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Karak T.,Pollution Control Board | Karak T.,Tea Research Association | Bhattacharyya P.,University of California at Riverside | Bhattacharyya P.,Indian Statistical Institute | And 3 more authors.
International Journal of Environmental Science and Technology | Year: 2013

The present article discusses an overview on the contamination of non-segregated open municipal solid waste (MSW) in and around a dumping site at Garchuk in Guwahati city, Assam, India. Analysis showed depth-wise variations in the concentrations of selected heavy metals in MSW and their subsequent accumulations with increasing depths. Zinc was the most abundant heavy metal in MSW. Six-step selective sequential extractions revealed that most of the heavy metals in MSW were in the residual phase except zinc. Analysis of the leachate from MSW showed high concentrations of fluoride, chloride, ammonium-nitrogen and the ratio of biological oxygen demand/chemical oxygen demand. Concentrations of all the heavy metals in the leachates were higher than the Indian national effluent standards. High amounts of biological oxygen demand, heavy metals, total and fecal coliforms in water samples from the adjoining water body (Deepor Beel, a Ramsar site) of the MSW dumping site indicated its unsuitability for domestic use. Principle component analysis showed that influence of MSW leachate was the major source of water contamination in Deepor Beel. Though accumulation of heavy metals in different vegetables growing in MSW dumping site did not exceed the recommended maximum intake, it was a significant additional source of heavy metals in cooked human diet. © 2013 Islamic Azad University (IAU).


Das G.C.,Institute of Advance Study in Science and Technology | Chakraborty R.,Institute of Advance Study in Science and Technology
Astrophysics and Space Science | Year: 2011

Our purpose is to examine the formation of different sheaths in rotating astroplasmas embedded in an ambient magnetic field. Sequel to our recent work (Das and Chakraborty in Astrophys. Space Sci., 2011) we remodeled our present study with the view to finding of robust sheath over the Earth's Moon along with the formation of dust clouds therein. Based on using the pseudopotential analysis, a modified Sagdeev potential equation has been derived, which, in turns, quantifies the interaction of Coriolis force and magnetic field and to derive the different natures of sheath and dust atmosphere. The application of this result to the input numeric data of the lunar environment and dynamical behaviors of dust levitation has been studied. Our study finds that the dust particles having a spatial segregation within the sheath region form dust clouds in spaces. © 2011 Springer Science+Business Media B.V.


Das G.C.,Institute of Advance Study in Science and Technology | Chakraborty R.,Institute of Advance Study in Science and Technology
Astrophysics and Space Science | Year: 2011

Pseudopotential analysis has been employed to derive a modified Sagdeev potential-like wave equation for studying the sheath formation in astroplasma problems. Complexity in process urges to derive the new findings numerically by using fourth-order Runge-Kutta method. Main emphasis has been given to investigate the role of Coriolis force on the formation and changes on coherent structures of sheath suitably thought for the configuration of astroplasma. Study determines the sheath thickness and potential variation with the interaction of Coriolis force and thereby finds dynamical behavior of levitated dust grains into the evaluated sheath region. This leads to find the dust size, and corresponding forces generated on dust grain with a view to relate theoretical observations to real astrophysical phenomena and could be of interest to explain formation of dust clouds in spaces. To support the observations, we some thoughtful numeric plasma parameters for the case of Earth's Moon, have taken for graphical presentations. Overall observations expect the study could be of interest as an advanced knowledge in rotating astroplasmas, and expecting many salient features which are yet to be known. © 2010 Springer Science+Business Media B.V.

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