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221.
使用超高效液相色谱ACQUITY UPLC快速分析醛酮类化合物   总被引:2,自引:0,他引:2  
醛酮类化合物是焚烧过程扩散到环境中的产物,这些化合物大部分都是已知的致癌物.因此,美国EPA和一些州开发了分析这些化合物的方法,包括US EPA TO5 (空气),方法554 (饮用水),方法8315 A选项1和2 (废水、土壤和空气),以及加利福尼亚州方法1004 (羰基化合物,机动车排放尾气中的醇类氧化物).这些方法使用二硝基苯肼(DNPH)衍生化这些化合物,然后用HPLC分离并紫外检测(吸收波长360nm),目标分析物因方法的不同而略有不同.当前使用的方法运行时间超过40min以上,需要设置多种色谱柱方可达到可接受的化合物分离度.  相似文献   
222.
Five aromatic hydrocarbons (benzene, toluene, and three isomeric xylenes) were monitored in indoor and outdoor air of 7 public buildings and 54 private homes, located in Barcelona City metropolitan area and in several rural areas of Catalonia. The sampling was carried out over four periods: spring-summer and winter of 2000, and summer and winter of 2001. Passive ORSA 5 Dra¨ger samplers were used for benzene, toluene, and xylenes (BTX) adsorption. BTX were extracted with carbon disulphide and analysed using ...  相似文献   
223.
224.
IntroductionAswangovernorate ,Egypt ,isfamousforbymonuments (Ancient,CopticandIslamic) .Thefoundationareofthefirstimportanceandcareshouldbetakentoseethattheyareconsolidatedandprotectedasforaspossiblefromtheinfiltrationofwater.Waterisamajorcauseofdamage ,no…  相似文献   
225.
ABSTRACT: Watershed functions that dominate the hydrologic environment are identified and discussed. Hydrological and ecological functions are considered in relation to the storm and annual hydrographs, and to water quality. Two integrative watershed responses to these functions are also articulated. Since most of the Earth's water is in storage, consideration of the hydrologic cycle as movement between water storage sites enhances this functional and response characterization of the watershed which, in turn, suggests guidance and direction for the restoration of watershed functions.  相似文献   
226.
Ammonia emission from grassland and livestock production systems in the UK   总被引:3,自引:0,他引:3  
Emissions of ammonia were measured from livestock excreta and fertilisers applied to grass swards, from grazed paddocks, from decomposing grass herbage and from an animal house containing dairy cows. Emissions from urine, dung, slurry and fertilisers were determined using a system of wind tunnels with each tunnel covering an area of 1 m(2). Emissions from grazed swards were determined using a micrometeorological mass balance method. From the results of these measurements, together with other published information, an inventory for ammonia emissions has been calculated for grassland and livestock production systems over the UK as a whole. It is estimated that emissions from grassland and cattle and sheep production amount to about 230 kt NH(3)-N annually, while emissions from pig and poultry production amount to about 40 kt and 80 kt NH(3)-N, respectively.  相似文献   
227.
Benthic invertebrates collected from an acid (pH 3.2) and an alkaline (pH 7.9) tailing pond in the Rouyn-Noranda mining region were compared with those of a control pond in order to assess the effects of the pH on the benthic community structure and on metal accumulation by invertebrates. The acid pond showed high mean soluble concentrations of aluminium (2600 ppb), copper (230 ppb), iron (6500 ppb) and zinc (4900 ppb) in the water and high mean concentrations of copper (340 ppm), iron (15,238 ppm) and zinc (445 ppm) in the sediments. The benthic fauna was dominated by Chironomus spp and the water beetle Ilybius sp. The Shannon-Weaver diversity index was 0.04. The alkaline pond had high mean sediment concentrations of cadmium (21 ppm), iron (15,823 ppm), manganese (658 ppm) and nickel (146 ppm). A total of 37 insect genera and a diversity index of 3.4 were recorded for this pond. Of the seven metals studied only copper and aluminium showed greater accumulations in the biota of the contaminated ponds than in that of the control. Insects dominated the benthic fauna in both contaminated ponds and crustacea in the control.  相似文献   
228.
The aim of the present paper is to assess the maturity degree reached by different samples of several mixtures from winery and distillery residues composted using the Rutgers composting system, by means of excitation-emission matrix (EEM) fluorescence spectroscopy. The composts were sampled once a week for about 200d. EEM spectra indicate the presence of different fluorophores. The fluorescence intensities of these peaks show trends related to the maturity of the composting samples selected. The "contour density" of EEM maps is strongly modified through time. We have used the quantitative method of fluorescence regional integration (FRI). The EEMs were delineated into five excitation-emission regions. The degree of compost maturity could be correlated with the percentage of the volumetric integration under the EEM within each region. Further refinement of these techniques should provide a relatively rapid method for assessing the suitability of the compost to soil application.  相似文献   
229.
Bioremediation of tributyltin (TBT) contaminated sediment was studied and degradation enhancement and improvement of bioavailability were also investigated. In TBT spiked sediment, the half-life of TBT in the control sample, representing natural attenuation, was 578 d indicating its persistence. In the stimulated sample (pH 7.5, aeration and incubated at 28 °C), the half-life was significantly reduced to 11 d. Further stimulation by nutrient addition (succinate, glycerol and l-arginine) or inoculation with Enterobacter cloacae (∼107 viable cells g−1 of sediment) resulted in half-life reduction to 9 and 10 d, respectively. In non-spiked sediment, the indigenous microorganisms were able to degrade aged TBT, but the extended period of contamination decreased the degradation efficiency. To improve bioavailability, addition of surfactant, adjustment of salinity and sonication were studied. The highest percentage solubilisation of TBT in water was obtained by adjusting salinity to 20 psu, which increased the solubility of TBT from 13% to 33%. Half-lives after bioavailability was improved were 5, 4 and 4 d for stimulation, stimulation w/nutrient addition and stimulation w/inoculation, respectively. However, natural attenuation in the control sample was not enhanced. The results show that providing suitable conditions is important in enhancing TBT biodegradation, and bioavailability improvement additionally increased the rate and degraded amount of TBT. Unfortunately, nutrient addition and inoculation of the degrader did not enhance the degradation appreciably.  相似文献   
230.
Antipredator behavior was used as a parameter to detect effects caused by exposure to the organotin compound bis(tributyltin)oxide (TBTO). Three groups of threespine sticklebacks (Gasterosteus aculeatus L.) were exposed to 3, 9 and 27 ppb TBTO, respectively. A fourth control group was given the same treatment as the other three groups, but no TBTO. Antipredator behavior of the fish was evoked using a dummy heron (Ardea cinerea) bill. TBTO exposure caused significant changes in the spatial position of the fish in the aquarium (P(Loc)), their response to predator attack (P(Res)), recovery time (P(Rec)) and latency time (P(Lat)). Some of the effects were, however, reversible after the exposure was terminated. We suggest that behavior as an indicator of pollution may be used as an ecologically relevant integrative biomarker.  相似文献   
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