title: Evaluation of liquid aerosol transport through porous media.
abstract: Application of remediation methods in contaminated vadose zones has been hindered by an inability to effectively distribute liquid- or solid-phase amendments. Injection as aerosols in a carrier gas could be a viable method for achieving useful distributions of amendments in unsaturated materials. The objectives of this work were to characterize radial transport of aerosols in unsaturated porous media, and to develop capabilities for predicting results of aerosol injection scenarios at the field-scale. Transport processes were investigated by conducting lab-scale injection experiments with radial flow geometry, and predictive capabilities were obtained by developing and validating a numerical model for simulating coupled aerosol transport, deposition, and multi-phase flow in porous media. Soybean oil was transported more than 2m through sand by injecting it as micron-scale aerosol droplets. Oil saturation in the sand increased with time to a maximum of 0.25, and decreased with radial distance in the experiments. The numerical analysis predicted the distribution of oil saturation with only minor calibration. The results indicated that evolution of oil saturation was controlled by aerosol deposition and subsequent flow of the liquid oil, and simulation requires including these two coupled processes. The calibrated model was used to evaluate field applications. The results suggest that amendments can be delivered to the vadose zone as aerosols, and that gas injection rate and aerosol particle size will be important controls on the process.
authors.affiliation: Environmental Engineering and Earth Sciences, Clemson University, Clemson, SC, USA. Electronic address: rhall@clemson.edu.
authors.forename: R
authors.initials: R
authors.lastname: Hall
authors.affiliation: Environmental Engineering and Earth Sciences, Clemson University, Clemson, SC, USA.
authors.forename: L
authors.initials: L
authors.lastname: Murdoch
authors.affiliation: Environmental Engineering and Earth Sciences, Clemson University, Clemson, SC, USA.
authors.forename: R
authors.initials: R
authors.lastname: Falta
authors.affiliation: Savannah River National Laboratory, Aiken, SC, USA.
authors.forename: B
authors.initials: B
authors.lastname: Looney
authors.affiliation: Savannah River National Laboratory, Aiken, SC, USA.
authors.forename: B
authors.initials: B
authors.lastname: Riha
mesh_terms: D000336:Aerosols / Q000032:analysis* / Q000737:chemistry; D002138:Calibration; D003198:Computer Simulation; D060587:Groundwater / Q000737:chemistry; D062070:Hydrology / Q000295:instrumentation / Q000379:methods*; D008962:Models, Theoretical; D010316:Particle Size; D016062:Porosity; D013024:Soybean Oil / Q000032:analysis / Q000737:chemistry
chemical_list: D000336:Aerosols; D013024:Soybean Oil
keywords: Aerosol; Bioremediation; Contamination; Model; Oil; Oxidation; Remediation; Transport; Vadose zone