The impacts of the meteorological condition and emissions reduction on the aerosol concentration over the Beijing-Tianjin-Hebei(BTH) region during the COVID-19 lockdown were analyzed by conducting three numerical expe...The impacts of the meteorological condition and emissions reduction on the aerosol concentration over the Beijing-Tianjin-Hebei(BTH) region during the COVID-19 lockdown were analyzed by conducting three numerical experiments,including one with the meteorological field in 2019 and MEIC-2019(2019 monthly Multi-resolution Emissions Inventory for China),one with the meteorological field in 2020 and MEIC-2019,and one with the meteorological field in 2020 and MEIC-2020,via a WRF-Chem model.The numerical experiments were performed from 3 to 16 February in 2019 and in 2020,during which a severe fog-haze event(3-16 February 2020) occurred in the BTH region,with a simulated maximum daily PM2.5 of 245μg m-3 in Tangshan and 175μg m-3 in Beijing.The results indicate that the daily PM2.5 decreased by 5-150μg m-3 due to the emissions reduction and increased by 10-175 μg m-3 due to the meteorological condition in Beijing,Shijiazhuang,Cangzhou,Handan,Hengshui,Chengde,Zhangjiakou,and Tangshan from 7 to 14 February.For the horizontal distribution,PM2.5 and different aerosol species concentrations from 7 to 14 February 2020 increased compared with those during the same period in 2019,indicating that the accumulation of pollutants caused by the unfavorable meteorological condition offset the decreases caused by the emissions reduction,leading to the high aerosol concentration during the COVID-19 lockdown.展开更多
The authors evaluated and compared the behavior of PM2.5 with respect to NOx and NH3 emission changes in high(the year 2013)and low(the year 2018)SO2 emission cases.Two groups of simulations were conducted based on an...The authors evaluated and compared the behavior of PM2.5 with respect to NOx and NH3 emission changes in high(the year 2013)and low(the year 2018)SO2 emission cases.Two groups of simulations were conducted based on anthropogenic emissions from China in 2013 and 2018,respectively.In each group of simulations,a respective 25%reduction in NOx and NH3 emissions were assumed.A sensitivity factor(β)was defined as the relative change in PM2.5 concentration due to 1%change in NOx or NH3 emissions.In the high SO2 emissions case,PM2.5 was more sensitive to NH3(0.31)emissions change than NOx(0.21).Due to the significant decrease in SO2 emissions from the high to low SO2 emissions case,the sensitivity of PM2.5 to NOx increased to 0.33,while its sensitivity to NH3 decreased to 0.22.The result implies that now and in the future,PM2.5 is/will be less sensitive to NH3 emissions change,while NOx emissions control is more effective in reducing the surface PM2.5 concentration.Seasonally,in the low SO2 emissions case,the sensitivities of PM2.5 to NOx and NH3 in winter were higher than those in summer,indicating that to dealwith severewinter hazemore attention should be paid to the emissions control of inorganic PM2.5 precursors,especially NOx.展开更多
Particle emission during manufacturing processes, whether chemical, physical or mechanical can represent a serious danger for environment and for occupational safety. Especially machining processes, particle emission ...Particle emission during manufacturing processes, whether chemical, physical or mechanical can represent a serious danger for environment and for occupational safety. Especially machining processes, particle emission could have an important impact on shop floor air quality and might jeopardise workers’ health. It is therefore important to find ways of reducing the particle emission at the source of manufacturing processes. To do so, there is a need to know the size, the quantity and the distribution of particles produced by processes currently used in industry. In this study, investigations are done to compare the particle emission (PM2.5) when polishing two granites (black and white). The black granite contained low Si concentration (about 10% Si) and the white granite contained high Si concentration (about 50% Si). Particle emission was monitored using the DustTrak II equipment with 2.5 μm impactor. The particle grain size was evaluated using X-ray diffraction techniques. Machining conditions leading to the generation of finer particles were identified.展开更多
To guarantee the blue skies for the 2022 Winter Olympics held in Beijing and Zhangjiakou from February 4 to 20,Beijing and its surrounding areas adopted a series of emission control measures.This provides an opportuni...To guarantee the blue skies for the 2022 Winter Olympics held in Beijing and Zhangjiakou from February 4 to 20,Beijing and its surrounding areas adopted a series of emission control measures.This provides an opportunity to determine the impacts of large-scale temporary control measures on the air quality in Beijing during this special period.Here,we applied the WRF-CMAQ model to quantify the contributions of emission reduction measures and meteorological conditions.Results show that meteorological conditions in 2022 decreased PM_(2.5)in Beijing by 6.9 and 11.8μg/m^(3)relative to 2021 under the scenarios with and without emission reductions,respectively.Strict emission reduction measures implemented in Beijing and seven neighboring provinces resulted in an average decrease of 13.0μg/m^(3)(-41.2%)in PM_(2.5)in Beijing.Over the entire period,local emission reductions contributed more to good air quality in Beijing than nonlocal emission reductions.Under the emission reduction scenario,local,controlled regions,other regions,and boundary conditions contributed 47.7%,42.0%,5.3%,and 5.0%to the PM_(2.5)concentrations in Beijing,respectively.The results indicate that during the cleaning period with the air masses from the northwest,the abatements of PM_(2.5)were mainly caused by local emission reductions.However,during the potential pollution period with the air masses from the east-northeast and west-southwest,the abatements of PM_(2.5)were caused by both local and nonlocal emission reductions almost equally.This implies that regional coordinated prevention and control strategies need to be arranged scientifically and rationally when heavy pollution events are forecasted.展开更多
鉴于烟台市本地化源成分谱研究缺乏的现状,以及颗粒物精细化来源解析及环境管理的需求,采用NK-ZXF颗粒物再悬浮采样器,对6家烟台市典型工业下载灰源样品进行再悬浮采样,构建6类〔燃煤电厂、供热锅炉、生物质锅炉、钢铁(烧结)行业、玻璃...鉴于烟台市本地化源成分谱研究缺乏的现状,以及颗粒物精细化来源解析及环境管理的需求,采用NK-ZXF颗粒物再悬浮采样器,对6家烟台市典型工业下载灰源样品进行再悬浮采样,构建6类〔燃煤电厂、供热锅炉、生物质锅炉、钢铁(烧结)行业、玻璃行业和垃圾处理行业〕PM2.5源成分谱,并对PM2.5源成分谱特征及其排放颗粒物携带重金属特征进行评估.结果表明:①燃煤电厂PM2.5源成分谱的标识组分包括Si、Cl^-和SO4^2-,其质量分数分别为15.2%、9.3%和7.8%;与燃煤电厂相比,供热锅炉排放的PM2.5中w(OC)偏高、w(SO4^2-)偏低;生物质锅炉排放的主要组分有K、Cl^-和OC等,其质量分数分别为7.4%、13.3%和8.6%;钢铁(烧结)行业PM2.5源成分谱中w(Ca)、w(Fe)和w(Cl^-)较高;SO4^2-和Ca为玻璃行业PM2.5源成分谱的主要组分,其质量分数分别为20.6%、8.2%;垃圾处理行业重金属质量分数最高,其主要组分为Cl^-和SO4^2-.②CD (coefficient of divergence,分歧系数)计算结果表明,各源成分谱有一定相异性(CD范围为0.53~0.70),其中生物质锅炉与垃圾处理行业PM2.5源成分谱差异(CD为0.70)最大.③各典型工业排放PM2.5所携带重金属特征显示,垃圾处理行业排放PM2.5中的重金属质量分数(2.3%)最高,燃煤电厂、供热锅炉、生物质锅炉和玻璃行业排放的重金属中Cr、Ni和Cu相对质量分数较高,钢铁行业和垃圾处理行业排放的重金属中Pb相对质量分数较高.研究显示,所构建的烟台市各典型工业排放PM2.5源成分谱特征鲜明,能够反映各行业PM2.5排放特征.展开更多
To achieve the goals of national sustainable development, the peaking control of CO2 emissions is pivotal, as well as other pollutants. In this paper, we build a Chinese inter-regional CGE model and simulate 13 polici...To achieve the goals of national sustainable development, the peaking control of CO2 emissions is pivotal, as well as other pollutants. In this paper, we build a Chinese inter-regional CGE model and simulate 13 policies and their combinations. By analyzing the energy consumptions, coal consumptions, relating emissions and their impacts on GDP, we found that with the structure adjustment policy, the proportion of coal in primary fossil fuels in 2030 will decrease from 53% to 48% and CO2 emissions will decrease by 11.3%-22.8% compared to the baseline scenario. With the energy intensity reduction policy, CO2 emissions will decrease by 33.3% in 2030 and 47.8% in 2050 than baseline scenario. Other pollutants will also be controlled as synergetic effects. In this study we also find that although the earlier the peaking time the better for emission amounts control, the economic costs can not be ignored. The GDP will decrease by 2.96%-8.23% under different scenarios. Therefore, integrated policy solutions are needed for realizing the peaks package and more targeted measures are required to achieve the peaks of other pollutants earlier.展开更多
Co-occurrence of surface ozone(O_(3))and fine particulate matter(PM_(2.5))pollution(CP)was frequently observed in Beijing-Tianjin-Hebei(BTH).More than 50%of CP days occurred during April-May in BTH,and the CP days rea...Co-occurrence of surface ozone(O_(3))and fine particulate matter(PM_(2.5))pollution(CP)was frequently observed in Beijing-Tianjin-Hebei(BTH).More than 50%of CP days occurred during April-May in BTH,and the CP days reached up to 11 in two months of 2018.The PM_(2.5)or O_(3) concentration associated with CP was lower than but close to that in O_(3) and PM_(2.5)pollution,indicating compound harms during CP days with double-high concentrations of PM_(2.5)and O_(3).CP days were significantly facilitated by joint effects of the Rossby wave train that consisted of two centers associated with the Scandinavia pattern and one center over North China as well as a hot,wet,and stagnant environmental condition in BTH.After 2018,the number of CP days decreased sharply while the meteorological conditions did not change significantly.Therefore,changes in meteorological conditions did not really contribute to the decline of CP days in 2019 and 2020.This implies that the reduction of PM_(2.5)emission has resulted in a reduction of CP days(about 11 days in 2019 and 2020).The differences in atmospheric conditions revealed here were helpful to forecast the types of air pollution on a daily to weekly time scale.The reduction in PM_(2.5)emission was the main driving factor behind the absence of CP days in 2020,but the control of surface O_(3) must be stricter and deeper.展开更多
基金This study was supported by the National Key R&D Program of China[grant number 2017YFB0503901)the National Natural Science Foundation of China[grant numbers 41830109 and 41830966]the Major Scientific and Technological Innovation Projects of Shandong Province[grant number 2018YFJH0901].
文摘The impacts of the meteorological condition and emissions reduction on the aerosol concentration over the Beijing-Tianjin-Hebei(BTH) region during the COVID-19 lockdown were analyzed by conducting three numerical experiments,including one with the meteorological field in 2019 and MEIC-2019(2019 monthly Multi-resolution Emissions Inventory for China),one with the meteorological field in 2020 and MEIC-2019,and one with the meteorological field in 2020 and MEIC-2020,via a WRF-Chem model.The numerical experiments were performed from 3 to 16 February in 2019 and in 2020,during which a severe fog-haze event(3-16 February 2020) occurred in the BTH region,with a simulated maximum daily PM2.5 of 245μg m-3 in Tangshan and 175μg m-3 in Beijing.The results indicate that the daily PM2.5 decreased by 5-150μg m-3 due to the emissions reduction and increased by 10-175 μg m-3 due to the meteorological condition in Beijing,Shijiazhuang,Cangzhou,Handan,Hengshui,Chengde,Zhangjiakou,and Tangshan from 7 to 14 February.For the horizontal distribution,PM2.5 and different aerosol species concentrations from 7 to 14 February 2020 increased compared with those during the same period in 2019,indicating that the accumulation of pollutants caused by the unfavorable meteorological condition offset the decreases caused by the emissions reduction,leading to the high aerosol concentration during the COVID-19 lockdown.
基金This work was supported by the National Natural Science Foundation of China[grant number 41805098].
文摘The authors evaluated and compared the behavior of PM2.5 with respect to NOx and NH3 emission changes in high(the year 2013)and low(the year 2018)SO2 emission cases.Two groups of simulations were conducted based on anthropogenic emissions from China in 2013 and 2018,respectively.In each group of simulations,a respective 25%reduction in NOx and NH3 emissions were assumed.A sensitivity factor(β)was defined as the relative change in PM2.5 concentration due to 1%change in NOx or NH3 emissions.In the high SO2 emissions case,PM2.5 was more sensitive to NH3(0.31)emissions change than NOx(0.21).Due to the significant decrease in SO2 emissions from the high to low SO2 emissions case,the sensitivity of PM2.5 to NOx increased to 0.33,while its sensitivity to NH3 decreased to 0.22.The result implies that now and in the future,PM2.5 is/will be less sensitive to NH3 emissions change,while NOx emissions control is more effective in reducing the surface PM2.5 concentration.Seasonally,in the low SO2 emissions case,the sensitivities of PM2.5 to NOx and NH3 in winter were higher than those in summer,indicating that to dealwith severewinter hazemore attention should be paid to the emissions control of inorganic PM2.5 precursors,especially NOx.
文摘Particle emission during manufacturing processes, whether chemical, physical or mechanical can represent a serious danger for environment and for occupational safety. Especially machining processes, particle emission could have an important impact on shop floor air quality and might jeopardise workers’ health. It is therefore important to find ways of reducing the particle emission at the source of manufacturing processes. To do so, there is a need to know the size, the quantity and the distribution of particles produced by processes currently used in industry. In this study, investigations are done to compare the particle emission (PM2.5) when polishing two granites (black and white). The black granite contained low Si concentration (about 10% Si) and the white granite contained high Si concentration (about 50% Si). Particle emission was monitored using the DustTrak II equipment with 2.5 μm impactor. The particle grain size was evaluated using X-ray diffraction techniques. Machining conditions leading to the generation of finer particles were identified.
基金supported by the National Natural Science Foundation of China (Nos.42175084,21577126,and 41561144004)the Department of Science and Technology of China (Nos.2018YFC0213506,2018YFC0213503,and 2016YFC0202702)+4 种基金the National Research Program for Key Issues in Air Pollution Control in China (No.DQGG0107)supported by the“Zhejiang 1000 Talent Plan”and Research Center for Air Pollution and Health in Zhejiang UniversityPengfei Li is supported by the National Natural Science Foundation of China (No.22006030)the Initiation Fund for Introducing Talents of Hebei Agricultural University (No.412201904)the Hebei Youth Top Q15 Fund (No.BJ2020032)。
文摘To guarantee the blue skies for the 2022 Winter Olympics held in Beijing and Zhangjiakou from February 4 to 20,Beijing and its surrounding areas adopted a series of emission control measures.This provides an opportunity to determine the impacts of large-scale temporary control measures on the air quality in Beijing during this special period.Here,we applied the WRF-CMAQ model to quantify the contributions of emission reduction measures and meteorological conditions.Results show that meteorological conditions in 2022 decreased PM_(2.5)in Beijing by 6.9 and 11.8μg/m^(3)relative to 2021 under the scenarios with and without emission reductions,respectively.Strict emission reduction measures implemented in Beijing and seven neighboring provinces resulted in an average decrease of 13.0μg/m^(3)(-41.2%)in PM_(2.5)in Beijing.Over the entire period,local emission reductions contributed more to good air quality in Beijing than nonlocal emission reductions.Under the emission reduction scenario,local,controlled regions,other regions,and boundary conditions contributed 47.7%,42.0%,5.3%,and 5.0%to the PM_(2.5)concentrations in Beijing,respectively.The results indicate that during the cleaning period with the air masses from the northwest,the abatements of PM_(2.5)were mainly caused by local emission reductions.However,during the potential pollution period with the air masses from the east-northeast and west-southwest,the abatements of PM_(2.5)were caused by both local and nonlocal emission reductions almost equally.This implies that regional coordinated prevention and control strategies need to be arranged scientifically and rationally when heavy pollution events are forecasted.
文摘鉴于烟台市本地化源成分谱研究缺乏的现状,以及颗粒物精细化来源解析及环境管理的需求,采用NK-ZXF颗粒物再悬浮采样器,对6家烟台市典型工业下载灰源样品进行再悬浮采样,构建6类〔燃煤电厂、供热锅炉、生物质锅炉、钢铁(烧结)行业、玻璃行业和垃圾处理行业〕PM2.5源成分谱,并对PM2.5源成分谱特征及其排放颗粒物携带重金属特征进行评估.结果表明:①燃煤电厂PM2.5源成分谱的标识组分包括Si、Cl^-和SO4^2-,其质量分数分别为15.2%、9.3%和7.8%;与燃煤电厂相比,供热锅炉排放的PM2.5中w(OC)偏高、w(SO4^2-)偏低;生物质锅炉排放的主要组分有K、Cl^-和OC等,其质量分数分别为7.4%、13.3%和8.6%;钢铁(烧结)行业PM2.5源成分谱中w(Ca)、w(Fe)和w(Cl^-)较高;SO4^2-和Ca为玻璃行业PM2.5源成分谱的主要组分,其质量分数分别为20.6%、8.2%;垃圾处理行业重金属质量分数最高,其主要组分为Cl^-和SO4^2-.②CD (coefficient of divergence,分歧系数)计算结果表明,各源成分谱有一定相异性(CD范围为0.53~0.70),其中生物质锅炉与垃圾处理行业PM2.5源成分谱差异(CD为0.70)最大.③各典型工业排放PM2.5所携带重金属特征显示,垃圾处理行业排放PM2.5中的重金属质量分数(2.3%)最高,燃煤电厂、供热锅炉、生物质锅炉和玻璃行业排放的重金属中Cr、Ni和Cu相对质量分数较高,钢铁行业和垃圾处理行业排放的重金属中Pb相对质量分数较高.研究显示,所构建的烟台市各典型工业排放PM2.5源成分谱特征鲜明,能够反映各行业PM2.5排放特征.
基金funded by the National Natural Fund of China(71173206)the Strategic Priority Research ProgramdClimate Change:Carbon Budget and Related Issues of the Chinese Academy of Sciences(XDA05150300)
文摘To achieve the goals of national sustainable development, the peaking control of CO2 emissions is pivotal, as well as other pollutants. In this paper, we build a Chinese inter-regional CGE model and simulate 13 policies and their combinations. By analyzing the energy consumptions, coal consumptions, relating emissions and their impacts on GDP, we found that with the structure adjustment policy, the proportion of coal in primary fossil fuels in 2030 will decrease from 53% to 48% and CO2 emissions will decrease by 11.3%-22.8% compared to the baseline scenario. With the energy intensity reduction policy, CO2 emissions will decrease by 33.3% in 2030 and 47.8% in 2050 than baseline scenario. Other pollutants will also be controlled as synergetic effects. In this study we also find that although the earlier the peaking time the better for emission amounts control, the economic costs can not be ignored. The GDP will decrease by 2.96%-8.23% under different scenarios. Therefore, integrated policy solutions are needed for realizing the peaks package and more targeted measures are required to achieve the peaks of other pollutants earlier.
基金supported by the National Natural Science Foundation of China(Grant No.42088101).
文摘Co-occurrence of surface ozone(O_(3))and fine particulate matter(PM_(2.5))pollution(CP)was frequently observed in Beijing-Tianjin-Hebei(BTH).More than 50%of CP days occurred during April-May in BTH,and the CP days reached up to 11 in two months of 2018.The PM_(2.5)or O_(3) concentration associated with CP was lower than but close to that in O_(3) and PM_(2.5)pollution,indicating compound harms during CP days with double-high concentrations of PM_(2.5)and O_(3).CP days were significantly facilitated by joint effects of the Rossby wave train that consisted of two centers associated with the Scandinavia pattern and one center over North China as well as a hot,wet,and stagnant environmental condition in BTH.After 2018,the number of CP days decreased sharply while the meteorological conditions did not change significantly.Therefore,changes in meteorological conditions did not really contribute to the decline of CP days in 2019 and 2020.This implies that the reduction of PM_(2.5)emission has resulted in a reduction of CP days(about 11 days in 2019 and 2020).The differences in atmospheric conditions revealed here were helpful to forecast the types of air pollution on a daily to weekly time scale.The reduction in PM_(2.5)emission was the main driving factor behind the absence of CP days in 2020,but the control of surface O_(3) must be stricter and deeper.
