Abstract:

Batch experiments were carried out to catch the natural attenuation rule of the petroleum hydrocarbons such as benzene, naphthalene, and phenanthrene in silt sandy, medium sandy, coarse and gravel sandy aquifers collected from the contaminated field site, respectively. The results showed that the natural attenuation of benzene, naphthalene, and phenanthrene in above four aquifer media, both in individual and mixed solute systems, follows the first-order kinetics among the four aquifer media, benzene and naphthalene attenuates as following: the silt sand > the medium sand≈the coarse sand > the gravel sand. For phenanthrene, the sequence of the attenuation rate is the silt sand≈the medium sand≈the coarse sand > the gravel sand. In investigated four aquifer media, the microdegradation plays an important role in the natural attenuation of benzene and naphthalene, while the adsorption onto the aquifer media is the most important for natural attenuation of phenanthrene. Besides, when the three components coexist, the natural attenuation of benzene and naphthalene gets faster while the natural attenuation of phenanthrene gets slower.

Key words: benzene, naphthalene, phenanthrene, natural attenuation, aquifers