In-situ remediation that combines biostimulation (electron donor injection) and often bioaugmentation (Dehalococcoides cultures) to drive complete anaerobic reductive dechlorination of TCE and PCE to ethene.
Enhanced Reductive Dechlorination is the dominant biological treatment for chlorinated ethene source zones and dissolved-phase plumes. An electron donor is injected to drive groundwater strongly reducing (ORP below roughly minus 200 mV), conditions under which Dehalococcoides species sequentially dechlorinate PCE to TCE to cis-1,2-DCE to vinyl chloride to ethene.
Performance is governed by donor distribution, sustained reducing conditions, and the presence of Dehalococcoides strains capable of the final two dechlorination steps. Sites lacking the required organisms accumulate cis-DCE or vinyl chloride, the latter a regulated carcinogen, which is why bioaugmentation with characterised dechlorinating cultures has become standard practice. ERD is often paired with ISCO or ISCR to first knock down the source mass and then complete dechlorination biologically.
Also known as: ERD, enhanced reductive dechlorination, anaerobic dechlorination.
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.