Soil fugitive dust(SFD)is characterized by a variety of sources and considerable spatialtemporal variability,exerting a significant impact on environmental air quality and ecological systems in cities across northern ...Soil fugitive dust(SFD)is characterized by a variety of sources and considerable spatialtemporal variability,exerting a significant impact on environmental air quality and ecological systems in cities across northern China.Multiple factors can shape SFD emission.Nevertheless,the current comprehension of its critical impact factors and quantitative methodologies remains constrained.This study utilizes interpretable machine learning techniques to identify the principal impact factors of SFD and their interactions while delineating their action thresholds.The findings reveal seasonal variations in impact factors and emphasize the substantial effect of bare soil source strength on SFD,including parameters such as bare soil area and soil moisture.Consequently,the Wind Erosion Equation model is optimized following these findings to localize its parameters and improve its capability to calculate hourly SFD emissions.The case application is validated using observational data,demonstrating the reliability and precision of the optimized methodology.This study provides insights and solutions for the local optimization of SFD parameterization schemes and further supports the formulation of precise prevention and control policies for SFD.展开更多
Fugitive emission from industrial sources may result in ozone formation and health risk,while the exact contribution of this source remains incompletely understood.In this study,emission characteristics,ozone formatio...Fugitive emission from industrial sources may result in ozone formation and health risk,while the exact contribution of this source remains incompletely understood.In this study,emission characteristics,ozone formation potential(OFP)and health risk of fugitive VOCs in7 representative industries were investigated.Chemical material industry was the dominant contributor to VOCs of fugitive emission in comparison with other industries.The OFP of VOCs from fugitive emission was in the range of 1.45×10^(3)-3.98×10^(5)μg/m^(3),with a higher value than that of organized emission in seven industries except for the coking industry and the chemical material industry,suggesting that fugitive VOCs should be taken into account while developing control strategies.Acetaldehyde,m,p-xylene,n-nonane,ethylene,vinyl chloridethe and other high OFP-contributing species were the major reactive species that should be targeted.Health risk assessment investigated non-cancer and cancer risks of fugitive VOCs in 7 industries were all above safe level(HR>1 and LCR>1×10^(-4)),posing remarkable health threats to human health.OVOCs were the main contributor to non-cancer risk,while halohydrocarbons and aromatics contributed most to cancer risks,posing remarkable health threat on human health.Our findings highlighted the contribution of fugitive VOCs on ozone formation and health risk was underestimated,indicating which should be considered in emission control strategies of industrial sources.展开更多
Fugitive emission has been becoming an important source of volatile organic compounds(VOCs) in pharmaceutical industry,but the exact contribution of fugitive emission remains incompletely understood.In present study,p...Fugitive emission has been becoming an important source of volatile organic compounds(VOCs) in pharmaceutical industry,but the exact contribution of fugitive emission remains incompletely understood.In present study,pollution characteristics,odorous activity and health risk of stack and fugitive emissions of VOCs from four functional units (e.g.,workshop,sewage treatment station,raw material storage and hazardous waste storage) of three representative pharmaceutical factories were investigated.Workshop was the dominant contributor to VOCs of fugitive emission in comparison with other functional units.Extreme high concentration of VOCs from fugitive emission in unsealed workshop (94.87 mg/m^(3))was observed relative to sealed one (1.18 mg/m^(3)),accounting for 31%and 5%of total VOCs,respectively.Fugitive emission of VOCs in the unsealed workshop mainly consisted of nhexane,1-hexene and dichloromethane.Odorous activity indexes and non-cancer hazard ratios of these VOCs from fugitive emission in the unsealed workshop were as high as that from stack exhaust.Furthermore,cancer risk of dichloromethane from fugitive emission and stack exhaust was up to (1.6-1.8)×10^(-5).Odorous activity or health risk index of the VOCs from fugitive emission was up to 13 or 11 times of the corresponding threshold value,posing remarkable health threat on pharmaceutical workers.Our?ndings highlighted the possibly underestimated contribution of fugitive emission on VOCs in the pharmaceutical industry.展开更多
Fugitive dust was cemented, forming larger particles bond in the calcite-consolidation-layer by microbial method. The particular composition, the morphology, and thermal decomposition properties of the samples were ch...Fugitive dust was cemented, forming larger particles bond in the calcite-consolidation-layer by microbial method. The particular composition, the morphology, and thermal decomposition properties of the samples were characterized by X-ray diffraction（XRD）, scanning electron microscopy（SEM）, Fourier transform infrared（FTIR） spectroscopy, and differential scanning calorimetry-thermogravimetry（DSC-TG）. The characterization data obtained showed that loose fugitive dust particles could be bonded and formed the consolidation-layer under the effect of calcite obtained by microbial method successfully. Meanwhile, the sample obtained by microbial method had superior wind-erosion resistance.展开更多
Fugitive road dust(FRD)contributes a great deal to urban rainwater and air pollution and is commonly controlled by water-sprinkling in most Chinese cities.However,there is a lack of information on its effectiveness.We...Fugitive road dust(FRD)contributes a great deal to urban rainwater and air pollution and is commonly controlled by water-sprinkling in most Chinese cities.However,there is a lack of information on its effectiveness.We used the Testing Re-entrained Aerosol Kinetic Emissions from Roads(TRAKER)method to monitor different types of roads in Baoding city before and within 1 hr after water-sprinkling and obtained the road dirtiness index(a)and PM concentration in the road environment(T^(∗)_(T)),to evaluate the removal efficiency for PM deposited on the road surface(ηa)and the reduction efficiency for the PM concentration in the road environment(ηPM).The results give that theηa for three types of roads is ranked:branch road(87%-–100%)>major arterial road(80%-83%)>minor arterial road(68%-77%),and the ηPM ranked:minor arterial road(70%)>branch road(46%-58%)>major arterial road(37%-53%).Theηa andηPM varied non-linearly with time and presented a quadratic curve.The average effective control time(ηa>0)was 62min on themajor andminor arterial roads,and much longer than 1 hr on branch roads.The ηPM values diminished completely by 72 min on average from the end of sprinkling for the three types of roads.Water-sprinkling can remove PM10 particles from the road surface and reduce their concentration in the road environment more thoroughly than PM2.5.Our findings could be helpful for controlling urban FRD emissions more efficiently and precisely.展开更多
This research assessed the environmental impact of cement silos emission on the existing concrete batching facilities in M35-Mussafah, Abu Dhabi, United Arab Emirates. These assessments were conducted using an air qua...This research assessed the environmental impact of cement silos emission on the existing concrete batching facilities in M35-Mussafah, Abu Dhabi, United Arab Emirates. These assessments were conducted using an air quality dispersion model (AERMOD) to predict the ambient concentration of Portland Cement particulate matter less than 10 microns (PM<sub>10</sub>) emitted to the atmosphere during loading and unloading activities from 176 silos located in 25 concrete batching facilities. AERMOD was applied to simulate and describe the dispersion of PM<sub>10</sub> released from the cement silos into the air. Simulations were carried out for PM<sub>10</sub> emissions on controlled and uncontrolled cement silos scenarios. Results showed an incremental negative impact on air quality and public health from uncontrolled silos emissions and estimated that the uncontrolled PM<sub>10</sub> emission sources contribute to air pollution by 528958.32 kg/Year. The modeling comparison between the controlled and uncontrolled silos shows that the highest annual average concentration from controlled cement silos is 0.065 μg/m<sup>3</sup>, and the highest daily emission value is 0.6 μg/m<sup>3</sup>;both values are negligible and will not lead to significant air quality impact in the entire study domain. However, the uncontrolled cement silos’ highest annual average concentration value is 328.08 μg/m<sup>3</sup>. The highest daily emission average value was 1250.09 μg/m<sup>3</sup>;this might cause a significant air pollution quality impact and health effects on the public and workers. The short-term and long-term average PM<sub>10</sub> pollutant concentrations at these receptors predicted by the air dispersion model are discussed for both scenarios and compared with local and international air quality standards and guidelines.展开更多
Eighty sites were set up to monitor road dust fall and 80 locations were selected to sample silt loading in April, August, and November 2007 and January 2008 in the Beijing metropolitan area. Fugitive road dust emissi...Eighty sites were set up to monitor road dust fall and 80 locations were selected to sample silt loading in April, August, and November 2007 and January 2008 in the Beijing metropolitan area. Fugitive road dust emission strengths were calculated using the AP-42 emission factor model. Silt loading on Beijing urban roads was typically less than 1.0 g/m^2, the PM10 emission strength was typically less than 100 kg/km·day, and road dust fall was typically less than 40 t/km^2·30day. The relationships between traffic volume, silt loading, fugitive road dust emission strength and road dust fall were studied in the Beijing metropolitan area. The results indicate that silt loading and emission factors are negatively correlated with traffic volume, but the PM10 emission rate and road dust-fall are positively correlated with traffic volume.展开更多
One of the main origins of fugitive dust emission arises from bulk handling in quarries or mines, in particular, from bulk materials falling from a hopper or a conveyor belt. Water-spraying systems, using two-phase no...One of the main origins of fugitive dust emission arises from bulk handling in quarries or mines, in particular, from bulk materials falling from a hopper or a conveyor belt. Water-spraying systems, using two-phase nozzles, are one of the methods to suppress such dust emission. In this work we tried to develop a mathematical model to correlate air humidity, water flux through the nozzle and the dust （in particular PM10） emission, in order to improve the application and efficiency of these systems. Sand from the Yellow River in China was dropped from a conveyor belt into a dust chamber at 1 kg·min^-1, wherefrom the emitted dust was sucked off and quantified via a cascade impactor. A two-phase nozzle was installed in the dust chamber with a water flux through the nozzle of 1.2 to 3 L·h^-1, whereas the relative air humidity changed between 55 and 73%. Dust emission was found to be linearly dependent on relative air humidity. Furthermore model equations were developed to describe the dependence of PM10 emission on water flux and relative air humidity.展开更多
As a new green and environmental material, bio-activated cementitious material is attracting extensive attention. This study confirmed that the bio-activated cementitious material could mineralize and cement fugitive ...As a new green and environmental material, bio-activated cementitious material is attracting extensive attention. This study confirmed that the bio-activated cementitious material could mineralize and cement fugitive dust into the cal- cite-consolidation-layer based on CO2 capture and utilization. The results illustrated that treatment processes （non-pressure spraying, pressure spraying, non-pressure blending and pressure blending） had a strong effect on the microstructure and prop- erties of calcite-consolidation-layer. According to the analysis of X-ray diffraction （XRD） and Fourier transform infrared （FTIR）, calcite was prepared by bio-activated cementitious material during the cementation process. Meanwhile, scanning electron microscopy （SEM） and thermogravimetric-differenfial scanning calorimetry （TG-DSC） were adopted to measure the corresponding variation of porous characteristics and calcite content caused by different treatment processes. The results indi- cated that the microstructure of calcite-consolidation-layer from the spraying process had lower porosity and higher content of calcite than from blending processes. In addition, the mechanical properties of calcite-consolidation-layer were also tested. The hardness and compressive strength, which reached 19.5 GPa and 0.6 MPa, respectively, of calcite-consolidation-layer from the pressure spraying process were higher than those from the other three treatment processes. Compared with the non-treatment process, the four treatment processes had superior wind erosion resistance. Under the wind speed of 12 m/s, the mass loss of calcite-consolidation-layer from the pressure spraying process decreased from 2150.2 to 23.8 g/（m^2 h）.展开更多
A new statute.“Hiding New and Old Fugitive Slaves of Manchus,”was added to the First version of the Qing code in 1647.and this statute surprisingly regulated that any offenders would be excluded from any amnesties.T...A new statute.“Hiding New and Old Fugitive Slaves of Manchus,”was added to the First version of the Qing code in 1647.and this statute surprisingly regulated that any offenders would be excluded from any amnesties.This is especially noteworthy because,according to both Ming and Qing codes,only severe crimes,such as treason and rebellion,were excluded from any amnesties.Previous scholars have not considered why the statute excluded any amnesties,nor have they analyzed how this amnesty policy was implemented in practice.This article contends that the exclusion did not arise from Manchu tradition.Instead,it was an exceptional response to the norms of amnesties in the Ming and Qing codes.Because the fugitive problem,involving slaves of Manchus fleeing from the banner system,endangered Manchus interests,the Qing court was compelled to exclude fugitive criminals from amnesties.However,the Qing court did not strictly apply the amnesty policy of this statute.Criminals in fugitive cases were sometimes pardoned because of amnesties during the Dorgon regency period.Dorgon,Shun/.hi.Oboi,and Kangxi all initially excluded those harboring fugitives from amnesties,but later changed their amnesty policies in this regard.Even though the crime of harboring fugitives became a permanent symbol of Manchu rule and was recorded in every emperor's enthronement edict from Kangxi to Xuantong.the Qing court gradually came to accept norms concerning amnesties as practiced in Han society and treated fugitive cases as ordinary court cases during and after the Kangxi emperor's reign.展开更多
China hopes the new international anticorruption convention will help it nab corrupt officials who have fled abroad The end of 2005 saw the birth of the UN Anticorruption Convention. Because many Chinese officials who...China hopes the new international anticorruption convention will help it nab corrupt officials who have fled abroad The end of 2005 saw the birth of the UN Anticorruption Convention. Because many Chinese officials who have fled overseas with state funds are still at large, China hopes that the first UN legal document to provide guidelines for international campaigns against corruption will help to bring展开更多
The measurement and assessment of dust emissions from different landforms are important to understand the atmospheric loading of PM10 （particulate matter ≤10 μm aerodynamic diameter） and to assess natural sources ...The measurement and assessment of dust emissions from different landforms are important to understand the atmospheric loading of PM10 （particulate matter ≤10 μm aerodynamic diameter） and to assess natural sources of dust; however, the methodology and technique for determining the dust still present significant research challenges. In the past, specialized field observation and field wind tunnel studies have been used to understand the dust emission. A series of wind tunnel tests were carried out to identify natural sources of dust and measure the magnitudes of dust emissions from different landforms. The method used in this study allowed the measurement of the PM10 emission rate using a laboratory based environmental boundary layer wind tunnel. Results indicated that PM10 emissions demonstrated strong temporal variation and were primarily driven by aerodynamic entrainment. Sand dunes, playa, and alluvial fans had the largest dust emission rates （0.8-5.4 mg/（me.s）） while sandy gravel, Gobi desert and abandoned lands had the lowest emission rates （0.003-0.126 mg/（m2.s））. Dust emissions were heavily dependent on the surface conditions, especially the availability of loose surface dust. High dust emissions were a result of the availability of dust- particle materials for entrainment while low dust emissions were a result of surface crusts and gravel cover. Soil surface property （surface crusts and gravel cover） plays an important role in controlling the availability of dust-sized particles for entrainment. The dust emission rate depended not only on the surface conditions but also on the friction velocity. The emission rate of PM10 varies as a power function of the friction velocity. Although dynamic abrasion processes have a strong influence on the amount of dust entrainment, aerodynamic entrainment may provide an important mechanism for dust emissions. Large volumes of dust entrained by aerodynamic entrainment cannot only occur at low shear velocity without saltation, but may dominate the entrainment process in many arid and semi-arid environments. So it may also be responsible for large magnitude dust storms. Playa and alluvial fan landforms, prior to developing a surface crust, may be the main sources of dust storms in Qinghai Province.展开更多
This study aimed to describe a Computational Fluid Dynamics(CFD) procedure using the ANSYS CFX software 16.1 and Design of Experiments for the determination of volume and extension of explosive atmospheres due to fugi...This study aimed to describe a Computational Fluid Dynamics(CFD) procedure using the ANSYS CFX software 16.1 and Design of Experiments for the determination of volume and extension of explosive atmospheres due to fugitive emissions of flammable gases.The multidimensional statistical sampling technique Latin Hypercube was used, which defined 100 simulations of random methane gas leak conditions.The CFD model proved to be robust in predicting the extension and volume of the explosive atmosphere for orifice diameters from 0.1 to2.5 mm, pressure from 0.1 MPa to 12 MPa and temperatures from 0 ℃ to 400 ℃.It was found that the calculation domain must be parameterized 8 m in length for each millimeter of the diameter of the source of release to ensure the predictions.In order not to lose precision for very small diameters, the mesh was parameterized with 50 elements along the orifice diameter.It was proved that gravity does not influence the extension and volume of the explosive atmosphere at sonic emissions.The deviation from the ideal gas behavior in the reservoir,achieved by applying the Soave–Redlich–Kwong equation of state, also has not significantly influenced the extension and volume of the explosive atmosphere.The results showed that the size of the explosive atmosphere varies directly with the diameter of the source emission and reservoir pressure, and inversely with the temperature of the reservoir.The diameter of the source is the parameter that has the major effect on the extension of the explosive atmosphere, followed by the pressure and lastly the temperature of the reservoir.展开更多
Fugitive dust is one of the well known problems in agriculture and it affects both humans and machine producing quality. Dust problems can seriously cause harmful diseases to workers and ruin expensive equipments. In ...Fugitive dust is one of the well known problems in agriculture and it affects both humans and machine producing quality. Dust problems can seriously cause harmful diseases to workers and ruin expensive equipments. In this study, a dust formation generated in open environment by vehicles was analyzed on unpaved roads. Formed dust was measured by calculating total forces on the PM10 （airborne particles smaller than 10 mm） of dust particles, such as air velocity, gravity forces and air turbulence generated by the moving vehicle. The water fogger nozzle discharge was measured to determine the approximate droplets quantity in the air. The foggers were used to suppress the generated dust in an open environment via installing a proposed automatic suppression system which opens automatically when vehicles pass under the system. The relationship between water droplet speed and ability of collecting fugitive dust showed that high air temperature above 40oC and wind speed above 10 m s-1 have negative effects on the system’s ability of collecting dust due to evaporation of small radius droplets and/or drifting water droplets away from the effective area. The overall system efficiency was found to be 85% and the proposed dust suppression system was found to be a satisfying solution for reducing fugitive dust hazards.展开更多
With policy incentives for the coalbed methane in energy industry,coalbed methane from coal production has been effectively improved by technology innovations in coalbed methane extraction and utilization.The progress...With policy incentives for the coalbed methane in energy industry,coalbed methane from coal production has been effectively improved by technology innovations in coalbed methane extraction and utilization.The progress of coalbed methane promotes the clean construction of energy system and contributes to carbon neutrality target.To quantitatively measure the contributions of the coalbed methane in energy industry,this paper builds a carbon emissions accounting system for coalbed methane in China and assesses the historical co-benefits of coalbed methane utilization from the aspects of emissions reduction,safety and economy.By using the parameters of gas content,raw coal production,gas extraction rate and utilization rate over the years,emissions reduction potential and economic viability of coal seam gas are estimated and the safety benefits of coal mine gas extraction are analyzed by using data for gas accidents and economic losses.The results reveal that with the increase in raw coal production,the great emission reduction potential of coalbed methane is expected to benefit clean energy system and the development of carbon neutrality by means of policy incentives and technology innovations.The co-benefit evaluation indicates the huge profitability of coalbed methane from 2012 to 2015 and the significance of emissions reduction and safety gain internalization.Safety benefits are obvious in the negative exponential function between the annual drainage quantities of coalbed methane and annual death tolls from coal mine gas accidents.Based on these results,relevant suggestions are put forward for sustainable development of the coalbed methane in energy industry.展开更多
This research study quantifies the PM<sub>10</sub> emission rates (g/s) from cement silos in 25 concrete batching facilities for both controlled and uncontrolled scenarios by applying the USEPA AP-42 guide...This research study quantifies the PM<sub>10</sub> emission rates (g/s) from cement silos in 25 concrete batching facilities for both controlled and uncontrolled scenarios by applying the USEPA AP-42 guidelines step-by-step approach. The study focuses on evaluating the potential environmental impact of cement dust fugitive emissions from 176 cement silos located in 25 concrete batching facilities in the M35 Mussafah industrial area of Abu Dhabi, UAE. Emission factors are crucial for quantifying the PM<sub>10</sub> emission rates (g/s) that support developing source-specific emission estimates for areawide inventories to identify major sources of pollution that provide screening sources for compliance monitoring and air dispersion modeling. This requires data to be collected involves information on production, raw material usage, energy consumption, and process-related details, this was obtained using various methods, including field visits, surveys, and interviews with facility representatives to calculate emission rates accurately. Statistical analysis was conducted on cement consumption and emission rates for controlled and uncontrolled sources of the targeted facilities. The data shows that the average cement consumption among the facilities is approximately 88,160 (MT/yr), with a wide range of variation depending on the facility size and production rate. The emission rates from controlled sources have an average of 4.752E<sup>-04</sup> (g/s), while the rates from uncontrolled sources average 0.6716 (g/s). The analysis shows a significant statistical relationship (p < 0.05) and perfect positive correlation (r = 1) between cement consumption and emission rates, indicating that as cement consumption increases, emission rates tend to increase as well. Furthermore, comparing the emission rates from controlled and uncontrolled scenarios. The data showed a significant difference between the two scenarios, highlighting the effectiveness of control measures in reducing PM<sub>10</sub> emissions. The study’s findings provide insights into the impact of cement silo emissions on air quality and the importance of implementing control measures in concrete batching facilities. The comparative analysis contributes to understanding emission sources and supports the development of pollution control strategies in the Ready-Mix industry.展开更多
China launched a campaign code-named Sky Net 2025 to hunt down corrupt fugitives,recover illegal proceeds and combat cross-border corruption,according to a meeting of the office for fugitive repatriation and asset rec...China launched a campaign code-named Sky Net 2025 to hunt down corrupt fugitives,recover illegal proceeds and combat cross-border corruption,according to a meeting of the office for fugitive repatriation and asset recovery under the Central Anti-Corruption Coordination Group held on March 24.展开更多
Particulate matter （PM） emissions from steelworks cause public concern. Although end-of-pipe and pro- cess integrated measures have led to a significant drop in emissions of large particles from stacks, fine aerosol...Particulate matter （PM） emissions from steelworks cause public concern. Although end-of-pipe and pro- cess integrated measures have led to a significant drop in emissions of large particles from stacks, fine aerosols were not specifically considered, nor were emissions from fugitive and open sources. In this study, we deployed aerosol samplers together with a scanning ultra-violet （UV） lidar to characterize total suspended particles （TSP）, PM10, and PM2.5, in emissions from a large integrated steelworks in Spain over a 16-day period. We determined the content of carbonaceous, soluble inorganic, mineral dust, and metal species. A positive matrix factorization was carried out on our dataset. Despite mineral dust being predominant in all size fractions, the steelworks was clearly a source of carbonaceous species, resulting in production of secondary inorganic aerosols. In particular, stack emissions were a major contributor of fine particles, while open sources dominated the emissions of TSP, yielding up to 80% of particles larger than PM10. UV lidar provided 2D maps of aerosols in real time, with an ability to detect PM emissions and to visualize complex plumes. We suggest that air quality management of steelworks needs to focus on controlling large and coarse oarticle emissions, esoeciallv those from onen sources.展开更多
基金supported by the General Program of National Natural Science Foundation of China(No.42275190)。
文摘Soil fugitive dust(SFD)is characterized by a variety of sources and considerable spatialtemporal variability,exerting a significant impact on environmental air quality and ecological systems in cities across northern China.Multiple factors can shape SFD emission.Nevertheless,the current comprehension of its critical impact factors and quantitative methodologies remains constrained.This study utilizes interpretable machine learning techniques to identify the principal impact factors of SFD and their interactions while delineating their action thresholds.The findings reveal seasonal variations in impact factors and emphasize the substantial effect of bare soil source strength on SFD,including parameters such as bare soil area and soil moisture.Consequently,the Wind Erosion Equation model is optimized following these findings to localize its parameters and improve its capability to calculate hourly SFD emissions.The case application is validated using observational data,demonstrating the reliability and precision of the optimized methodology.This study provides insights and solutions for the local optimization of SFD parameterization schemes and further supports the formulation of precise prevention and control policies for SFD.
基金supported by the National Natural Science Foundation of China (No.42177420)。
文摘Fugitive emission from industrial sources may result in ozone formation and health risk,while the exact contribution of this source remains incompletely understood.In this study,emission characteristics,ozone formation potential(OFP)and health risk of fugitive VOCs in7 representative industries were investigated.Chemical material industry was the dominant contributor to VOCs of fugitive emission in comparison with other industries.The OFP of VOCs from fugitive emission was in the range of 1.45×10^(3)-3.98×10^(5)μg/m^(3),with a higher value than that of organized emission in seven industries except for the coking industry and the chemical material industry,suggesting that fugitive VOCs should be taken into account while developing control strategies.Acetaldehyde,m,p-xylene,n-nonane,ethylene,vinyl chloridethe and other high OFP-contributing species were the major reactive species that should be targeted.Health risk assessment investigated non-cancer and cancer risks of fugitive VOCs in 7 industries were all above safe level(HR>1 and LCR>1×10^(-4)),posing remarkable health threats to human health.OVOCs were the main contributor to non-cancer risk,while halohydrocarbons and aromatics contributed most to cancer risks,posing remarkable health threat on human health.Our findings highlighted the contribution of fugitive VOCs on ozone formation and health risk was underestimated,indicating which should be considered in emission control strategies of industrial sources.
基金supported by the National Key R&D Program of China (No. 2019YFC0214402)the National Nature Science Foundation of China (Nos. 41805103, 42177354, and 21777032)+1 种基金the Natural Science Foundation of Guangdong Province (No. 2021A1515011492)the Science and Technology Program of Guangzhou (No. 202102020451)。
文摘Fugitive emission has been becoming an important source of volatile organic compounds(VOCs) in pharmaceutical industry,but the exact contribution of fugitive emission remains incompletely understood.In present study,pollution characteristics,odorous activity and health risk of stack and fugitive emissions of VOCs from four functional units (e.g.,workshop,sewage treatment station,raw material storage and hazardous waste storage) of three representative pharmaceutical factories were investigated.Workshop was the dominant contributor to VOCs of fugitive emission in comparison with other functional units.Extreme high concentration of VOCs from fugitive emission in unsealed workshop (94.87 mg/m^(3))was observed relative to sealed one (1.18 mg/m^(3)),accounting for 31%and 5%of total VOCs,respectively.Fugitive emission of VOCs in the unsealed workshop mainly consisted of nhexane,1-hexene and dichloromethane.Odorous activity indexes and non-cancer hazard ratios of these VOCs from fugitive emission in the unsealed workshop were as high as that from stack exhaust.Furthermore,cancer risk of dichloromethane from fugitive emission and stack exhaust was up to (1.6-1.8)×10^(-5).Odorous activity or health risk index of the VOCs from fugitive emission was up to 13 or 11 times of the corresponding threshold value,posing remarkable health threat on pharmaceutical workers.Our?ndings highlighted the possibly underestimated contribution of fugitive emission on VOCs in the pharmaceutical industry.
基金Funded by the National Natural Science Foundation of China(No.51372038)the Scientific Research Foundation of Graduate School of Southeast University(YBJJ1566)
文摘Fugitive dust was cemented, forming larger particles bond in the calcite-consolidation-layer by microbial method. The particular composition, the morphology, and thermal decomposition properties of the samples were characterized by X-ray diffraction（XRD）, scanning electron microscopy（SEM）, Fourier transform infrared（FTIR） spectroscopy, and differential scanning calorimetry-thermogravimetry（DSC-TG）. The characterization data obtained showed that loose fugitive dust particles could be bonded and formed the consolidation-layer under the effect of calcite obtained by microbial method successfully. Meanwhile, the sample obtained by microbial method had superior wind-erosion resistance.
基金supported by the National Key R&D Program of China (No. 2019YFC0214200)the National Research Program for Key Issues in Air Pollution Control of China (No. DQGG030405)the National Basic Science Research Program of the Chinese Research Academy of Environmental Sciences (No. JY21277132-201309406)
文摘Fugitive road dust(FRD)contributes a great deal to urban rainwater and air pollution and is commonly controlled by water-sprinkling in most Chinese cities.However,there is a lack of information on its effectiveness.We used the Testing Re-entrained Aerosol Kinetic Emissions from Roads(TRAKER)method to monitor different types of roads in Baoding city before and within 1 hr after water-sprinkling and obtained the road dirtiness index(a)and PM concentration in the road environment(T^(∗)_(T)),to evaluate the removal efficiency for PM deposited on the road surface(ηa)and the reduction efficiency for the PM concentration in the road environment(ηPM).The results give that theηa for three types of roads is ranked:branch road(87%-–100%)>major arterial road(80%-83%)>minor arterial road(68%-77%),and the ηPM ranked:minor arterial road(70%)>branch road(46%-58%)>major arterial road(37%-53%).Theηa andηPM varied non-linearly with time and presented a quadratic curve.The average effective control time(ηa>0)was 62min on themajor andminor arterial roads,and much longer than 1 hr on branch roads.The ηPM values diminished completely by 72 min on average from the end of sprinkling for the three types of roads.Water-sprinkling can remove PM10 particles from the road surface and reduce their concentration in the road environment more thoroughly than PM2.5.Our findings could be helpful for controlling urban FRD emissions more efficiently and precisely.
文摘This research assessed the environmental impact of cement silos emission on the existing concrete batching facilities in M35-Mussafah, Abu Dhabi, United Arab Emirates. These assessments were conducted using an air quality dispersion model (AERMOD) to predict the ambient concentration of Portland Cement particulate matter less than 10 microns (PM<sub>10</sub>) emitted to the atmosphere during loading and unloading activities from 176 silos located in 25 concrete batching facilities. AERMOD was applied to simulate and describe the dispersion of PM<sub>10</sub> released from the cement silos into the air. Simulations were carried out for PM<sub>10</sub> emissions on controlled and uncontrolled cement silos scenarios. Results showed an incremental negative impact on air quality and public health from uncontrolled silos emissions and estimated that the uncontrolled PM<sub>10</sub> emission sources contribute to air pollution by 528958.32 kg/Year. The modeling comparison between the controlled and uncontrolled silos shows that the highest annual average concentration from controlled cement silos is 0.065 μg/m<sup>3</sup>, and the highest daily emission value is 0.6 μg/m<sup>3</sup>;both values are negligible and will not lead to significant air quality impact in the entire study domain. However, the uncontrolled cement silos’ highest annual average concentration value is 328.08 μg/m<sup>3</sup>. The highest daily emission average value was 1250.09 μg/m<sup>3</sup>;this might cause a significant air pollution quality impact and health effects on the public and workers. The short-term and long-term average PM<sub>10</sub> pollutant concentrations at these receptors predicted by the air dispersion model are discussed for both scenarios and compared with local and international air quality standards and guidelines.
文摘Eighty sites were set up to monitor road dust fall and 80 locations were selected to sample silt loading in April, August, and November 2007 and January 2008 in the Beijing metropolitan area. Fugitive road dust emission strengths were calculated using the AP-42 emission factor model. Silt loading on Beijing urban roads was typically less than 1.0 g/m^2, the PM10 emission strength was typically less than 100 kg/km·day, and road dust fall was typically less than 40 t/km^2·30day. The relationships between traffic volume, silt loading, fugitive road dust emission strength and road dust fall were studied in the Beijing metropolitan area. The results indicate that silt loading and emission factors are negatively correlated with traffic volume, but the PM10 emission rate and road dust-fall are positively correlated with traffic volume.
文摘One of the main origins of fugitive dust emission arises from bulk handling in quarries or mines, in particular, from bulk materials falling from a hopper or a conveyor belt. Water-spraying systems, using two-phase nozzles, are one of the methods to suppress such dust emission. In this work we tried to develop a mathematical model to correlate air humidity, water flux through the nozzle and the dust （in particular PM10） emission, in order to improve the application and efficiency of these systems. Sand from the Yellow River in China was dropped from a conveyor belt into a dust chamber at 1 kg·min^-1, wherefrom the emitted dust was sucked off and quantified via a cascade impactor. A two-phase nozzle was installed in the dust chamber with a water flux through the nozzle of 1.2 to 3 L·h^-1, whereas the relative air humidity changed between 55 and 73%. Dust emission was found to be linearly dependent on relative air humidity. Furthermore model equations were developed to describe the dependence of PM10 emission on water flux and relative air humidity.
基金supported by the National Nature Science Foundation of China(Grant No.51372038)the Key Research and Development Program of Jiangsu Science and Technology Department(Grant No.BE2015678)+1 种基金the Science and Technology Research Program of Jiangsu Transport Department(Grant No.2015T32)the Scientific Research Foundation of Graduate School of Southeast University(Grant No.YBJJ1566)
文摘As a new green and environmental material, bio-activated cementitious material is attracting extensive attention. This study confirmed that the bio-activated cementitious material could mineralize and cement fugitive dust into the cal- cite-consolidation-layer based on CO2 capture and utilization. The results illustrated that treatment processes （non-pressure spraying, pressure spraying, non-pressure blending and pressure blending） had a strong effect on the microstructure and prop- erties of calcite-consolidation-layer. According to the analysis of X-ray diffraction （XRD） and Fourier transform infrared （FTIR）, calcite was prepared by bio-activated cementitious material during the cementation process. Meanwhile, scanning electron microscopy （SEM） and thermogravimetric-differenfial scanning calorimetry （TG-DSC） were adopted to measure the corresponding variation of porous characteristics and calcite content caused by different treatment processes. The results indi- cated that the microstructure of calcite-consolidation-layer from the spraying process had lower porosity and higher content of calcite than from blending processes. In addition, the mechanical properties of calcite-consolidation-layer were also tested. The hardness and compressive strength, which reached 19.5 GPa and 0.6 MPa, respectively, of calcite-consolidation-layer from the pressure spraying process were higher than those from the other three treatment processes. Compared with the non-treatment process, the four treatment processes had superior wind erosion resistance. Under the wind speed of 12 m/s, the mass loss of calcite-consolidation-layer from the pressure spraying process decreased from 2150.2 to 23.8 g/（m^2 h）.
基金This article is supported by the National Social Science Fund of China(Project No.15BZS068).
文摘A new statute.“Hiding New and Old Fugitive Slaves of Manchus,”was added to the First version of the Qing code in 1647.and this statute surprisingly regulated that any offenders would be excluded from any amnesties.This is especially noteworthy because,according to both Ming and Qing codes,only severe crimes,such as treason and rebellion,were excluded from any amnesties.Previous scholars have not considered why the statute excluded any amnesties,nor have they analyzed how this amnesty policy was implemented in practice.This article contends that the exclusion did not arise from Manchu tradition.Instead,it was an exceptional response to the norms of amnesties in the Ming and Qing codes.Because the fugitive problem,involving slaves of Manchus fleeing from the banner system,endangered Manchus interests,the Qing court was compelled to exclude fugitive criminals from amnesties.However,the Qing court did not strictly apply the amnesty policy of this statute.Criminals in fugitive cases were sometimes pardoned because of amnesties during the Dorgon regency period.Dorgon,Shun/.hi.Oboi,and Kangxi all initially excluded those harboring fugitives from amnesties,but later changed their amnesty policies in this regard.Even though the crime of harboring fugitives became a permanent symbol of Manchu rule and was recorded in every emperor's enthronement edict from Kangxi to Xuantong.the Qing court gradually came to accept norms concerning amnesties as practiced in Han society and treated fugitive cases as ordinary court cases during and after the Kangxi emperor's reign.
文摘China hopes the new international anticorruption convention will help it nab corrupt officials who have fled abroad The end of 2005 saw the birth of the UN Anticorruption Convention. Because many Chinese officials who have fled overseas with state funds are still at large, China hopes that the first UN legal document to provide guidelines for international campaigns against corruption will help to bring
基金supported by the National Basic Research Program of China (2016YFA0601901, 2013CB956001)
文摘The measurement and assessment of dust emissions from different landforms are important to understand the atmospheric loading of PM10 （particulate matter ≤10 μm aerodynamic diameter） and to assess natural sources of dust; however, the methodology and technique for determining the dust still present significant research challenges. In the past, specialized field observation and field wind tunnel studies have been used to understand the dust emission. A series of wind tunnel tests were carried out to identify natural sources of dust and measure the magnitudes of dust emissions from different landforms. The method used in this study allowed the measurement of the PM10 emission rate using a laboratory based environmental boundary layer wind tunnel. Results indicated that PM10 emissions demonstrated strong temporal variation and were primarily driven by aerodynamic entrainment. Sand dunes, playa, and alluvial fans had the largest dust emission rates （0.8-5.4 mg/（me.s）） while sandy gravel, Gobi desert and abandoned lands had the lowest emission rates （0.003-0.126 mg/（m2.s））. Dust emissions were heavily dependent on the surface conditions, especially the availability of loose surface dust. High dust emissions were a result of the availability of dust- particle materials for entrainment while low dust emissions were a result of surface crusts and gravel cover. Soil surface property （surface crusts and gravel cover） plays an important role in controlling the availability of dust-sized particles for entrainment. The dust emission rate depended not only on the surface conditions but also on the friction velocity. The emission rate of PM10 varies as a power function of the friction velocity. Although dynamic abrasion processes have a strong influence on the amount of dust entrainment, aerodynamic entrainment may provide an important mechanism for dust emissions. Large volumes of dust entrained by aerodynamic entrainment cannot only occur at low shear velocity without saltation, but may dominate the entrainment process in many arid and semi-arid environments. So it may also be responsible for large magnitude dust storms. Playa and alluvial fan landforms, prior to developing a surface crust, may be the main sources of dust storms in Qinghai Province.
基金Petrobras (0050.0093154.14.9)–Petróleo Brasileiro S.A.for the financial and technical support
文摘This study aimed to describe a Computational Fluid Dynamics(CFD) procedure using the ANSYS CFX software 16.1 and Design of Experiments for the determination of volume and extension of explosive atmospheres due to fugitive emissions of flammable gases.The multidimensional statistical sampling technique Latin Hypercube was used, which defined 100 simulations of random methane gas leak conditions.The CFD model proved to be robust in predicting the extension and volume of the explosive atmosphere for orifice diameters from 0.1 to2.5 mm, pressure from 0.1 MPa to 12 MPa and temperatures from 0 ℃ to 400 ℃.It was found that the calculation domain must be parameterized 8 m in length for each millimeter of the diameter of the source of release to ensure the predictions.In order not to lose precision for very small diameters, the mesh was parameterized with 50 elements along the orifice diameter.It was proved that gravity does not influence the extension and volume of the explosive atmosphere at sonic emissions.The deviation from the ideal gas behavior in the reservoir,achieved by applying the Soave–Redlich–Kwong equation of state, also has not significantly influenced the extension and volume of the explosive atmosphere.The results showed that the size of the explosive atmosphere varies directly with the diameter of the source emission and reservoir pressure, and inversely with the temperature of the reservoir.The diameter of the source is the parameter that has the major effect on the extension of the explosive atmosphere, followed by the pressure and lastly the temperature of the reservoir.
基金funded by the Special Program on the S&T of China for the Pollution Control and Treatment of Water Bodies(2008ZX07421-001)the Foundamental Research Funds for the Central Universities, China
文摘Fugitive dust is one of the well known problems in agriculture and it affects both humans and machine producing quality. Dust problems can seriously cause harmful diseases to workers and ruin expensive equipments. In this study, a dust formation generated in open environment by vehicles was analyzed on unpaved roads. Formed dust was measured by calculating total forces on the PM10 （airborne particles smaller than 10 mm） of dust particles, such as air velocity, gravity forces and air turbulence generated by the moving vehicle. The water fogger nozzle discharge was measured to determine the approximate droplets quantity in the air. The foggers were used to suppress the generated dust in an open environment via installing a proposed automatic suppression system which opens automatically when vehicles pass under the system. The relationship between water droplet speed and ability of collecting fugitive dust showed that high air temperature above 40oC and wind speed above 10 m s-1 have negative effects on the system’s ability of collecting dust due to evaporation of small radius droplets and/or drifting water droplets away from the effective area. The overall system efficiency was found to be 85% and the proposed dust suppression system was found to be a satisfying solution for reducing fugitive dust hazards.
基金support from the National Natural Science Foundation of China(No.71704178)Beijing Excellent Talent Program(No.2017000020124G133)+1 种基金the Fundamental Research Funds for the Central Universities(Nos.2022SKNY01,2022YJSNY04)The suggestions from the Workshop of the Chinese Academy of Engineering are also appreciated.
文摘With policy incentives for the coalbed methane in energy industry,coalbed methane from coal production has been effectively improved by technology innovations in coalbed methane extraction and utilization.The progress of coalbed methane promotes the clean construction of energy system and contributes to carbon neutrality target.To quantitatively measure the contributions of the coalbed methane in energy industry,this paper builds a carbon emissions accounting system for coalbed methane in China and assesses the historical co-benefits of coalbed methane utilization from the aspects of emissions reduction,safety and economy.By using the parameters of gas content,raw coal production,gas extraction rate and utilization rate over the years,emissions reduction potential and economic viability of coal seam gas are estimated and the safety benefits of coal mine gas extraction are analyzed by using data for gas accidents and economic losses.The results reveal that with the increase in raw coal production,the great emission reduction potential of coalbed methane is expected to benefit clean energy system and the development of carbon neutrality by means of policy incentives and technology innovations.The co-benefit evaluation indicates the huge profitability of coalbed methane from 2012 to 2015 and the significance of emissions reduction and safety gain internalization.Safety benefits are obvious in the negative exponential function between the annual drainage quantities of coalbed methane and annual death tolls from coal mine gas accidents.Based on these results,relevant suggestions are put forward for sustainable development of the coalbed methane in energy industry.
文摘This research study quantifies the PM<sub>10</sub> emission rates (g/s) from cement silos in 25 concrete batching facilities for both controlled and uncontrolled scenarios by applying the USEPA AP-42 guidelines step-by-step approach. The study focuses on evaluating the potential environmental impact of cement dust fugitive emissions from 176 cement silos located in 25 concrete batching facilities in the M35 Mussafah industrial area of Abu Dhabi, UAE. Emission factors are crucial for quantifying the PM<sub>10</sub> emission rates (g/s) that support developing source-specific emission estimates for areawide inventories to identify major sources of pollution that provide screening sources for compliance monitoring and air dispersion modeling. This requires data to be collected involves information on production, raw material usage, energy consumption, and process-related details, this was obtained using various methods, including field visits, surveys, and interviews with facility representatives to calculate emission rates accurately. Statistical analysis was conducted on cement consumption and emission rates for controlled and uncontrolled sources of the targeted facilities. The data shows that the average cement consumption among the facilities is approximately 88,160 (MT/yr), with a wide range of variation depending on the facility size and production rate. The emission rates from controlled sources have an average of 4.752E<sup>-04</sup> (g/s), while the rates from uncontrolled sources average 0.6716 (g/s). The analysis shows a significant statistical relationship (p < 0.05) and perfect positive correlation (r = 1) between cement consumption and emission rates, indicating that as cement consumption increases, emission rates tend to increase as well. Furthermore, comparing the emission rates from controlled and uncontrolled scenarios. The data showed a significant difference between the two scenarios, highlighting the effectiveness of control measures in reducing PM<sub>10</sub> emissions. The study’s findings provide insights into the impact of cement silo emissions on air quality and the importance of implementing control measures in concrete batching facilities. The comparative analysis contributes to understanding emission sources and supports the development of pollution control strategies in the Ready-Mix industry.
文摘China launched a campaign code-named Sky Net 2025 to hunt down corrupt fugitives,recover illegal proceeds and combat cross-border corruption,according to a meeting of the office for fugitive repatriation and asset recovery under the Central Anti-Corruption Coordination Group held on March 24.
文摘Particulate matter （PM） emissions from steelworks cause public concern. Although end-of-pipe and pro- cess integrated measures have led to a significant drop in emissions of large particles from stacks, fine aerosols were not specifically considered, nor were emissions from fugitive and open sources. In this study, we deployed aerosol samplers together with a scanning ultra-violet （UV） lidar to characterize total suspended particles （TSP）, PM10, and PM2.5, in emissions from a large integrated steelworks in Spain over a 16-day period. We determined the content of carbonaceous, soluble inorganic, mineral dust, and metal species. A positive matrix factorization was carried out on our dataset. Despite mineral dust being predominant in all size fractions, the steelworks was clearly a source of carbonaceous species, resulting in production of secondary inorganic aerosols. In particular, stack emissions were a major contributor of fine particles, while open sources dominated the emissions of TSP, yielding up to 80% of particles larger than PM10. UV lidar provided 2D maps of aerosols in real time, with an ability to detect PM emissions and to visualize complex plumes. We suggest that air quality management of steelworks needs to focus on controlling large and coarse oarticle emissions, esoeciallv those from onen sources.
