Vapor phase sorption of benzene by cationic surfactant modified soil

The effect of cationic surfactant treatment on the vapor phase sorption of benzene by a desert soil has been investigated. Three cationic surfactants were studied benzyldimethylsterylammonium chloride (BDMS), cetylpyridinium chloride(CPYR), and cetyltrimethylammonium bromide (CTMA). Surfactant treatment resulted in a drastic decrease in the surface area of the soil (19 m2/g to 2.7 m2/g). Under the driest conditions (<0.5% water by weight), benzene sorption, by the soil, was drastically decreased by treatment with all three cationic surfactants. However, sorption of benzene was greater for surfactant treated soil than for untreated soil when some water (water> 1%) was present. Surfactant treatment can be used to attenuate the vapor phase migration of volatile hydrocarbons.