Effects of Surfactants on Solubilization of Perchloroethylene (PCE) and Trichloroethylene (TCE)

Abstract

Enhanced solubilization of dense nonaqueous phase liquids (DNAPLs) especially chlorinated hydrocarbons using four types of surfactants was investigated. The solubilization kinetics of perchloroethylene PCE (100 mg/L solubility in water) and trichloroethylene TCE (1000 mg/L) in anionic (sodium dodecyl sulfate (SDS)), nonionic (Triton X-100), cationic (cetyltrimethylammonium bromide (CTAB)), and a biosurfactant (UH biosurfactant) were investigated at room temperature in continuously stirred batch reactors. The size distribution of surfactant micelles were measured using the dynamic light scattering device (DLS). The mean size of SDS, CTAB, Triton X-100, and UH biosurfactant micelles were 4.2 nm, 3.8 nm, 4.5 nm, and 59.1 nm, respectively. Micelle partition coefficients (Km) and molar solubility ratio (MSR) for PCE and TCE in 10 g/L of surfactant solutions have been quantified, and the solubility of PCE and TCE in the surfactant solutions increased by about 10-fold. Solubilization kinetics for PCE and TCE in various surfactant solutions was represented using a hyperbolic relationship. Also the relationship between solubility and interfacial surface tension reduction was investigated. Of the surfactants studied, Triton X-100 had the highest PCE solubilized per gram of surfactant, whereas for TCE, biosurfactant had the highest TCE solubility per gram of surfactant.

The Effect of NaCl on the Krafft Temperature and Related Behavior of Cetyltrimethylammonium Bromide in Aqueous Solution

“…Figure 9 shows the effect of surfactant concentration on SRB solubilization in pure water and in aqueous NaCl solution. The solubilization capacity or solubilizing power of a surfactant, which can be obtained from the slope of the line after the CMC, is usually expressed as the molar solubilization ratio (MSR) [49,50]. In the case of SRB, the MSR values of CTAB in pure water and in 0.01 M NaCl solution are found to be 0.20 9 10 -3 and 0.66 9 10 -3 , respectively.…”

“…Due to the presence of the counter-ion the electrostatic repulsion between the head groups at the micelle surface is greatly reduced. Again the presence of the counter-ion imparts an increase in the micellar aggregation number resulting in an increase in the solubilization capacity [50,51]. This occurs due to the reduction in the electrostatic repulsions between the charged head groups of the surfactant in the presence of the counter ion with a consequent decrease in the surface area of the head group and the CMC.…”

Removal of tetrachloroethylene from homogeneous and heterogeneous porous media: Combined effects of surfactant solubilization and oxidant degradation

“…chemical oxidation [6,13,14] have been applied to remove DNAPLs from the source zone. Among them, surfactant flushing is a costeffective remediation option that can treat an extensive range of DNAPL contaminants including PCE [15,16]. Field-scale tests, however, showed that some surfactants can only remove 50-60% of the contaminants in typical DNAPL source zones [4].…”

“…Field-scale tests, however, showed that some surfactants can only remove 50-60% of the contaminants in typical DNAPL source zones [4]. Among the most commonly used surfactants for soil and groundwater remediation, polyoxyethylene sorbitan monooleate (Tween 80) is regarded as a promising remediation agent for chlorinated solvents because it is not only effective, but also biodegradable under aerobic and anaerobic conditions [16][17][18]. Laboratory tests of Tween 80 flushing showed that it can potentially recover more than 70% PCE [19].…”

Molecular dynamics simulation of some cyclic compounds solubilization into the nanometric core of Cetyltrimethylammonium Bromide micelle

“…There are many theoretical and experimental studies on the solubilization and solubilization location of hydrophobic materials such as drugs [7,8], dyes [9,10], oils [11] and other organic compounds [12][13][14][15][16] within the micelles. Recognizing of these solubilization sites is very essential and helps us to have a better understanding of solubilizate characteristics in micelle, to investigate reaction mechanism in micellar systems and to design the micellar systems to reach the favorite properties.…”