利用京津冀及周边地区大气污染综合立体监测网,在京津冀大气污染传输通道城市(“2+26”城市)开展了PM2.5及其化学组分长期连续观测,并对数据进行深入分析.结果表明:①2017年、2018年和2019年采暖季“2+26”城市PM2.5浓度平均值分别为(84...利用京津冀及周边地区大气污染综合立体监测网,在京津冀大气污染传输通道城市(“2+26”城市)开展了PM2.5及其化学组分长期连续观测,并对数据进行深入分析.结果表明:①2017年、2018年和2019年采暖季“2+26”城市PM2.5浓度平均值分别为(84±62)(95±63)和(80±61)μg m 3,达到了京津冀及周边地区2019—2020年秋冬季PM2.5平均浓度同比下降4%的目标;与PM2.5浓度变化相似,其主要化学组分——有机物(OM)浓度最大值出现在2018年采暖季,但二次无机盐(硝酸盐、硫酸盐和铵盐)浓度呈逐年上升趋势,而元素碳、氯盐、地壳物质和微量元素浓度均呈逐年下降趋势.②OM、硝酸盐、硫酸盐、铵盐、地壳物质、元素碳、氯盐和微量元素浓度空间分布存在明显差异.受污染物排放、气象条件以及地形因素的共同影响,PM2.5及其化学组分浓度高值区主要出现在太行山传输通道城市(保定市、石家庄市、邢台市、邯郸市、安阳市和新乡市).③不同空气质量状况下,“2+26”城市PM2.5化学组分浓度年际变化相似,即随空气污染的加重,硝酸盐、硫酸盐和铵盐占PM2.5的比例均上升,而OM占比下降.研究显示,采暖季“2+26”城市空气质量总体得到改善,但需进一步加强对PM2.5中二次组分的科学管控.展开更多
Accurate determination of the atmospheric particulate matter mass concentration and chemical composition is helpful in exploring the causes and sources of atmospheric enthalpy pollution and in evaluating the rationali...Accurate determination of the atmospheric particulate matter mass concentration and chemical composition is helpful in exploring the causes and sources of atmospheric enthalpy pollution and in evaluating the rationality of environmental air quality control strategies.Based on the sampling and chemical composition data of PM2.5 in different key regions of China in the CARE-China observation network,this research analyzes the environmental air quality data released by the China National Environmental Monitoring Centre during the studied period to determine the changes in the particulate matter mass concentration in key regions and the evolution of the corresponding chemical compositions during the implementation of the Action Plan for Prevention and Control of Air Pollution from 2013-2017.The results show the following.(1)The particulate matter mass concentration in China showed a significant downward trend;however,the PM2.5 annual mass concentration in 64%of cities exceeds the New Chinese Ambient Air Quality Standard(CAAQS)GradeⅡ(GB3095-2012).The region to the east of the Taihang Mountains,the Fenhe and Weihe River Plain and the Urumqi-Changji regions in Xinjiang,all have PM2.5 concentration loading that is still high,and heavy haze pollution occurred frequently in the autumn and winter.(2)During the heavy pollution in the autumn and winter,the concentrations of sulfate and organic components decreased significantly.The mean SO42-concentration in PM2.5 decreased by 76%,12%,81%and 38%in Beijing-Tianjin-Hebei(BTH),the Pearl River Delta(PRD),the Sichuan-Chongqing region(SC)and the Fenhe and Weihe River Plain,respectively.The mean organic matter(OM)concentration decreased by 70%,44%,48%and 31%,respectively,and the mean concentration of NH4+decreased by 68%,1.6%,38%and 25%,respectively.The mean elemental carbon(EC)concentration decreased by 84%and 20%in BTH and SC,respectively,and it increased by 61%and 11%in the PRD and Fenhe and Weihe River Plain,respectively.The mean concentration of mineral and unresolved chemica展开更多
To identify and apportion the sources of the ambient PM2.5 in the urban area of Hangzhou, China, PM2.s samples were collected at three sites in the city from April 2004 to March 2005. Water-soluble ions, metal element...To identify and apportion the sources of the ambient PM2.5 in the urban area of Hangzhou, China, PM2.s samples were collected at three sites in the city from April 2004 to March 2005. Water-soluble ions, metal elements, and total carbon （TC） in PM2.s samples were analyzed. The results indicated that the 24-h mean concentrations of PM2.5 ranged from 17.1 to 267.0 μg/m^3, with an annual average value of 108.2 μg/m^3. Moreover, the seasonal mean values for PM2.5 in spring, summer, autumn, and winter were 116, 73.1, 114.2, and 136.0μg/m^3, respectively. According to the Chinese ambient quality standard, at least 70% of the monitoring data exceeded the limit value. The total contribution of water-soluble ions, including F^-, CI^-, NO3^-, SO4^2- , NH4^＋, K^＋, and Na^＋, to PM2.5 mass varied from 32.3% to 36.7%. SO4^2- , NO3^-, and NH4^＋ were the main constituents of the ions, with contributions to PM2.5 varying from 14.1% to 14.7%, 6.0% to 7.89;, and 6.4% to 7.7%, respectively. In addition, the annual mean mass fraction of TC in PM2.5 was 27.8%. The annual average total contribution of the group of elements of Zn, Pb, Cu, Mn, Cr, Ni, Se, Mo, Cd, Sb, and Ag to the aerosol was in the range of 1.7-2.0%. Furthermore, positive matrix factorization was applied to analyze the PM2.5 data collected from the central area, and five factors were identified. The factor contributions to PM2.5 mass were 12.8%, 31.9%, 10.1%, 17.2%, and 27.9%, respectively. Iron/steel manufacturing and secondary aerosol were the main sources for the fine particles. These findings may have significance for controlling the atmospheric contamination in the city.展开更多
Aerosol samples for PM2.5 were collected in Beijing for 38 consecutive days from March to April 2001 using an IMPROVE Sampler. Concentrations of 20 elements in PM2.5 were determined using a PIXE method. Results show t...Aerosol samples for PM2.5 were collected in Beijing for 38 consecutive days from March to April 2001 using an IMPROVE Sampler. Concentrations of 20 elements in PM2.5 were determined using a PIXE method. Results show that the average mineral dust concentration of PM2.5 was 14.6 mg/m3 during the observation period. On the sand-dust event days of March 21 and April 10, dust PM2.5 mass concentrations were 62.4 and 54.1 mg/m3, respectively. These demonstrate that fine particle pollution by dust event in Beijing was very severe. The enrichment factors of S and Cu reached minimums on the dusty days and were high on the non-dusty days. It is considered that enrichment factors of elements in PM2.5, which are associated with human activities, can probably provide an effective method to distinguish local sources from external sources of dust. Factor analysis on the chemical composition in PM2.5 shows that sources of crustal matters, anthropogenic emission, and oil combustion contributed to PM2.5 levels in air in the springtime of 2001 in Beijing.展开更多
文摘利用京津冀及周边地区大气污染综合立体监测网,在京津冀大气污染传输通道城市(“2+26”城市)开展了PM2.5及其化学组分长期连续观测,并对数据进行深入分析.结果表明:①2017年、2018年和2019年采暖季“2+26”城市PM2.5浓度平均值分别为(84±62)(95±63)和(80±61)μg m 3,达到了京津冀及周边地区2019—2020年秋冬季PM2.5平均浓度同比下降4%的目标;与PM2.5浓度变化相似,其主要化学组分——有机物(OM)浓度最大值出现在2018年采暖季,但二次无机盐(硝酸盐、硫酸盐和铵盐)浓度呈逐年上升趋势,而元素碳、氯盐、地壳物质和微量元素浓度均呈逐年下降趋势.②OM、硝酸盐、硫酸盐、铵盐、地壳物质、元素碳、氯盐和微量元素浓度空间分布存在明显差异.受污染物排放、气象条件以及地形因素的共同影响,PM2.5及其化学组分浓度高值区主要出现在太行山传输通道城市(保定市、石家庄市、邢台市、邯郸市、安阳市和新乡市).③不同空气质量状况下,“2+26”城市PM2.5化学组分浓度年际变化相似,即随空气污染的加重,硝酸盐、硫酸盐和铵盐占PM2.5的比例均上升,而OM占比下降.研究显示,采暖季“2+26”城市空气质量总体得到改善,但需进一步加强对PM2.5中二次组分的科学管控.
基金supported by the Ministry of Science and Technology National Key Research and Development Program (Grant No. 2017YFC0210000)the Fundamental Heavy Pollution Cause and Governance Research Project (Grant No. DQGG0101)the Beijing Municipal Science and Technology Commission Capital Blue Sky Action and Cultivation Project (Grant No. Z181100005418014)
文摘Accurate determination of the atmospheric particulate matter mass concentration and chemical composition is helpful in exploring the causes and sources of atmospheric enthalpy pollution and in evaluating the rationality of environmental air quality control strategies.Based on the sampling and chemical composition data of PM2.5 in different key regions of China in the CARE-China observation network,this research analyzes the environmental air quality data released by the China National Environmental Monitoring Centre during the studied period to determine the changes in the particulate matter mass concentration in key regions and the evolution of the corresponding chemical compositions during the implementation of the Action Plan for Prevention and Control of Air Pollution from 2013-2017.The results show the following.(1)The particulate matter mass concentration in China showed a significant downward trend;however,the PM2.5 annual mass concentration in 64%of cities exceeds the New Chinese Ambient Air Quality Standard(CAAQS)GradeⅡ(GB3095-2012).The region to the east of the Taihang Mountains,the Fenhe and Weihe River Plain and the Urumqi-Changji regions in Xinjiang,all have PM2.5 concentration loading that is still high,and heavy haze pollution occurred frequently in the autumn and winter.(2)During the heavy pollution in the autumn and winter,the concentrations of sulfate and organic components decreased significantly.The mean SO42-concentration in PM2.5 decreased by 76%,12%,81%and 38%in Beijing-Tianjin-Hebei(BTH),the Pearl River Delta(PRD),the Sichuan-Chongqing region(SC)and the Fenhe and Weihe River Plain,respectively.The mean organic matter(OM)concentration decreased by 70%,44%,48%and 31%,respectively,and the mean concentration of NH4+decreased by 68%,1.6%,38%and 25%,respectively.The mean elemental carbon(EC)concentration decreased by 84%and 20%in BTH and SC,respectively,and it increased by 61%and 11%in the PRD and Fenhe and Weihe River Plain,respectively.The mean concentration of mineral and unresolved chemica
基金financially supported by the National Natural Science Foundation of China(41073019)
文摘To identify and apportion the sources of the ambient PM2.5 in the urban area of Hangzhou, China, PM2.s samples were collected at three sites in the city from April 2004 to March 2005. Water-soluble ions, metal elements, and total carbon （TC） in PM2.s samples were analyzed. The results indicated that the 24-h mean concentrations of PM2.5 ranged from 17.1 to 267.0 μg/m^3, with an annual average value of 108.2 μg/m^3. Moreover, the seasonal mean values for PM2.5 in spring, summer, autumn, and winter were 116, 73.1, 114.2, and 136.0μg/m^3, respectively. According to the Chinese ambient quality standard, at least 70% of the monitoring data exceeded the limit value. The total contribution of water-soluble ions, including F^-, CI^-, NO3^-, SO4^2- , NH4^＋, K^＋, and Na^＋, to PM2.5 mass varied from 32.3% to 36.7%. SO4^2- , NO3^-, and NH4^＋ were the main constituents of the ions, with contributions to PM2.5 varying from 14.1% to 14.7%, 6.0% to 7.89;, and 6.4% to 7.7%, respectively. In addition, the annual mean mass fraction of TC in PM2.5 was 27.8%. The annual average total contribution of the group of elements of Zn, Pb, Cu, Mn, Cr, Ni, Se, Mo, Cd, Sb, and Ag to the aerosol was in the range of 1.7-2.0%. Furthermore, positive matrix factorization was applied to analyze the PM2.5 data collected from the central area, and five factors were identified. The factor contributions to PM2.5 mass were 12.8%, 31.9%, 10.1%, 17.2%, and 27.9%, respectively. Iron/steel manufacturing and secondary aerosol were the main sources for the fine particles. These findings may have significance for controlling the atmospheric contamination in the city.
基金supported by the National Natural Science Foundation of China(Grant No.40205017)the Knowledge Innovation Project(Grant No.KZCX2-305)Hundred Talents Program(Global Environmental Change)by the Chinese Academy of Sciences.
文摘Aerosol samples for PM2.5 were collected in Beijing for 38 consecutive days from March to April 2001 using an IMPROVE Sampler. Concentrations of 20 elements in PM2.5 were determined using a PIXE method. Results show that the average mineral dust concentration of PM2.5 was 14.6 mg/m3 during the observation period. On the sand-dust event days of March 21 and April 10, dust PM2.5 mass concentrations were 62.4 and 54.1 mg/m3, respectively. These demonstrate that fine particle pollution by dust event in Beijing was very severe. The enrichment factors of S and Cu reached minimums on the dusty days and were high on the non-dusty days. It is considered that enrichment factors of elements in PM2.5, which are associated with human activities, can probably provide an effective method to distinguish local sources from external sources of dust. Factor analysis on the chemical composition in PM2.5 shows that sources of crustal matters, anthropogenic emission, and oil combustion contributed to PM2.5 levels in air in the springtime of 2001 in Beijing.
