Phytoremediation of an aged petroleum contaminated soil using endophyte infected and non-infected grasses.
Phytoremediation is a promising technique for cleaning petroleum contaminated soils. In this study, the effects of two grass species (Festuca arundinacea Schreb. and Festuca pratensis Huds.), infected (E(+)) and non-infected (E(-)) by endophytic fungi (Neotyphodium coenophialum and Neotyphodium uncinatum, respectively) on the degradation of petroleum hydrocarbons in an aged petroleum contaminated soil was investigated. Plants were grown in the soil for 7 months and unplanted soil considered as control. At the end of the experiment, total and oil-degrading bacteria, dehydrogenase activity, water-soluble phenols, total petroleum hydrocarbons (TPH) and polycyclic aromatic hydrocarbons (PAHs) contents were measured in the soil. The results demonstrated that E(+) plants contained more root and shoot biomass than E(-) plants and created higher levels of water-soluble phenols and dehydrogenase activity in the soil, while there was no significant difference in bacterial counts of planted soils. Planting stimulated total and oil-degrading bacterial numbers, dehydrogenase activity and the soil content of water-soluble phenols. Regardless of endophyte infection, PAH and TPH removal in the rhizosphere of plants were 80-84 and 64-72% respectively, whereas the removals in controls were 56 and 31%, respectively. It was revealed that TPHs in retention time range of n-alkanes with C(10)-C(25) chain lengths and TPH were more degraded in the rhizosphere of E(+) plants compared to E(-) ones. Thus, grasses infected with endophytic fungi could be more efficient for removal of TPH from oil-contaminated soils.
Department of Soil Science, Guilan University, Rasht, Iran. soleimani57@yahoo.com
Mohsen
M
Soleimani
Majid
M
Afyuni
Mohammad A
MA
Hajabbasi
Farshid
F
Nourbakhsh
Mohammad R
MR
Sabzalian
Jan H
JH
Christensen
D001673:Biodegradation, Environmental; D052918:Environmental Restoration and Remediation / Q000379:methods; D031751:Festuca / Q000254:growth & development / Q000378:metabolism* / Q000382:microbiology; D055328:Neotyphodium / Q000472:pathogenicity; D010578:Petroleum / Q000032:analysis / Q000378:metabolism*; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis / Q000378:metabolism; D058441:Rhizosphere; D012989:Soil Pollutants / Q000032:analysis / Q000378:metabolism*
D010578:Petroleum; D011084:Polycyclic Aromatic Hydrocarbons; D012989:Soil Pollutants