Assessment of Certain Plant Species degrading Total Petroleum Hydrocarbons in Contaminated Soil

Abstract

Biological techniques, especially phytoremediation, have long been recognized as cost-effective and environment friendly to eliminate pollutants from soil. This article is based on a study conducted to assess the capability of alfalfa, ryegrass and white clover to remove total petroleum hydrocarbons (TPHs) from soil. The presence of petroleum contamination significantly decreased germination percentage and rate along with biomass of alfalfa and white clover compared to uncontaminated soil. With regards to ryegrass, there was no significant difference in seed germination percentage and biomass, although the presence of petroleum decreased seed germination rate. The results indicated that these plants had effect on TPHs remediation; and removal of TPH from soil was directly related to density levels and time. Therefore, alfalfa and ryegrass in their highest density levels reduced the maximum concentration of TPHs at the end of the experiment by almost 64.41% and 60.36%, respectively, whereas only slight changes were observed in non-vegetated soil.