Assessment of Phytoremediation Efficiency on reducing oilhydrocarbons from clay-silt soil using Aeluropus littaralis

Soil polluted with total petroleum hydrocarbon (TPHs) is a great threat to human health. Phytoremediation, the use of vegetation for treatment of contaminated soils, is an attractive and cost-effective alternative to reduce pollutant from soil. This paper evaluates the effects of the plant and nutrients on the removal of TPHs from soil. Soils were collected at depth of 0-30 cm, and then polluted with 1 and 2.5 % w/w of crude oil. After preparing the experimental pots, Rhizosphere microbial number, plant biomass, and residual TPHs were determined. TPHs and heterotrophic bacterial number were measured by GC and HPC method respectively. Data were analyzed using the Statistical Package for Social Sciences (SPSS 17 for Windows) software and Excel. It was found that the average percent of TPH removal in planted soil (28.42%) was higher than that in unplanted soil (12.2%) (p<0.05). Moreover, the average percent of TPH removal in treatments received nutrient and free nutrient treatments was 35.5and 17.7% respectively. Generally compared with the other studies, high clay and salinity of the experimental soil had a negative effect on phytoremediation efficiency. Finally, regarding to the high clay and salinity of the experimental soil, the phytoremediation efficiency was relatively desirable.