Optimal flow rates and well locations for soil vapor extraction design

Abstract

A mixed-integer programming model to determine the optimum number of wells, their Ž . locations and pumping rates for soil vapor extraction SVE is developed by coupling an air flow Ž . simulation model AIR3D to the GAMS optimization software. The model was tested for sensitivity of the vertical discretization of the domain, the number of potential well locations, the number of constraints, and the screen length of the wells. It was shown that these variables affected the optimal solution. It was also shown that the installation costs of the wells in the model influenced the optimal design. This was demonstrated by comparing the results of the mixed-integer programming model to a linear programming model in which the installation costs of the wells were neglected. The mixed-integer programming model could be useful in the design process in cases of short remediation times when the installation costs of wells could be significant. Numerous test cases with results are presented to demonstrate the applicability and usefulness of the model. q

Simulation and optimization technologies for petroleum waste management and remediation process control

“…SVE and BV are similar, in that they both employ vadose zone wells and pumps to generate gas flow through the unsaturated zone, but differ fundamentally in the mechanism of contaminant removal (Rathfelder et al, 2000). In SVE, air is introduced into the vadose zone to increase the volatilization of contaminant and a vacuum is created by extracting the air and contaminant vapor using extraction wells (Regalbuto et al, 1988;Johnson et al, 1994;Sawyer and Kamakoti, 1998). In BV, the activity of the indigenous bacteria is enhanced by inducing air (or oxygen) flow into the unsaturated zone (using extraction or injection wells) and, if necessary, by adding nutrients (Conner, 1988;Dupont, 1993;Hinchee, 1994).…”

“…The radius of influence and in situ bioremediation rates could be estimated using the proposed air flow model. Sawyer and Kamakoti (1998) coupled an air flow simulation model (AIR3D) to a mixed-integer programming model to determine the optimum number of wells, their locations and pumping rates for soil vapor extraction. The proposed SVE management model could be useful in the design process in cases of short remediation times when the installation costs of wells could be significant.…”

Application of multiphase transport models to field remediation by air sparging and soil vapor extraction

“…single phase flow, by ignoring the effect of the soil moisture condition in the vadose zone. Sawyer and Kamakoti [20], realizing the analogy between flow equations, went one step further and used MOD-FLOW as a design tool for SVE systems. In this paper, we used the unsaturated steady state flow model SPARG, developed by Mohtar et al [21], to supplement the transient multiphase model.…”

Multiple Linear Regression and Artificial Neural Networks to Predict Time and Efficiency of Soil Vapor Extraction

“…Kaleris and Croise (1997) predicted the remediation time for continuous and pulsed SVE using the mixed petroleum engineering reservoir numerical model and based on local equilibrium mass transfer. Sawyer and Kamakoti (1998) had a more simple approach by directly using air flow rates for estimating the closure time of SVE. Barnes (2003) incorporated in their model principles of uncertainty analysis, soil gas flow with contaminant vapor transport and decision theory.…”