HYDROCARBON DEGRADATION AND ACCUMULATION BY SANSEVIERIALIBERICA GEROME AND LABROY POLLUTED WITH CRUDE OIL, A RESEARCH PROJECT TOPIC ON PLANT SCIENCE
The capability of Sansevierialiberica to withstand crude oil pollution, degrade and/or accumulate the contaminant was investigated using 0.3, 1.3 and 6.3% v/w concentrations of crude oil to pollute soil vegetated with the stem cuttings of the plant. These treatments were repeated in unvegetated soils and the control had no crude oil pollution. The experiment was carried out in 3 replicates in a completely randomized design. Total Petroleum Hydrocarbons (TPH) were determined for all soil samples (vegetated and unvegetated)as well as the leaves, stem and roots using Gas Liquid Chromatography (GLC). Vegetative parameters namely; number of leaves, leaf area, plant height and stem circumference were determined for both control and polluted plants before and after pollution. The results showed that percentage TPH degraded in the vegetated soil was 95.8, 88.5 and 68.1% for 0.3, 1.3 and 6.3% v/w concentrations, respectively. S liberica alone degraded 0.87, 2.92 and 2.29% for the same treatments. Percentage accumulations of 0.3% v/w crude oil pollution for the leaf, stem and root were 0.002, 0.036 and 0.209%, respectively, those of 1.3% v/w were 0.004, 0.067 and 0.315%, respectively while those of 6.3% v/w were 0.008, 0.085 and 0.43%, respectively. Means for the vegetative parameters for the plant parts showed that there were significant (P< 0.05) differences in some vegetative parameters after contamination with crude oil. Therefore there was phytoremediation and accumulation of hydrocarbons by S. liberica.
1.1 Crude oil/or hydrocarbon pollution
Crude oil is a crucial energy resource and vital industrial raw material. With increasing industrial production, oil pollution has become a serious worldwide environmental problem, especially at the oil mining stage in the field (Zhu et al., 2013). Large-scale crude oil spills on soil, leakages from pipelines, underground and surface fuel storage tanks, indiscriminate spills and careless disposal and mismanagement of wastes and other petroleum by-products constitute the major sources of petroleum contamination in our environment. Oil spillage on soil has many detrimental effects on the composition, structure and functioning of terrestrial ecosystems, including loss of biodiversity (Osuji et al., 2004).