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901.
南京市大气可吸入颗粒物中多环芳烃的分布状况 总被引:2,自引:0,他引:2
采集南京市大厂和山西路两地区四季度大气PM10样品,用索氏提取-高效液相色谱技术分析其多环芳烃组成及含量,结果表明,两地区多环芳烃总量在42.561ng/m3~121.890ng/m3之间,大厂区浓度明显高于山西路地区,是山西路地区的1.169~2.628倍。大厂地区PAHs总量受季节影响不大,山西路地区浓度与季节呈一定的相关性,即春季>冬季>夏季>秋季,两地区PAHs中蒽、荧蒽、苯并[b]荧蒽、苯并[g,h,i]苝含量相对都较高,表明燃煤和交通是南京市的主要污染源,大厂区燃煤污染更为明显。 相似文献
902.
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905.
浊点萃取-高效液相色谱测定土壤及底泥中痕量多环芳烃 总被引:3,自引:0,他引:3
采用阴离子表面活性剂十二烷基硫酸钠(SDS)超声波辅助浊点萃取(CPE),高效液相色谱法(HPLC)测定土壤及底泥中痕量多环芳烃(PAHs),在SDS浓度为2.75%,HCl用量为4.2mol·l-1,平衡温度为70℃.恒温时间为50min的最佳条件下,萘、芴、苊烯、菲和芘的方法检测限分别:31.40,18.84,12.56,94.20和31.40μg·l-1,线性范嗣为0-10.0 mg·l-1. 相似文献
906.
氯代芳香化合物的KOW与对数拓扑指数和路径指数的相关性 总被引:3,自引:1,他引:2
本文用1gKow表征氯代芳香化合物的生物降解能力,并分别以对数拓扑指数(LTI)和路径指数(PI)为自变量,建立了新的预测模型。结果表明,回归方程的预测值与实验值十分吻合,相关系数接近于1,平均标准偏差小于0.1。 相似文献
907.
Robin D. Calfee Edward E. Little Laverne Cleveland Mace G. Barron 《Environmental science and pollution research international》1999,6(4):207-212
Traditionally, the toxic effects of petroleum have been investigated by conducting studies in the absence of ultraviolet radiation
(UV). Photomediated toxicity is often not considered, and the toxic effects of an oil spill can be grossly underestimated.
The toxicity of a weathered oil collected from a monitoring well at an abandoned oil field toCeriodaphnia dubia was examined in the presence of UV. A solar simulator equipped with UVB, UVA, and cool white lamps was used to generate environmentally
comparable solar radiation intensities.C. dubia were exposed to six concentrations of water accommodated fractions (WAF) of weathered oil in conjunction with three levels
of laboratory simulated UV (Reference = < 0.002 μW/cm2UVB; 3.0 μW/cm2 UVA; Low = 0.30 μW/cm2 UVB; 75.0 μW/cm2 UVA; High = 2.0 μW/cm2 UVB; 340.0 μW/cm2 UVA) and visible light. Seven day static renewal bioassays were used to characterize WAF/UV toxicity. WAF toxicity significantly
(p < 0.05) increased when the organisms were exposed to WAF in the presence of UV. The photoenhanced toxicity of the WAF increased
with WAF concentration within each UV regime. Relative to the reference light regime, the average number of neonates from
adults exposed to 1.6 mg TPH/L decreased significantly by 20% within the low light regime, and by 60% within the high light
regime. These results indicate that organisms exposed to dissolved-phase weathered oil in the presence of environmentally
realistic solar radiation, exhibit 1.3–2.5 times greater sensitivity, relative to organisms exposed under traditional laboratory
fluorescent lighting. 相似文献
908.
Nitrosomonas europaea, a model ammonia oxidizing bacterium, was exposed to a wide variety of aromatic hydrocarbons in 3 h batch assays. The expression of NE1545, a phenol sentinel gene involved in fatty acid metabolism, was monitored via quantitative real-time polymerase chain reaction (qRT-PCR) and a Coulter Counter technique was used to monitor changes in cell volume. Decreases in cell volume and NE1545 gene expression correlated strongly with exposure to aromatic hydrocarbons that possessed a single polar group substitution (e.g. phenol and aniline). Aromatic hydrocarbons that contain no polar group substitutions (e.g. toluene) or multiple polar group substitutions (e.g. p-hydroquinone) caused negligible changes in NE1545 expression and cell volume. The oxidation of aromatic hydrocarbons by N. europaea from configurations without a single polar group to one with two polar groups (e.g. p-cresol oxidized to 4-hydroxybenzyl alcohol) and from configurations with no polar groups to one with a single polar group (e.g. ethylbenzene oxidized to 4-ethylphenol) greatly influenced NE1545 gene expression and observed changes in cell volume. Nitrification inhibition in N. europaea by the aromatic hydrocarbons was found to be completely reversible; however, the decreases in cell volume were not reversible suggesting a physical change in cell membrane composition. Ammonia monooxygenase blocking studies showed that the chemical exposure that was responsible for the cell volume decrease and up-regulation in gene expression and not the observed inhibition. N. europaea is the first bacterium shown to experience significant changes in cell volume when exposed to μM concentrations of aromatic hydrocarbons, three orders of magnitude lower than previous studies with other bacteria. 相似文献
909.
Oliveira C Martins N Tavares J Pio C Cerqueira M Matos M Silva H Oliveira C Camões F 《Chemosphere》2011,83(11):1588-1596
Atmospheric aerosols of four aerodynamic size ranges were collected using high volume cascade impactors in an extremely busy roadway tunnel in Lisbon (Portugal). Dust deposited on the tunnel walls and guardrails was also collected. Average particle mass concentrations in the tunnel atmosphere were more than 30 times higher than in the outside urban background air, revealing its origins almost exclusively from fresh vehicle emissions. Most of the aerosol mass was concentrated in submicrometer fractions (65%), and polycyclic aromatic hydrocarbons (PAH) were even more concentrated in the finer particles with an average of 84% of total PAH present in sizes smaller than 0.49 μm. The most abundant PAH were methylated phenanthrenes, fluoranthene and pyrene. About 46% of the total PAH mass was attributed to lower molecular weight compounds (two and three rings), suggesting a strong influence of diesel vehicle emissions on the production of local particulate PAH. The application of diagnostic ratios confirmed the relevance of this source of PAH in the tunnel ambient air. Deposited dust presented PAH profiles similar to the coarser aerosol size range, in agreement with the predominant origin of coarser aerosol particles from soil dust resuspension and vehicle wear products. 相似文献
910.
The suitability of the salt-marsh species Halimione portulacoides, Scirpus maritimus, Juncus maritimus and an association of the last two for remediation of petroleum hydrocarbons (PHC) in soil was investigated. An outdoor laboratory experiment (microcosm-scale) was carried out using contaminated soil collected in a refinery, as a complement of another study carried out in the refinery environment (mesocosm-scale). Soil samples with old contamination (mainly crude oil) and with a mixture of the old and recent (turbine oil) contamination were tested. Studies in both micro- and mesocosm-scale provided results coherent in substance. The presence of S. maritimus caused removal of old contamination which was refractory to natural attenuation (after 7 months of exposure, efficiency was 13% when only old contamination was present and 40% when the soil also contained recent contamination). H. portulacoides (only included in the microcosm-scale study) revealed also potentiality for PHC remediation, although with less efficiency than S. maritimus. Degradation of recent contamination was also faster in the presence of plants (after 7 months: 100% in the presence of S. maritimus vs. 63% in its absence). As these species are common in salt marsh areas in Atlantic coast of Europe, it is probable they will be also useful for recovering coast sediments. In contrast, J. maritimus and association did not reveal capability to remove PHC from soil, the presence of J. maritimus inhibiting the capability of S. maritimus. 相似文献