Ship emissions contribute considerably to air pollution and are expected to decline under domestic policies and international cooperation such as green shipping corridors(GSCs).However,evaluation of the emission reduc...Ship emissions contribute considerably to air pollution and are expected to decline under domestic policies and international cooperation such as green shipping corridors(GSCs).However,evaluation of the emission reduction potential by the Domestic Emission Control Area(DECA)policy and GSC cooperation is still lacking.Here,a series of multi-year high spatiotemporal ship emission inventories around Hainan,a representative island province of China,were developed with the state-of-the-art Shipping Emission Inventory Model.The improved origin-destination identification algorithm allowed emission allocation to port level.The emission reduction potential of the DECA policy and Hainan's joining GSCwas analyzed.In 2022,ship emission intensity in waters 12 Nm from Hainan(Hainan-12Nm)were 6.4%-7.4% of that in waters 12 Nm from China.From 2019 to 2022,Hainan-12Nm emissions dropped by 66.7%-77.8% for SO_(2) and PM2.5.Ideally,with adequate ultra-low-sulfur fuel,DECA can reduce SO_(2) and PM2.5 emissions by 16.6% and 22.4% yearly compared with no-DECA scenario.However,emission reduction would drop markedly if ultra-low-sulfur fuel is short in supply.Emissions of voyages passing through 200 Nm from Hainan took up 1%-4%of international shipping emissions,implying great emission reduction potential for Hainan's establishing GSCs,especially considering the flourishing South-South trade.This study provides a thorough assessment of the current state of shipping emissions around Hainan as well as offers excellent data support for Hainan to further advance the future upgrade of ship emission management policies.展开更多
Chinese diesel trucks are the main contributors to NOx and particulate matter(PM)vehicle emissions.An increase in diesel trucks could aggravate air pollution and damage human health.The Chinese government has recently...Chinese diesel trucks are the main contributors to NOx and particulate matter(PM)vehicle emissions.An increase in diesel trucks could aggravate air pollution and damage human health.The Chinese government has recently implemented a series of emission control technologies andmeasures for air quality improvement.This paper summarizes recent control technologies and measures for diesel truck emissions in China and introduces the comprehensive application of control technologies and measures in Beijing-Tianjin-Hebei and surrounding regions.Remote onlinemonitoring technology has been adopted according to the China VI standard for heavy-duty diesel trucks,and control measures such as transportation structure adjustment and heavy pollution enterprise classification control continue to support the battle action plan for pollution control.Perspectives and suggestions are provided for promoting pollution control and supervision of diesel truck emissions:adhere to the concept of overall management and control,vigorously promote the application of systematic and technological means in emission monitoring,continuously facilitate cargo transportation structure adjustment and promote new energy freight vehicles.This paper aims to accelerate the implementation of control technologies and measures throughout China.China is endeavouring to control diesel truck exhaust pollution.China is willing to cooperate with the world to protect the global ecological environment.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
This paper describes the relation and difference of "emission up to standards" and "total quantity control" ofmain atmospheric pollutants, as well as their legal status. It points out that the tota...This paper describes the relation and difference of "emission up to standards" and "total quantity control" ofmain atmospheric pollutants, as well as their legal status. It points out that the total quantity control is a good approachto solve a problem that environmental quality do not yet reach the requirements in an area where emission concentrationhas came up to standards, or to solve a problem that the interregional transportation of pollutants (e. g. acid rain) arises.And further, it put forward five proposals for the total quantity control.[展开更多
The regional air quality modeling system RAMS （Regional Atmospheric Modeling System）-CMAQ （Community Multi-scale Air Quality modeling system） is applied to analyze temporal and spatial variations in surface ozone ...The regional air quality modeling system RAMS （Regional Atmospheric Modeling System）-CMAQ （Community Multi-scale Air Quality modeling system） is applied to analyze temporal and spatial variations in surface ozone concentration over Beijing and its surrounding region from July to October 2008.Comparison of simulated and observed meteorological elements and concentration of nitrogen oxides （NOx） and ozone at one urban site and three rural sites during Olympic Games show that model can generally reproduce the main observed feature of wind,temperature and ozone,but NOx concentration is overestimated.Although ozone concentration decreased during Olympics,high ozone episodes occurred on 24 July and 24 August with concentration of 360 and 245 μg/m 3 at Aoyuncun site,respectively.The analysis of sensitive test,with and without emission controls,shows that emission controls could reduce ozone concentration in the afternoon when ozone concentration was highest but increase it at night and in the morning.The evolution of the weather system during the ozone episodes （24 July and 24 August） indicates that hot and dry air and a stable weak pressure field intensified the production of ozone and allowed it to accumulate.Process analysis at the urban site and rural site shows that under favorable weather condition on 24 August,horizontal transport was the main contributor of the rural place and the pollution from the higher layer would be transported to the surface layer.On 24 July,as the wind velocity was smaller,the impact of transport on the rural place was not obvious.展开更多
This paper tries to integrate game theory, a very useful tool to resolve conflict phenomena, with optimal capital cost allocation issue in total emission control. First the necessity of allocating optimal capital cos...This paper tries to integrate game theory, a very useful tool to resolve conflict phenomena, with optimal capital cost allocation issue in total emission control. First the necessity of allocating optimal capital costs fairly and reasonably among polluters in total emission control was analyzed. Then the possibility of applying game theory to the issue of the optimal capital cost allocation was expounded. Next the cooperative N person game model of the optimal capital cost allocation and its solution ways including method based on Shapley value, least core method, weak least core methods, proportional least core method, CGA method, MCRS method and so on were delineated. Finally through application of these methods it was concluded that to apply game theory in the optimal capital cost allocation issue is helpful to implement the total emission control planning schemes successfully, to control pollution effectively, and to ensure sustainable development.展开更多
Diesel vehicles have caused serious environmental problems in China.Hence,the Chinese government has launched serious actions against air pollution and imposed more stringent regulations on diesel vehicle emissions in...Diesel vehicles have caused serious environmental problems in China.Hence,the Chinese government has launched serious actions against air pollution and imposed more stringent regulations on diesel vehicle emissions in the latest China VI standard.To fulfill this stringent legislation,two major technical routes,including the exhaust gas recirculation(EGR)and high-efficiency selective catalytic reduction(SCR)routes,have been developed for diesel engines.Moreover,complicated aftertreatment technologies have also been developed,including use of a diesel oxidation catalyst(DOC)for controlling carbon monoxide(CO)and hydrocarbon(HC)emissions,diesel particulate filter(DPF)for particle mass(PM)emission control,SCR for the control of NOx emission,and an ammonia slip catalyst(ASC)for the control of unreacted NH3.Due to the stringent requirements of the China VI standard,the aftertreatment system needs to be more deeply integrated with the engine system.In the future,aftertreatment technologies will need further upgrades to fulfill the requirements of the near-zero emission target for diesel vehicles.展开更多
Frequent occurrences of extreme heat are causing severe ozone pollution over China.This study examined the driving factors of urban ozone pollution in China during the extremely hot summer of 2022 and the impact of em...Frequent occurrences of extreme heat are causing severe ozone pollution over China.This study examined the driving factors of urban ozone pollution in China during the extremely hot summer of 2022 and the impact of emission control strategies using surface measurements and the GEOS-Chem model.The results show that ozone pollution was extremely severe in summer 2022,with a significant rebound by 12-15 ppbv in the North China Plain(NCP),Yangtze River Delta(YRD),and Sichuan basin(SCB),compared to 2021.Especially over the NCP,the MDA8(maximum daily 8-hourly average)ozone exceeded 160 ppbv,and the number of ozone exceedances was over 42 days.Based on an IPR(integrated process rate)analysis,the authors found that the net chemical production was the dominant factor contributing to the strong ozone increase in summer 2022.For example,in June over the NCP,the net chemical production resulted in an increase by 3.08 Gg d^(−1)(∼270%)in ozone mass change.Sensitivity simulations showed that both NO_(x)(nitrogen oxides)and VOC(volatile organic compound)reductions were important over the NCP,and NO_(x)reductions were more important than VOCs over southern China.To keep the ozone of 2022 at the same level as 2021,a joint reduction of NO_(x)and VOCs by at least 50%-60%would have been required.This study highlights the urgency to develop effective ozone management since extreme heat will become more frequent.展开更多
As part of a comprehensive environmental management system, many countries establish emission control targets for mass emissions of a pollutant. Such targets are often the key objective of an environmental policy, suc...As part of a comprehensive environmental management system, many countries establish emission control targets for mass emissions of a pollutant. Such targets are often the key objective of an environmental policy, such as an emission trading program. In China, however, it is more than just an objective of one particular policy; it has become a concept that has influenced many national environmental policies and activities. The objective of this article is to review the implementation of the total emission control policy in the past 10 years and explore emerging issues in its implementation. The article has three sections: a summary of the implementation experience, issues with the design and implementation of the policy, and policy recommendations.展开更多
Vessel emissions have contributed a great deal to air quality deterioration in China.Hence,the Chinese government has promulgated a series of stringent emission regulations.It is in this context that vessel emission c...Vessel emissions have contributed a great deal to air quality deterioration in China.Hence,the Chinese government has promulgated a series of stringent emission regulations.It is in this context that vessel emission control technology research is in full swing.In particular,during the 13th Five-Year Plan,the air pollution control technology of vessels has greatly improved.Vessel emission control has followed two main governance routes:source emission reduction and aftertreatment technology.Source control focuses on alternative fuels,with two main directions,the development of new fuels and the modification of existing fuels.Moreover,after-treatment technologies have also been developed,including wet desulfurization technology using seawater or alkaline liquids as wet washing liquids and selective catalytic reduction(SCR)for the control of NOx emission.Due to China’s increasingly stringent emissions standards and regulations,work on the development of clean alternative fuels and further upgrading the collaborative application of after-treatment technologies to meet the near-zero-emissions requirements of vessels is still necessary.展开更多
Extensive studies on aerosol chemistry have been carried out in megacities in China,however,aerosol characterization in Central China Plain(CCP)is limited.Here we conducted real-time measurements of fine particle comp...Extensive studies on aerosol chemistry have been carried out in megacities in China,however,aerosol characterization in Central China Plain(CCP)is limited.Here we conducted real-time measurements of fine particle composition with a time-of-flight aerosol chemical speciation monitor in Kaifeng,Henan province in October 2019.Our results showed that nitrate and organics constituted the major fraction of non-refractory PM_(2.5)for the entire study,on average accounting for 34%and 33%,respectively.However,aerosol composition was substantially different among four periods due to different meteorological conditions and chemical processing.For instance,nitrate presented the lowest contribution during the first period due to evaporative loss associated with high temperature(T),and then rapidly increased during polluted periods as a function of relative humidity(RH).Positive matrix factorization analysis showed the dominance of secondary organic aerosol(SOA)in OA,and also the changes in OA composition under different T and RH levels.In addition,this study is unique with two periods of local emission controls.Back trajectory and coefficient of divergence analysis showed that air pollution in CCP was overall homogeneously distributed.As a result,the effectiveness of local emission controls in this region was strongly affected by meteorological conditions and regional transport.We found that one of the periods with emission control even showed the highest concentrations for the entire study.Our results point towards the limited effect of local emission controls in mitigating air pollution in CCP,and highlight the importance of joint emission controls under unfavorable meteorological conditions.展开更多
Based on satellite observations, the effects of emission reduction measures on air pollutants （NO2 （nitrogen dioxide）, SO2 （sulfur dioxide）, and aerosols） were estimated in Beijing and its surroundings during th...Based on satellite observations, the effects of emission reduction measures on air pollutants （NO2 （nitrogen dioxide）, SO2 （sulfur dioxide）, and aerosols） were estimated in Beijing and its surroundings during the 2015 World Championships and Parade （WCP） held in Beijing. Compared with the same period in the previous three years （2012-2014）, the tropospheric vertical column densities of NO2 and SO2 in 2015 were significantly reduced in Beijing and its surroundings. During the WCP, aerosol optical depth was reduced most significantly in Beijing, while NO2 and SO2 were reduced most significantly in Hebei and Tianjin, respectively. The meteorological conditions were also favorable during this period. During the WCP, the North China Plain was located under high pressure from the north of China. A southward pressure gradient force and weak northerly and northeasterly winds blocked the transport of pollution from southern and western parts of the industrial area （Hebei, Shanxi and Shandong provinces）. Cold air masses pushed southwards weakly. These conditions were beneficial to the removal of air pollutants in Beijing.展开更多
The iron and steel production process is one of the predominant anthropogenic sources of atmospheric mercury emissions worldwide. In this study, field tests were conducted to study mercury emission characteristics and...The iron and steel production process is one of the predominant anthropogenic sources of atmospheric mercury emissions worldwide. In this study, field tests were conducted to study mercury emission characteristics and mass flows at two iron and steel plants in China. It was found that low-sulfur flue gas from sintering machines could contribute up to41% of the total atmospheric mercury emissions, and desulfurization devices could remarkably help reduce the emissions. Coal gas burning accounted for 17%–49% of the total mercury emissions, and therefore the mercury control of coal gas burning, specifically for the power plant burning coal gas to generate electricity, was significantly important. The emissions from limestone and dolomite production and electric furnaces can contribute29.3% and 4.2% of the total mercury emissions from iron and steel production. More attention should be paid to mercury emissions from these two processes. Blast furnace dust accounted for 27%–36% of the total mercury output for the whole iron and steel production process. The recycling of blast furnace dust could greatly increase the atmospheric mercury emissions and should not be conducted. The mercury emission factors for the coke oven,sintering machine and blast furnace were 0.039–0.047 g Hg/ton steel, and for the electric furnace it was 0.021 g Hg/ton steel. The predominant emission species was oxidized mercury, accounting for 59%–73% of total mercury emissions to air.展开更多
The COVID-19 lockdowns led to abrupt reductions in human-related emissions worldwide and had an unintended impact on air quality improvement.However,quantifying this impact is difficult as meteorological conditions ma...The COVID-19 lockdowns led to abrupt reductions in human-related emissions worldwide and had an unintended impact on air quality improvement.However,quantifying this impact is difficult as meteorological conditions may mask the real effect of changes in emissions on the observed concentrations of pollutants.Based on the air quality and meteorological data at 35 sites in Beijing from 2015 to 2020,a machine learning technique was applied to decouple the impacts of meteorology and emissions on the concentrations of air pollutants.The results showed that the real(“deweathered”)concentrations of air pollutants(expect for O 3)dropped significantly due to lockdown measures.Compared with the scenario without lockdowns(predicted concentrations),the observed values of PM_(2.5),PM_(10),SO_(2),NO_(2),and CO during lockdowns decreased by 39.4%,50.1%,51.8%,43.1%,and 35.1%,respectively.In addition,a significant decline for NO_(2)and CO was found at the background sites(51%and 37.8%)rather than the traffic sites(37.1%and 35.5%),which is different from the common belief.While the primary emissions reduced during the lockdown period,episodic haze events still occurred due to unfavorable meteorological conditions.Thus,developing an optimized strategy to tackle air pollution in Beijing is essential in the future.展开更多
The Yangtze River Delta（YRD） region is one of the most prosperous and densely populated regions in China and is facing tremendous pressure to mitigate vehicle emissions and improve air quality.Our assessment has rev...The Yangtze River Delta（YRD） region is one of the most prosperous and densely populated regions in China and is facing tremendous pressure to mitigate vehicle emissions and improve air quality.Our assessment has revealed that mitigating vehicle emissions of NOx would be more difficult than reducing the emissions of other major vehicular pollutants（e.g.,CO,HC and PM_（2.5）） in the YRD region.Even in Shanghai,where the emission control implemented are more stringent than in Jiangsu and Zhejiang,we observed little to no reduction in NOx emissions from 2000 to 2010.Emission-reduction targets for HC,NOx and PM_（2.5） are determined using a response surface modeling tool for better air quality.We design city-specific emission control strategies for three vehicle-populated cities in the YRD region：Shanghai and Nanjing and Wuxi in Jiangsu.Our results indicate that even if stringent emission control consisting of the Euro 6/VI standards,the limitation of vehicle population and usage,and the scrappage of older vehicles is applied,Nanjing and Wuxi will not be able to meet the NOx emissions target by 2020.Therefore,additional control measures are proposed for Nanjing and Wuxi to further mitigate NOx emissions from heavy-duty diesel vehicles.展开更多
As the largest iron and steel producer in China, a part of Baosteel moved out of Shanghai deserves close attention due to its environmental impact. To understand the effect of Baosteel emission control on air quality ...As the largest iron and steel producer in China, a part of Baosteel moved out of Shanghai deserves close attention due to its environmental impact. To understand the effect of Baosteel emission control on air quality in Shanghai, daily PM10, PM2.5, SO2, NO2 and CO were measured from 2010 to 2016. Concentrations of pollutants in Baoshan District presented a decreased trend during 2010-2016, with a reduction rate of 28.6% for PM10, 67.3% for SO2, 8.6% for NO2 and 42.0% for CO. However, fine particle pollution in Baoshan District during 2012-2016 seems to become more prominent, with PM2.5 concentration of 47 ± 28, 45 ± 33, 38 ± 24, 54 ± 41 and 51 ± 34 μg/m^3, respectively, indicating a slight increase of 8.5% in PM2.5. Concentrations of PM10 and CO decreased by 12.5% and 33.8% in the second half year in 2016 （compared with that in 2015） probably due to closure of blast furnace of Baosteel. Baosteel was identified as the largest pollution source in Baoshan District. Emission from Baosteel accounted for 58.0% of SO2, 43.6% of NO2 and 79.3% of dust in total emission from Baoshan District during 2010-2015. Meanwhile, pollutant emission and coal consumption from Baosteel decreased by 52.0% for SO2, 40.1% for NO2, 15.7% for dust and 22% for coal consumption. Energy consumption in Baoshan District reduced by 31% from 2011 to 2015. Air quality improvement in Shanghai was attributed to local emission reduction, together with regional air quality improvement.展开更多
China’s emission control for nonroad diesel mobile machinery(NDMM)must deal with a fast increase in stock as well as regulations that are two decades behind those for on-road vehicles.This study provides the first la...China’s emission control for nonroad diesel mobile machinery(NDMM)must deal with a fast increase in stock as well as regulations that are two decades behind those for on-road vehicles.This study provides the first large-scale review and evaluation of China’s NDMM policies,along with emission measurements and an investigation on diesel fuel quality.The sulfur contents of the investigated diesel declined from 430 ppm(median value)in 2011 to6-8 ppm during the 2017-2018 period.The emission control of NO_(x)and PM greatly improved with the shift from the China II to China IV standards,as demonstrated by engine tests and field NO_(x)measurements.However,the NO_(x)emission factors for non-type-approved engines were approximately twice the limits of the China II standards.Emission compliance based on bench tests was not sufficient to control actual emissions because the field-measured NO_(x)emission factors of all machinery ranged from 24%to 225%greater than the respective emission limits for the engines.These circumstances adversely affected the effectiveness of the regulations and policies for China’s emission control of NDMM.Nevertheless,the policies on new and in-use NDMM,as well as diesel fuel quality,prevented NO_(x)and PM emissions amounting to 4.4 Tg and 297.8 Gg during the period 2008-2017,respectively.The emission management strategy contributed to enhancing the international competitiveness of China’s NDMM industries by promoting advanced technologies.For effective NDMM emission control in the future,portable testing and noncontact remote supervision should be strengthened;also,the issue of noncompliant diesel should be addressed through rigorous control measures and financial penalties.展开更多
The Co_(3)O_(4)nanoparticles,dominated by a catalytically active(110)lattice plane,were synthesized as a low-temperature NO_(x) adsorbent to control the cold start emissions from vehicles.These nanoparticles boast a s...The Co_(3)O_(4)nanoparticles,dominated by a catalytically active(110)lattice plane,were synthesized as a low-temperature NO_(x) adsorbent to control the cold start emissions from vehicles.These nanoparticles boast a substantial quantity of active chemisorbed oxygen and lattice oxygen,which exhibited a NO_(x) uptake capacity commensurate with Pd/SSZ-13 at 100℃.The primary NO_(x) release temperature falls within a temperature range of 200-350℃,making it perfectly suitable for diesel engines.The characterization results demonstrate that chemisorbed oxygen facilitate nitro/nitrites intermediates formation,contributing to the NO_(x) storage at 100℃,while the nitrites begin to decompose within the 150-200℃range.Fortunately,lattice oxygen likely becomes involved in the activation of nitrites into more stable nitrate within this particular temperature range.The concurrent processes of nitrites decomposition and its conversion to nitrates results in a minimal NO_(x) release between the temperatures of 150-200℃.The nitrate formed via lattice oxygen mainly induces the NO_(x) to be released as NO_(2) within a temperature range of 200-350℃,which is advantageous in enhancing the NO_(x) activity of downstream NH_(3)-SCR catalysts,by boosting the fast SCR reaction pathway.Thanks to its low cost,considerable NO_(x) absorption capacity,and optimal release temperature,Co_(3)O_(4)demonstrates potential as an effective material for passive NO_(x) adsorber applications.展开更多
A three-way catalyst comprised novel oxygen storage components for emission control in natural gas powered engines was prepared. The addition of novel oxygen storage components to the Pd/γ-Al2O3 catalysts resulted ...A three-way catalyst comprised novel oxygen storage components for emission control in natural gas powered engines was prepared. The addition of novel oxygen storage components to the Pd/γ-Al2O3 catalysts resulted in improved activities of the fresh and aged catalyst by lowering the light-off temperature for methane in natural gas engines exhaust.展开更多
The requirements that a business needs to consider when building a wood panels manufacturing plant are much the same as they have been for decades, but today there is also the need for multiple environmental studies a...The requirements that a business needs to consider when building a wood panels manufacturing plant are much the same as they have been for decades, but today there is also the need for multiple environmental studies and permits. These are costly and time consuming additional expenses that often are the longest lead-time items on any project. Most industrialized countries have legislation in place to limit and control the negative impact that emission of pollutants may have on the environment. This paper discusses what is actually happening inside wood drying plants, and the prerequisite conditions for genesis of pyrolytic products relative to the operational parameters, such as choice of input raw materials, driers design and operational regime, choice of fuels for the heat generation and how these factors influence production of stack emission. The characterization of emission condensate by analytical methods is described, and survey of emission control system in use worldwide is described, and means of investigating what may be the optimum design for the control of emission is discussed. Alternate uses of utilizing the condensate, other than burning, are presented for consideration.展开更多
基金supported by the National Natural Science Foundation of China(No.42325505)the National Key R&D Program of China(No.2022YFC3704200)the Tsinghua University Initiative Scientific Research Program.
文摘Ship emissions contribute considerably to air pollution and are expected to decline under domestic policies and international cooperation such as green shipping corridors(GSCs).However,evaluation of the emission reduction potential by the Domestic Emission Control Area(DECA)policy and GSC cooperation is still lacking.Here,a series of multi-year high spatiotemporal ship emission inventories around Hainan,a representative island province of China,were developed with the state-of-the-art Shipping Emission Inventory Model.The improved origin-destination identification algorithm allowed emission allocation to port level.The emission reduction potential of the DECA policy and Hainan's joining GSCwas analyzed.In 2022,ship emission intensity in waters 12 Nm from Hainan(Hainan-12Nm)were 6.4%-7.4% of that in waters 12 Nm from China.From 2019 to 2022,Hainan-12Nm emissions dropped by 66.7%-77.8% for SO_(2) and PM2.5.Ideally,with adequate ultra-low-sulfur fuel,DECA can reduce SO_(2) and PM2.5 emissions by 16.6% and 22.4% yearly compared with no-DECA scenario.However,emission reduction would drop markedly if ultra-low-sulfur fuel is short in supply.Emissions of voyages passing through 200 Nm from Hainan took up 1%-4%of international shipping emissions,implying great emission reduction potential for Hainan's establishing GSCs,especially considering the flourishing South-South trade.This study provides a thorough assessment of the current state of shipping emissions around Hainan as well as offers excellent data support for Hainan to further advance the future upgrade of ship emission management policies.
基金supported by the National Key Research and Development Project (No.2022YFB2602001)the National Research Program for Key Issues in Air Pollution Control (No.DQGG0207).
文摘Chinese diesel trucks are the main contributors to NOx and particulate matter(PM)vehicle emissions.An increase in diesel trucks could aggravate air pollution and damage human health.The Chinese government has recently implemented a series of emission control technologies andmeasures for air quality improvement.This paper summarizes recent control technologies and measures for diesel truck emissions in China and introduces the comprehensive application of control technologies and measures in Beijing-Tianjin-Hebei and surrounding regions.Remote onlinemonitoring technology has been adopted according to the China VI standard for heavy-duty diesel trucks,and control measures such as transportation structure adjustment and heavy pollution enterprise classification control continue to support the battle action plan for pollution control.Perspectives and suggestions are provided for promoting pollution control and supervision of diesel truck emissions:adhere to the concept of overall management and control,vigorously promote the application of systematic and technological means in emission monitoring,continuously facilitate cargo transportation structure adjustment and promote new energy freight vehicles.This paper aims to accelerate the implementation of control technologies and measures throughout China.China is endeavouring to control diesel truck exhaust pollution.China is willing to cooperate with the world to protect the global ecological environment.
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This paper describes the relation and difference of "emission up to standards" and "total quantity control" ofmain atmospheric pollutants, as well as their legal status. It points out that the total quantity control is a good approachto solve a problem that environmental quality do not yet reach the requirements in an area where emission concentrationhas came up to standards, or to solve a problem that the interregional transportation of pollutants (e. g. acid rain) arises.And further, it put forward five proposals for the total quantity control.[
基金supported by the National Natural Science Foundation of China (No. 20937001)
文摘The regional air quality modeling system RAMS （Regional Atmospheric Modeling System）-CMAQ （Community Multi-scale Air Quality modeling system） is applied to analyze temporal and spatial variations in surface ozone concentration over Beijing and its surrounding region from July to October 2008.Comparison of simulated and observed meteorological elements and concentration of nitrogen oxides （NOx） and ozone at one urban site and three rural sites during Olympic Games show that model can generally reproduce the main observed feature of wind,temperature and ozone,but NOx concentration is overestimated.Although ozone concentration decreased during Olympics,high ozone episodes occurred on 24 July and 24 August with concentration of 360 and 245 μg/m 3 at Aoyuncun site,respectively.The analysis of sensitive test,with and without emission controls,shows that emission controls could reduce ozone concentration in the afternoon when ozone concentration was highest but increase it at night and in the morning.The evolution of the weather system during the ozone episodes （24 July and 24 August） indicates that hot and dry air and a stable weak pressure field intensified the production of ozone and allowed it to accumulate.Process analysis at the urban site and rural site shows that under favorable weather condition on 24 August,horizontal transport was the main contributor of the rural place and the pollution from the higher layer would be transported to the surface layer.On 24 July,as the wind velocity was smaller,the impact of transport on the rural place was not obvious.
文摘This paper tries to integrate game theory, a very useful tool to resolve conflict phenomena, with optimal capital cost allocation issue in total emission control. First the necessity of allocating optimal capital costs fairly and reasonably among polluters in total emission control was analyzed. Then the possibility of applying game theory to the issue of the optimal capital cost allocation was expounded. Next the cooperative N person game model of the optimal capital cost allocation and its solution ways including method based on Shapley value, least core method, weak least core methods, proportional least core method, CGA method, MCRS method and so on were delineated. Finally through application of these methods it was concluded that to apply game theory in the optimal capital cost allocation issue is helpful to implement the total emission control planning schemes successfully, to control pollution effectively, and to ensure sustainable development.
基金supported by the National Key R&D Program of China(No.2017YFC0211101)the Key Project of National Natural Science Foundation(No.21637005)+1 种基金the Cultivating Project of Strategic Priority Research Program of Chinese Academy of Sciences(No.XDPB1902)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA23010200)。
文摘Diesel vehicles have caused serious environmental problems in China.Hence,the Chinese government has launched serious actions against air pollution and imposed more stringent regulations on diesel vehicle emissions in the latest China VI standard.To fulfill this stringent legislation,two major technical routes,including the exhaust gas recirculation(EGR)and high-efficiency selective catalytic reduction(SCR)routes,have been developed for diesel engines.Moreover,complicated aftertreatment technologies have also been developed,including use of a diesel oxidation catalyst(DOC)for controlling carbon monoxide(CO)and hydrocarbon(HC)emissions,diesel particulate filter(DPF)for particle mass(PM)emission control,SCR for the control of NOx emission,and an ammonia slip catalyst(ASC)for the control of unreacted NH3.Due to the stringent requirements of the China VI standard,the aftertreatment system needs to be more deeply integrated with the engine system.In the future,aftertreatment technologies will need further upgrades to fulfill the requirements of the near-zero emission target for diesel vehicles.
基金supported by the National Key Research and Development Program of China[grant number 2022YFE0136100]the National Natural Science Foundation of China[grant number 42205114].
文摘Frequent occurrences of extreme heat are causing severe ozone pollution over China.This study examined the driving factors of urban ozone pollution in China during the extremely hot summer of 2022 and the impact of emission control strategies using surface measurements and the GEOS-Chem model.The results show that ozone pollution was extremely severe in summer 2022,with a significant rebound by 12-15 ppbv in the North China Plain(NCP),Yangtze River Delta(YRD),and Sichuan basin(SCB),compared to 2021.Especially over the NCP,the MDA8(maximum daily 8-hourly average)ozone exceeded 160 ppbv,and the number of ozone exceedances was over 42 days.Based on an IPR(integrated process rate)analysis,the authors found that the net chemical production was the dominant factor contributing to the strong ozone increase in summer 2022.For example,in June over the NCP,the net chemical production resulted in an increase by 3.08 Gg d^(−1)(∼270%)in ozone mass change.Sensitivity simulations showed that both NO_(x)(nitrogen oxides)and VOC(volatile organic compound)reductions were important over the NCP,and NO_(x)reductions were more important than VOCs over southern China.To keep the ozone of 2022 at the same level as 2021,a joint reduction of NO_(x)and VOCs by at least 50%-60%would have been required.This study highlights the urgency to develop effective ozone management since extreme heat will become more frequent.
文摘As part of a comprehensive environmental management system, many countries establish emission control targets for mass emissions of a pollutant. Such targets are often the key objective of an environmental policy, such as an emission trading program. In China, however, it is more than just an objective of one particular policy; it has become a concept that has influenced many national environmental policies and activities. The objective of this article is to review the implementation of the total emission control policy in the past 10 years and explore emerging issues in its implementation. The article has three sections: a summary of the implementation experience, issues with the design and implementation of the policy, and policy recommendations.
基金supported by the National Key Research and Development Program of China(No.2019YFC0214803)。
文摘Vessel emissions have contributed a great deal to air quality deterioration in China.Hence,the Chinese government has promulgated a series of stringent emission regulations.It is in this context that vessel emission control technology research is in full swing.In particular,during the 13th Five-Year Plan,the air pollution control technology of vessels has greatly improved.Vessel emission control has followed two main governance routes:source emission reduction and aftertreatment technology.Source control focuses on alternative fuels,with two main directions,the development of new fuels and the modification of existing fuels.Moreover,after-treatment technologies have also been developed,including wet desulfurization technology using seawater or alkaline liquids as wet washing liquids and selective catalytic reduction(SCR)for the control of NOx emission.Due to China’s increasingly stringent emissions standards and regulations,work on the development of clean alternative fuels and further upgrading the collaborative application of after-treatment technologies to meet the near-zero-emissions requirements of vessels is still necessary.
基金supported by the National Key Research and Development Program of China(No.2019YFC0214200)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA23020301)。
文摘Extensive studies on aerosol chemistry have been carried out in megacities in China,however,aerosol characterization in Central China Plain(CCP)is limited.Here we conducted real-time measurements of fine particle composition with a time-of-flight aerosol chemical speciation monitor in Kaifeng,Henan province in October 2019.Our results showed that nitrate and organics constituted the major fraction of non-refractory PM_(2.5)for the entire study,on average accounting for 34%and 33%,respectively.However,aerosol composition was substantially different among four periods due to different meteorological conditions and chemical processing.For instance,nitrate presented the lowest contribution during the first period due to evaporative loss associated with high temperature(T),and then rapidly increased during polluted periods as a function of relative humidity(RH).Positive matrix factorization analysis showed the dominance of secondary organic aerosol(SOA)in OA,and also the changes in OA composition under different T and RH levels.In addition,this study is unique with two periods of local emission controls.Back trajectory and coefficient of divergence analysis showed that air pollution in CCP was overall homogeneously distributed.As a result,the effectiveness of local emission controls in this region was strongly affected by meteorological conditions and regional transport.We found that one of the periods with emission control even showed the highest concentrations for the entire study.Our results point towards the limited effect of local emission controls in mitigating air pollution in CCP,and highlight the importance of joint emission controls under unfavorable meteorological conditions.
基金supported by the European Community’s Seventh Framework Program[grant number 606719]the Public Industry-specific Fund for Meteorology[grant number GYHY201106045]the National Science Foundation of China[grant number 41575144]
文摘Based on satellite observations, the effects of emission reduction measures on air pollutants （NO2 （nitrogen dioxide）, SO2 （sulfur dioxide）, and aerosols） were estimated in Beijing and its surroundings during the 2015 World Championships and Parade （WCP） held in Beijing. Compared with the same period in the previous three years （2012-2014）, the tropospheric vertical column densities of NO2 and SO2 in 2015 were significantly reduced in Beijing and its surroundings. During the WCP, aerosol optical depth was reduced most significantly in Beijing, while NO2 and SO2 were reduced most significantly in Hebei and Tianjin, respectively. The meteorological conditions were also favorable during this period. During the WCP, the North China Plain was located under high pressure from the north of China. A southward pressure gradient force and weak northerly and northeasterly winds blocked the transport of pollution from southern and western parts of the industrial area （Hebei, Shanxi and Shandong provinces）. Cold air masses pushed southwards weakly. These conditions were beneficial to the removal of air pollutants in Beijing.
基金supported by the Major State Basic Research Development Program of China (973 Program) (No. 2013CB430001)the Natural Science Foundation of China (No. 21077065)
文摘The iron and steel production process is one of the predominant anthropogenic sources of atmospheric mercury emissions worldwide. In this study, field tests were conducted to study mercury emission characteristics and mass flows at two iron and steel plants in China. It was found that low-sulfur flue gas from sintering machines could contribute up to41% of the total atmospheric mercury emissions, and desulfurization devices could remarkably help reduce the emissions. Coal gas burning accounted for 17%–49% of the total mercury emissions, and therefore the mercury control of coal gas burning, specifically for the power plant burning coal gas to generate electricity, was significantly important. The emissions from limestone and dolomite production and electric furnaces can contribute29.3% and 4.2% of the total mercury emissions from iron and steel production. More attention should be paid to mercury emissions from these two processes. Blast furnace dust accounted for 27%–36% of the total mercury output for the whole iron and steel production process. The recycling of blast furnace dust could greatly increase the atmospheric mercury emissions and should not be conducted. The mercury emission factors for the coke oven,sintering machine and blast furnace were 0.039–0.047 g Hg/ton steel, and for the electric furnace it was 0.021 g Hg/ton steel. The predominant emission species was oxidized mercury, accounting for 59%–73% of total mercury emissions to air.
基金This work was supported by the National Natural Science Foundation of China(Grant number 42077204)the National Key Research and Development Project(Grant number 2017YFC0210103)with data support provided by the National Earth System Science Data Center,National Science&Technology Infrastructure of China(http://www.geodata.cn).
文摘The COVID-19 lockdowns led to abrupt reductions in human-related emissions worldwide and had an unintended impact on air quality improvement.However,quantifying this impact is difficult as meteorological conditions may mask the real effect of changes in emissions on the observed concentrations of pollutants.Based on the air quality and meteorological data at 35 sites in Beijing from 2015 to 2020,a machine learning technique was applied to decouple the impacts of meteorology and emissions on the concentrations of air pollutants.The results showed that the real(“deweathered”)concentrations of air pollutants(expect for O 3)dropped significantly due to lockdown measures.Compared with the scenario without lockdowns(predicted concentrations),the observed values of PM_(2.5),PM_(10),SO_(2),NO_(2),and CO during lockdowns decreased by 39.4%,50.1%,51.8%,43.1%,and 35.1%,respectively.In addition,a significant decline for NO_(2)and CO was found at the background sites(51%and 37.8%)rather than the traffic sites(37.1%and 35.5%),which is different from the common belief.While the primary emissions reduced during the lockdown period,episodic haze events still occurred due to unfavorable meteorological conditions.Thus,developing an optimized strategy to tackle air pollution in Beijing is essential in the future.
基金sponsored by the National Science&Technology Pillar Program of China(No.2013BAC13B03)the National Natural Science Foundation of China(Nos.51322804 and 91544222)
文摘The Yangtze River Delta（YRD） region is one of the most prosperous and densely populated regions in China and is facing tremendous pressure to mitigate vehicle emissions and improve air quality.Our assessment has revealed that mitigating vehicle emissions of NOx would be more difficult than reducing the emissions of other major vehicular pollutants（e.g.,CO,HC and PM_（2.5）） in the YRD region.Even in Shanghai,where the emission control implemented are more stringent than in Jiangsu and Zhejiang,we observed little to no reduction in NOx emissions from 2000 to 2010.Emission-reduction targets for HC,NOx and PM_（2.5） are determined using a response surface modeling tool for better air quality.We design city-specific emission control strategies for three vehicle-populated cities in the YRD region：Shanghai and Nanjing and Wuxi in Jiangsu.Our results indicate that even if stringent emission control consisting of the Euro 6/VI standards,the limitation of vehicle population and usage,and the scrappage of older vehicles is applied,Nanjing and Wuxi will not be able to meet the NOx emissions target by 2020.Therefore,additional control measures are proposed for Nanjing and Wuxi to further mitigate NOx emissions from heavy-duty diesel vehicles.
基金supported by the Ministry of Science and Technology of China(Nos.2016YFC0202700,2016YFE0112200)the National Natural Science Foundation of China(Nos.21527814,91743202)the Marie Sklodowska-Curie Actions(No.H2020-MSCA-RISE-2015-690958)
文摘As the largest iron and steel producer in China, a part of Baosteel moved out of Shanghai deserves close attention due to its environmental impact. To understand the effect of Baosteel emission control on air quality in Shanghai, daily PM10, PM2.5, SO2, NO2 and CO were measured from 2010 to 2016. Concentrations of pollutants in Baoshan District presented a decreased trend during 2010-2016, with a reduction rate of 28.6% for PM10, 67.3% for SO2, 8.6% for NO2 and 42.0% for CO. However, fine particle pollution in Baoshan District during 2012-2016 seems to become more prominent, with PM2.5 concentration of 47 ± 28, 45 ± 33, 38 ± 24, 54 ± 41 and 51 ± 34 μg/m^3, respectively, indicating a slight increase of 8.5% in PM2.5. Concentrations of PM10 and CO decreased by 12.5% and 33.8% in the second half year in 2016 （compared with that in 2015） probably due to closure of blast furnace of Baosteel. Baosteel was identified as the largest pollution source in Baoshan District. Emission from Baosteel accounted for 58.0% of SO2, 43.6% of NO2 and 79.3% of dust in total emission from Baoshan District during 2010-2015. Meanwhile, pollutant emission and coal consumption from Baosteel decreased by 52.0% for SO2, 40.1% for NO2, 15.7% for dust and 22% for coal consumption. Energy consumption in Baoshan District reduced by 31% from 2011 to 2015. Air quality improvement in Shanghai was attributed to local emission reduction, together with regional air quality improvement.
基金supported by the National Key Research and Development Program(Nos.2019YFC0214800 and 2016YFC0208004)the National Natural Science Foundation of China(Nos.41822505 and 42061130213)+1 种基金supported by the Royal Society of the UK through the Newton Advanced Fellowship(No.NAFR1201166)the Tsinghua University Initiative Scientific Research Program(No.2019Z02CAU)。
文摘China’s emission control for nonroad diesel mobile machinery(NDMM)must deal with a fast increase in stock as well as regulations that are two decades behind those for on-road vehicles.This study provides the first large-scale review and evaluation of China’s NDMM policies,along with emission measurements and an investigation on diesel fuel quality.The sulfur contents of the investigated diesel declined from 430 ppm(median value)in 2011 to6-8 ppm during the 2017-2018 period.The emission control of NO_(x)and PM greatly improved with the shift from the China II to China IV standards,as demonstrated by engine tests and field NO_(x)measurements.However,the NO_(x)emission factors for non-type-approved engines were approximately twice the limits of the China II standards.Emission compliance based on bench tests was not sufficient to control actual emissions because the field-measured NO_(x)emission factors of all machinery ranged from 24%to 225%greater than the respective emission limits for the engines.These circumstances adversely affected the effectiveness of the regulations and policies for China’s emission control of NDMM.Nevertheless,the policies on new and in-use NDMM,as well as diesel fuel quality,prevented NO_(x)and PM emissions amounting to 4.4 Tg and 297.8 Gg during the period 2008-2017,respectively.The emission management strategy contributed to enhancing the international competitiveness of China’s NDMM industries by promoting advanced technologies.For effective NDMM emission control in the future,portable testing and noncontact remote supervision should be strengthened;also,the issue of noncompliant diesel should be addressed through rigorous control measures and financial penalties.
基金supported by the National Natural Science Foundation of China(22006044,22006043)External Cooperation Program of Science and Technology Planning of Fujian Province(2023I0018)+2 种基金the Fujian Province Science and Technology Program Funds(2020H6013)the National Engineering Laboratory for Mobile Source Emission Control Technology(NELMS2020A03)the Scientific Research Funds of Huaqiao University(605-50Y200270001)。
文摘The Co_(3)O_(4)nanoparticles,dominated by a catalytically active(110)lattice plane,were synthesized as a low-temperature NO_(x) adsorbent to control the cold start emissions from vehicles.These nanoparticles boast a substantial quantity of active chemisorbed oxygen and lattice oxygen,which exhibited a NO_(x) uptake capacity commensurate with Pd/SSZ-13 at 100℃.The primary NO_(x) release temperature falls within a temperature range of 200-350℃,making it perfectly suitable for diesel engines.The characterization results demonstrate that chemisorbed oxygen facilitate nitro/nitrites intermediates formation,contributing to the NO_(x) storage at 100℃,while the nitrites begin to decompose within the 150-200℃range.Fortunately,lattice oxygen likely becomes involved in the activation of nitrites into more stable nitrate within this particular temperature range.The concurrent processes of nitrites decomposition and its conversion to nitrates results in a minimal NO_(x) release between the temperatures of 150-200℃.The nitrate formed via lattice oxygen mainly induces the NO_(x) to be released as NO_(2) within a temperature range of 200-350℃,which is advantageous in enhancing the NO_(x) activity of downstream NH_(3)-SCR catalysts,by boosting the fast SCR reaction pathway.Thanks to its low cost,considerable NO_(x) absorption capacity,and optimal release temperature,Co_(3)O_(4)demonstrates potential as an effective material for passive NO_(x) adsorber applications.
基金the National Natural Science Foundation of China(No:20273043)the Ministry of Education of China for providing financial support for this project
文摘A three-way catalyst comprised novel oxygen storage components for emission control in natural gas powered engines was prepared. The addition of novel oxygen storage components to the Pd/γ-Al2O3 catalysts resulted in improved activities of the fresh and aged catalyst by lowering the light-off temperature for methane in natural gas engines exhaust.
文摘The requirements that a business needs to consider when building a wood panels manufacturing plant are much the same as they have been for decades, but today there is also the need for multiple environmental studies and permits. These are costly and time consuming additional expenses that often are the longest lead-time items on any project. Most industrialized countries have legislation in place to limit and control the negative impact that emission of pollutants may have on the environment. This paper discusses what is actually happening inside wood drying plants, and the prerequisite conditions for genesis of pyrolytic products relative to the operational parameters, such as choice of input raw materials, driers design and operational regime, choice of fuels for the heat generation and how these factors influence production of stack emission. The characterization of emission condensate by analytical methods is described, and survey of emission control system in use worldwide is described, and means of investigating what may be the optimum design for the control of emission is discussed. Alternate uses of utilizing the condensate, other than burning, are presented for consideration.
