Defining the air sparging radius of influence for groundwater remediation

A theoretical study of air sparging for the removal of volatile organic compounds (VOCs) from groundwater is presented. A simple relationship is developed between the observed subsurface pressure increase due to sparging and the gas saturation at that location, thus providing a quantitative measure of the sparging radius of influence. Multiphase numerical simulations using a radially symmetric cylindrical geometry are used to confirm this relation, and to relate the injected gas radius of influence to the zone of VOC cleanup during sparging. These simulations also illustrate the transient and steady-state behavior of air sparging systems in both homogeneous and heterogeneous systems.