title: Smoldering Remediation of Coal-Tar-Contaminated Soil: Pilot Field Tests of STAR.
abstract: Self-sustaining treatment for active remediation (STAR) is an emerging, smoldering-based technology for nonaqueous-phase liquid (NAPL) remediation. This work presents the first in situ field evaluation of STAR. Pilot field tests were performed at 3.0 m (shallow test) and 7.9 m (deep test) below ground surface within distinct lithological units contaminated with coal tar at a former industrial facility. Self-sustained smoldering (i.e., after the in-well ignition heater was terminated) was demonstrated below the water table for the first time. The outward propagation of a NAPL smoldering front was mapped, and the NAPL destruction rate was quantified in real time. A total of 3700 kg of coal tar over 12 days in the shallow test and 860 kg over 11 days in the deep test was destroyed; less than 2% of total mass removed was volatilized. Self-sustaining propagation was relatively uniform radially outward in the deep test, achieving a radius of influence of 3.7 m; strong permeability contrasts and installed barriers influenced the front propagation geometry in the shallow test. Reductions in soil hydrocarbon concentrations of 99.3% and 97.3% were achieved in the shallow and deep tests, respectively. Overall, this provides the first field evaluation of STAR and demonstrates that it is effective in situ and under a variety of conditions and provides the information necessary for designing the full-scale site treatment.
authors.affiliation: Savron , 130 Stone Road West, Guelph, ON, Canada N1G 3Z2.
authors.forename: Grant C
authors.initials: GC
authors.lastname: Scholes
authors.affiliation: Department of Civil and Environmental Engineering, The University of Western Ontario , London, ON, Canada N6A 5B9.
authors.forename: Jason I
authors.initials: JI
authors.lastname: Gerhard
authors.affiliation: Savron , 130 Stone Road West, Guelph, ON, Canada N1G 3Z2.
authors.forename: Gavin P
authors.initials: GP
authors.lastname: Grant
authors.affiliation: Savron , 130 Stone Road West, Guelph, ON, Canada N1G 3Z2.
authors.forename: David W
authors.initials: DW
authors.lastname: Major
authors.affiliation: DuPont Corporate Remediation Group , Chestnut Run Plaza Building 730, Wilmington, Delaware 19805, United States.
authors.forename: John E
authors.initials: JE
authors.lastname: Vidumsky
authors.affiliation: Department of Civil and Environmental Engineering, University of Strathclyde , 75 Montrose Street, Glasgow G1 1XJ, United Kingdom.
authors.forename: Christine
authors.initials: C
authors.lastname: Switzer
authors.affiliation: School of Civil Engineering, University of Queensland , Brisbane 4072, Australia.
authors.forename: Jose L
authors.initials: JL
authors.lastname: Torero
mesh_terms: D003031:Coal; D003033:Coal Tar / Q000737:chemistry*; D004787:Environmental Pollution / Q000032:analysis*; D052918:Environmental Restoration and Remediation / Q000379:methods*; D006838:Hydrocarbons / Q000302:isolation & purification; D008970:Molecular Weight; D010578:Petroleum / Q000032:analysis; D010865:Pilot Projects; D012987:Soil; D012989:Soil Pollutants / Q000032:analysis*; D013696:Temperature; D014835:Volatilization
chemical_list: D003031:Coal; D006838:Hydrocarbons; D010578:Petroleum; D012987:Soil; D012989:Soil Pollutants; D003033:Coal Tar