The increased occurrence of smoggy days in major Chinese cities is of major concern to the general public. This paper explores the major sources of PM2.5 pollutants, a key contributor to the smog in Beijing, one of Ch...The increased occurrence of smoggy days in major Chinese cities is of major concern to the general public. This paper explores the major sources of PM2.5 pollutants, a key contributor to the smog in Beijing, one of China’s largest cities. Evidence indicates that the secondary PM2.5 particles formed through NOx, SOx, NH3, VOCs, etc. have a strong impact on human health. As a result, PM2.5 pollution control should not simply focus on controlling particulate emission, but should involve adopting an integrated multi-pollutant control strategy. In addition to identifying the major sources of PM2.5, this paper explores its impact on environmental and human health. Although the intention of this research is not to provide solutions for reducing PM2.5 pollution, the paper analyzes the United States’ experience with establishing PM2.5 standards and mandates. Specifically, this paper focuses on the air quality control strategies adopted in California since the 1940s and draws parallels with present-day China. The research suggests that adequate government regulation, public awareness, regional collaboration and industrial compliance are keys to successfully controlling PM2.5 pollution.展开更多
Domestic coal stoves are widely used in countryside and greenbelt residents in China for heating and cooking,and emit considerable pollutants to the atmosphere because of no treatment of their exhaust,which can result...Domestic coal stoves are widely used in countryside and greenbelt residents in China for heating and cooking,and emit considerable pollutants to the atmosphere because of no treatment of their exhaust,which can result in deteriorating local air quality.In this study,a dynamic smog chamber was used to investigate the real-time emissions of gaseous and particulate pollutants during the combustion process and a static smog chamber was used to investigate the fume evolution under simulate light irradiation.The real-time emissions revealed that the total hydrocarbon （THC） and CO increased sharply after ignition,and then quickly decreased,indicating volatilization of hydrocarbons with low molecular weight and incomplete combustion at the beginning stage of combustion made great contribution to these pollutants.There was evident shoulder peak around 10min combustion for both THC and CO,revealing the emissions from vitrinite combustion.Additionally,another broad emission peak of CO after 30min was also observed,which was ascribed to the incomplete combustion of the inertinite.Compared with THC and CO,there was only one emission peak for NOx,SO 2 and particular matters at the beginning stage of combustion.The fume evolution with static chamber simulation indicated that evident consumption of SO 2 and NOx as well as new particle formation were observed.The consumption rates for SO 2 and NOx were about 3.44% hr-1 and 3.68% hr-1,the new particle formation of nuclei particles grew at a rate of 16.03 nm/hr during the first reaction hour,and the increase of the diameter of accumulation mode particles was evident.The addition of isoprene to the diluted mixture of the fume could promote O 3 and secondary particle formation.展开更多
This paper discusses the two major root causes of smog in China.The first one is the distributed coal combustion in many small and medium sized boilers which have no emission control systems installed.To resolve this ...This paper discusses the two major root causes of smog in China.The first one is the distributed coal combustion in many small and medium sized boilers which have no emission control systems installed.To resolve this problem,there are several ways,such as increasing the centralized coal combustion for heat and power cogeneration;or converting coal to SNG in areas where there is enough water resource and removing the pollutants of the coal in the centralized coal to SNG plant,or refining the coal and making it cleaner first before combustion.The second major cause of smog is the low quality diesel and outdated diesel engines used in China.To solve this problem,there are some ways,such as improving the diesel quality to meet the national V standard,and meanwhile,enhancing the law enforcement to eliminate these outdated diesel engines that do not meet the national emission standards;in addition,combusting cleaner and cheaper fuel such as methanol or DME in the diesel engines is also an option for certain areas where there are abundant alternative fuels such as methanol to replace diesel.展开更多
文摘The increased occurrence of smoggy days in major Chinese cities is of major concern to the general public. This paper explores the major sources of PM2.5 pollutants, a key contributor to the smog in Beijing, one of China’s largest cities. Evidence indicates that the secondary PM2.5 particles formed through NOx, SOx, NH3, VOCs, etc. have a strong impact on human health. As a result, PM2.5 pollution control should not simply focus on controlling particulate emission, but should involve adopting an integrated multi-pollutant control strategy. In addition to identifying the major sources of PM2.5, this paper explores its impact on environmental and human health. Although the intention of this research is not to provide solutions for reducing PM2.5 pollution, the paper analyzes the United States’ experience with establishing PM2.5 standards and mandates. Specifically, this paper focuses on the air quality control strategies adopted in California since the 1940s and draws parallels with present-day China. The research suggests that adequate government regulation, public awareness, regional collaboration and industrial compliance are keys to successfully controlling PM2.5 pollution.
基金supported by the Central Public-Interest Scientific Institution Basal Research Fund (No. 2009KYYW01)the National Natural Science Foundation of China (No. 40705043)the Open Foundation of Environmental Simulation and Pollution Control State Key Laboratories (Peking University)
文摘Domestic coal stoves are widely used in countryside and greenbelt residents in China for heating and cooking,and emit considerable pollutants to the atmosphere because of no treatment of their exhaust,which can result in deteriorating local air quality.In this study,a dynamic smog chamber was used to investigate the real-time emissions of gaseous and particulate pollutants during the combustion process and a static smog chamber was used to investigate the fume evolution under simulate light irradiation.The real-time emissions revealed that the total hydrocarbon （THC） and CO increased sharply after ignition,and then quickly decreased,indicating volatilization of hydrocarbons with low molecular weight and incomplete combustion at the beginning stage of combustion made great contribution to these pollutants.There was evident shoulder peak around 10min combustion for both THC and CO,revealing the emissions from vitrinite combustion.Additionally,another broad emission peak of CO after 30min was also observed,which was ascribed to the incomplete combustion of the inertinite.Compared with THC and CO,there was only one emission peak for NOx,SO 2 and particular matters at the beginning stage of combustion.The fume evolution with static chamber simulation indicated that evident consumption of SO 2 and NOx as well as new particle formation were observed.The consumption rates for SO 2 and NOx were about 3.44% hr-1 and 3.68% hr-1,the new particle formation of nuclei particles grew at a rate of 16.03 nm/hr during the first reaction hour,and the increase of the diameter of accumulation mode particles was evident.The addition of isoprene to the diluted mixture of the fume could promote O 3 and secondary particle formation.
文摘This paper discusses the two major root causes of smog in China.The first one is the distributed coal combustion in many small and medium sized boilers which have no emission control systems installed.To resolve this problem,there are several ways,such as increasing the centralized coal combustion for heat and power cogeneration;or converting coal to SNG in areas where there is enough water resource and removing the pollutants of the coal in the centralized coal to SNG plant,or refining the coal and making it cleaner first before combustion.The second major cause of smog is the low quality diesel and outdated diesel engines used in China.To solve this problem,there are some ways,such as improving the diesel quality to meet the national V standard,and meanwhile,enhancing the law enforcement to eliminate these outdated diesel engines that do not meet the national emission standards;in addition,combusting cleaner and cheaper fuel such as methanol or DME in the diesel engines is also an option for certain areas where there are abundant alternative fuels such as methanol to replace diesel.
