The Geo-Cleanse® Process is a patented, in-situ chemical oxidation technology that uses Fenton’s reagent to reduce organic contaminant concentrations in soil and groundwater. The reaction is based on chemistry reported in 1898 by H.J.H Fenton. This chemistry was modified by GCI for use in in-situ environmental applications. The Geo-Cleanse® Process is an aggressive, low pressurized injection of concentrated hydrogen peroxide and ferrous iron catalyst (Fenton’s reagent) that generates a hydroxyl free radical, which acts as the active oxidizing agent. The basic radical-producing reaction is:

where H₂O₂ is hydrogen peroxide, Fe⁺² is ferrous iron, OH· is hydroxyl free radical, OH - is hydroxyl ion, and Fe⁺³ is ferric iron.

The hydroxyl free radical generated by Fenton’s reagent is a powerful, non-selective oxidant. Oxidation of an organic compound by Fenton’s reagent is rapid and exothermic (heat-producing) and results in the reduction of contaminants to primarily carbon dioxide and oxygen:

Treatable Contaminants

GCI has used the Geo-Cleanse® Process and Fenton’s reagent to treat a large variety of contaminants including:

• BTEX and other petroleum hydrocarbons
• Chlorinated Ethanes (1,1,1-TCA) and Ethenes (TCE, PCE)
  
• Free-Phase NAPL
  
• MGP Constituents (MAH and PAH)
• Pesticides
• Explosives
  
  

Strengths of Fenton’s Reagent		Limitations of Fenton’s Reagent
	Highest oxidizing mass per dollar		pH greater than ~8
	Remediation of chlorinated solvents, including ethanes		Shallow Contamination (grade to ~5 ft)
	Destruction of NAPL or free-phase contamination		Areas where soil loading factors may vary
	Source reduction with a natural attenuation plan		High Hardness above ~400 mg/L
	Saturated and unsaturated environments
	Efficient in a relatively short period of time
	Most versatile in terms of contaminants

Example Chlorinated Solvent Fenton’s Reagent Oxidation Pathway [view]