In situ soil flushing for contaminant remediation using cosolvents and/or surfactants
- Environmental Protection Agency, Ada, OK (United States). Robert S. Kerr Environmental Research Lab.
In situ soil washing of contaminants by fluids such as water, alkalis, cosolvents, and surfactants rely on the displacement of a contaminant from aquifer solids and pores into the mobile fluid phase to achieve removal. Water flushing is frequently limited by sorption of contaminants to aquifer solids and, in case of non-aqueous phase liquids (NAPLs), by the immobilization of pure organics as residual saturation and free pools. Conventional pump-and-treat ground water remediation of NAPLs may take hundreds to thousands of pore volumes of water to remove all the trapped source. Cosolvents and surfactants are solutions that are being considered for injection into porous media to enhance the solubility of contaminants and/or mobilize them by altering the chemical partitioning so that bulk fluid properties change. In situ cosolvent soil washing uses hydrophilic organic water-miscible solvents such as alcohols to enhance contaminant removal. Solvent/water mixtures have been shown to significantly improve the solubility of contaminants by miscible or immiscible displacement. Additionally, the retardation of hydrophobic hydrocarbons by soils is decreased. In situ surfactant soil washing uses anionic and nonionic surface-active compounds having a hydrophobic tail and hydrophilic head group. The principal mechanisms for contaminant removal by surfactants are solubilization via micellization or mobilization via interfacial tension reduction.
- OSTI ID:
- 6839514
- Report Number(s):
- CONF-9410209-; CODEN: GRWAAP
- Journal Information:
- Ground Water; (United States), Vol. 32:5; Conference: Ground water remediation: existing technology and future direction, Las Vegas, NV (United States), 9-12 Oct 1994; ISSN 0017-467X
- Country of Publication:
- United States
- Language:
- English
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