Growth Responses and Phytoremediation Characteristics of Mirabilis Jalapa L. in Benzo[a]pyrene and Pyrene Co-contaminated Soils

Pot culture experiments were conducted to investigate the effect of Benzo[a]pyrene(B[a]P) and pyrene on seed germination and growth factors of Mirabilis Jalapa L. and their uptake, accumulation and dissipation. The results showed that B[a]P and pyrene at the lower concentrations could accelerate seed germination and photosynthesis rate. There weren't significant relationships between shoot height, root length, or biomass and the concentrations of B[a]P and pyrene in soil. The relative absorptivity of B[a]P and pyrene in roots of M. Jalapa was less than 11%. But the amount of B[a]P and pyretic in shoots was close to zero. The relative removal rate of B[a]P and pyrene was up to 83-99% and 5-98%, respectively. Therefore, Plant-promoted rhizomorph biodegradation is the dominant contribution to remove B[a]P and pyrene. M. Jalapa might be useful for phytoremediation of B[a]P and pyrenc co-contaminated sites.