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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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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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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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K. Srinivasamoorthy C. Nanthakumar M. Vasanthavigar K. Vijayaraghavan R. Rajivgandhi S. Chidambaram P. Anandhan R. Manivannan S. Vasudevan 《Arabian Journal of Geosciences》2011,4(1-2):91-102
A total of 162 groundwater samples for three representative seasons were collected from Salem district of Tamilnadu, India to decipher hydrogeochemistry and groundwater quality for determining its suitability for drinking and agricultural proposes. The water is neutral to alkaline in nature with pH ranging from 6.6 to 8.6 with an average of 8.0. Higher electrical conductivity was observed during post-monsoon season. The abundance of major ions in the groundwater was in the order of $ {\text{Na} > \text{Ca} > \text{Mg} > \text{K} = \text{Cl} > \text{HC}}{{\text{O}}_3}\; > \;{\text{S}}{{\text{O}}_4}\; > \;{\text{N}}{{\text{O}}_3} $ . Piper plot reveals the dominance of geochemical facies as mixed Ca–Mg–Cl, Na–Cl, Ca–HCO3, Ca–Na–HCO3, and Ca–Cl type. NO3, Cl, SO4, and F exceed the permissible limit during summer and post-monsoon seasons. Sodium adsorption ratio was higher during post-monsoon and southwest monsoon season indicating high and low salinity, satisfactory for plants having moderate salt tolerance on soils. Permeability index of water irrespective of season falls in class I and class II indicating water is moderate to good for irrigation purposes. As per the classification of water for irrigation purpose, water is fit for domestic and agricultural purposes with minor exceptions irrespective of seasons. 相似文献
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Ankam Durga Prasad Lori Rastogi Vinod Kumar Verma Vasudevan Krishna Kumari Sudhakar Yadlapalli Kulamani Dash 《Geostandards and Geoanalytical Research》2023,47(3):629-636
The National Centre for Compositional Characterisation of Materials (NCCCM) / Bhabha Atomic Research Centre (BARC) and National Aluminium Company Limited (NALCO), India have produced an Indian origin bauxite certified reference material (CRM), referred to as BARC-B1201, certified for major (Al2O3, Fe2O3, SiO2, TiO2, loss on ignition - LOI) and trace contents (V2O5, MnO, Cr2O3, MgO). Characterisation was undertaken by strict adherence to ISO Guides. A method previously developed and validated in our laboratory, using single step bauxite dissolution and subsequent quantitation (of Al2O3, Fe2O3, SiO2, TiO2, V2O5, MnO, Cr2O3 and MgO) by ICP-AES (SSBD ICP-AES) was used for homogeneity studies and an inter-laboratory comparison exercise (ILCE) of the candidate CRM. LOI was determined by thermo-gravimetric analysis. Property values were assigned after an ILCE with participation from seventeen reputed government and private sector laboratories in India. The CRM was certified for nine property values: Al2O3, Fe2O3, SiO2, TiO2, V2O5, MnO, Cr2O3, MgO and LOI, which are traceable to SI units. 相似文献
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Application of a syntactic pattern recognition technique, seismic skeletonization, to deep crustal seismic reflection data allows attributes such as energies, lengths and dips to be associated with individual reflection events. Some of these attributes exhibit fractal properties, e.g. the relationship between seismic event lengths and their spatial distribution throughout the crust. This approach provides a new technique to analyse complex geometry on seismic reflection data.Dedicated to Professor William George Laidlaw on his SIXTIETH birthday 相似文献
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Randhir Singh B. G. Vasudevan P. K. Pal P. C. Joshi 《Journal of Earth System Science》2004,113(1):89-101
Microwave sensor MSMR (Multifrequency Scanning Microwave Radiometer) data onboard Oceansat-1 was used for retrieval of monthly
averages of near surface specific humidity (Q
a) and air temperature (T
a) by means of Artificial Neural Network (ANN). The MSMR measures the microwave radiances in 8 channels at frequencies of 6.6,
10.7, 18 and 21 GHz for both vertical and horizontal polarizations.
The artificial neural networks (ANN) technique is employed to find the transfer function relating the input MSMR observed
brightness temperatures and output (Q
a andT
a) parameters. Input data consist of nearly 28 months (June 1999 – September 2001) of monthly averages of MSMR observed brightness
temperature and surface marine observations ofQ
a
andT
a
from Comprehensive Ocean-Atmosphere Data Set (COADS).
The performance of the algorithm is assessed with independent surface marine observations. The results indicate that the combination
of MSMR observed brightness temperatures as input parameters provides reasonable estimates of monthly averaged surface parameters.
The global root mean square (rms) differences are 1.0‡C and 1.1 g kg−1 for air temperature and surface specific humidity respectively. 相似文献