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Lan Y, Zhou L, Liu S, Wan R, Wang N, Chen D, Li Y, Jiang Y, Rao Z, Jiang W, Song D, Tan Q, Yang F. Light absorption enhancement of black carbon and its impact factors during winter in a megacity of the Sichuan Basin, China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 918:170374. [PMID: 38307267 DOI: 10.1016/j.scitotenv.2024.170374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2023] [Revised: 01/07/2024] [Accepted: 01/21/2024] [Indexed: 02/04/2024]
Abstract
Carbonaceous aerosols play a vital role in global climate patterns due to their potent light absorption capabilities. However, the light absorption enhancement effect (Eabs) of black carbon (BC) is still subject to great uncertainties due to factors such as the mixing state, coating material, and particle size distribution. In this study, fine particulate matter (PM2.5) samples were collected in Chengdu, a megacity in the Sichuan Basin, during the winter of 2020 and 2021. The chemical components of PM2.5 and the light absorption properties of BC were investigated. The results revealed that secondary inorganic aerosols and carbonaceous aerosols were the dominant components in PM2.5. Additionally, the aerosol filter filtration-dissolution (AFD) treatment could improve the accuracy of measuring elemental carbon (EC) through thermal/optical analysis. During winter in Chengdu, the absorption enhancement values of BC ranged between 1.56 and 2.27, depending on the absorption wavelength and the mixing state of BC and non-BC materials. The presence of internally mixed BC and non-BC materials significantly contributed to Eabs, accounting for an average of 68 % at 405 nm and 100 % at 635 nm. The thickness of the BC coating influenced Eabs, displaying an increasing-then-decreasing trend. This trend was primarily attributed to the hygroscopic growth and dehydration shrinkage of particulate matter. Nitrate, as the major component of BC coating, played a crucial role in the lensing effect and exhibited fast growth during variation in Eabs. By combining the results from PMF, we identified the secondary formation and vehicle emission as the primary contributors to Eabs. Consequently, this study can provide valuable insights into the optical parameters, which are essential for assessing the environmental quality, improving regional atmospheric conditions, and formulating effective air pollution control strategies.
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Affiliation(s)
- Yuting Lan
- College of Architecture and Environment, Sichuan University, Chengdu 610065, China; College of Carbon Neutrality Future Technology, Sichuan University, Chengdu 610065, China; Sichuan University Yibin Park, Yibin Institute of Industrial Technology, Yibin 644600, China
| | - Li Zhou
- College of Architecture and Environment, Sichuan University, Chengdu 610065, China; College of Carbon Neutrality Future Technology, Sichuan University, Chengdu 610065, China; Sichuan University Yibin Park, Yibin Institute of Industrial Technology, Yibin 644600, China.
| | - Song Liu
- College of Architecture and Environment, Sichuan University, Chengdu 610065, China; College of Carbon Neutrality Future Technology, Sichuan University, Chengdu 610065, China; Sichuan University Yibin Park, Yibin Institute of Industrial Technology, Yibin 644600, China
| | - Ruilin Wan
- College of Architecture and Environment, Sichuan University, Chengdu 610065, China; College of Carbon Neutrality Future Technology, Sichuan University, Chengdu 610065, China; Sichuan University Yibin Park, Yibin Institute of Industrial Technology, Yibin 644600, China
| | - Ning Wang
- College of Architecture and Environment, Sichuan University, Chengdu 610065, China; College of Carbon Neutrality Future Technology, Sichuan University, Chengdu 610065, China; Sichuan University Yibin Park, Yibin Institute of Industrial Technology, Yibin 644600, China
| | - Dongyang Chen
- College of Architecture and Environment, Sichuan University, Chengdu 610065, China; College of Carbon Neutrality Future Technology, Sichuan University, Chengdu 610065, China; Sichuan University Yibin Park, Yibin Institute of Industrial Technology, Yibin 644600, China
| | - Yi Li
- College of Architecture and Environment, Sichuan University, Chengdu 610065, China; College of Carbon Neutrality Future Technology, Sichuan University, Chengdu 610065, China; Sichuan University Yibin Park, Yibin Institute of Industrial Technology, Yibin 644600, China
| | - Yan Jiang
- Sichuan Ecological Environment Monitoring Center, Chengdu 610091, China
| | - Zhihan Rao
- College of Architecture and Environment, Sichuan University, Chengdu 610065, China; College of Carbon Neutrality Future Technology, Sichuan University, Chengdu 610065, China; Sichuan University Yibin Park, Yibin Institute of Industrial Technology, Yibin 644600, China; Sichuan Ecological Environment Monitoring Center, Chengdu 610091, China
| | - Wanting Jiang
- Chengdu Academy of Environmental Sciences, Chengdu 610072, China
| | - Danlin Song
- Chengdu Academy of Environmental Sciences, Chengdu 610072, China
| | - Qinwen Tan
- Chengdu Academy of Environmental Sciences, Chengdu 610072, China
| | - Fumo Yang
- College of Architecture and Environment, Sichuan University, Chengdu 610065, China; College of Carbon Neutrality Future Technology, Sichuan University, Chengdu 610065, China; Sichuan University Yibin Park, Yibin Institute of Industrial Technology, Yibin 644600, China
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Liu P, Zhou H, Chun X, Wan Z, Liu T, Sun B. Characteristics and sources of carbonaceous aerosols in a semi-arid city: Quantifying anthropogenic and meteorological impacts. CHEMOSPHERE 2023; 335:139056. [PMID: 37247672 DOI: 10.1016/j.chemosphere.2023.139056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 05/21/2023] [Accepted: 05/26/2023] [Indexed: 05/31/2023]
Abstract
Carbonaceous aerosols have great adverse impacts on air quality, human health, and climate. However, there is a limited understanding of carbonaceous aerosols in semi-arid areas. The correlation between carbonaceous aerosols and control measures is still unclear owing to the insufficient information regarding meteorological contribution. To reveal the complex relationship between control measures and carbonaceous aerosols, offline and online observations of carbonaceous aerosols were conducted from October 8, 2019 to October 7, 2020 in Hohhot, a semi-arid city. The characteristics and sources of carbonaceous aerosols and impacts of anthropogenic emissions and meteorological conditions were studied. The annual mean concentrations (± standard deviation) of fine particulate matter (PM2.5), organic carbon (OC), and elemental carbon (EC) were 42.81 (±40.13), 7.57 (±6.43), and 2.25 (±1.39) μg m-3, respectively. The highest PM2.5 and carbonaceous aerosol concentrations were observed in winter, whereas the lowest was observed in summer. The result indicated that coal combustion for heating had a critical role in air quality degradation in Hohhot. A boost regression tree model was applied to quantify the impacts of anthropogenic emissions and meteorological conditions on carbonaceous aerosols. The results suggested that the anthropogenic contributions of PM2.5, OC, and EC during the COVID-19 lockdown period were 53.0, 15.0, and 2.36 μg m-3, respectively, while the meteorological contributions were 5.38, 2.49, and -0.62 μg m-3, respectively. Secondary formation caused by unfavorable meteorological conditions offset the emission reduction during the COVID-19 lockdown period. Coal combustion (46.4% for OC and 35.4% for EC) and vehicular emissions (32.0% for OC and 50.4% for EC) were the predominant contributors of carbonaceous aerosols. The result indicated that Hohhot must regulate coal use and vehicle emissions to reduce carbonaceous aerosol pollution. This study provides new insights and a comprehensive understanding of the complex relationships between control strategies, meteorological conditions, and air quality.
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Affiliation(s)
- Peng Liu
- College of Geographical Sciences, Inner Mongolia Normal University, Hohhot, 010022, China.
| | - Haijun Zhou
- College of Geographical Sciences, Inner Mongolia Normal University, Hohhot, 010022, China; Provincial Key Laboratory of Mongolian Plateau's Climate System, Inner Mongolia Normal University, Hohhot, 010022, China; Inner Mongolia Repair Engineering Laboratory of Wetland Eco-environment System, Inner Mongolia Normal University, Hohhot, 010022, China.
| | - Xi Chun
- College of Geographical Sciences, Inner Mongolia Normal University, Hohhot, 010022, China; Provincial Key Laboratory of Mongolian Plateau's Climate System, Inner Mongolia Normal University, Hohhot, 010022, China; Inner Mongolia Repair Engineering Laboratory of Wetland Eco-environment System, Inner Mongolia Normal University, Hohhot, 010022, China.
| | - Zhiqiang Wan
- College of Geographical Sciences, Inner Mongolia Normal University, Hohhot, 010022, China; Provincial Key Laboratory of Mongolian Plateau's Climate System, Inner Mongolia Normal University, Hohhot, 010022, China; Inner Mongolia Repair Engineering Laboratory of Wetland Eco-environment System, Inner Mongolia Normal University, Hohhot, 010022, China.
| | - Tao Liu
- Environmental Monitoring Center Station of Inner Mongolia, Hohhot, 010011, China.
| | - Bing Sun
- Hohhot Environmental Monitoring Branch Station of Inner Mongolia, Hohhot, 010030, China.
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Liu S, Luo Q, Feng M, Zhou L, Qiu Y, Li C, Song D, Tan Q, Yang F. Enhanced nitrate contribution to light extinction during haze pollution in Chengdu: Insights based on an improved multiple linear regression model. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 323:121309. [PMID: 36822310 DOI: 10.1016/j.envpol.2023.121309] [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: 10/19/2022] [Revised: 02/14/2023] [Accepted: 02/15/2023] [Indexed: 06/18/2023]
Abstract
In recent years, the annual mean concentration of PM2.5 has decreased in Chengdu, China; however, atmospheric visibility has not improved accordingly. Low-visibility events occurred even when the PM2.5 mass concentrations were below the national ambient air quality secondary standard (daily mean concentration, 75 μg/m3). In this study, the non-linear relationship between PM2.5 and visibility was analyzed under different NO3- mass fractions in PM2.5 based on 2-year field observation data. The results indicated that NO3- formation contributed to particulate pollution events and reduced atmospheric visibility. Multiple linear regression was used to propose a localized reconstruction equation for the light-scattering coefficient. According to the maximum likelihood estimation method and log-transformed residuals, the mass scattering coefficients (MSEs) of organic matter (OM), NH4NO3, and (NH4)2SO4 in Chengdu were 7.42, 3.83, and 3.80, respectively. OM and NH4NO3 contributed to more than 50% of the light-extinction coefficient (bext). NH4NO3 was the main pollutant causing the substantial increase in bext. Chengdu has a high relative humidity (annual mean 70%), and under such conditions, the contribution of NH4NO3 to bext was considerably enhanced through hygroscopic growth and heterogeneous reactions. This study estimated the localized MSEs of OM, NH4NO3, and (NH4)2SO4 in Chengdu and emphasized that effective control measures to reduce nitrate and its precursors could simultaneously ameliorate air quality and visibility in humid regions with poor atmospheric visibility.
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Affiliation(s)
- Song Liu
- College of Architecture and Environment, Sichuan University, Chengdu, 610065, China; Yibin Institute of Industrial Technology, Sichuan University Yibin Park, Yibin, 644000, China
| | - Qiong Luo
- College of Architecture and Environment, Sichuan University, Chengdu, 610065, China; College of Environmental and Chemical Engineering, Chongqing Three Gorges University, Chongqing 404020, China
| | - Miao Feng
- Chengdu Academy of Environmental Sciences, Chengdu, 610072, China
| | - Li Zhou
- College of Architecture and Environment, Sichuan University, Chengdu, 610065, China; Yibin Institute of Industrial Technology, Sichuan University Yibin Park, Yibin, 644000, China; College of Carbon Neutrality Future Technology, Sichuan University, Chengdu, 610065, China.
| | - Yang Qiu
- College of Architecture and Environment, Sichuan University, Chengdu, 610065, China
| | - Chunyuan Li
- College of Architecture and Environment, Sichuan University, Chengdu, 610065, China; Yibin Institute of Industrial Technology, Sichuan University Yibin Park, Yibin, 644000, China
| | - Danlin Song
- Chengdu Academy of Environmental Sciences, Chengdu, 610072, China
| | - Qinwen Tan
- Chengdu Academy of Environmental Sciences, Chengdu, 610072, China
| | - Fumo Yang
- College of Architecture and Environment, Sichuan University, Chengdu, 610065, China; Yibin Institute of Industrial Technology, Sichuan University Yibin Park, Yibin, 644000, China; College of Environmental and Chemical Engineering, Chongqing Three Gorges University, Chongqing 404020, China; College of Carbon Neutrality Future Technology, Sichuan University, Chengdu, 610065, China
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Mo Y, Shi G, Jiang X, Luo T, Zhou S, Yang F. Transport Channels of Air Pollutants Affecting the Southern Sichuan Basin Based on Gridded Dispersion Simulation. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:5396. [PMID: 37048010 PMCID: PMC10094188 DOI: 10.3390/ijerph20075396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/14/2023] [Accepted: 03/29/2023] [Indexed: 06/19/2023]
Abstract
Air pollutants suspended in the atmosphere have a large impact on air quality, climate, and human health. As one of the important populated and industrialized regions in China, the Sichuan Basin (SCB) has confronted severe air pollution in recent years. Previous studies have shown that regional transport played a significant role in the formation of regional pollution in the SCB, particularly in the southern basin. Using Yibin and Zigong as representative receptor cities, we further identified the transport channels affecting the southern basin by conducting gridded dispersion simulations. A total of seven channels were identified, including three for cyclonic transport, three through the mountainous areas between the Longquan Mountain and the Huaying Mountain, and one along the Yangtze River. Varying seasonal distributions of their occurrence frequencies were observed. Furthermore, observational evidence for several universal channels was presented during a typical transport case. The transport pathways identified in this study can guide the planning of regional distribution of emission sources and the measures for regional joint prevention and control of air pollution.
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Affiliation(s)
- Yinpeng Mo
- Department of Environmental Science and Engineering, Sichuan University, Chengdu 610065, China
- College of Carbon Neutrality Future Technology, Sichuan University, Chengdu 610065, China
| | - Guangming Shi
- College of Carbon Neutrality Future Technology, Sichuan University, Chengdu 610065, China
- National Engineering Research Center on Flue Gas Desulfurization, Chengdu 610065, China
| | - Xia Jiang
- Yibin Eco-environment Monitoring Station, Yibin 644002, China
| | - Tianzhi Luo
- Yibin Eco-environment Monitoring Station, Yibin 644002, China
| | - Shuhua Zhou
- Yibin Eco-environment Monitoring Station, Yibin 644002, China
| | - Fumo Yang
- College of Carbon Neutrality Future Technology, Sichuan University, Chengdu 610065, China
- National Engineering Research Center on Flue Gas Desulfurization, Chengdu 610065, China
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Liu X, Zhu R, Jin B, Zu L, Wang Y, Wei Y, Zhang R. Emission characteristics and light absorption apportionment of carbonaceous aerosols: A tunnel test conducted in an urban with fully enclosed use of E10 petrol. ENVIRONMENTAL RESEARCH 2023; 216:114701. [PMID: 36332670 DOI: 10.1016/j.envres.2022.114701] [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: 09/26/2022] [Revised: 10/26/2022] [Accepted: 10/28/2022] [Indexed: 06/16/2023]
Abstract
To reduce the heavy dependence on petroleum, bioethanol has been increasingly employed as an alternative and sustainable transportation fuel. However, the characteristics of black carbon (BC) emissions from E10 petrol vehicles (i.e., ethanol-gasoline containing 10% ethanol) are still unclear, especially under real driving conditions. Here, a tunnel test was conducted during a cold winter. This tunnel was characterized by heavy traffic comprising more than 98% E10-fueled gasoline vehicles (GVs). Real-time BC concentrations, traffic parameters and meteorological conditions were recorded during the sampling campaign. The average BC concentration inside the tunnel (10.94 ± 5.02 μg m-3) was almost twice the background concentration. Based on aethalometer AE33 in situ measurements and the minimum R-squared (MRS) method, real-time aerosol light absorption was apportioned. The light absorption proportions of BC, primary brown carbon (BrC1) and secondary brown carbon (BrC2) were 79.86%, 2.78% and 17.36%, respectively, at 370 nm. The BC emission factor (EFBC) of the E10-fueled vehicles was 1.09 ± 0.49 mg km-1·veh-1 and 15.24 ± 6.85 mg·(kg fuel)-1, lower than those of traditional gasoline fueled vehicles in previous studies. This study can support the compilation of vehicular BC emission inventories, provide recommendations for biofuel policies and contribute to comprehensively understanding the climatic impact of E10 petrol.
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Affiliation(s)
- Xinhui Liu
- School of Ecology and Environment, Zhengzhou University, Zhengzhou, 450001, China; School of Environment, Beijing Normal University, Beijing, 100875, China.
| | - Rencheng Zhu
- School of Ecology and Environment, Zhengzhou University, Zhengzhou, 450001, China; Research Centre of Engineering and Technology for Synergetic Control of Environmental Pollution and Carbon Emissions of Henan Province, Zhengzhou University, Zhengzhou, 450001, China.
| | - Boqiang Jin
- School of Ecology and Environment, Zhengzhou University, Zhengzhou, 450001, China.
| | - Lei Zu
- State Environmental Protection Key Laboratory of Vehicle Emission Control and Simulation, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
| | - Yunjing Wang
- State Environmental Protection Key Laboratory of Vehicle Emission Control and Simulation, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
| | - Yangbing Wei
- School of Ecology and Environment, Zhengzhou University, Zhengzhou, 450001, China.
| | - Ruiqin Zhang
- School of Ecology and Environment, Zhengzhou University, Zhengzhou, 450001, China.
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