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1.
采用石墨炉原子吸收法对空气中铬酸雾进行测定,方法在待测液中铬质量浓度为1~10μg/L范围内线性良好,r=0.999 6,检出限为0.001 mg/m~3,测定结果的相对标准差为1.64%~4.53%,样品加标回收率为91.0%~95.4%,且用该方法与《固定污染源排气中铬酸雾的测定二苯基碳酰二肼分光光度法》(HJ/T 29—1999)分别测定实际样品中铬的质量浓度,结果无明显差异。  相似文献   

2.
采用ASE萃取-弗罗里硅土净化-HPLC法和ASE萃取-GPC净化-HPLC法测定土壤中苯并(a)芘,并将2种方法的测定结果作比对。试验表明,方法在0.02 mg/L~0.500 mg/L之间线性良好,当取样量为10 g时,弗罗里硅土净化土壤样品方法检出限为8.93×10~(-5)mg/kg,平均加标回收率为72.7%~73.8%,3次测定结果的RSD为4.0%~4.5%;凝胶色谱净化土壤样品方法检出限为1.98×10~(-5)mg/kg,平均加标回收率为88.8%~90.2%,3次测定结果的RSD为2.1%~2.8%。  相似文献   

3.
采用Tenax GR吸附-热脱附-气质联用法对固定污染源废气中50种挥发性有机物(VOCs)进行测定。结果显示,Tanax GR吸附管对于丙酮、环戊酮、2-庚酮、2-壬酮及六甲基二硅氧烷的吸附能力相对较差,但丙酮、环戊酮、2-庚酮、2-壬酮在2~30 ng范围内呈现良好的线性关系,且相关系数(R 2)>0.99,六甲基二硅氧烷在2~50 ng范围内呈现良好的线性关系,R^2=0.994,其他45种化合物在2~100 ng范围内呈现良好的线性关系,R^2>0.995。当采样体积为300 mL时,50种化合物的检出限为0.0003~0.0096 mg/m^3,测定下限为0.0011~0.0384 mg/m^3,相对标准偏差(RSD)<15.98%,加标回收率为78.15%~120.90%。该方法操作简单、灵敏度高、准确性好,能够满足固定污染源废气中痕量VOCs的快速检测。  相似文献   

4.
用玻璃纤维滤筒采集固定污染源废气颗粒物,借助硝酸和氢氟酸的作用,使滤筒和废气颗粒物在160℃下消解,再用原子荧光法测定消解液中总汞。用50%热硝酸溶液处理玻璃纤维滤筒,消除滤筒本底值不一对测定结果的干扰,并优化消解过程,使该方法在0.050μg/L~1.00μg/L范围内线性良好。当采样体积为10 L时,方法检出限为4.5×10~(-5)mg/m~3,空白加标样6次测定结果的RSD为7.2%,加标回收率为87.0%~113%。将该方法用于测定某固定污染源废气颗粒物中总汞,测定值在标准排放限值内。  相似文献   

5.
通过色谱-质谱联用法(简称GC-MS),利用低温冷阱技术对大气中的VOCs进行浓缩富集,然后经过加热解吸分别至毛细管色谱柱和FID检测器及MS检测器,对大气中98种挥发性有机化合物(VOCs)进行分离、定性、定量测定。方法检出限为0.008×10-9~0.100×10-9(V/V);线性相关系数的平方值为0.992 7~1,相对标准偏差为4.0%~20.2%,总体标准偏差为0.154 2~0.952 1。  相似文献   

6.
介绍了固定污染源中挥发性有机物(VOCs)的主要采样方法,并重点介绍了动态稀释法在固定污染源中采样的应用。采用动态稀释法取样,对某汽车企业涂装车间的排放废气进行了定性分析,并对其中主要的10种VOCs进行了定量分析。研究了方法测定的稳定性,10种化合物相对标准偏差为9%~32%,符合工况变动范围。将不同采样时间及不同吸附材料的测定结果与在线监控数据进行比较,结果显示动态稀释法的测定结果均在实际工况波动范围内,说明该方法能够较好地满足汽车涂装行业VOCs的采样要求。  相似文献   

7.
气相色谱法同时测定制药企业废气中多种挥发性有机物   总被引:1,自引:0,他引:1  
针对典型制药产品青霉素、阿莫西林、维生素C、对乙酰氨基酚生产过程的挥发性有机物(VOCs)排放特点,建立了吸附-解吸-气相色谱法同时检测制药企业废气中丙酮、乙酸乙酯、异丙醇、苯、甲苯、乙酸丁酯和正丁醇等7种特征VOCs的分析方法。采用活性炭采样管采样-二硫化碳解吸-毛细管色谱柱分离,在解吸时间30 min、柱温35℃保持6 min、30℃/min速率升温到200℃保持2 min的色谱分析条件下,各挥发性有机物可以实现良好的分离;7种物质标准曲线相关系数为0.999 8~0.999 9,相对标准偏差为1.1%~3.2%,检出限为0.004 mg/m3~0.014 mg/m3,7种物质的解吸效率为83.1%~105.1%。结果表明,该方法适用于典型制药企业固定污染源排放废气中特征VOCs的测定。  相似文献   

8.
采用顶空-气相色谱法测定固定污染源废气中甲胺、二甲胺、乙胺、二乙胺和三乙胺,通过优化相关测定条件,使5种挥发性脂肪胺在0.005 mg/L~25.0 mg/L范围内线性良好,方法检出限为0.004 mg/m3~0.4 mg/m3 (以采集20 L空气样品计)。5种挥发性脂肪胺的加标回收率为91.0%~113%,6次测定结果的RSD≤7.4%。  相似文献   

9.
针对《固定污染源废气硫酸雾的测定离子色谱法》在污染源测定过程中SO_2引入的正干扰问题,通过实验进行了干扰物确认及消除方式研究。结果表明,在无氧条件下,SO_2不会对硫酸雾产生正干扰,而在有氧气存在条件下标准方法中的碱性吸收液会吸收部分SO_2并最终转化为SO_4~(2-),使硫酸雾测定结果偏高。硫酸生产企业测定结果显示被吸收的SO_2约占其排放量的30%~59%。在原有吸收液中加入1%甲醛作为改进吸收液,可使采集到的SO_2以SO_3~(2-)形式稳定存在,不会对目标化合物SO_4~(2-)产生干扰且稳定时间至少为30 d。采用改进吸收液采集硫酸雾可有效防止SO_2引入正干扰,且对硫酸雾测定结果无影响。  相似文献   

10.
固相萃取-高效液相色谱法测地表水中11种酚类化合物   总被引:1,自引:1,他引:0  
建立了固相萃取-高效液相色谱法同时测定地表水中11种酚类化合物的方法。水样经过全自动固相萃取仪富集,以HLB柱为萃取柱,乙腈(含1%乙酸)为洗脱剂,用高效液相色谱仪分析定量。该方法在0.5~5.0 mg/L范围内线性良好,相关系数为0.999 6~0.999 9,11种酚类化合物的纯水加标回收率为82.0%~111%,地表水加标回收率为98.5%~116%,精密度为3.58%~4.67%,检出限为1×10-4~5×10-4mg/L,该方法简单实用、准确可靠,可用于地表水中酚类化合物的同时测定。  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.
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   

16.
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   

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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