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排序方式: 共有48条查询结果,搜索用时 15 毫秒
1.
R. Jayashree Ph.D. N. Vasudevan S. Chandrasekaran 《International Journal of Environmental Science and Technology》2006,3(3):251-259
Soil pollution due to hydrophobic organic compounds is a wide environmental problem. Extensive use of endosulfan in cotton and paddy to meet the needs of the growing population has led to contamination of soil and other ecosystems. Endosulfan is hydrophobic, highly toxic to aquatic and human population and persists in soil for more than a year. To overcome the problem of hydrophobicity and limited availability, surfactants play a major role in soil remediation. In the present study, the potential of non-ionic synthetic surfactants (Tween 80, Triton X-100) and biosurfactant (Surfactin produced by Bacillus subtilis) for enhancing the release of endosulfan from contaminated agricultural soils was evaluated using the batch method. Incorporation of the surfactant concentrations at above Criticle Miceller Concentration (0.5, 1 and 2 g/L) into soil enhances the release of endosulfan. Surfactin produced from Bacillus subtilis recorded maximum (91.5%) recovery. The observed order of recovery being surfactin > Tween 80 > Triton X-100. The result suggest that surfactants could help in the remediation of soils polluted by pesticides. 相似文献
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Martha Tapas Ranjan Roy Priyom Jain Nirmala Khanna Kirti Mrinalni K. Kumar K. Vinod Rao P. V. N. 《Landslides》2021,18(6):2125-2141
Landslides - India ranks first in the world in terms of fatal landslides. Large vulnerable area (0.42 million km2), high population density and monsoon rainfall make India’s landslide... 相似文献
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Multivariate statistical analysis of geochemical data of groundwater in Veeranam catchment area,Tamil Nadu 总被引:1,自引:0,他引:1
M. Suvedha B. Gurugnanam M. Suganya S. Vasudevan 《Journal of the Geological Society of India》2009,74(5):573-578
The study of hydrogeochemistry of the Mio-Pliocene sedimentary rock aquifer system in Veeranam catchment area produced a large
geochemical dataset. Groundwater samples were collected at 52 sites over 963.86 km2 area and analyzed for major ions. The large number of data can lead to difficulties in the integration, interpretation and
representation of the results. Two multivariate statistical methods, Hierarchical cluster analysis (HCA) and Factor analysis
(FA), were applied to a subgroup of the dataset to evaluate their usefulness to classify the groundwater samples, and to identify
geochemical processes controlling groundwater geochemistry. Hydrochemical data for 52 groundwater samples were subjected to
Q- and R- mode factor and cluster analysis. R-mode analysis reveals the inter-relations among the variables studied and the
Q-mode analysis reveals the inter-relations among the samples studied. The R-mode factor analysis shows that Ca, Mg and Cl
with HCO3 account for most of the electrical conductivity, total dissolved solids and total hardness of groundwater. The ‘single dominance’
nature of the majority of the factors in the R-mode analysis indicates non-mixing or partial mixing of different types of
groundwater. Both Q-mode factor and Q-mode cluster analyses indicate an exchange between the river water and the groundwater
in the vicinity. The rock water interaction like flood basin back swamp deposits of silty clayey formation is the major cause
for the cluster II classification. Cluster classification map reveals that 58% of the study area comes under cluster II classification. 相似文献
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Nirmala Kumari Amares Chattopadhyay Abhishek K. Singh Sanjeev A. Sahu 《Acta Geophysica》2017,65(1):189-205
The present study investigates the propagation of shear wave (horizontally polarized) in two initially stressed heterogeneous anisotropic (magnetoelastic transversely isotropic) layers in the crust overlying a transversely isotropic gravitating semi-infinite medium. Heterogeneities in both the anisotropic layers are caused due to exponential variation (case-I) and linear variation (case-II) in the elastic constants with respect to the space variable pointing positively downwards. The dispersion relations have been established in closed form using Whittaker’s asymptotic expansion and were found to be in the well-agreement to the classical Love wave equations. The substantial effects of magnetoelastic coupling parameters, heterogeneity parameters, horizontal compressive initial stresses, Biot’s gravity parameter, and wave number on the phase velocity of shear waves have been computed and depicted by means of a graph. As a special case, dispersion equations have been deduced when the two layers and half-space are isotropic and homogeneous. The comparative study for both cases of heterogeneity of the layers has been performed and also depicted by means of graphical illustrations. 相似文献
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Balamurugan Palani Sivaprakasam Vasudevan Thirunavukkarasu Ramkumar 《Arabian Journal of Geosciences》2017,10(20):449
The present study investigates the anthropogenic metal input into the lake system, the toxic metal pollution in the sediments of Kodaikanal Lake. Surface sediment samples were collected at seven locations to represent its spatial variability within the lake. Samples were subjected to analyze for Fe, Co, Cr, Mn, Ni, Zn, Cd, Cu, Ag, Pb, Hg, and As by energy dispersive X-ray fluorescence (EDXRF) and their concentrations in lake sediments range from 102,000–109,000, 561–2699, 292–544, 211–482, 79–163, 57–265, 57–74, 37–92, 46–59, 20–97, 19–30, to 13–24 mg/kg, respectively. The sources of pollution were inferred through spatial and statistical analyses. Most of the toxic metal contents in the sediments are found to exceed the background concentration in all locations. The enrichment factor (EF) and index of geoaccumulation (I geo) of Hg, Co, Cd, and Ag showed that sediments of Kodaikanal Lake exhibit the probability of anthropogenic influence. The significant Pearson’s correlation coefficient is also suggesting that they probably originated from the same source of occurrence. The contamination factor and degree of contamination of the Kodaikanal Lake sediments are strongly polluted in terms of most of the examined metals. The study also provides environmentally significant information about anthropogenic influence on the lake sediments. 相似文献
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