Ma. Hasegawa et al., LIQUID-LIQUID, EXTRACTION FOR SURFACTANT-CONTAMINANT SEPARATION AND SURFACTANT REUSE, Journal of environmental engineering, 123(7), 1997, pp. 691-697
Liquid-liquid extraction was investigated for use with surfactant enha
nced subsurface remediation. A surfactant liquid-liquid extraction mod
el (SLLEM) was developed for batch equilibrium conditions based on con
taminant partitioning between micellar, water, and solvent phases. The
accuracy of this fundamental model was corroborated with experimental
results (using naphthalene and phenanthrene as contaminants and squal
ane as the extracting solvent). The SLLEM model was then expanded to n
onequilibrium conditions. The effectiveness of this nonequilibrium mod
el was corroborated with experimental results from continuous flow hol
low fiber membrane systems. The validated models were used to conduct
a sensitivity analysis evaluating the effects of surfactants on the re
moval of the contaminants in liquid-liquid extraction systems. In addi
tion, liquid-liquid extraction is compared to air stripping for surfac
tant-contaminant separation. Finally, conclusions are drawn as to the
impact of surfactants on liquid-liquid extraction processes, and the s
ignificance of these impacts on the optimization of surfactant-enhance
d subsurface remediation.