Germination, Survival, Growth Response of Eight Desert Plants to Oil Pollution and Removal Efficiency of Total Petroleum Hydrocarbon (TPHs)

The purpose of this study was to compare the effect of different concentrations of total petroleum hydrocarbon (TPHs) on plants in laboratory and the greenhouse, including seed germination, seeding survival, plant height, root length, biomass, and evaluate the removal efficiency of TPHs by 8 desert plants (Alhagi sparsifolia, Kalidium foliatum, Nitraria tangutorum, Lycium ruthenicum, Medicago sativa, Tamarix ramosissima, Suaeda altissima and Elaeagnus angustifolia). The results showed that seed germination response is not significant with all species in different treatments (0, 5, 10, 20 g/kg) but seedling survival was more sensitive than germination and all species could survived well in low TPHs contaminated soil. The seedling height, root length and their biomass of all tested plants were significantly reduced in higher concentration of TPHs contaminated soil. The average removal efficiency of TPHs by tested plants over the 120-day culture period was 56.1– 63.6%, 49.5–58.8% and 46.7–57.8% in different contamination concentration, when the removal rate by natural attenuation was 42.1, 41.8 and 37.6%, respectively. This indicated that all tested plants had a peculiar tolerance to petroleum contamination and could effectively degenerate TPHs. In addition, K. foliatum has the highest removal efficiency in 5 g/kg and 10 g/kg concentration of contamination soil. However, the removal efficiency of TPHs of L. ruthenicum in 20 g/kg concentration of contamination soil was higher than other species. Considering of growth and removal efficiency, L. ruthenicum, E. angustifolia and N. tangutorum, widely spread species in Xinjiang, can be effectively applied to phytoremediation of petroleum contaminated soil (≤20 g/kg).