Hydrogen peroxide catalyzed by ferrous iron to generate hydroxyl radicals, used in ISCO for fast, aggressive oxidation of petroleum hydrocarbons, chlorinated solvents, and PAHs. Short-lived in the subsurface, exothermic, and operationally demanding.
Fenton's reagent combines hydrogen peroxide (H2O2) and ferrous iron (Fe2+) to produce hydroxyl radicals, among the strongest oxidants applied in remediation. Modified Fenton's chemistry adjusts pH and chelates iron to allow operation at near-neutral pH and at depth. Reactivity is broad: BTEX, PAHs, chlorinated solvents, and many pesticides are destroyed.
Operational reality limits Fenton's deployment. Reaction is exothermic, with temperatures and gas evolution that can lift overburden and threaten worker safety at high peroxide doses. Half-life in the subsurface is short (hours to a few days), so radius of influence is small and multiple closely spaced injection points are required. Fenton's is best applied to compact, well-characterised source zones rather than diffuse plumes.
Also known as: Fenton's reagent, Fenton, modified Fenton's, catalyzed hydrogen peroxide.
In-Situ Chemical Oxidation (ISCO): treatment approach
In-situ chemical oxidation: injection of a chemical oxidant — permanganate, persulfate, or Fenton's reagent — directly into contaminated soil or groundwater to destroy dissolved-phase organic contaminants without excavation.
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.