首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
建立了一种采用吹扫捕集气质联用法同时测定水中氯乙烯、乙醛、丙烯醛、丙烯腈、吡啶和松节油的分析方法,研究并优化了吹扫捕集前处理条件参数。结果表明,吹扫时间、吹扫温度和脱附时间是影响目标物的吹扫捕集效率的关键因素;优化后方法线性良好,相关系数均大于0.999,检出限范围为0.20~1.48μg/L,加标回收率范围为86.9%~105%,相对标准偏差为1.1%~9.8%。建立的吹扫捕集GC-MS联用法简便、快速、灵敏度高、定性定量准确可靠,可同时满足对自来水、地表水、地下水等水样中痕量氯乙烯、乙醛、丙烯醛、丙烯腈、吡啶和松节油监测的要求。  相似文献   

2.
Rapid development and application of nanomaterials and nanotechnology make assessment of their potential health and environmental impacts on humans, non-human biota, and ecosystems imperative. Here we show that pumpkin plants (Cucurbita maxima), grown in an aqueous medium containing magnetite (Fe3O4) nanoparticles, can absorb, translocate, and accumulate the particles in the plant tissues. These results suggest that plants, as an important component of the environmental and ecological systems, need to be included when evaluating the overall fate, transport and exposure pathways of nanoparticles in the environment.  相似文献   

3.
甲胺、二甲胺及三甲胺的气相色谱测定   总被引:13,自引:0,他引:13  
采用气相色谱法、大口径毛细管柱分离了甲胺、二甲胺、三甲胺.用氮磷检测器(NPD)检测,得到了良好的分离效果和很高的灵敏度,检测限可达0.025mg/L.同时,对甲胺类在NPD和氢火焰离子化检测器(FID)上的灵敏度作了比较,发现甲胺类物质在NPD上的灵敏度大大高于FID,因此,前者特别适用于检测环境试样中低含量甲胺类有机物的监测.  相似文献   

4.
Total suspended particle (TSP) collected at the fifth floor of House Dust in Hunan University, China, was analyzed in terms of microscopic morphology and chemical composition. The fine particles (50?nm-2?μm) in the TSP were analyzed by a high-resolution transmission electron microscope equipped with an energy-dispersive X-ray analyzer (HRTEM/EDS). Results showed that the particles were in shapes of plate, irregular and agglomerate. Based on EDS results, these fine particulate matter was primarily composed of Fe-rich (35.82-61.29%), Ca-rich (30.18-36.77%) and Si-rich (18.95-32.28%) particles. Other elements mainly including Mg (0.47-4.97%), Al (0.45-14.57%), S (0.45-4.73%), K (1.13-2.13%) and Zn (0.67-3.85%) were also observed. The sources analysis indicated that the HRTEM particles mainly originated from coal combustion, traffic emission, vehicles exhaust emission and fugitive soil or cement particulate matter. The coarse particles (4-50?μm) were detected by environmental scanning electron microscopy coupled with energy-dispersive X-ray detector (ESEM/EDS). Based on a simple algorithm, ESEM particles were categorized into five groups: C-bearing (46.15%, 67% and 86.98%), Si + Ca-bearing (21.48?+?11.80%, 16.51?+?10.81% and 16.32?+?10.62%), Si + Al-bearing (20.06?+?12.40%, 20.16?+?11.22% and 15.31?+?11.25%), Si-bearing (34.40%, 26.92% and 27.15%) particles and aggregates, most of which exhibit obvious crystalline structure, and these ESEM particles mainly derived from vehicles exhaust emission, coal combustion, soil, and biomass burning, while the aggregates are indicative of atmospheric reaction progress. HRTEM/EDS and ESEM/EDS are mutual complementary in analyzing the characteristic and determining the sources of TSP.  相似文献   

5.
The metal accumulation potential of Bacopa monnieri L. was assessed under simulated laboratory conditions. This study was carried out in mixed metals (Cu, Cd, Pb, Cr, Mn) condition and repeated exposures in artificial contaminated soil. The growing shoots were planted in garden subsoil containing 3, 16, 32, 64, 160 M each of the above metals. After 8 weeks, plants were refeeded to three times higher concentrations of each metal than initially used to assess the maximum accumulating potential of the metals. The accumulation of the metals by the root and shoot was concentration and duration dependent. The metal accumulation was considerably higher in the fine root than in the shoot and showed the following order : Mn > Cr > Cu > Cd > Pb. The plants showed high tolerance to the metals as no visible phytotoxic symptom was produced after 8 weeks. However, as a result of combined metal toxicity, chlorophyll content was reduced by 62% after 12 weeks. The highest metal concentration was lethal to the plant at 16 weeks. In view of their high tolerance, the plants of B. monnieri may be considered for the amelioration of industrially-polluted wetlands experiencing regular flushing of wastewaters.  相似文献   

6.
7.
The lagoon system of Navachiste-Macapule is located in northern Mexico, in the state of Sinaloa, with an area of 24,000 ha. The main economic activity in the area is agriculture, and the lagoon lies next to the irrigation district ID-063 which covers 116,615 ha. The purpose of this study is to evaluate the levels of pollution generated by organochlorine pesticides (OC) in the surface sediments of the lagoon and in the agricultural drains of the ID-063 that are supposedly transported into the system as a result of agricultural activities and runoff from adjacent land. For this, between 2006 and 2007, 45 surface sediment samples were collected (warm dry, rainy and cold dry) from 15 sampling sites, during the three climatic seasons. Of these, eight were located inside the lagoon in marine conditions (salinity >31 PSU) and seven in the agricultural drains of the ID-063 in freshwater conditions (salinity <5 PSU). The average concentration of the OC in the sediments was 44.75 ng g − 1, among which the group of the alicyclic compounds presented the greatest concentrations. The average value of the total organic carbon (TOC) in the sediments of the system was 0.90%. The sediments collected inside the lagoon had an average OC concentration of 18.97 ng g − 1, and the predominant type of sediment was fine to very fine sand. The average OC concentration in the sediments collected in the agricultural drains was 75.69 ng g − 1, where fine sediments (silt) were predominant. The presence of methoxychlor, endrin and heptachlor suggested that these compounds were continuously used in the system, even though their use is forbidden in Mexico.  相似文献   

8.
建立了一种吹扫捕集-气相色谱/质谱法同时测定水中的乙醛、丙烯醛、丙烯腈、吡啶、松节油和丁基黄原酸的分析方法。结果表明,吹扫时间、脱附时间、脱附温度和盐酸用量是影响目标化合物测定的关键因素,对吹扫捕集条件优化后,各目标化合物线性良好,相关系数均0.998,检出限为0.13~2.22μg/L,加标回收率为80.5%~111%,相对标准偏差为1.1%~10.9%,能够满足地表水环境质量标准的要求。  相似文献   

9.
The composition and variability of airborne fungal spores were studied using two complementary sampling methods in an outdoor environment in Kolkata suburb for 2 years, from November 2002 to October 2004. For monitoring the total fungal spore burden in the air, Burkard 7-day volumetric sampler was used, whereas Andersen two-sage viable sampler was used for isolating the cultivable airborne fungi. Among the 37 fungal spore types identified in the air samples, the predominant ones were Cladosporium, unidentified ascospores, unidentified basidiospores, Aspergilli/Penicilli, Nigrospora, Periconia, Chaetomium, Drechslera, Alternaria, Coprinus, Ganoderma, Pithomyces, and rust spores. Only six fungal spore types (Alternaria, Aspergilli/Penicilli, Cladosporium, Curvularia, Drechslera, and Nigrospora) were recovered in common by the two samplers. For Aspergilli/Penicilli, Drechslera, and Nigrospora, the spore concentration was underestimated in the non-viable sampling method (Burkard sampler). In general, higher spore count was recorded in winter. The highest fungal species variability was observed in early monsoon (June). Relative humidity could significantly predict the seasonal periodicity of the maximum number of airborne spores. The total airborne fungi concentration recorded in the study (15-16?×?10(3) spores m(-3) of air) was lower than the proposed threshold limit value for clinical significance, suggesting apparently no or less airborne-fungi-exposure-related health risk in the sampling area. Cladosporium cladosporioides was recorded beyond the proposed threshold limit value in January 2003 and March 2004; Aspergillus fumigatus and Aspergillus nidulans in winter that might have posed considerable health risk to sensitized individuals.  相似文献   

10.
Methane fluxes from Beijing ricefields as affected by organic amendment, water regime, crop establishment method, and rice cultivar were measured with a closed chamber method in 1990, 1991, 1995, and 1996. Total fluxes from plots receiving high organic amendment always exceeded those from the low-input plots. Compared with continuous flooding, intermittent irrigation (there were a few days of no standing water between two irrigations) and constant moisture (the field had no standing water, but remained saturated) reduced methane emission rate by 25.4 and 58.4%, respectively. Methane flux from a dry-seeded rice field was 75.2% lower than from a transplanted ricefield although both dry-seeded rice plots and transplanted ricefields were initially flooded at the same time. Rice cultivars differed in methane emission rates by 9.0–55.7%. Emission rates were positively correlated with aboveground dry matter production and root weight, but not grain yield. Intermittent irrigation and rice cultivar seem to be the most promising methods for mitigating methane emission from ricefields; they do not affect rice yield and are easily implemented at the farm level.  相似文献   

11.
采用固相萃取-高效液相色谱(SPE - HPLC)二极管阵列检测器同时测定水中呋喃丹、甲萘威和阿特拉津,以甲醇-水为流动相,采用梯度洗脱方式,选择220 nm为检测波长,二氯甲烷为洗脱剂.呋喃丹在0.200 mg/L ~5.00 mg/L、甲萘威和阿特拉津在0.020 mg/L~5.00 mg/L范围内线性良好,检出限...  相似文献   

12.
采用KOH梯度淋洗离子色谱法测定地表水和饮用水中ClO2-、BrO3-和ClO3-,在试验确定的条件下,3种离子与F-、Cl-、NO2-、NO3-、SO2-4、Br-、I-等7种离子分离度良好。 ClO2-、BrO3-、ClO3-在50.0μg/L~1000μg/L范围内线性良好,检出限分别为5.2μg/L、8.9μg/L、7.6μg/L,环境水样加标平行测定的RSD分别为2.1%~5.4%、4.1%~5.4%、2.5%~4.8%,两个质量浓度水平加标的平均回收率分别为93.7%~96.5%、90.3%~94.8%、98.7%~111%。  相似文献   

13.
This research was conducted to search and identify spontaneously growing heavy metal-tolerant plant species that are potentially useful for phytoremediation in contaminated sediment. Five sites were selected for collection of plants growing on polluted shore (river bank) sediment of the Xiang River, China. The concentrations of Zn, Pb, Cu and Cd in plants, sediments, and grasshoppers were determined using flame atomic absorption spectrophotometer (AAS700, Perkin-Elmer, USA). Considering translocation factor and bioaccumulation factor, Rumex crispus (Polygonaceae), Rumex dentatus (Polygonaceae), and Lagopsis supina (Labiatae) could be potentially useful for phytostabilization of metals. R. crispus can be considered potentially useful for phytoextraction of Cd. In light of the biomagnification factors, grasshoppers are deconcentrators for Pb and Cd, microconcentrators for Zn and macroconcentrators for Cu to the plants, respectively. To the best of our knowledge, the present study is the first report on Zn, Pb, Cu and Cd accumulation in R. crispus and L. supina, providing a pioneer contribution to the very small volume of data available on the potential use of native plant species from contaminated sediments in phytostabilization and phytoremediation technologies.  相似文献   

14.
Natural and chemically enhanced phytoextraction potentials of maize (Zea mays L.) and sesbania (Sesbania aculeata Willd.) were explored by growing them on two soils contaminated with heavy metals. The soils, Gujranwala (fine, loamy, mixed, hyperthermic Udic Haplustalf) and Pacca (fine, mixed, hyperthermic Ustollic Camborthid), were amended with varying amounts of ethylenediaminetetraacetic acid (EDTA) chelating agent, at 0, 1.25, 2.5, and 5.0 mM kg?1 soil to enhance metal solubility. The EDTA was applied in two split applications at 46 and 60 days after sowing (DAS). The plants were harvested at 75 DAS. Addition of EDTA significantly increased the lead (Pb) and cadmium (Cd) concentrations in roots and shoots, uptake, bioconcentration factor, and phytoextraction rate over the control. Furthermore, addition of EDTA also significantly increased the soluble fractions of Pb and Cd in soil over the controls; the maximum increase of Pb and Cd was 13.1-fold and 3.1-fold, respectively, with addition of 5.0 mM EDTA kg?1soil. Similarly, the maximum Pb and Cd root and shoot concentrations, translocation, bioconcentration, and phytoextraction efficiency were observed at 5.0 mM EDTA kg?1 soil. The results suggest that both crops can successfully be used for phytoremediation of metal-contaminated calcareous soils.  相似文献   

15.
This study aimed to assess soil quality by chemical and ecotoxicological investigations and to check the correspondence between soil metal concentrations and ecotoxicity. For these purposes, surface soils collected at four adjacent roadside urban parks and at a former industrial area were characterized for C/N, organic matter content, texture, and pH. Cr, Cu, Ni and Pb, chosen among the most representative soil metal contaminants, were measured as total content and as available and water soluble fractions. In addition, the total concentrations of the investigated metals were used to calculate two chemical indices: the contamination and the potential ecological risk factors. The toxicity of the investigated soils was evaluated by an ecotoxicity test battery carried out on both soil samples (Vibrio fischeri, Heterocypris incongruens and Sinapis alba) and elutriates (Vibrio fischeri, Daphnia magna and Selenastrum capricornutum). The findings, both by the chemical and ecotoxicological approaches, would suggest that the soils with high metal contamination pose ecological risks. On the other hand, moderately metal contaminated soils did not exclude soil ecotoxicity. In fact, toxic effects were also highlighted in soils with low metal content, toxicity being affected by metal availability and soil characteristics. Moreover, the results suggest the importance of using a battery of tests to assess soil ecotoxicity.  相似文献   

16.
Accumulation of metals in soil at elevated concentrations causes risks to the environmental quality and human health for more than one hundred million people globally. The rate of metal release and the alteration of metal distribution in soil phases after soil washing with a sulfosuccinamate surfactant solution (Aerosol 22) were evaluated for four contaminated soils. Furthermore, a sequential extraction scheme was carried out using selective extractants (HAcO, NH(2)OH·HCl, H(2)O(2) + NH(4)AcO) to evaluate which metal species are extracted by A22 and the alteration in metal distribution upon surfactant-washing. Efficiency of A22 to remove metals varied among soils. The washing treatment released up to 50% of Cd, 40% of Cu, 20% of Pb and 12% of Zn, mainly from the soluble and reducible soil fractions, therefore, greatly reducing the fraction of metals readily available in soil. Metal speciation analysis for the solutions collected upon soil washing with Aerosol 22 further confirmed these results. Copper and lead in solution were mostly present as soluble complexes, while Cd and Zn were present as free ions. Besides, redistribution of metals in soil was observed upon washing. The ratios of Zn strongly retained in the soil matrix and Cd complexed with organic ligands increased. Lead was mobilized to more weakly retained forms, which indicates a high bioavailability of the remaining Pb in soil after washing. Comprehensive knowledge on chemical forms of metals present in soil allows a feasible assessment of the environmental impact of metals for a given scenario, as well as possible alteration of environmental conditions, and a valuable prediction for potential leaching and groundwater contamination.  相似文献   

17.
Surface sediment samples from Strymonikos and Ierissos Gulfs wereanalyzed for Cu, Pb, Zn, Cr and Ni. The results showed that the sediment of Ierissos Gulf is more polluted with Cu, Pb, and Zn ascompared to that of Strymonikos Gulf. The benthal area located off the load-out facility of the mining operations in the town of Stratoni, in Ierissos Gulf is established as the most pollutedregion. The distribution of Cr and Ni in both gulfs indicates thenatural origin of these metals with the weathering of Strymon River and of other smaller rivers rocks being responsible for their enrichment.  相似文献   

18.
A GC-MS procedure for the determination of hydrocarbons in air samples from Oviedo, Spain, was developed. Air hydrocarbons were sampled with a high volume sampler equipped with a holder containing a glass fiber filter, to trap the particulate phase, and two polyurethane foams to capture hydrocarbons of the vapour phase. Compounds were extracted with CH2Cl2 by Soxhlet extraction and then fractionated using column chromatography with alumina silica. Analyses of the fractions were performed by GC-MS in the electron ionization mode. PAHs and n-alkanes were the compounds examined in this work. Samples collected in the vicinity of the Faculty of Chemistry (a semi-urban area) were analysed. The total concentration of PAHs in the air samples analysed ranged from 28 to 76 ng m(-3). The total concentration of n-alkanes and PAHs in the vapour phase exceeded the concentration in the particulate phase in the samples analysed.  相似文献   

19.
In the environment of a lead smeltery contamination with lead, zinc and cadmium was measured over a 15-year period. Efficient bag filters were installed in order to remove dust from the flue gases. This measure of improvement resulted in a drastic reduction of lead, zinc and cadmium content in suspended particles (by 92, 94 and 89%), to a lesser extent in depositions (by 79, 75 and 68%), whereas in household dust the reduction was considerably lower (by 53, 55 and 70%). It can be assumed that household dust contains also redispersed soil particles on which the dust from the smeltery flue gases has deposited over years. To determine to what extent contaminated soil continues to cause increased population exposure directly or through plants or pastures, in the period 1981–1985 the content of metallic ions in the soil was measured at three depths. Selective solubility of soil metallic compounds was analysed in water, in 1 mol ammoniumacetate solution and in 0.05 mol ethylenediaminetetra-acetic acid (EDTA) solution in relation to their solubility in suspended particles, depositions and household dust. A considerably low portion of soluble metallic compounds was found in the soil and physico-chemical characteristics of the soil and portion of metallic ions bound to fulvice and humic acids were determined. The behaviour of metallic ions in contact with soil samples was studied in laboratory and it was found that approximately 50% of lead, 70% of zinc and 7% of cadmium ions change into non-soluble or poorly soluble compounds. By qualitative phase analysis in the non-soluble fraction PbO2, Pb3P4O13, Zn(OH)2, ZnO, Fe2O3 and Cd(OH)2 were identified.  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号