Volume No. 3 Issue No.: 2 Page No.: 380-387 Oct-Dec 2008

 

DISSOLUTION OF NAPL IN A HETEROGENEOUS SATURATED AQUIFER

 

Pavithra M.* and Indumathi M. Nambi

EWRE Division, Department of Civil Engineering,
Indian Institute of Technology Madras, (INDIA)

 

Received on : July 7, 2008

 

ABSTRACT

 

Effective remediation of the NAPL contaminated sites entails a detailed understanding of the entrapment and subsequent dissolution of the NAPL. Early efforts on the dissolution of the NAPL in heterogeneous system have identified that initial NAPL saturation and the grain size of the sand have significant impact on effluent concentration. The present study focuses on analyzing the system sensitivity to the variation of the NAPL configuration, variation of the aqueous flow rate and also the dynamic behavior of the system at a different scale of observation. O-Toluidine, a chlorinated solvent with density 1.004 g/ml and solubility of 16500 mg/L was used as the NAPL for Dissolution studies. The result profess that theory of equilibrium is independent of scale of observation. Another critical finding is that aqueous flow rate and rate limited behavior are directly proportional. For every one fold increase in aqueous flow rate, the time of occurrence of rate limited behavior was decreased by almost two folds. This finding is crucial in estimating the optimal aqueous flow rate that can be applied in any flushing technique.

 

Keywords : Aqueous flow rates, Dissolution, Mass flux, NAPL, Flushing technique

 

 

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