Phytoremediation of Polycyclic Aromatic Hydrocarbons in Soil: Part I. Dissipation of Target Contaminants

Abstract

Phytoremediation has been demonstrated to be a viable cleanup alternative for soils contaminated with petroleum products. This study evaluated the application of phytoremediation to soil from a manufactured gas plant (MGP) site with high concentrations of recalcitrant, polycyclic aromatic hydrocarbons (PAHs). Two greenhouse studies investigated the potential dissipation and plant translocation of PAHs by fescue (Festuca arundinacea) and switchgrass (Panicum virgatum) in the first experiment and zucchini (Curcubita pepo Raven) in the second. The MGP soil was highly hydrophobic and initially inhibited plant growth. Two unplanted controls were established with and without fertilization. In the first experiment, concentrations of PAHs decreased significantly in all treatments after 12 mo. Plant biomass and microbial numbers were statistically equivalent among plant species. PAH concentrations in plant biomass were negligible for fescue and switchgrass. In the second experiment, zucchini enhanced the dissipation of several PAHs after 90 d of treatment when compared to the unvegetated soil. Plant tissue concentrations of PAHs were not elevated in the zucchini roots and shoots, and PAHs were not detectable in the fruit.

Landfarmed oil sludge as a carbon source for Canavalia ensiformis during phytoremediation

“…The detectable PAHs in the plants were the same as those identified in Cofield et al (2007): Anthracene, pyrene, and benzo(a)anthracene found in roots and leaves of the jack beans. The following were also found: acenaphthylene (roots), benzo(k)fluoranthene (stems and beans), and benzo(a)pyrene (stems).…”

“…The initial and final soil chromatograms established that rhizodegradation and perhaps phytodegradation occurred. Cofield et al (2007) indicated most of the phytoremediation of polyaromatic hydrocarbons may have occurred in the roots of fescue (Festuca arundinacea), switchgrass (Panicum virgatum), and zucchini (Curcubita pepo) due to the presence of greater levels of aliphatic and PAHs found in the roots.…”

“…The seeds and the bean pods were crushed and mixed. TPHs and polycyclic aromatic hydrocarbons (PAHs) were identified separately using a gas chromatography-mass spectrometry-flame ionization detector (GC-MS-FID) as described by Cofield et al (2007). Plant samples were previously washed gently with distilled water to clean their surfaces and to remove, as far as possible, compounds that could interfere with the analysis.…”

Degradation of Polycyclic Aromatic Hydrocarbons from Soil Leachate by Water Hyacinth (Eichhornia crassipes)

“…However, in conducting investigations into the capability of four plants species namely; F. arundinacea, ryegrass (Lolium perenne), alfalfa (Medicago sativa) and oil-rape seed (Brassica napus) grown alone and in combination to degrade phenanthrene and pyrene in spiked soil, Cheema et al (2009) had noted higher degradation rates of PAHs in the combined plant cultivation (99% phenanthrene and 88% pyrene), compared to the single plant cultivation (97 and 79% of phenanthrene and pyrene), suggesting that enhanced rhizoremediation could be achieved using combined plant cultivation. As a viable clean up alternative for soils contaminated with petroleum products, Cofield, Schwab, and Banks (2007) evaluated the potential of F. arundinacea, P. virgatum, and zucchini (Curcubita pepo) in remediating soil from a gas plant. It was revealed that concentrations of PAHs decreased significantly in all treatments after 90 days.…”

Effects of alfalfa and organic fertilizer on benzo[a]pyrene dissipation in an aged contaminated soil

“…Bioremediation is regarded as a promising strategy for restoring contaminated agricultural soils (Peng et al 2008; Silva et al 2009; Zhang et al 2010). Numerous studies have shown that many plant species may promote PAH degradation in soils because plant root exudates, rich in organic acids and mineral nitrogen, may increase the indigenous soil microbial population including PAH-degrading microorganisms (Wetzel et al 1997; Binet et al 2000; Liste and Alexander 2000; Muratova et al 2003; Cofield et al 2007; Wei and Pan 2010; Teng et al 2011). Other studies have also shown that some plants may inhibit the removal of PAHs from contaminated soil (Cofield et al 2007; Smith et al 2008).…”