Surfactants for ground water remediation

Ground water contamination is a most intractable form of pollution. Spilled solvent or fuel liquids are trapped below the water table by colloidal forces. Surfactants may be used to dramatically improve contaminated aquifer remediation rates. Principal remediation mechanisms include micellar solubilization and mobilization of the trapped liquids by lowering of the oil/water interfacial tension. Surfactant selection is a key to the successful design of a remediation effort, and involves consideration of factors including Krafft Point, surfactant adsorption onto the aquifer solids, and the phase behavior of the oil/water/surfactant system. Successful field demonstrations have occurred in recent months and the technology is moving rapidly toward commercialization. Critical research issues remain including acceptable clean-up levels, surfactant/contaminant in situ biodegradation rates, and surfactant decontamination and reuse. (C) 1999 Elsevier Science B.V. All rights reserved.