Petroleum exploitation in oilfields, especially
drilling, generates an oily sludge mixed with hydrocarbons
and mineral solids. This oily sludge is sometimes treated
by bioremediation and phytoremediation. This investigation
established that landfarmed oil sludge provided adequate
soil conditions to grow jack beans (
Canavalia ensiformis
) that in turn rhizo- and phytoremediated residual
aliphatic and aromatic hydrocarbons in the soil. Landfarming
oily sludge adequately reduced jack bean phytotoxicity.
Rhizo- and phytodegradation reduced total
petroleum hydrocarbons by 57.38 % during 4 months of
growing jack beans. Aliphatic hydrocarbons were detected
in the roots but not in the aerial parts. Polycyclic aromatic
hydrocarbons were translocated to the roots, stems, leaves,
and beans, requiring successive cropping to manage all
risks associated with some aromatic hydrocarbons found
such as: acenaphthylene, anthracene, pyrene,
benzo(a)anthracene, benzo(k)fluoranthene, and benzo(a)-
pyrene. Landfarming and phytoremediation, perhaps with
successive crops, holds the promise of providing inexpensive
management of extensive oily wastes when sufficient
land is available.
