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1.
Huan Jing Ke Xue ; 44(7): 3627-3636, 2023 Jul 08.
Artículo en Chino | MEDLINE | ID: mdl-37438262

RESUMEN

The Beijing-Tianjin-Hebei-Shandong Region (BTHS Region) is a crucial area for China to achieve synergy between pollution reduction and carbon emissions reduction. The demand for coordinated emissions reduction through source control measures such as energy transition and industrial restructuring are becoming increasingly necessary owing to the limited emissions reductions potential of end-of-pipe control measures. An assessment of the emissions reductions potential through strengthening the end-of-pipe control in the BTHS Region, as well as the environmental and health co-benefits from accelerated energy transition and industrial restructuring, was conducted using scenario simulation analysis based on the REACH model. The results showed that the rapid implementation of the best available end-of-pipe control technologies in the BTHS Region would result in 3.3 µg·m-3 reduction in PM2.5 concentration in 2035, but this would not be sufficient to achieve the PM2.5 concentration control targets. Accelerating the energy transition and the industrial restructuring are necessary for the BTHS Region to achieve air quality standards, which would reduce the PM2.5 concentrations by 6.3 µg·m-3 in 2035. The environmental and health co-benefits brought by the accelerated transition could partially or entirely offset the additional socio-economic cost (compared to that of the current policy efforts) of approximately 0.9%-2.5% of the total regional GDP in achieving the PM2.5 concentration control target paid by the four provinces.

2.
Huan Jing Ke Xue ; 44(5): 2409-2420, 2023 May 08.
Artículo en Chino | MEDLINE | ID: mdl-37177916

RESUMEN

Air quality data from 33 environment sites and five regional sites from 2018 to 2020, as well as meteorological data, were used to research PM2.5 variation,spatial and temporal change, diurnal variation, and heavy pollutions in Beijing. The annual average mass concentrations of PM2.5 in Beijing were 51, 42, and 38 µg·m-3, which showed great progress in air quality improvement. However, the PM2.5 concentration in 2020 was still 8.6% above the national limit value despite a 30.9% decline since 2017. The PM2.5 south-north gradient in Beijing remained throughout the three years, but this pattern showed a less significant trend. The highest monthly mean PM2.5 concentrations in Beijing tended to occur in January-March, with the lowest in August-September. NOx, CO, and PM2.5 concentrations were significantly higher in the heating season than in the non-heating season by 58.4%, 52.9%, and 27.5%, respectively. Diurnal variation showed that greater PM2.5 concentrations were observed at nighttime during the heating season and, conversely, at noontime during the non-heating season. Sixteen pollution episodes occurred in Beijing over the last three years, resulting in 25 heavy pollution days distributed in autumn-winter of 2018-2020. The regional heavy pollution characteristics of PM2.5 in Beijing were significant. Through analysis, a continuous pollution reduction was still the most important reason for the yearly decrease in PM2.5. The concentrations of organic matter, elemental carbon, and crustal matter in the PM2.5 in Beijing decreased by 43.3%, 53.2%, and 51.5% since 2017, respectively, and nitrate, sulfate, and ammonium decreased by 34.2%, 52.2%, and 43.7%.The results showed that the control effect of PM2.5 in Beijing was obvious.

4.
Huan Jing Ke Xue ; 42(2): 584-594, 2021 Feb 08.
Artículo en Chino | MEDLINE | ID: mdl-33742852

RESUMEN

Continuous on-line observation of particulate matter and PM2.5 chemical composition was conducted from October 15th to November 7th 2019 in East China. During the observation period, a wide range of dust-related processes took place. According to supplementary urban air quality assessment affected by dust (hereafter referred to as supplementary provisions), the observations were divided into four stages including pre-dust event, dust Ⅰ, dust Ⅱ, and post-dust event. The dust Ⅰ stage represented the processes of transportation and retention, while the dust Ⅱ stage represented processes of backflow from the sea and scavenging. The start time of the studied dust event was October 29th 08:00-09:00 based on the supplementary provisions, dust tracers, and air quality models; however, disagreements existed between these data sources with respect to the finishing time. The supplementary provisions could not effectively distinguish backflow dust from sea, and results from different dust tracers were variable. The WRF-CMAQ model simulated dust variation trends well but overestimated short-term suspended dust and backflow dust. PM10, PM2.5, and trace element concentrations were much higher during dust events than during non-dust periods, with highest daily concentrations of (234.8±125.5), (76.8±22.5), and (17.54±10.5) µg·m-3, respectively, which occurred on October 29th. During the dust event, concentration of crustal elements were remarkably high in PM2.5. At the same time, secondary ions (SO42-, NO3-, and NH4+) contributed less to PM2.5 mass concentrations. Four major crustal elements (Al, Si, Ca, and Fe) accounted for 23.5% and 13.7% of the mass concentration of PM2.5 and secondary ions accounted for 24.3% and 41.9% during dust Ⅰ and dust Ⅱ stages, respectively. Based on PMF source apportionment, Ca abundance, PM2.5/PM10 in dust sources, and the reconstruction of crustal material, dust particulates accounted for 43.4%-50.0% of PM2.5 and backflow dust accounted for 19.2%-24.7% of PM2.5.

5.
Huan Jing Ke Xue ; 40(3): 1035-1042, 2019 Mar 08.
Artículo en Chino | MEDLINE | ID: mdl-31087949

RESUMEN

To identify the main sources of PM2.5 in Beijing-Tianjin-Hebei (BTH) region, PM2.5 samples were collected at four suburban sites in BTH region during autumn and winter in 2014-2015. Source apportionment of PM2.5 was conducted using the chemical mass balance model (CMB). It shows that the main sources of PM2.5 in autumn and winter were secondary aerosols (36%-58%), traffic (8%-26%), residential coal combustion (8%-16%), and biomass burning (5%-16%). Secondary nitrate was the most important source of PM2.5 at most sites during autumn and winter (11%-27%). The source apportionment at different pollution levels indicates that the coherence of the increasing trend of different sources among the four sites were much more obvious in autumn than in winter. Also, the increasing contribution of secondary sources (47.2-115.7 µg·m-3) was much higher than that of primary sources (29.5-43.4 µg·m-3) in autumn, but such trend was not significant in winter. The total contribution of coal combustion at suburban sites was quite similar to that in urban sites, but in suburban areas residential coal combustion dominates the contribution from coal combustion. Thus, it is very necessary for suburban areas of the BTH region to control emissions from residential coal combustion.

6.
Int J Oncol ; 53(1): 339-348, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-29750424

RESUMEN

Doxorubicin (Dox) is widely used in the treatment of triple-negative breast cancer cells (TNBCs), however resistance limits its effectiveness. Cancer stem cells (CSCs) are associated with Dox resistance in MCF-7 estrogen receptor positive breast cancer cells. Signal transducer and activator of transcription 3 (Stat3) may functionally shift non-CSCs towards CSCs. However, whether Stat3 drives the formation of CSCs during the development of resistance in TNBC, and whether a Stat3 inhibitor reverses CSC-mediated Dox resistance, remains to be elucidated. In the present study, human MDA-MB-468 and murine 4T1 mammary carcinoma cell lines with the typical characteristics of TNBCs, were compared with estrogen receptor-positive MCF-7 cells as a model system. The MTT assay was used to detect cytotoxicity of Dox. In addition, the expression levels of CSC-specific markers and transcriptional factors were measured by western blotting, immunofluorescence staining and flow cytometry. The mammosphere formation assay was used to detect stem cell activity. Under long-term continuous treatment with Dox at a low concentration, TNBC cultures not only exhibited a drug-resistant phenotype, but also showed CSC properties. These Dox-resistant TNBC cells showed activation of Stat3 and high expression levels of pluripotency transcription factors octamer-binding transcription factor-4 (Oct-4) and c-Myc, which was different from the high expression of superoxide dismutase 2 (Sox2) in Dox-resistant MCF-7 cells. WP1066 inhibited the phosphorylation of Stat3, and decreased the expression of Oct-4 and c-Myc, leading to a reduction in the CD44-positive cell population, and restoring the sensitivity of the cells to Dox. Taken together, a novel signal circuit of Stat3/Oct-4/c-Myc was identified for regulating stemness-mediated Dox resistance in TNBC. The Stat3 inhibitor WP1066 was able to overcome the resistance to Dox through decreasing the enrichment of CSCs, highlighting the therapeutic potential of WP1066 as a novel sensitizer of Dox-resistant TNBC.


Asunto(s)
Factor 3 de Transcripción de Unión a Octámeros/genética , Proteínas Proto-Oncogénicas c-myc/genética , Factor de Transcripción STAT3/genética , Neoplasias de la Mama Triple Negativas/tratamiento farmacológico , Apoptosis/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Doxorrubicina/administración & dosificación , Doxorrubicina/efectos adversos , Resistencia a Antineoplásicos/genética , Femenino , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Células MCF-7 , Células Madre Neoplásicas/efectos de los fármacos , Células Madre Neoplásicas/patología , Piridinas/administración & dosificación , Transducción de Señal/efectos de los fármacos , Neoplasias de la Mama Triple Negativas/genética , Neoplasias de la Mama Triple Negativas/patología , Tirfostinos/administración & dosificación
7.
Environ Sci Technol ; 51(22): 13502-13508, 2017 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-29076729

RESUMEN

Lead (Pb) pollution emission from China is becoming a potential worldwide threat. Pb isotopic composition analysis is a useful tool to accurately trace the Pb sources of aerosols in atmosphere. In this study, a comprehensive data set of Pb isotopes for coals, Pb/Zn ores, and fuels from China was presented. The ratios of 206Pb/207Pb and 208Pb/206Pb in the coals were in the range of 1.114-1.383 and 1.791-2.317, similar to those from Europe, Oceania, and South Asia, but different from those from America (p < 0.01). The Pb/Zn ores had 206Pb/207Pb and 208Pb/206Pb in 1.020-1.183 and 2.088-2.309, less radiogenic than the coals. Leaded gasolines showed similar Pb isotopic compositions to Pb/Zn ores, with unleaded gasolines and diesels being mixed sources. The average Pb isotopic ratios of gasolines and diesels were significantly different (p < 0.01) from those of coals in China, leading to the possibility to discriminate Pb in fuels from in coals. Urban aerosols demonstrated similar Pb isotopic compositions to coals, Pb/Zn ores, and fuels in China. After removing the leaded gasoline, the Pb in aerosols is more radiogenic, supporting the heavy contribution of coal combustion to the atmospheric Pb pollution.


Asunto(s)
Carbón Mineral , Plomo , Zinc , Asia , China , Monitoreo del Ambiente , Europa (Continente) , Isótopos
8.
Huan Jing Ke Xue ; 38(3): 867-875, 2017 Mar 08.
Artículo en Chino | MEDLINE | ID: mdl-29965555

RESUMEN

This study chose two months (January and July) in 2012 which represent winter and summer respectively, to assess the effects of fine particle(PM2.5) pollution elimination due to emission control from different sectors in the Bejing-Tianjin-Hebei region by using CMAQ/2D-VBS modeling system. The results showed that, industrial emissions contributed most to PM2.5 pollution in the Beijing-Tianjin-Hebei region, followed by domestic emissions, while the contribution of per ton emission reduced for industrial sectors subject to domestic sectors. The total contribution and contribution of per ton emission reduced for transportation and power plant were both at low level. Among industrial sectors, the iron, steel and metallurgical industry was the greatest contributor, followed by cement industry, industrial boiler, coking industry, lime and bricks industry and chemical industry. It was found that the contribution of each emission source had significant association with its primary PM2.5 emission level. The control of NOx emissions would promote the formation of PM2.5, and atmospheric vertical diffusion effect was weak during wintertime in the Beijing-Tianjin-Hebei region. As a result, emission control of various sectors was universally more effective for PM2.5 pollution mitigation in summer than in winter. Emission control in summer was significantly more effective for transportation, powerplant, cement industry, industrial boiler and lime and bricks industry. Due to considerable emissions in heating season, domestic emissions showed more contribution in winter. Agricultural sources showed greater contribution per emission reduction in winter by the reason of substantial emissions from straw open burning during this time. With respect to a certain reduction ratio of emission, future control strategies should pay more attention to industrial emissions, especially to the primary PM2.5 emissions. In details, priorities should be given to NOx and SO2 emission control for iron, steel and metallurgical industry, NOx emission control for cement industry and SO2 and NMVOC emission control for coking industry. Besides, domestic emission control should also be taken into consideration, and it will be more effective in winter.

9.
Huan Jing Ke Xue ; 37(2): 459-65, 2016 Feb 15.
Artículo en Chino | MEDLINE | ID: mdl-27363131

RESUMEN

Waste incineration is one of the important atmospheric mercury emission sources. The aim of this article is to explore the atmospheric mercury pollution level of waste incineration industry from Chongqing. This study investigated the mercury emissions from a municipal solid waste incineration plant and a medical waste incineration plant in Chongqing. The exhaust gas samples in these two incineration plants were obtained using USA EPA 30B method. The mercury concentrations in the fly ash and bottom ash samples were analyzed. The results indicated that the mercury concentrations of the municipal solid waste and medical waste incineration plant in Chongqing were (26.4 +/- 22.7) microg x m(-3) and (3.1 +/- 0.8) microg x m(-3) in exhaust gas respectively, (5279.2 +/- 798.0) microg x kg(-1) and (11,709.5 +/- 460.5) microg x kg(-1) in fly ash respectively. Besides, the distribution proportions of the mercury content from municipal solid waste and medical waste in exhaust gas, fly ash, and bottom ash were 34.0%, 65.3%, 0.7% and 32.3%, 67.5%, 0.2% respectively; The mercury removal efficiencies of municipal solid waste and medical waste incineration plants were 66.0% and 67.7% respectively. The atmospheric mercury emission factors of municipal solid waste and medical waste incineration plants were (126.7 +/- 109.0) microg x kg(-1) and (46.5 +/- 12.0) microg x kg(-1) respectively. Compared with domestic municipal solid waste incineration plants in the Pearl River Delta region, the atmospheric mercury emission factor of municipal solid waste incineration plant in Chongqing was lower.


Asunto(s)
Contaminantes Atmosféricos/análisis , Atmósfera/análisis , Incineración , Mercurio/análisis , China , Ceniza del Carbón/análisis , Residuos Industriales , Residuos Sanitarios , Residuos Sólidos
10.
Huan Jing Ke Xue ; 37(9): 3290-3299, 2016 Sep 08.
Artículo en Chino | MEDLINE | ID: mdl-29964761

RESUMEN

Continuous monitoring of gaseous elemental mercury (GEM), reactive gaseous mercury (RGM) and particulate mercury (PBM) was conducted in the Dongtan wetland park in Chongming Island, Shanghai from March 2014 to February 2015. The average concentrations of GEM, RGM, and PBM were (2.75±1.13) ng·m-3, (13.39±15.95) pg·m-3, and (21.89±40.42) pg·m-3, respectively, higher than the background concentrations of Northern Hemisphere. The atmospheric mercury showed obvious seasonal variations, with the highest seasonal average GEM concentration in summer (3.65 ng·m-3), which was mainly influenced by natural sources, while lower GEM concentrations appeared in autumn and winter influenced mainly by anthropogenic sources. The concentration of RGM was highest in spring and lowest in winter, mainly influenced by the wind direction, while PBM showed higher concentrations in autumn and winter, when heavy fine particulate pollution episodes occurred frequently. The concentrations of GEM and PBM were generally elevated in nighttime and lower in daytime caused by the mixing condition of the air masses. Most of the high RGM concentration values occurred in the afternoon of all seasons due to the higher atmospheric oxidation. The concentrations of GEM and PBM were higher in the west wind due to the emission from anthropogenic sources in Shanghai, Jiangsu, etc. The RGM concentration in southeast wind was obviously higher than those in other wind directions. The RGM was mainly from the anthropogenic sources, and the smaller wind in the southeast direction was against the dispersion of RGM.

11.
Huan Jing Ke Xue ; 37(10): 3766-3773, 2016 Oct 08.
Artículo en Chino | MEDLINE | ID: mdl-29964407

RESUMEN

Municipal solid waste (MSW) incineration is one of the most important atmospheric mercury emission sources. To investigate the mercury concentrations of MSW and mercury emission characteristics in incineration plants, this study analyzed the MSW sampled in 3 typical MSW incineration plants in Shanghai, Guangzhou and Wuhu respectively. The exhaust gas samples in incineration plants were sampled by using OH (Ontario Hydro) method. The mercury concentrations in fly ash, and bottom ash samples were also analyzed. The results indicated that mercury concentrations of MSW in Shanghai, Guangzhou, and Wuhu incineration plants were (0.39±0.04) mg·kg-1, (0.57±0.05) mg·kg-1, and (0.27±0.08) mg·kg-1 respectively. The mercury concentrations of exhaust gas in Guangzhou, Wuhu MSW incineration plants were (9.5±3.9) µg·m-3 and (24.1±6.0) µg·m-3 respectively; Particulate mercury (Hgp), gaseous oxidized mercury (Hg2+), and gaseous elemental mercury (Hg0) represented (0.9±0.8)%, (89.0±5.4)%, (10.1±4.6)% in Guangzhou MSW incineration plant, and (1.0±0.8)%, (65.4±27.6)%, (33.6±27.5)% in Wuhu MSW incineration plant, respectively. Gaseous oxidized mercury (Hg2+) of exhaust gas in different incineration process showed different distribution proportions. Besides, mercury removal efficiency of Guangzhou, Wuhu MWS incineration plants was 96.7% and 33.7%, respectively. The atmospheric mercury emission factors of Shanghai, Guangzhou, and Wuhu MSW incineration plants were (0.156±0.016) mg·kg-1, (0.019±0.002) mg·kg-1, (0.178±0.027) mg·kg-1 respectively. Compared with MSW incineration plants in Japan and Korea, the atmospheric mercury emission factor of Guangzhou incineration plant was slightly lower; Atmospheric mercury emission factors of Shanghai and Wuhu MSW incineration plants were close to those of domestic fractional MSW incineration plants.

12.
Huan Jing Ke Xue ; 34(2): 712-7, 2013 Feb.
Artículo en Chino | MEDLINE | ID: mdl-23668145

RESUMEN

The farming soil and vegetable samples around a large-scale zinc smelter were collected for mercury content analyses, and the single pollution index method with relevant regulations was used to evaluate the pollution status of sampled soils and vegetables. The results indicated that the surface soil and vegetables were polluted with mercury to different extent. Of the soil samples, 78% exceeded the national standard. The mercury concentration in the most severely contaminated area was 29 times higher than the background concentration, reaching the severe pollution degree. The mercury concentration in all vegetable samples exceeded the standard of non-pollution vegetables. Mercury concentration, in the most severely polluted vegetables were 64.5 times of the standard, and averagely the mercury concentration in the vegetable samples was 25.4 times of the standard. For 85% of the vegetable samples, the mercury concentration, of leaves were significantly higher than that of roots, which implies that the mercury in leaves mainly came from the atmosphere. The mercury concentrations in vegetable roots were significantly correlated with that in soils, indicating the mercury in roots was mainly from soil. The mercury emissions from the zinc smelter have obvious impacts on the surrounding soils and vegetables. Key words:zinc smelting; mercury pollution; soil; vegetable; mercury content


Asunto(s)
Contaminación de Alimentos , Mercurio/análisis , Contaminantes del Suelo/análisis , Verduras/química , Zinc , China , Monitoreo del Ambiente , Metalurgia
13.
Huan Jing Ke Xue ; 34(1): 1-7, 2013 Jan.
Artículo en Chino | MEDLINE | ID: mdl-23487910

RESUMEN

The ambient concentrations of total gaseous mercury (TGM) in Chongming Island, Shanghai, were continuously observed using the Tekran 2537B mercury analyzer from 15th September to 17th December, 2009. The average concentration of TGM during our observation is (2.50 +/- 1.50) ng x m(-3), much higher than the background TGM of north hemisphere. The TGM concentration increased from September to December. During September to December, the concentration peaks appear during 08:00-10:00 am and the daytime TGM concentration approximately equaled that in the night. The TGM in Chongming significantly correlated with concentrations of CO, which indicates that TGM most likely comes from the coal combustion of power plants and industrial boilers. The back trajectory analysis demonstrates the atmospheric mercury in Chongming Island mainly comes from inland China, especially Jiangsu province and Shandong province which locate in the northwest of Chongming. The mercury concentrations are lower in September and October since the airflow is mainly from the eastern ocean. In November and December, the atmospheric mercury content is much higher because the northwest wind brings the pollutants from the western industrial areas.


Asunto(s)
Contaminantes Atmosféricos/análisis , Monitoreo del Ambiente , Mercurio/análisis , Atmósfera/análisis , China , Población Rural , Estaciones del Año
14.
Huan Jing Ke Xue ; 33(9): 2993-9, 2012 Sep.
Artículo en Chino | MEDLINE | ID: mdl-23243850

RESUMEN

The amount of fly ash produced during coal combustion is around 400 million tons per year in China. About 65%-68% of fly ash is used in building material production, road construction, architecture and agriculture. Some of these utilization processes include high temperature procedures, which may lead to mercury re-emissions. In this study, experiments were designed to simulate the key process in cement production and steam-cured brick production. A temperature programmed desorption (TPD) method was used to study the mercury transformation in the major utilization processes. Mercury re-emission during the fly ash utilization in China was estimated based on the experimental results. It was found that mercury existed as HgCl2 (Hg2 Cl2), HgS and HgO in the fly ash. During the cement production process, more than 98% of the mercury in fly ash was re-emitted. In the steam-curing brick manufacturing process, the average mercury re-emission percentage was about 28%, which was dominated by the percentage of HgCl2 (Hg2 Cl2). It is estimated that the mercury re-emission during the fly ash utilization have increased from 4.07 t in 2002 to 9.18 t in 2008, of which cement industry contributes about 96.6%.


Asunto(s)
Ceniza del Carbón/química , Materiales de Construcción/análisis , Contaminantes Ambientales/análisis , Mercurio/análisis , Eliminación de Residuos/métodos , China , Monitoreo del Ambiente
15.
Environ Sci Technol ; 45(13): 5477-82, 2011 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-21615081

RESUMEN

Laboratory measurements were conducted to determine particle size distribution and polycyclic aromatic hydrocarbons (PAHs) emissions from the burning of rice, wheat, and corn straws, three major agricultural crop residues in China. Particle size distributions were determined by a wide-range particle spectrometer (WPS). PAHs in both the particulate and gaseous phases were simultaneously collected and analyzed by GC-MS. Particle number size distributions showed a prominent accumulation mode with peaks at 0.10, 0.15, and 0.15 µm for rice, wheat, and corn-burned aerosols, respectively. PAHs emission factors of rice, wheat, and corn straws were 5.26, 1.37, and 1.74 mg kg(-1), respectively. It was suggested that combustion with higher efficiency was characterized by smaller particle size and lower PAHs emission factors. The total PAHs emissions from the burning of three agricultural crop residues in China were estimated to be 1.09 Gg for the year 2004.


Asunto(s)
Contaminantes Atmosféricos/análisis , Productos Agrícolas/química , Incineración , Hidrocarburos Policíclicos Aromáticos/análisis , Eliminación de Residuos/métodos , China , Cromatografía de Gases y Espectrometría de Masas , Oryza , Tamaño de la Partícula , Análisis Espectral , Triticum , Zea mays
16.
Huan Jing Ke Xue ; 32(2): 305-12, 2011 Feb.
Artículo en Chino | MEDLINE | ID: mdl-21528547

RESUMEN

This study analyzed the uncertainties in the Chinese anthropogenic volatile organic compound (VOC) emission inventory. The uncertainty evaluation system for input information including activity data and emission factors was established to provide the probability density function of each input datum. Monte Carlo method was applied to propagate the uncertainties of emissions' input data and calculate the probability density function of total VOC emissions. The results indicated that the Chinese national anthropogenic VOC emissions in year 2005 had a log-normal distribution, with a relative standard deviation of 52%, and with 95% confidence interval of [- 51%, + 133%]. However, if the traditional method for error analysis was used based on the same input information, the uncertainty of the 2005 VOC emission inventory calculated was 40% lower than the former results. In addition, sensitivity analysis was conducted to identify the 20 most sensitive inputs influencing the uncertainty of emissions, which will be helpful to improve the accuracy of VOC emission inventory in the future.


Asunto(s)
Contaminantes Atmosféricos/análisis , Monitoreo del Ambiente/métodos , Compuestos Orgánicos Volátiles/análisis , China , Método de Montecarlo , Incertidumbre
17.
Huan Jing Ke Xue ; 32(12): 3515-21, 2011 Dec.
Artículo en Chino | MEDLINE | ID: mdl-22468511

RESUMEN

Biofuel combustion is an important source of VOCs in China. Measurements were conducted to determine the characteristics of VOCs emitted from combustion of 5 typical biofuels. A carbon mass balance method was used to determine VOCs emission factors. The emission factors of the total VOCs from agricultural residues and wood combustion are (4.37 +/- 2.23) g x kg(-1) and (2.12 +/- 0.77) g x kg(-1), respectively. The emission factors of the agricultural residues are higher than those of the wood. Aromatics and aldehydes dominate the VOC emissions, both accounting for over 25% of the total VOC emissions. Distribution of VOC components from agricultural residues and wood combustion are similar, except for halogenated hydrocarbons and nitriles. On the basis of measured emission factors and the published maximum incremental reactivity values for VOCs, the ozone forming potential (OFPs) of speciated VOCs is estimated. The results indicate that the average OFPs of the total VOCs from agricultural residues and wood combustion are (16.9 +/- 8.2) g x kg(-1) and (10.8 +/- 4.9) g x kg(-1), respectively. The components with the highest OFPs values are: aldehydes, aromatics and alkenes/alkynes. Aldehydes accounts for over 50% of the total OFPs.


Asunto(s)
Contaminantes Atmosféricos/análisis , Biocombustibles/efectos adversos , Monitoreo del Ambiente , Compuestos Orgánicos Volátiles/análisis , China
18.
Huan Jing Ke Xue ; 31(7): 1457-63, 2010 Jul.
Artículo en Chino | MEDLINE | ID: mdl-20825010

RESUMEN

Ammonia has both direct and indirect impacts on important environmental issues including acid deposition, regional fine particles and eutrophication. Estimation of anthropogenic ammonia emissions will provide valuable information for the pollution control of acid deposition and regional fine particle. Based on the provincial activity data on N-fertilizer application, livestock farming, N-fertilizer production and populations, this paper uses emission factor method to estimate China's atmospheric ammonia emissions, analyzes its historical trends and presents its geographical distributions from year 1994 to 2006. The national total atmospheric ammonia emissions are estimated to be 11.06 million tons (Mt) in 1994, which increase quickly to 16.07 Mt in 2006. Emissions from livestock farming, N-fertilizer application, N-fertilizer production and human excreta have increased from 4.47 Mt, 5.94 Mt, 0.09 Mt, and 0.59 Mt in 1994 to 6.61 Mt, 8.68 Mt, 0.14 Mt, 0.65 Mt respectively in 2006. Livestock farming and N-fertilizer application are the most important ammonia emission sources, which contributed 40.79 and 55.53 percent of total emissions respectively in 2006. In 2006, the average ammonia emission intensity is 1.67 t x km(-2) but there are large variations among atmospheric ammonia emissions from each province. Emissions from provinces including Henan, Shandong, Hebei, Sichuan and Jiangsu accounted for 40.82 percent of national emissions.


Asunto(s)
Contaminantes Atmosféricos/análisis , Amoníaco/análisis , Productos Agrícolas , Monitoreo del Ambiente , Ganado , Animales , China , Fertilizantes , Humanos , Tamaño de la Partícula
19.
Huan Jing Ke Xue ; 31(7): 1464-9, 2010 Jul.
Artículo en Chino | MEDLINE | ID: mdl-20825011

RESUMEN

A multi-level assessment index system was established to quantitatively and comprehensively evaluate the performance of typical nitrogen oxide control technologies for coal-fired power plants. Comprehensive fuzzy evaluation was conducted to assess six NO, control technologies, including low NO, burner (LNB), over the fire (OFA), flue gas reburning (Reburning), selective catalyst reduction (SCR), selective non-catalyst reduction (SNCR) and hybrid SCR/SNCR. Case studies indicated that combination of SCR and LNB are the optimal choice for wall-fired boilers combusting anthracite coal which requires NO, removal efficiency to be over 70%, however, for W-flame or tangential boilers combusting bituminous and sub-bituminous coal which requires 30% NO, removal, LNB and reburning are better choices. Therefore, we recommend that in the developed and ecological frangible regions, large units burning anthracite or meager coal should install LNB and SCR and other units should install LNB and SNCR. In the regions with environmental capacity, units burning anthracite or meager coal shall install LNB and SNCR, and other units shall apply LNB to reduce NO, emissions.


Asunto(s)
Contaminantes Atmosféricos/aislamiento & purificación , Carbón Mineral , Residuos Industriales/prevención & control , Óxidos de Nitrógeno/aislamiento & purificación , Centrales Eléctricas , Contaminación del Aire/análisis , Contaminación del Aire/prevención & control , Catálisis , Lógica Difusa , Oxidación-Reducción
20.
Huan Jing Ke Xue ; 30(10): 2809-15, 2009 Oct 15.
Artículo en Chino | MEDLINE | ID: mdl-19968091

RESUMEN

Based on the current consumptions and forecast consumptions of paints in China, using the volatile organic compounds (VOC) contents of paints calculated as emission factors, an emission inventory model was established to calculate provincial, sector-specific, and species-specific VOC emissions during 2005-2020. The results indicated that the VOC amount emitted from paint use was 1883 kt in 2005, of which aromatics, alcohol compounds, ester compounds, ether compounds and ketone compounds were the main species. The maximum incremental reactivity (MIR,O3/VOC) of VOC emitted in 2005 was about 3.6 g/kg, and the toxic VOC accounted for 31% of the total in weight. The VOC emissions would increase to 5673 kt in 2020 if there were no further control policies and actions taken. Therefore, it is essential to implement the VOC emission control from paint uses as soon as possible. Two control scenarios were developed to evaluate the potential of VOC emission reductions. In 2020, VOC emissions from paint uses might be controlled at 3 519 kt through the improvement of paints quality to the level of that in developed countries in 1990s and installation of waste gas treatment equipments in newly-built factories. VOC emissions could be further reduced to 2243 kt if the quality of decorative paint and wood paint would be improved to the current level of that in developed countries and all factories install waste gas treatment equipments. All these control measures also helpe to reduce the toxicity and atmospheric oxidation reactivity of VOC emissions.


Asunto(s)
Contaminación del Aire Interior/análisis , Monitoreo del Ambiente/métodos , Pintura , Compuestos Orgánicos Volátiles/análisis , China , Monitoreo del Ambiente/estadística & datos numéricos , Predicción
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