Sorption model of trichloroethylene (TCE) and benezene in municipal landfill materials

Abstract

This research is intended to establish a mathematical model describing the mass transfer of trace gas in landfill. Experimental data used for calibration were reported by Stiegler et al. [ 1989]. Transfer mechanisms of TCE and benzene (trace gases) in clay, compost, filter sand, granular activated carbon, newsprint, and expanded polystyrene (landfill materials) were investigated by mathematical modeling. A kinetic model incorporating advection, dispersion, and sorption processes was proposed to simulate the breakthrough curve for one-dimensional transport of trace gases through landfill materials. By employing a constant effective diffusivity for each sorption stage, this mathematical model can simulate breakthrough curves for both saturated (Ce/C0 = 1) and unsaturated conditions. The sorption rate was found to be proportional to the difference between equilibrium and instantaneous concentration of trace gas on sorbing material. The sorption mechanism predominated at the beginning of the transfer process, whereas the final equilibrium was primarily affected by diffusivity.