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61.
小清河水体和沿岸地下水中有机污染物的监测及其毒性分析 总被引:4,自引:0,他引:4
本文对小清河水体和沿岸地下水中的有机污染物进行了色-质联用分析,共检出有机污染物13类93种。并对其毒性效应进行了分析和评价。 相似文献
62.
超临界二氧化碳萃取-GC/MS测定土壤中的多环芳烃 总被引:10,自引:2,他引:10
本文开发了一种采用超临界二氧化碳萃取土壤中多环芳烃、不须经过纯化步骤,直接可用于GC/MS分析的简便、高效的方法。本实验中超临界革取的流体是二氧化碳,改善剂是5%的二氯甲烷/甲醇,萃取温度为120℃、压力为34MPa。GC/MS分析时除了采用外标外,还加入了6种同位素PAHs内标以校正各段PAHs的响应因子。采用本方法成功地测定了我国未开垦森林土壤中的PAHs。 相似文献
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64.
Atmospheric aerosols are an important contributing factor to turbidity in urban areas besides having impact on health. Aerosol characteristics show a high degree of variability in space and time as anthropogenic share of total aerosol loading is quite substantial and is essential to monitor the aerosol features over long time scales. In the present study extensive observations of columnar aerosol optical depth (AOD), total columnar ozone (TCO) and precipitable water content (PWC) have been carried over a tropical urban city of Hyderabad, India. Significant variations of AOD have been observed during course of the day with low values of AOD during morning and evening hours and high values during afternoon hours. Spectral variation of AOD exhibits high AOD at smaller wavelengths and vice versa except a slight enhancement in AOD at 500 nm. Anomalies in AOD, particulate matter and black carbon concentrations have been observed during May, 2003. Back trajectory analysis of air mass during these episodes suggested variation in air mass trajectories. Analysis of the results suggests that air trajectories from land region north of study area cause high loading of atmospheric aerosols. The results are discussed in the paper. 相似文献
65.
大气颗粒物中元素碳的直接测定 总被引:4,自引:1,他引:4
对原来用元素分析仪测定大气颗粒物样品中有机碳、元素碳的方法[1 ] 进行改进 ,将差减法间接测定元素碳改为一步直接测定元素碳。有机碳、元素碳的测量标准偏差的平均值分别为 0 35 %、0 34% ,提高了元素碳的测量精度 ,同时避免了误差传递 ,解决了差减法测定元素碳时出现负值的情况。 相似文献
66.
固定化微生物处理有机污染物的研究进展 总被引:4,自引:0,他引:4
综述了近年来固定化微生物技术用于有机污染物治理中的最新进展,这些有机污染物包括难降解有机污染物(酚类、芳香烃类等)及其它化合物(DMP、甲硫醇恶臭气体、制药废水等)。此外,对藻类固定化技术作了简介,并对固定化技术的应用前景及存在问题进行了评述。 相似文献
67.
68.
活性炭法测量室内空气中氡浓度的影响因素研究 总被引:1,自引:0,他引:1
探讨了各种因素对活性炭法测量室内空气中氡浓度的影响,并提出既能保证检测质量,又能符合工程检测需要、提高检测效率的检测条件范围。 相似文献
69.
D. M. Whelpdale P. W. Summers E. Sanhueza 《Environmental monitoring and assessment》1997,48(3):217-247
This paper presents a summary of globalacid deposition flux data taken from a globalassessment report on acid deposition prepared forUNEP/WMO (Whelpdale and Kaiser, 1996). There is a largevariation in the spacial coverage and reliability ofmonitoring around the world. Many more stationsmeasure wet deposition than collect appropriate datafor estimating dry deposition. The widespread regionswith highest precipitation concentrations anddeposition fluxes of sulphate and nitrate coincideclosely with the regions of highest density ofSO2 and NOx precursor emissions occurringprimarily in the mid-latitude, northern hemispherebelt where a large fraction of the worlds fossilfuels is consumed. Organic acids in precipitation makea minor contribution to acidity (<20%) inindustrial regions, but in the rest of the world theyare of same order, or even exceed, inorganic acids.Less is known about dry deposition, but it appears topredominate near strong emission sources with wetdeposition predominating farther downwind. The molarratio of the N/S contribution to acidic deposition isclose to 1.0 over large areas of Europe and NorthAmerica, but is highly variable elsewhere, beinghighest in equatorial regions due to biomass burningand lowest near smelters and other large sources of SO2. 相似文献
70.
William F. Laurance 《Environmental monitoring and assessment》2000,61(1):113-122
This paper describes four global-change phenomena that are having major impacts on Amazonian forests. The first is accelerating deforestation and logging. Despite recent government initiatives to slow forest loss, deforestation rates in Brazilian Amazonia have increased from 1.1 million ha yr–1 in the early 1990s, to nearly 1.5 million ha yr–1 from 1992–1994, and to more than 1.9 million ha yr–1 from 1995–1998. Deforestation is also occurring rapidly in some other parts of the Amazon Basin, such as in Bolivia and Ecuador, while industrialized logging is increasing dramatically in the Guianas and central Amazonia.The second phenomenon is that patterns of forest loss and fragmentation are rapidly changing. In recent decades, large-scale deforestation has mainly occurred in the southern and eastern portions of the Amazon — in the Brazilian states of Pará, Maranho, Rondônia, Acre, and Mato Grosso, and in northern Bolivia. While rates of forest loss remain very high in these areas, the development of major new highways is providing direct conduits into the heart of the Amazon. If future trends follow past patterns, land-hungry settlers and loggers may largely bisect the forests of the Amazon Basin.The third phenomenon is that climatic variability is interacting with human land uses, creating additional impacts on forest ecosystems. The 1997/98 El Niño drought, for example, led to a major increase in forest burning, with wildfires raging out of control in the northern Amazonian state of Roraima and other locations. Logging operations, which create labyrinths of roads and tracks in forsts, are increasing fuel loads, desiccation and ignition sources in forest interiors. Forest fragmentation also increases fire susceptibility by creating dry, fire-prone forest edges.Finally, recent evidence suggests that intact Amazonian forests are a globally significant carbon sink, quite possibly caused by higher forest growth rates in response to increasing atmospheric CO2 fertilization. Evidence for a carbon sink comes from long-term forest mensuration plots, from whole-forest studies of carbon flux and from investigations of atmospheric CO2 and oxygen isotopes. Unfortunately, intact Amazonian forests are rapidly diminishing. Hence, not only is the destruction of these forests a major source of greenhouse gases, but it is reducing their intrinsic capacity to help buffer the rapid anthropogenic rise in CO2. 相似文献