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171.
In order to investigate the distribution pattern of individual organochlorine compounds in soil samples collected from the sites (Canary Island – Spain, China, Germany, India, Romania, Russia, Serbia, Swiss, UK) affected by industrial activities to the more remote areas, principal component analysis was performed on the data taken from literature. Loading plots pointed out the strong correlation among the variables. Score plots revealed similar PCB- and OCP-soil patterns for majority of the investigated sites. Nevertheless, the temporal differences of PCB-soil loads have been identified: the late 1990s and early 2000s concentrations are similar to those of the early 1940s, and they are below the levels existed in 1980. The most pronounced PCB concentrations characterized the soil from 1966. For OCPs the influence of sites location on the detected concentration has been revealed: China and India were characterized by comparably higher loads of DDX (DDT and its metabolites) and of HCH-isomers, respectively. 相似文献
172.
173.
Oil spills due to oil pipelines is a very frequent problem in Mexico. Petroleos Mexicanos (PEMEX), very concerned with the
environmental agenda, has been developing inspection and correction plans for zones around oil pipelines pumping stations
and pipeline right-of-way. These stations are located at regular intervals of kilometres along the pipelines. In this study,
two sections of an oil pipeline and two pipeline pumping stations zones are characterized in terms of the presence of Total
Petroleum Hydrocarbons (TPHs) and Polycyclic Aromatic Hydrocarbons (PAHs). The study comprehends sampling of the areas, delimitation
of contamination in the vertical and horizontal extension, analysis of the sampled soils regarding TPHs content and, in some
cases, the 16 PAHs considered as priority by USEPA, calculation of areas and volumes contaminated (according to Mexican legislation,
specifically NOM-EM-138-ECOL-2002) and, finally, a proposal for the best remediation techniques suitable for the contamination
levels and the localization of contaminants. 相似文献
174.
大玉竹低聚糖硫酸酯抗HSV-2病毒活性的研究 总被引:8,自引:0,他引:8
从传统中药大玉竹中提取低聚糖Poos,用吡啶-氯磺酸法制备了它的硫酸酯衍生物S-Poos,产物经红外鉴定,证实Poos硫酸酯化后羟基连上硫酸基,硫含量为8.47%,取代度(Ds)为0.6体外实验研究了Poos、S-Poos对非洲绿猴肾细胞(Vero)的细胞毒怀和抗单纯疱疹病毒2型(HSV-2)活性。结果表明,Poos和S-Poos都无细胞毒性。Poos本身无抗病毒活性,对HSV-2引起的细胞病变和 相似文献
175.
谷氨酰胺转胺酶(MTG)分批发酵中温度对S.mobaraense生长及产酶影响的模型化 总被引:2,自引:0,他引:2
研究了2.5L小罐培养过程中控制温度为25℃~35℃时对细胞生长和MTG合成的影响.结果表明当控制相对较低的温度时,细胞生长的延滞期较长,当控制温度较高时,细胞生长的延滞期较短,达到最大DCW和最高MTG酶活的时间均较短;通过研究各种不同模型对细胞生长的影响得到最适合描述S.mobaraense生长与温度之间的关系方程为Schoolfield方程;通过对最大DCW和最大MTG酶活进行数学模拟,发现方程X(U)=-a 相似文献
176.
177.
The interactions of zebra mussels, invertebrates, fish, and microorganisms were studied experimentally. Trends in the distribution
of total bacterial biomass, the abundance of heterotrophic organisms, and their functional activities in water and grounds
were analyzed. The most favorable conditions for development of bacteria developed in June, in the presence of fish and without
zebra mussels. In experimental ecosystems with zebra mussels, a decrease in the abundance and activity of microorganisms and
a change of dominant yeast forms were observed. 相似文献
178.
采用气相色谱法测定土壤中37种有机磷农药,当取样量为10 g时,37种有机磷农药方法检出限为0. 002~0. 015 mg/kg,测定下限为0. 008~0. 060 mg/kg。低含量加标样品中有机磷农药的加标回收率为72. 8%~104%,相对标准偏差为4. 2%~13. 8%;中含量加标样品中有机磷农药的加标回收率为71. 5%~101%,相对标准偏差为4. 3%~13. 5%;高含量加标样品中有机磷农药的加标回收率为74. 6%~109%,相对标准偏差为6. 8%~14. 6%。该方法灵敏度高、分离效果好、重现性好,能够满足土壤中37种有机磷农药残留检测的要求。 相似文献
179.
Vera Ferreira André Samora-Arvela 《Journal of Environmental Planning and Management》2016,59(7):1238-1256
Climate and land-use/cover changes (LUCC) influence soil erosion vulnerability in the semi-arid region of Alqueva, threatening the reservoir storage capacity and sustainability of the landscape. Considering the effect of these changes in the future, the purpose of this study was to investigate soil erosion scenarios using the Revised Universal Soil Loss Equation (RUSLE) model. A multi-agent system combining Markov cellular automata with multi-criteria evaluation was used to investigate LUCC scenarios according to delineated regional strategies. Forecasting scenarios indicated that the intensive agricultural area as well as the sparse and xerophytic vegetation and rainfall-runoff erosivity would increase, consequently causing the soil erosion to rise from 1.78 Mg ha?1 to 3.65 Mg ha?1 by 2100. A backcasting scenario was investigated by considering the application of soil conservation practices that would decrease the soil erosion considerably to an average of 2.27 Mg ha?1. A decision support system can assist stakeholders in defining restrictive practices and developing conservation plans, contributing to control the reservoir's siltation. 相似文献
180.