Halis Simsek Abe 527 Computer Modeling in Environmental & Natural Resources Engineering Final Project Progress Report Evaluation of the Airfix Model Using Experimental Data

SPARG/AIRFIX is developed by Mohtar and Rahbeh in 2001 as a practical unsaturated flow and multiphase transport model that can be used for the design and operation of sparging and soil vapor extraction systems [5]. The model uses first order kinetics to represent the mass transfer among the aqueous, gaseous, solid, and NAPL phases. The theoretical basis of the model is build on the fact that soil particles are surrounded by water films which isolate the gaseous and non-aqueous phases. Therefore, the contaminant mass transfer can take place across the aqueous-solid (sorption/de-sorption), aqueous-gaseous (stripping), aqueous-NAPL (dissolution), and gaseousNAPL (volatilization) interfaces. To simulate the air flow distribution, the model incorporates numerical code derived from the SPARG model developed by Mohtar et al [6]. The model is based on steady state unsaturated flow equations. In this study, Model evaluation and sensitivity analysis are conducted by using real field data and compared with the known outputs to understand model usability and accuracy to remediate the contaminant soil and water.