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1.
嘉善夏季典型时段大气VOCs的臭氧生成潜势及来源解析   总被引:2,自引:0,他引:2  
2016年8—9月对长三角南部区域嘉善的大气中挥发性有机化合物(VOCs)变化特征、臭氧生成潜势、臭氧生成控制敏感性和来源进行了研究。结果表明,观测期间VOCs总平均值为27.3×10-9,表现为烷烃卤代烃含氧有机物芳香烃烯烃炔烃;VOCs浓度变化较大,早晚出现峰值,与风速呈负相关的关系,与温度没有明显相关性。VOCs的臭氧生成潜势表现为芳香烃烯烃烷烃含氧有机物卤代烃炔烃。甲苯等10种物质对臭氧生成潜势的贡献达到63%。夏季典型时段臭氧生成对VOCs较敏感,属于VOCs控制区。观测期间测得对VOCs浓度贡献较大的物种来源于溶剂涂料和工业排放。  相似文献   

2.
利用南京市2022年挥发性有机物(VOCs)在线监测数据,对VOCs污染特征、来源及对臭氧的影响进行了分析研究。结果表明:2022年南京市φ(TVOCs)年均值为25.1×10-9,其中各组分占比为烷烃>含氧挥发性有机物(OVOCs)>氯代烃>烯烃>芳香烃>炔烃。TVOCs及烷烃、烯烃和芳香烃的体积分数季节变化表现为冬季>秋季>春季>夏季,φ(OVOCs)季节变化表现为夏季>秋季>春季>冬季。烷烃、烯烃和炔烃日变化呈“双峰型”特征,芳香烃和氯代烃为“单峰型”。臭氧生成潜势(OFP)贡献总体表现为OVOCs>烯烃>芳香烃>烷烃>氯代烃>炔烃,但冬季烯烃的贡献率最高。南京市臭氧生成的关键VOCs物种为乙醛、乙烯、丙烯、间/对-二甲苯和甲苯。正交矩阵因子分解结果显示,机动车尾气、生物质燃烧和工业生产是南京VOCs的主要来源;对南京臭氧生成贡献最大的VOCs来源为溶剂涂料使用和石化行业。  相似文献   

3.
利用无人机对某石化工业园区地面至100 m大气中的VOCs进行监测,通过不同高度数据对比,总结该石化工业园区挥发性有机物的垂直分布特征,并分析其化学反应活性。监测结果表明,VOCs体积分数和总臭氧生成潜势随高度增加均呈下降趋势,地面和15~30 m高度的VOCs浓度及臭氧生成潜势基本一致。主要VOCs物种浓度垂直分布特征可分为均匀分布、随高度增加浓度不断降低、随高度增加浓度先升后降3种。含氧有机物和烷烃在大气中体积分数较大,主要特征挥发性有机物为丙酮、乙醛、乙烷、乙醇等;臭氧生成潜势贡献较大的组分为含氧有机物、烯烃和炔烃,关键活性物质为甲醛、乙醛、丁烯醛、正丁醛等。含氧有机物的体积分数和臭氧生成潜势贡献在地面至100 m高度都明显高于其他组分,应作为VOCs浓度和化学活性控制的重点。  相似文献   

4.
基于2016—2022年南京市大气挥发性有机物(VOCs)自动监测数据,分析VOCs污染特征及其臭氧生成潜势(OFP)。结果表明:2016—2022年南京市大气VOCs及其组分体积分数均显著下降,TVOCs 7年均值为21.7×10-9,各组分占比从大到小依次为烷烃>烯烃>芳香烃>炔烃;TVOCs及烷烃、烯烃、芳香烃季节变化一致,均为冬季>秋季>春季>夏季,炔烃为冬季>春季>秋季>夏季;TVOCs及烷烃、烯烃、炔烃月变化整体呈“V”字型特征,芳香烃近似为“W”型;除炔烃外,小时体积分数日变化基本呈“单峰型”特征。2016—2022年OFP年际变化呈显著下降趋势,7年均值为132.1 μg/m3;OFP贡献较大的组分为烯烃(39.1%)和芳香烃(38.1%),臭氧生成的VOCs关键物种为乙烯、间/对二甲苯、甲苯、丙烯和异戊二烯,控制烯烃和芳香烃排放有利于南京市的臭氧污染防治。  相似文献   

5.
运用大气挥发性有机物(VOCs)快速在线连续自动监测系统,于2018年7月对南通市区环境空气中VOCs进行观测,分析VOCs的浓度状况、组成特征、对臭氧生成潜势的贡献及主要来源。结果表明:观测期间共检出100种VOCs,总挥发性有机物(TVOCs)的平均体积分数为(38. 18±23. 63)×10^-9,各物种体积分数从大到小顺序依次为烷烃>含氧有机物>芳香烃>卤代烃>烯、炔烃;芳烃和烯烃是最主要的活性物种,间/对二甲苯、甲苯、邻二甲苯等是VOCs的关键活性组分;利用PMF模型解析得到VOCs的主要污染来源是工业排放与溶剂使用、机动车尾气排放、燃料挥发排放和生物源排放。  相似文献   

6.
2017年9月1日至11月30日采用Syntech Spectras GC955在线气相色谱仪对杭州市不同功能区大气环境中的挥发性有机化合物(VOCs)进行了在线连续监测,分析了不同功能区VOCs及各组分的体积分数、日变化规律及大气化学反应活性。结果显示,下沙周边工业区总VOCs浓度整体高于朝晖周边居民区,其中夜间更为显著。烷烃和芳香烃浓度在夜间时段工业区较居民区高得更为明显,其中芳香烃组分表现尤为突出,2个功能区烯烃体积分数相差不大。杭州市主要VOCs体积分数总体上在国内处于中间水平。不同功能区烷烃和芳香烃均呈现夜间浓度高于白天的日变化特征,居民区各VOCs组分日变化基本呈现双峰结构,工业区烷烃和芳香烃体积分数日变化呈现单峰结构,烯烃体积分数没有明显的日变化特征。不同功能区中芳香烃对臭氧生成潜势贡献最大,烯烃次之,烷烃贡献最小。下沙周边工业区大气化学活性(尤其是芳香烃组分)较朝晖周边居民区强。同种VOCs物质在不同功能区对臭氧生成潜势的贡献大小不同,但关键贡献物质均为低碳烷烃、低碳烯烃及苯系物。  相似文献   

7.
为研究菏泽市环境空气中VOCs的污染特征,参照EPA TO-15方法对菏泽市环境空气中的VOCs进行分析,并对VOCs的组成、浓度状况、来源和对臭氧生成潜势的贡献等进行探讨。结果表明,该市环境空气中共定性检出挥发性有机物82种,其中烷烃和苯系物分别占有机物种类的29%、22%,VOCs平均浓度为25.6μg/m3。监测期间,环境空气中的VOCs主要来自汽车尾气排放、汽油蒸汽、液态石油的挥发,其中交通尾气排放是该区域监测期间的主要排放源。烷烃、芳烃是对菏泽市环境空气中臭氧生成潜势贡献较大的关键活性组分,其对臭氧生产潜势的贡献率分别为32.6%、49.9%。  相似文献   

8.
对桂林市城区大气中挥发性有机物(VOCs)的污染特征,以及VOCs对臭氧(O3)和二次有机气溶胶(SOA)的生成潜势进行了研究。结果显示,研究期间,共检出VOCs物种78种,平均体积分数为21.32×10-9,表现为芳香烃(67.82%)烷烃(19.56%)卤代烃(7.50%)烯烃(2.86%)含氧挥发性有机物(1.41%)。VOCs体积分数空间分布呈现市中心和下风向郊区两个高值区。通过苯与甲苯的浓度比值发现,林科所VOCs主要来自交通源和生物源,师专甲山校区VOCs主要是来自交通源,其余测点VOCs主要来自交通源、工业源和外来传输源。分析乙苯和间/对二甲苯的浓度比值发现,电子科大尧山校区气团光化学年龄较大,光化学反应活性相对较强烈;旅游学院、华侨旅游经开区、大埠中心校气团光化学年龄较小,光化学反应活性相对较弱。VOCs对O3生成潜势最大的为芳香烃(93.81%),其次是烷烃(7.22%)和烯烃(4.75%);对SOA生成潜势最大的为芳香烃(97.45%),其次是烷烃(2.55%)。  相似文献   

9.
2017年3月-5月采用大气挥发性有机物在线连续自动监测系统对徐州市新城区大气中102种VOCs进行观测,分析徐州市春季大气中VOCs的体积和组成特征。结果发现:观测期间,徐州市大气中VOCs的小时体积分数为(3.81~221.85)×10~(-9),平均体积分数为27.97×10~(-9);各物种体积占比依次为烷烃、含氧有机物、卤代烃、芳香烃和烯(炔)烃;占比最高的5种污染物是乙烷、丙酮、乙烯、乙炔和丙烷。徐州市臭氧处在VOCs控制区,对臭氧生成潜势(OFP)贡献率最大的是含氧有机物(33.99%)和芳香烃(32.21%);关键活性组分是乙烯、正己醛、甲苯、间/对-二甲苯和丁烯酮。  相似文献   

10.
2018年4月至2019年3月对杭州市城区大气中117种挥发性有机物(VOCs)开展了为期一年的手工采样观测,分析了VOCs各组分的浓度特征、臭氧生成潜势(OFP)和二次有机气溶胶(SOA)生成潜势。结果显示,观测期杭州市大气VOCs体积分数均值为(56.72±29.56)×10-9,含氧挥发性有机物(OVOCs)、烷烃和卤代烃是其主要组分,分别占33.86%、30.70%、15.73%。VOCs体积分数前10位的物种为丙烷、甲醛、异丁烷、乙烷、乙酸乙酯、二氯甲烷、正丁烷、丙酮、甲苯和1,2-二氯乙烷。杭州市VOCs的OFP为135.18×10-9,各VOCs组分的OFP贡献为OVOCs(45%) > 芳香烃(22%) > 烯烃和炔烃(21%) > 烷烃(11%) > 卤代烃(1%),其中甲醛、乙烯和乙醛是OFP主要贡献者。SOA生成潜势为1.64 μg/m3,芳香烃是最重要的SOA前体物。SOA生成潜势最大的5种VOCs物种为甲苯、对/间二甲苯、乙苯、邻二甲苯和苯,因此控制来自机动车尾气和溶剂使用过程中产生的VOCs可有效降低SOA的生成。通过甲苯与苯体积分数比分析发现,杭州市城区芳香烃除了来自机动车尾气以外,在春、夏季和秋、冬季还分别受到生物质燃烧和涂料溶剂的影响;分析了乙烷与乙炔体积分数比、乙炔与CO体积分数比,发现杭州市气团的老化程度呈现整体较高的特点。  相似文献   

11.
微波消解-原子吸收光度法测定土壤中铜锌铅镉镍铬   总被引:24,自引:5,他引:24       下载免费PDF全文
用微波消解-原子吸收光度法测定土壤中铜,锌,铅,镉,镍和铬。通过硝酸-氢氟酸-过氧化氢体系消解液对土壤样品消解,选择出微波最佳消解条件。对硝酸-盐酸-过氧化氢体系消解液和硝酸-氢氟酸-过氧化氢体系消解液进行消解对比试验,发现前者不能将土壤样品完全消解,后者能将样品消解完全,但需将消解液中剩余的酸赶尽,否则测定结果将明显偏低。微波消解土壤与传统电热消解相比,操作简便快速,可提高工作效率。  相似文献   

12.
Material Disposal Area G is the primary low-levelradioactive waste disposal site at Los Alamos NationalLaboratory, New Mexico, and is adjacent to Pueblo of SanIldefonso lands. Pueblo residents and Los Alamos scientists areconcerned about radiological doses resulting from uptake of AreaG radionuclides by mule deer (Odocoileus hemionus) andRocky Mountain elk (Cervus elaphus), then consumption ofdeer and elk meat by humans. Tissue samples were collected fromdeer and elk accidentally killed near Area G and were analyzedfor 3H, 90Sr, total U, 238Pu, 239, 240Pu,241Am, and 137Cs. These data were used to estimatehuman doses based on meat consumption of 23 kg y-1. Humandoses were also modeled using RESRAD, and dose rates to deer andelk were estimated with a screening model. Dose estimates tohumans from tissue consumption were 2.9 × 10-3 mSv y-1and 1.6 × 10-3 mSv y-1 from deer and elk, respectively,and RESRAD dose estimates were of the same order of magnitude. Estimated dose rates to deer and elk were 2.1 × 10-4 mGyd-1 and 4.7 × 10-4 mGy d-1, respectively. Allestimated doses were significantly less than established exposurelimits or guidelines.  相似文献   

13.
An important research area in life sciences is devoted to modeling, prediction, and dynamics of gene-expression patterns. As clearly understood in these days, this enterprise cannot become satisfactory without acknowledging the role of the environment. To a representation of past, present, and most likely future states, we also encounter measurement errors and uncertainties. This paper surveys and improves recent advances in understanding the foundations and interdisciplinary implications of the newly introduced gene–environment networks, and it integrates the important theme of carbon dioxide emission reduction into the networks and dynamics. We also introduce some operational and managerial issues of practical working and decision making, expressed in terms of sliding windows, quadrants (modules) of parametric effects, and navigating (controlling) between such effects and directing them. Given data from DNA microarray experiments and environmental records, we extract nonlinear ordinary differential equations that contain parameters that have to be determined. For this, we employ modern (Chebychevian) approximation and (generalized semi-infinite) optimization. After this is provided, time- discretized dynamical systems are studied. A combinatorial algorithm with polyhedra sequences allows to detect the region of parametric stability. Finally, we analyze the topological landscape of gene–environment networks with its structural (in)stability. By embedding as a module and investigating CO2 emission control and figuring out game theoretical aspects, we conclude. This pioneering work is theoretically elaborated, practically devoted to health care, medicine, education, living conditions, and environmental protection, and it invites the readers to future research.   相似文献   

14.
The aim of the study was to determine the extent of heavy metal pollution in the vicinity of a lead battery manufacturing plant in the Czech Republic, both in the general environment and within homes. Topsoils (0–5 cm) were sampled from 100 sites along 4 transects which crossed the battery factory, the town centre and outlying rural areas. Housedust samples were collected from 15 plant-workers' homes and 15 non plant-workers' homes located at various distances from the factory. Samples were analysed for levels of Pb, Zn, Cd, Cu, As and Sb, using ICP-AES. Soil concentrations of Pb, Cd, As and Sb peaked at the perimeter fence of the battery factory with Pb levels of up to 12 650 g g> -1. Concentrations of these metals decreased exponentially within 500 m of the plant. Whilst the battery factory does appear to be a source of all the metals with the exception of Zn, emissions do not appear to be transported to any great extent over distances of more than 0.5 km. Topsoil and housedust concentrations of Pb, Zn, Cd, Cu, As and Sb in the general Mlada Boleslav area do not appear to be significantly different from those recorded in a large scale survey of urban soils in the United Kingdom. A comparison of housedust Pb concentrations in homes of plant workers and non-plant workers suggests that there may be a small input of Pb into the home environment by battery plant employees.  相似文献   

15.
This paper gives mathematical details and sample applications of SWAGMAN Farm (SWAGMAN, Salt Water and Groundwater Management), a farm-scale hydrologic economic model that integrates agronomic, climatic, irrigation, hydrogeological and economic aspects of irrigated agriculture. The model is capable of determining optimum mix of land use to keep watertable and soil salinity within acceptable limits while maximising the economic returns. Alternatively, the model can simulate water and salt balance and economics of a given cropping preference. Web-based and Geographic Information Systems versions of the model are available for integration with the environmental reporting systems of the irrigation areas.  相似文献   

16.
The San Francisco Estuary Regional Monitoring Program for Trace Substances (RMP) began in 1993 and is sponsored by 74 local, state, and federal agencies and companies through their discharge or Bay use permits. The RMP monitors water, sediment, toxicity, and bivalve bioaccumulation at 25 sites in the Bay that are considered to represent "background" conditions. Several major environmental issues have been identified by the RMP. Polychlorinated biphenyls and mercury were often above water quality guidelines, and often occurred in fish tissues above U.S. Environmental Protection Agency (U.S. EPA) screening values. Concentrations do not appear to be decreasing, suggesting continuing inputs. Episodes of aquatic toxicity often occurred following runoff events that transport contaminants into the Bay from urbanized and agricultural portions of the watershed. Sediment toxicity occurred throughout the Bay, and has been correlated with concentrations of specific contaminants (chlordanes, polynuclear aromatic hydrocarbons) at some locations; mixtures of contaminants were probably also important. Since the RMP does not monitor all ecosystem components, assessments of the overall condition of the Bay cannot be made. However, in terms of contamination, the RMP samples suggest that the South Bay, and North Bay sites are moderately contaminated.  相似文献   

17.
A migratory population of 78 pairs of Osprey (Pandion haliaetus) nesting along the Willamette River in westernOregon was studied in 1993. The study was designed to determinecontaminant concentrations in eggs, contaminant concentrationsin fish species predominant in the Ospreys diet, andBiomagnification Factors (BMFs) of contaminants from fish specieseaten to Osprey eggs. Ten Osprey eggs and 25 composite samplesof fish (3 species) were used to evaluate organochlorine (OC)pesticides, polychlorinated biphenyls (PCBs), polychlorinateddibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans(PCDFs). Mercury was also analyzed in fish. Geometric meanresidues in Osprey eggs were judged low, e.g., DDE 2.3 g g-1 wet weight (ww), PCBs 0.69 g g-1, 2,3,7,8-TCDD 2.3 ng kg-1, and generally well below known threshold values for adverse effects on productivity, and the population was increasing. Osprey egg residue data presentedby River Mile (RM) are discussed, e.g., higher PCDDs were generally found immediately downstream of paper mills and eggsfrom the Willamette River had significantly elevated PCBs and PCDDs compared to reference eggs collected nearby in the CascadeMountains. Prey remains at nest sites indicated that the Largescale Sucker (Catostomus macrocheilus) and NorthernPikeminnow (Ptychocheilus oregonensis) accounted for an estimated 90.1% of the biomass in the Osprey diet, and composite samples of these two species were collected from different sampling sites throughout the study area for contaminant analyses. With the large percentage of the fishbiomass in the Osprey diet sampled for contaminants (and fisheaten by Ospreys similar in size to those chemically analyzed),and fish contaminant concentrations weighted by biomass intake, a mean BMF was estimated from fish to Osprey eggs for the largeseries of contaminants. BMFs ranged from no biomagnification(0.42) for 2,3,7,8-TCDF to 174 for OCDD. Our findings for themigratory Osprey were compared to BMFs for the resident HerringGull (Larus argentatus), and differences are discussed. Webelieve a BMF approach provides some basic understanding ofrelationships between contaminant burdens in prey species offish-eating birds and contaminants incorporated into their eggs,and may prove useful in understanding sources of contaminants inmigratory species although additional studies are needed.  相似文献   

18.
The draft of the German guideline to calculate automobile exhaust dispersion is explained. It contains a two-stage-system: For first quick estimates the guideline contains the simple models MLuS and STREET. In case these models are not applicable or their results shows concentration levels close to the air quality standards, the more complex models PROKAS_V and MISKAM are recommended. PROKAS_V is a Gaussian plume model, MISKAM is a 3-dimensional microscale non hydrostatic flow model for built-up areas with an Eulerian dispersion model. The guideline comprises cases in rural areas without or with few adjacent buildings as well as urban areas with buildings near the roads. The contribution gives information about the models, typical results and some of the problems showing up presently.  相似文献   

19.
The population counts of hydrocarbon-utilising yeasts weremonitored at six sampling stations in the Benin City municipalarea over a four-week period. Although the population countswere relatively constant in each locality, the highest countsoccurred in areas heavily polluted by domestic and industrialeffluents. A total of thirty-five hydrocarbon-degrading yeastswere isolated from soil at the sampling stations usingn-hexadecane as sole carbon source. The isolates were identifiedas belonging to the genera Candida (27 strains), Endomycopsis (4 strains). All the organisms grew on long-chainn-alkane, kerosene, diesel oil and crude oil but failed to growon short-chain n-alkane, aromatic and alicyclic hydrocarbons.Measurement of growth attributes of the isolates usingn-hexadecane, diesel oil and crude oil as substrates showed thatthe Candida species were better utilizers of hydrocarbonsubstrates relative to Endomycopsis and Schizosaccharomyces species.  相似文献   

20.
The stable nitrogen isotope ratios of some biota have been used as indicators of sources of anthropogenic nitrogen. In this study the relationships of the stable nitrogen isotope ratios of marsh plants, Iva frutescens (L.), Phragmites australis (Cav.) Trin ex Steud, Spartina patens (Ait.) Muhl, Spartina alterniflora Loisel, Ulva lactuca (L.), and Enteromorpha intestinalis (L.) with wastewater nitrogen and land development in New England are described. Five of the six plant species (all but U. lactuca) showed significant relationships of increasing δ 15N values with increasing wastewater nitrogen. There was a significant (P < 0.0001) downward shift in the δ 15N of S. patens (6.0 ± 0.48‰) which is mycorrhizal compared with S. alterniflora (8.5 ± 0.41‰). The downward shift in δ 15N may be caused by the assimilation of fixed nitrogen in the roots of S. patens. P. australis within sites had wide ranges of δ 15N values, evidently influenced by the type of shoreline development or buffer at the upland border. In residential areas, the presence of a vegetated buffer (n = 24 locations) significantly (P < 0.001) reduced the δ 15N (mean = 7.4 ± 0.43‰) of the P. australis compared to stands where there was no buffer (mean = 10.9 ± 1.0‰; n = 15). Among the plant species, I. frutescens located near the upland border showed the most significant (R 2 = 0.64; P = 0.006) inverse relationship with the percent agricultural land in the watershed. The δ 15N of P. australis and I. frustescens is apparently an indicator of local inputs near the upland border, while the δ 15N of Spartina relates with the integrated, watershed-sea nitrogen inputs.  相似文献   

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