Aquifer washing by micellar solutions: 2. DNAPL recovery mechanism for an optimized alcohol-surfactant-solvent solution

摘要

A large sand column experiment is used to illustrate the principle of complex organic contaminants(DNAPL)recovery by a chemical solution containing an alcohol(n-butanol), a surfactant(Hostapur SAS), and two solvents(d-limonene ad toluene). The washing solutions is pushed by viscous polymer solutions to keep the displacement stable. The main NAPL recovery mechanisms identified are:(1)immiscible displacement by oil saturation increase(oil swelling,) oil viscosity reduction, interfacial tension lowering, and relative permeability increase;(2) miscible NAPL displacement by solubilization.