Injection of air below the water table to strip dissolved VOCs into the vadose zone for capture by SVE. Used for chlorinated solvents and petroleum hydrocarbons in permeable saturated formations.
Air Sparging injects compressed air through wells screened below the water table. The air rises as bubbles through the saturated zone, partitioning volatile contaminants out of groundwater and into the moving gas. The contaminant-laden vapour rises into the vadose zone, where it is captured by an overlying SVE network and treated above ground.
Sparging is most effective in coarse, homogeneous, permeable formations. In fine-grained or layered soils, air channels preferentially rather than diffusing uniformly, leaving stagnation zones untreated. Operating pressure and flow are tuned to avoid lifting groundwater out of the well, fracturing the formation, or driving contaminants laterally beyond the SVE capture zone.
Also known as: air sparging, in-situ air sparging, IAS.
Petroleum Hydrocarbons: treatment approach
The full spectrum of petroleum-derived organic compounds — crude oil, condensate, diesel, gasoline, jet fuel, and bunker fuel — reported analytically as total petroleum hydrocarbons (TPH) in gasoline-range (C6–C10), diesel-range (C10–C28), and heavy-range (C28–C40) fractions.
An ex-situ soil treatment process that heats contaminated soil to volatilize and separate organic contaminants from the soil matrix, after which the liberated vapors are captured and treated, usually in a high-temperature oxidizer.
A thermal desorption configuration where the heat source contacts the soil directly inside the rotary unit, delivering high heat-transfer efficiency and supporting higher treatment temperatures.
A thermal desorption configuration where heat is conducted through the wall of the treatment vessel without combustion gases contacting the soil, producing a concentrated, lower-volume vapor stream suitable for condensation and recovery.
Treatment that heats contaminated soil and groundwater in place, typically with electrical resistance, thermal conduction, or steam injection, to volatilize and recover contaminants without excavation. Used where excavation is impractical or where the contaminant zone sits beneath active infrastructure.