Effect of dispersion coefficient on PLNA/gas mass transfer coefficient determination

Abstract

Organic pollutants are one of the most pollutants in soils. To evaluate pollutant propagation and to apply a remediation technology, it is necessary to know transfer parameters between pollutant and soil components. Evaporation of the Non Aqueous Phase Liquid “NAPL” is one of the most phenomenon, studied mainly when the Soil Vapor Extraction is used. NAPL/gas mass transfer coefficient is the parameter describing this evaporation phenomenon. Many relations are defined to determine this coefficient with neglecting the dispersion coefficient. In this paper, empirical models for determination of NAPL/gas lumped mass transfer coefficient “l” from literature are tested. Results are compared to analytic solution of the convection dispersion equation results. The influence of the longitudinal dispersivity aLonl determination was evaluated. It has been shown that dispersion coefficient can be neglected in the model of l determination for pore’s velocity more than 0.1 cm.s-1. The correction is need for low pore’s velocity.

Keywords

• porous media
• NAPL/gas mass transfer coefficient
• longitudinal dispersivity