Surfactant solubilization, phenanthrene

Surfactant Solubilization of Phenanthrene in Soil-Aqueous Systems and Its Effects on Biomineralization... 

A series of related experiments investigated nonionic surfactant sorption onto soil, mechanisms of nonionic surfactant solubilization of polycyclic aromatic hydrocarbon (PAH) compounds from soil, and microbial mineralization of phenanthrene in soil-aqueous systems with nonionic surfactants. Surfactant solubilization of PAH from soil at equilibrium can be characterized with a physicochemical model by using parameters obtained from independent tests in aqueous and soil-aqueous systems. The microbial degradation of phenanthrene in soil-aqueous systems is inhibited by addition of alkyl ethoxylate, alkylphenyl ethoxylate, or sorbitan- (Tween-) type nonionic surfactants at doses that result in micellar solubilization of phenanthrene from soil. Available data suggest that the inhibitory effect on phenanthrene biodegradation is reversible and not a specific, toxic effect. 

Different Tween-type nonionic surfactants enhanced phenanthrene biodegradation Surfactant solubilization of HCs increases bioavailability 29... 

Guerin and Jones (29) reported that the use of various Tween-type nonionic surfactants in aqueous media solubilized phenanthrene to different degrees and enhanced phenanthrene utilization. The order of enhancement did not correlate directly with increased solubility, a result suggesting physiological as well as physicochemical effects of surfactants. However, Aiba et al. (37) and Mimura et al. (50) observed that the growth rates of certain yeast strains actually decreased in the presence of artificial surfactants, presumably by in-... 

It can be observed from the results that soil composition has a profound influence on the desorption and solubilization behaviors of phenanthrene. It is much more difficult to desorb and solubilize phenanthrene from glacial till than from kaolin, probably due to the strong binding characteristics of phenanthrene to organic matter. The hydrophilicity and concentration of the surfactant/cosolvent affects phenanthrene desorption and solubilization significantly. As hydrophilic surfactants are less prone to sorption onto soil particle surfaces, more surfactant molecules are available for micellar solubilization, resulting in better performance. In addition, more micelles are available for phenanthrene solubilization at higher surfactant concentrations. 

A combined effect of natural organic matter and surfactants on the apparent solubility of polycyclic aromatic hydrocarbons (PAHs) is reported in the paper of Cho et al. (2002). Kinetic studies were conducted to compare solubilization of hydro-phobic contaminants such as naphthalene, phenanthrene, and pyrene into distilled water and aqueous solutions containing natural organic matter (NOM) and sodium dodecyl sulfate (SDS) surfactant. The results obtained after 72hr equilibration are reproduced in Fig. 8.19. The apparent solubility of the three contaminants was higher in SDS and NOM solutions than the solubility of these compounds in distilled water. When a combined SDS-NOM aqueous solution was used, the apparent solubility of naphthalene, phenanthrene, and pyrene was lower than in the NOM-aqueous solution. 

Yang, J., Liu, X., Long, T. et al. (2003). Influence of nonionic surfactant on the solubilization and biodegradation of phenanthrene. Journal of Environmental Sciences (China), 15, 859-62. 

Understanding of surfactant sorption onto soil is needed to assess surbctant mobility in soil and surfactant-fecilitated transport of hydrophobic pollutants in soil/aqueous systems. Micelle-like amphiphilic nano-sized polyurethane (APU) particles synthaized from amphiphilic urethane acrylate anionomers could solubilize a model hydrophobic pollutant, phenanthrene wiliiin their hydrophobic interiors. Batch experiments were conducted with soil slurries to compare APU Sodium Dodecyl Sulfrde (SDS), anionic surfrictant for the sorption onto soil. APU particles (KniH).2 mUg) were weakly adsorbed onto the sandy soil compared to SDS (Ksui =l.3 mL/g), due to their chemically ciosslinked structure. Compared with SDS, APU particles exhibited the higher extraction efficiency to remove phenanthrene from the contaminated sandy soil. 

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