Fig. 3a shows that BJ andMSexhibited an increase in uptake with an increase in concentration. BJ had significantly higher uptake compared to MS at low concentrations (5–20 ppm) with approximately 3-fold greater uptake than MS. However, the rate of increase in uptake with an increase in concentration (5–20 ppm) slowed beyond these concentrations. This might be because of an increase in the fixed charge at the root cell surface which is believed to increase the resistance to metal uptake by slowing metal ion diffusion through the cell wall. At higher concentrations (40–80 ppm),MS exhibited higher comparative uptake than BJ