Phytoremediation of a pyrene-contaminated soil by Cannabis sativa L. at different initial pyrene concentrations

This study proposes the phytoremediation of a pyrene (PYR)-contaminated soil by Cannabis sativa L. The experimental campaign was conducted along a 60 days period using three different initial PYR concentrations (i. e., 50, 100 and 150 mg kg TS-1 of soil) in 300 mL volume pots under greenhouse conditions (18-25 ?C and 45-55% humidity). After 60 days of hemp growth and flourishing, the highest PYR removal reached approximately 95% in planted soil, 35% higher than in the unplanted control. PYR accumulation was observed in both roots and aerial parts of the plant, with a higher PYR uptake at increasing initial PYR concentrations in soil. The initial PYR concentration affected the growth and, thus, the phytoremediation potential of C. sativa L., which was the result of different removal mechanisms. Overall, the lowest initial PYR concentration was the one that resulted in the highest PYR removal. The interaction between the plant roots and microorganisms in rhizosphere was likely associated with PYR removal in this study. The highest DHO activity of 66.26 mu g INTF g(-1) TS-1 was observed in the soil spiked with 50 mg PYR.kg TS-1.

Automated summary

This study proposes the use of Cannabis sativa L. for the phytoremediation of PYR-contaminated soil. The results showed that the highest PYR removal rate achieved by hemp was approximately 95%, which was 35% higher compared to the unplanted control. The initial PYR concentration affected the growth and phytoremediation potential of C. sativa L., with lower initial concentrations resulting in higher PYR removal. The interaction between plant roots and rhizosphere microorganisms may play a role in PYR removal.