Using Sweet Sorghum Varieties for the Phytoremediation of Petroleum-Contaminated Salinized Soil: A Preliminary Study Based on Pot Experiments

Abstract

Using energy plants to repair salinized soils polluted by petroleum is an efficient way to solve the problem of farmland reduction and prevent pollutants from entering the food chain simultaneously. In this study, pot experiments were conducted for the purposes of preliminarily discussing the potential of using an energy plant, sweet sorghum (Sorghum bicolor (L.) Moench), to repair petroleum-polluted salinized soils and obtain associated varieties with excellent remediation performance. The emergence rate, plant height and biomass of different varieties were measured to explore the performance of plants under petroleum pollution, and the removal of petroleum hydrocarbons in soil with candidate varieties was also studied. The results showed that the emergence rate of 24 of the 28 varieties were not reduced by the addition of 1.0 × 104 mg/kg petroleum in soils with a salinity of 0.31%. After a 40-day treatment in salinized soil with petroleum additions of 1.0 × 104 mg/kg, 4 potential well-performed varieties including Zhong Ketian No. 438, Ke Tian No. 24, Ke Tian No. 21 (KT21) and Ke Tian No. 6 with a plant height of >40 cm and dry weight of >4 g were screened. Obvious removal of petroleum hydrocarbons in the salinized soils planted with the four varieties were observed. Compared with the treatment without plants, the residual petroleum hydrocarbon concentrations in soils planted with KT21 decreased by 69.3%, 46.3%, 56.5%, 50.9% and 41.4%, for the additions of 0, 0.5 × 104, 1.0 × 104, 1.5 × 104 and 2.0 × 104 mg/kg, respectively. In general, KT21 had the best performance and application potential to remediate petroleum-polluted salinized soil.