Alkylpolyglycosides—based formulations for sustainable remediation of contaminated aquifers: Lab-scale process study for NAPL solubilization assessment

In the context of the surfactant-enhanced remediation of polluted sites, this work focuses on the development of non-ionic alkylpolyglucosidic (APG) surfactant formulations with different additives for the solubilization and mobilization of strongly adsorbed organic pollutants. The study involved three consecutive phases to evaluate the effect of the additives on surface behavior and the potential improvement in alkylpolyglycoside surfactant’s capability to solubilize toluene and perchloroethylene (PCE), selected as reference contaminants. After a chemical–physical characterization phase, the APG-based formulations were first used in a batch configuration test, in which the formulations’ solubilization ability was indirectly assessed by observing the effect on pollutants’ adsorption. Lastly, a continuous configuration column experiment was performed to simulate the flushing process of a synthetic matrix previously contaminated with strongly adsorbed toluene or PCE. The results showed that the presence of additives firstly reduced the ability of the surfactant to form micelles, increasing the CMC, but at the same time improved the ability to reduce surface tension. Moreover, the addition of the additives overall resulted in a significant improvement in adsorbed pollutant removal in a minimal volume of fed solution, reaching 96% and 99% efficiencies for toluene and PCE, respectively, compared with 76% and 92%, for toluene and PCE, respectively, in the presence of free-additive APG surfactant.