Biodegradation kinetics of naphthalene in nonaqueous phase liquid-water mixed batch systems: Comparison of model predictions and experimental results

Abstract The kinetics of esterification reaction between acetic acid and methanol was studied with the Indion 180 catalyst in the temperature range between 323.15 and 353.15K, and the catalyst loading between 0.01 g/cc to0.05 g/cc. The effects of temperature, catalyst loading, size of the catalyst and agitation speed on the reaction rate were investigated. The experimental results have shown the negligible effect of mass transfer resistances on the reaction rate. A second order kinetic rate expression was used to correlate the experimental data. An activity based kinetic model was also developed for the esterification process, which was validated against experimental results. The activity based model is found advantageous as it involves only two reaction rate parameters which were determined based on the kinetic rate parameters of the concentration based model. The comparison of the model predictions with the experimental results for different temperature and catalyst loading conditions has shown the better suitability of the activity based kinetic model for the esterification process with Indion 180 catalyst.

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Additions and Corrections: Interfacial Films in Coal Tar Nonaqueous-Phase Liquid-Water Systems

Environmental Science & Technology ◽

10.1021/es00053a600 ◽

1994 ◽

Vol 28 (4) ◽

pp. 756-756 ◽

Cited By ~ 4

Author(s):

Richard G. Luthy ◽

Anuradha. Ramaswami ◽

Subhasis. Ghoshal ◽

Wolf. Merkel

Keyword(s):

Liquid Water ◽

Coal Tar ◽

Water Systems ◽

Nonaqueous Phase Liquid ◽

Phase Liquid ◽

Interfacial Films

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Numerical simulations of a light nonaqueous phase liquid (LNAPL) movement in variably saturated soils with capillary hysteresis

Canadian Geotechnical Journal ◽

10.1139/cgj-2012-0165 ◽

2014 ◽

Vol 51 (9) ◽

pp. 1046-1062 ◽

Cited By ~ 12

Author(s):

Amin Y. Pasha ◽

Liming Hu ◽

Jay N. Meegoda

Keyword(s):

Numerical Simulation ◽

Numerical Simulations ◽

Vadose Zone ◽

Experimental Results ◽

Centrifuge Test ◽

Nonaqueous Phase Liquid ◽

Capillary Fringe ◽

Capillary Hysteresis ◽

Phase Liquid ◽

Light Nonaqueous Phase Liquid

The fate and transport of pollutants in the subsurface is usually predicted using numerical simulations. Comparisons of the simulation results with experimental data are required to validate the numerical codes. In this paper, the nonaqueous phase liquid (NAPL) simulator code was used to numerically simulate two centrifugal light nonaqueous phase liquid (LNAPL) transport experiments. The numerical predictions were compared with the centrifugal test results and the impact of capillary hysteresis was evaluated. It was concluded that the simulation with the nonhysteretic model slightly underestimated the LNAPL volume retained in the vadose zone, and the average error of the predicted LNAPL saturation in the vadose zone and along the plume centerline was approximately 5% to 10%. The application of capillary hysteresis for the numerical simulation of the second centrifuge test has eliminated this error. In addition, accounting for hysteresis in the numerical simulation of the second centrifuge test has considerably improved the predicted results with respect to the size of the lens-shaped plume within the capillary fringe. However, there were inconsistencies between the numerical and experimental results, especially with respect to the time for the LNAPL to reach the groundwater level. This was found to be due to overestimation of the simulated downward infiltration of the LNAPL in the capillary fringe. It was found that the pore-connectivity parameter with a value of 0.66 for the relative permeability–saturation model produced the best comparison with experimental results.

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