Chemical Oxidation Techniques for in Situ Remediation of Hydrocarbon Impacted Soils

Increasing concerns over health and ecological impacts of contaminated sites are leading to the development of cost effective remediation techniques for reducing the mass, mobility and/or toxicity of contaminated soils and groundwater. Amongst these, in situ chemical oxidation techniques are evolving as an effective way of remediating contaminated soil. In situ chemical oxidation involves the introduction of chemical oxidants into subsurface soil and groundwater to destroy organic contaminants and has been applied at the field scale to a number of sites throughout North America. These have been found to be extremely effective in degrading a variety of contaminants including: chlorinated solvents such as perchloroethylene (PCE), trichloroethylene (TCE) and vinyl chloride (VC); and methyl-tert-butyl-ether (MTBE), polyaromatic hydrocarbons (PAH), benzene, toluene, ethylbenzene and xylene (BTEX) and others. This paper provides a general overview of in situ chemical oxidation technology by examining various oxidants and their reaction chemistry, the effect of geology and hydrogeology on oxidant performance, oxidant delivery methods and future research needs.