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1.
利用泉州城区2017年全年连续观测的O_3和气象要素资料,统计了臭氧浓度的分布特征,分析了气象要素对O_3质量浓度的影响,对比了O_3超标日和非超标日的气象要素特征。结果表明:(1)泉州市O_3质量浓度月变化呈双峰形,春季最高,夏季最低;日变化呈单峰形,最大值出现在13:00—14:00,最小值出现在06:00—07:00,上下游站O_3浓度存在明显传输效应。(2)泉州O_3质量浓度与相对湿度呈负相关,其相关性最高;与风速呈正相关,其相关系数最低,且存在明显区位性差异;与气温的相关性比较复杂,既有正相关,也有负相关。(3)各站点O_3小时质量浓度超标时,均对应2个气象要素区间值。(4)对比污染日非污染日发现,污染日相对湿度较低(50%~60%),非污染日较高(70%~80%);污染日温度略低于非污染日;污染日风向总体为西南偏南,非污染日风向为西南-东南。  相似文献   

2.
京津冀区域臭氧污染趋势及时空分布特征   总被引:15,自引:11,他引:4  
为研究京津冀区域的臭氧(O_3)污染情况及其时空分布特征,对2013—2015年京津冀区域13个城市80个国家环境空气监测点位的监测数据进行了统计分析。结果表明:2013—2015年,京津冀区域O_3污染状况整体呈加重趋势,其中2014年污染状况最为严重。13个城市中O_3污染最严重的城市为北京和衡水,连续3年均超标,且处于上升态势中。区域内不同城市O_3污染趋势并不相同。京津冀区域O_3浓度变化呈明显的季节变化特征,春末和夏季的O_3污染最严重。O_3-8 h(臭氧日最大8 h均值)年均值的高值区主要分布在北京中北部、承德和衡水等,2013—2015年第90百分位O_3-8 h的高值区均集中分布在北京。O_3的浓度峰值时间要晚于NOx2~5 h。O_3在春、夏季呈单峰分布,白天15:00左右出现最大值,在秋、冬季浓度较低,全天波动不大。  相似文献   

3.
2013—2015年,天津市臭氧(O_3)浓度整体呈下降趋势,污染状况略低于京津冀区域的其他城市。O_3浓度春、夏季高,冬季低,高值主要集中在5—9月,浓度从早上06:00开始升高,至中午14:00达到峰值。污染主要集中在中心城区、西部和北部地区,东部、南部和西南部地区污染相对较轻。O_3浓度在温度303 K以上、相对湿度70%以下或西南风为主导时较高。VOCs/NOx比值低于8,O_3的生成处于VOCs控制区。芳香烃类和烯烃类对天津市O_3生成贡献最大,其中,乙烯和甲苯为O_3生成潜势贡献最大的物种,其次为间/对二甲苯、丙烯、邻二甲苯、异戊二烯、反-2-丁烯、乙苯等,通过控制汽车尾气、化工行业及溶剂使用等对O_3生成潜势贡献大的VOCs排放源可有效控制天津市O_3污染。  相似文献   

4.
河源夏季臭氧污染特征及其成因   总被引:1,自引:0,他引:1  
2015年9月至2016年8月,在广东河源城区内采用在线连续观测,分析该地区近地面臭氧(O_3)及其前体物的变化规律和相关性,重点探讨了夏季O_3污染特征及成因。结果表明,河源市城区O_3总超标天数为10 d,主要集中在7—9月。O_3浓度变化呈现明显的春、冬季低,夏、秋季高的季节变化。O_3浓度日变化呈典型单峰特征,前体物主要呈双峰变化。O_3小时浓度和CO无明显的相关性,与NO2浓度呈现较高的负相关关系;气象及HYSPLIT-4模型计算综合分析结果表明,夏季污染时段河源高空、低空气团大部来自西南方向,夏季O_3污染主要来源于珠三角区域传输和本地源排放。  相似文献   

5.
海口市臭氧污染特征   总被引:8,自引:7,他引:1  
基于2013—2015年海口市4个空气质量自动监测站点数据,结合气象资料,分析了海口市O_3的污染特征。结果表明:海口市O_3总体优良,优良天数比例为99.4%,污染天数均为轻度污染;在良和污染天数中,O_3作为首要污染物的天数占40%,超过其他5项污染物占比。海口市10月O_3浓度最高。O_3月均浓度与温度呈负相关关系,同时与风向有密切关系:5—8月气温较高,以南风为主,O_3浓度较低;1月北风频率较高,易受外来污染传输作用,O_3浓度相对较高。O_3超标日以东北风为主,日变化并未呈现单峰型特征,12:00—22:00时段O_3浓度在10%范围内小幅变化。台风外围型和北方冷高压底部型是造成海口市O_3超标的2类典型天气形势。  相似文献   

6.
郑州市近地面臭氧污染特征及气象因素分析   总被引:1,自引:0,他引:1  
利用国控站点空气质量在线监测数据,识别郑州市2015年近地面臭氧(O_3)污染状况、特征及与颗粒物和氮氧化物水平关系,并以烟厂站为例分析郑州市O_3污染与气象要素的相关性。结果表明:郑州市O_3日最大8 h平均值具有明显季节变化,呈现出夏季春季秋季冬季的特征,夏季岗李水库站O_3月均质量浓度为155.5μg/m3,其余站点月均质量浓度为110~150μg/m3;夏季O_3每日最大8 h浓度具有显著"周末效应",其他季节较不明显;O_3小时浓度日变化呈单峰型分布,在15:00—16:00达到峰值,早晨07:00达到谷值;前体物NOx小时浓度日变化呈双峰型分布,与O_3具有显著负相关性;气象因素相关性分析结果表明,郑州市O_3污染日多出现于高温、低湿和微风等条件,这些气象因素有利于O_3生成和累积。  相似文献   

7.
利用西安市环境监测站超级站2013年9月1日—2015年5月31日黑碳气溶胶(BC)的监测数据,研究空气中BC浓度特征及其与气象因素和常规污染物相关性。结果表明:BC小时平均浓度均值在春季、夏季和冬季的变化趋势呈"W"型,秋季呈"V"型,且冬季的第一个最低值和峰值比春季和夏季的分别延迟1 h和2~3 h,且20:00~次日6:00秋季BC小时平均浓度均值高于当年冬季。BC浓度在秋季和冬季较高,夏季较低。冬季BC/PM_(2.5)基本最低,秋季BC/PM_(2.5)相对最高。BC日平均浓度与气温、降水和风速的日平均值为极负显著相关,且风速小于1.0 m/s时,其与风速呈最显著的负相关。除O_3外,BC日平均浓度与其他常规空气污染物浓度呈显著相关,表明其同源性很强,且受机动车尾气排放的影响更大。  相似文献   

8.
新《环境空气质量标准》(GB 3095—2012)实施以来的监测结果表明,我国第一批实施新标准的74个重点城市光化学烟雾污染总体呈加重趋势,2016年O_3日最大8 h平均质量(O_3-8 h)浓度第90百分位数为154μg/m~3,其O_3超标天数比例平均达到8.6%,其中京津冀区域O_3-8 h第90百分位数为172μg/m~3,超过国家二级标准限值,O_3超标天数比例平均达到13.6%,京津冀区域已成为我国光化学烟雾污染最为严重的区域。为有效控制光化学烟雾污染,当前亟需构建我国的光化学烟雾污染监测网络,各地区应因地制宜,科学布设监测点位,拟设点位应涵盖城市主城区的上风向区域、主城区核心区O_3前体物浓度较高的区域、主城区边缘或外围O_3浓度较高区域、主城区下风向区域;监测项目方面应注意同步开展O_3、挥发性有机物(VOCs)和NO_x的监测;监测时段方面应重点关注4—9月我国光化学污染较为严重的时段,确保客观反映污染状况,为有效开展大气光化学烟雾污染防治提供技术支撑。  相似文献   

9.
利用2016年南京市臭氧(O_3)及前体物监测数据,对南京市O_3污染现状、变化特征及其与前体物的关系进行分析。结果表明,2016年南京市O_3超标56 d,超标率15.3%,O_3日最大8 h滑动平均值的第90百分位数为184μg/m~3,超标0.15倍。O_3超标主要集中在4—9月份,日变化呈现"单峰"型特征,峰值出现在14:00,而上午8:00—10:00时段O_3浓度升幅最显著,小时浓度升幅超过20%。前体物VOCs和NO_2浓度变化与O_3呈反相关,且VOCs和NO_2浓度冬季最高,夏季最低,秋季和春季基本相当。  相似文献   

10.
为研究焦作市大气污染特征及其相关性,对2015—2017年焦作市4个国控空气监测点位的监测数据进行统计分析。结果表明:2015—2017年城区环境空气污染SO_2、NO_2、CO、PM_(10)、PM_(2.5)浓度均呈逐年下降趋势;大气污染浓度季节变化特征明显,PM_(10)、PM_(2.5)、SO_2、NO_2、CO的浓度均为冬季最高、夏季最低,空气质量指数也在冬季达到最高值; O_3浓度则为夏季最高、冬季最低。2017年焦作市沙尘天气共计36 d,严重影响了环境空气中颗粒物的浓度。由PM_(2.5)与PM_(10)的比值说明大气颗粒物污染以PM_(2.5)为主。通过SPSS软件分析,SO_2、NO_2、CO、PM_(10)、PM_(2.5)浓度间呈两两正相关,O_3浓度与NO_2、CO呈负相关。  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.
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   

13.
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   

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.
Assessments of long-term relationships between changes innutrient inputs and wetland nutrient concentrations can becomplicated by fluctuations in other environmental factors aswell as by problems typical of long-term monitoring data.Consequently, statistical analysisof these types of data sets requirescareful consideration of environmental covariates, potentialbiases in the monitoring design, and irregularities caused bychanges in field sampling protocols. We evaluated therelationship between anthropogenic phosphorus (P) inputs andwater-column total P (TP) concentrations in a northernEverglades marsh by statistically analyzing available datacollected from several sampling programs over the past 20 years(1978–1997). Canal inputs of agricultural runoff contributemost of the P to the marsh and have produced a zone ofenrichment within the marsh during the past few decades.Regression analyses showed that both canal and marsh TPconcentrations increased during the 1980s and then decreased inthe 1990s. However, the statistical relationship between canal Pinputs and marsh TP, while significant, generally was weakexcept for marsh locations adjacent to the canal. Strongerrelationships existed between marsh TP and hydrologic parameterssuch as marsh water depth, which is controlled by changes inweather patterns and marsh management. In particular, dryconditions during the 1980s may have contributed to observedincreases in marsh P concentrations and the movement of a P`front' further into the marsh. Higher rainfall and water depthsand agricultural best management programs initiated during the1990s have been associated with reduced P concentrations incanal waters entering the marsh. While it is anticipated thatthis reduction eventually will result in lower marsh TPconcentrations, this effect is not yet evident, possibly due tointernal loading of P from enriched marsh soils. Our findingsillustrate some of the environmental factors that can complicateattempts to develop empirical relationships between P inputs andwetland P concentrations and to use such relationships to forecast changesin marsh concentrations based on past monitoring data alone.  相似文献   

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