Journal of Environmental Science and Health Part a Toxic Hazardous Substances Environmental Engineering, May 9, 2012
The effects of nonionic surfactants on degradation of engine oil in metal contaminated soil using... more The effects of nonionic surfactants on degradation of engine oil in metal contaminated soil using Indian mustard (Brassica juncea) were investigated. Triton X-100 and Tween 80 were individually applied to test pots in which the soil had been earlier spiked with 500 mg kg(-1) of used engine oil, 500 mg kg(-1) of PbCl(2) and 50 mg kg(-1) of CdCl(2). For he application of Tween 80 to the soil, the fractions of rhizodegraded oil and the fractions of removed metals from the soil were well correlated. On the other hand, such a correlation did not exist between the fractions of rhizodegraded oil and the fractions of removed metals for the application of Triton X-100 to the soil. It was observed that Triton X-100 caused a significant decrease in basal soil respiration (BSR) which can be attributed to a reduction in microbial activity. This, in turn, resulted in a reduction of the rhizodegraded oil fraction. Tween 80 proved to be effective in the rhizodegradation of oil under aerobic conditions. Further, this surfactant seems to have the positive effect on the soil microbial population when viewed in terms of BSR.
Résumé/Abstract Junctions are of considerable importance in the study of open-channel flows. For ... more Résumé/Abstract Junctions are of considerable importance in the study of open-channel flows. For dividing flow at right-angled junctions of rectangular open channels, an estimate of the discharge ratio is obtained in terms of the Froude numbers in the main channel ...
Journal of Irrigation and Drainage Engineering, 2011
ABSTRACT Sharp open-channel bends are commonly encountered in hydraulic engineering design. Distu... more ABSTRACT Sharp open-channel bends are commonly encountered in hydraulic engineering design. Disturbances such as secondary flows and flow separation caused by the bend may persist for considerable distances in the downstream channel. A simple way of reducing these disturbances is through the insertion of vertical vanes in the bend section. A laser Doppler anemometry (LDA) unit was used to measure the three-dimensional mean and turbulent velocity components of flow in an experimental rectangular open-channel bend. Flow characteristics of the bend with no vanes are compared with those of bends having one or three vertical vanes. The size of the flow separation zone at the inner wall of the bend was determined from dye visualization data and confirmed with mean streamwise velocity data. Results show that the vertical vanes are effective in considerably reducing flow separation, intensity of secondary flows, and turbulence energy in the downstream channel. Furthermore, energy loss for bends with vanes is slightly less than for the no-vane case. DOI: 10.1061/(ASCE)IR.1943-4774.0000337. (C) 2011 American Society of Civil Engineers.
Journal of Environmental Science and Health Part a Toxic Hazardous Substances Environmental Engineering, May 9, 2012
The effects of nonionic surfactants on degradation of engine oil in metal contaminated soil using... more The effects of nonionic surfactants on degradation of engine oil in metal contaminated soil using Indian mustard (Brassica juncea) were investigated. Triton X-100 and Tween 80 were individually applied to test pots in which the soil had been earlier spiked with 500 mg kg(-1) of used engine oil, 500 mg kg(-1) of PbCl(2) and 50 mg kg(-1) of CdCl(2). For he application of Tween 80 to the soil, the fractions of rhizodegraded oil and the fractions of removed metals from the soil were well correlated. On the other hand, such a correlation did not exist between the fractions of rhizodegraded oil and the fractions of removed metals for the application of Triton X-100 to the soil. It was observed that Triton X-100 caused a significant decrease in basal soil respiration (BSR) which can be attributed to a reduction in microbial activity. This, in turn, resulted in a reduction of the rhizodegraded oil fraction. Tween 80 proved to be effective in the rhizodegradation of oil under aerobic conditions. Further, this surfactant seems to have the positive effect on the soil microbial population when viewed in terms of BSR.
Résumé/Abstract Junctions are of considerable importance in the study of open-channel flows. For ... more Résumé/Abstract Junctions are of considerable importance in the study of open-channel flows. For dividing flow at right-angled junctions of rectangular open channels, an estimate of the discharge ratio is obtained in terms of the Froude numbers in the main channel ...
Journal of Irrigation and Drainage Engineering, 2011
ABSTRACT Sharp open-channel bends are commonly encountered in hydraulic engineering design. Distu... more ABSTRACT Sharp open-channel bends are commonly encountered in hydraulic engineering design. Disturbances such as secondary flows and flow separation caused by the bend may persist for considerable distances in the downstream channel. A simple way of reducing these disturbances is through the insertion of vertical vanes in the bend section. A laser Doppler anemometry (LDA) unit was used to measure the three-dimensional mean and turbulent velocity components of flow in an experimental rectangular open-channel bend. Flow characteristics of the bend with no vanes are compared with those of bends having one or three vertical vanes. The size of the flow separation zone at the inner wall of the bend was determined from dye visualization data and confirmed with mean streamwise velocity data. Results show that the vertical vanes are effective in considerably reducing flow separation, intensity of secondary flows, and turbulence energy in the downstream channel. Furthermore, energy loss for bends with vanes is slightly less than for the no-vane case. DOI: 10.1061/(ASCE)IR.1943-4774.0000337. (C) 2011 American Society of Civil Engineers.
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