The potential of gibberellic acid 3 (GA3) and Tween-80 induced phytoremediation of co-contamination of Cd and Benzo[a]pyrene (B[a]P) using Tagetes patula

The present study was conducted to investigate the effectiveness of GA3 and Tween-80 on enhancing the phytoremediation of Cd–B[a]P co-contaminated soils. Results showed that the addition of GA3 and GA3–Tween-80 enhanced Tagetes patula growth by 14%–32% and 23%–55%, respectively, relative to the control group. However, under independent GA3-treated soils, Cd and B[a]P concentrations in the shoots of the plants decreased by 15%–33% and 15%–53%, respectively, compared with CK. By contrast, the shoot concentration and accumulation of Cd under GA3–Tween-80 treatment increased by 0.01–0.46 and 1.33–1.55 times, respectively, whereas those of B[a]P increased from 0.57 to 0.82, and 1.33 to 1.55 times, respectively, compared with those of the control. Optimal result for Cd phytoextraction was obtained under combined 5 mmol Tween-80 kg−1 and 1 mmol GA3 kg−1 treatment, and the maximum removal rate of B[a]P was obtained after the application of 5 mmol Tween-80 kg−1 and 5 mmol GA3 kg−1.

► Phytoremediation is a cost-effective, environment-friendly and sustainable method.
► Tagetes patula has been validated as a Cd hyperaccumulator recently.
► It's feasible to clean Cd–B[a]P contaminated soils using GA3 and Tween-80.