| Title |
Sorptive Properties of BTEX and Surfactant on Surfactant Flushing for Removal of LNAPL in Contaminated Zone |
| Authors |
이재원(Jae Won Lee),박준범(Jun Boum Park),박규홍(Kyoo Hong Park) |
| Abstract |
The sorptive properties of BTEX (Benzene, Toluene, Ethylbenzene, p-Xylene, m-Xylene, o-Xylene) and surfactant onto clay particles were measured in the absence and presence of anionic and nonionic surfactants. The potential effects of nonionic and anionic surfactant sorption onto soil include i) an increase of the fractional organic carbon content in the soil ; ii) a decrease of the transport velocity of surfactant in the subsurface ; and iii) a decrease of the amount of surfactant available in bulk solution for micellar solubilization of hydrophobic organic compounds in soil/aqueous system. Sorption of the surfactant was adequately described by the Langmuir isotherm equations. It was suggested that the surfactants of low concentration might promote the partitioning of sorbed aromatic compounds such as BTEX in polluted soils even when surfactant induced desorption was not initiated. Surfactant/BTEX sorption test and pH test were conducted to optimize treatment conditions applicable to enhanced desorption mechanisms with additives of hydrotrope and Na₃PO₄. As results, Na₃PO₄ effectively reduced sorption of BTEX and surfactant micelle onto clay. When Na₃PO₄ was mixed with surfactants, however, pH was increased to 12 and thus clay particles were become more stable resulting in pore clogging. Anionic surfactant and the additive of SXS (Sodium Xylene Sulfonate) reduced the sorption onto clay particles by the repulsion between the negatively charged soil surface and the negatively ionized surfactant and additive. However, the long-time use of the surfactant and the additives clogged the pores by dispersing clay paricles, and reduced the efficiency of the recovery. |