Effects of aging on the extractability of naphthalene and phenanthrene from Mediterranean soils.

The effects of aging on the extractability of naphthalene and phenanthrene were investigated using laboratory batch assays. Experiments have been conducted with three soil matrices: a silty clay and two soils with different organic contents. Aging was conducted under abiotic conditions in water saturated and nonsaturated conditions, under a constant temperature (20 degrees C). The mobility of sorbed contaminants was evaluated through successive extractions in water, methanol, butanol and dichloromethane. Experimental results showed a reduction of the extractability of both naphthalene and phenanthrene with increasing aging times. The observed effects of aging might be related to slow diffusion of naphthalene and phenanthrene in sorbent microporosity and/or organic phases and possible evolutions of pollutant-sorbent interactions.