An Optimized Surfactant Formulation for the Remediation of Diesel Oil Polluted Sandy Aquifers

Abstract

Reduction of hydraulic conductivity during the treatment of hydrocarbon polluted soils by using surfactants may be an inconvenience for a good recovery of the pollutant. The purpose of the present research work is to determine the main factor responsible for this reduction and by the same way to give an application solution to this problem. Experimental studies on sand filled laboratory columns have shown that the reduction of hydraulic conductivity can be due neither to the precipitation of the anionic surfactants in the presence of calcium ions nor to the clay minerals present in small proportion in the porous medium. We point out that this phenomenon is essentially due to the agglomeration of micelles and show that addition of 4 wt % of butyl alcohol under specific conditions contributes to improving both the injectability of the surfactant solution and the efficiency of the treatment. The optimized surfactant formulation, containing a mixture of two commercial surfactants and this cosolvent, palliates the reduction of hydraulic conductivity and decreases the interfacial tension by a factor of 100. As a consequence, after three pore volumes of injected surfactant solution, 85% of the trapped oil is removed compared to 11.4% obtained without cosolvent.

Toluene Solubilization Induces Different Modes of Mixed Micelle Growth

“…However, solubilization power, the number of molecules solubilized per molecule of surfactant, was only weakly dependent on the factors mentioned above. Changes in micelle size and shape during solubilization lead to changes in the system properties, for example in viscosity and conductivity . Because these properties have an impact on surfactant performance in many applications, further studies on solubilization-induced micelle swelling are valuable.…”

Fluorine-free and hydrophobic hexadecyltrimethoxysilane-TiO2 coated mesh for gravity-driven oil/water separation

“…4b, the θw data from Fig. 7, the interfacial tension, γwo, between water and diesel oil [68], as well as the coating thickness provided in the literature [40]. Table 2 indicates that the ΔPc value was larger than the ΔPm.…”

Volatilization of Non-Aqueous Phase Liquid in Porous Media: Vapor Phase Mass Transfer Characteristics

“…The collected soil samples were used to estimate the total surfactant mass (Mt) in unsaturated soil-water system for each ring. The mass was extracted and analyzed by two-phase Hyamine 1622 titration method (Brewer, 1972;Bettahar et al, 1999) . The surfactant concentration in the bulk aqueous phase was also determined by the same titration technique and was converted to the surfactant mass in liquid phase (A) in each ring using moisture content for that ring.…”