oxidant-rich flames (Φ < 1) were characterized by larger particle size, lower particle number concentration, higher black carbon (BC) concentration, lower brown carbon BrC.[BC](-1) than fuel-rich flames (Φ > 1). To investigate the polycyclic aromatic hydrocarbons (PAH) formation online, we developed a new method for quantification by using the one (13)C-containing doubly charged PAH ion in a high-resolution time-of-flight aerosol mass spectrometry (HR-ToF-AMS). The time-resolved concentration showed that the larger PAHs prevailed in the fuel-rich flames and diminished in the oxidant-rich flames. By comparison with the offline in situ derivatization-thermal-desorption gas-chromatography time-of-flight mass spectrometry (IDTD-GC-ToF-MS), we found that the concentration by using the HR-ToF-AMS was underestimated, especially for lower mass PAHs (C14-C18) in the fuel-rich flames possibly due to size limitation and degradation of semi-volatile species under high vacuum and desorption temperature in the latter. For oxidant-rich flames, the large PAHs (C20 and C22) were detected in the HR-ToF-AMS while it was not possible in IDTD-GC-ToF-MS due to matrix effect. The PAH formation was discussed based on the combination of our results and with respect to Φ settings.
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Affiliation(s)
- Laarnie Mueller
- Joint Mass Spectrometry Center, Cooperation Group Comprehensive Molecular Analytics, Helmholtz Zentrum Muenchen, Ingolstaedter Landstr. 1, 85764, Neuherberg, Germany
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