## 3 Results and Discussion
### Concentration of PTEs in the Soil and Plant Biomass
Only in the case of Zn was the limit value of 0.6 mg/kg exceeded, which also had to do with the increased Zn content in the soil as mentioned above. It further follows from Table 1 that the concentrations of monitored heavy metals differed in the shoot and root biomass. Concentrations of Zn, Se, Hg, and Pb were higher in the shoot biomass than in the root biomass. However, these differences were not significant (Table 1). Thus, the values indicate that _M. albus_ stored PTEs in shoot and root biomass relatively evenly, and was not able to transport a significant amount of PTEs from root to shoot. This may be related to the characteristics of legumes which are generally not considered as crops suitable for phytoremediation [45]. It can be also noted that concentrations of Ni, Cu, Cd, As, and Sb were higher in the root biomass than in the shoot biomass. A significant difference was recorded only in the case of As. It can be deduced from this that in the white sweet clover, some of the monitored PTEs were transported more either into the shoot biomass or into the root biomass. Amounts of heavy metals in the soil environment are shown in Table 1. [PERSON] et al. [46] studied the phytoremediation potential of nine native plants from Egypt growing in a sewage sludge dump in the Nile River delta. They confirmed that the ability of plants to accumulate PTEs highly depends on the plant species and on pollution in the location. Similar results were obtained by [PERSON] et al. [47], who studied the phytoremediation potential of various \begin{table}
\begin{tabular}{c c c c} \hline  & **Shoot** & **Root** & **Soil** \\ \hline Sb & \(0.55\pm 0.08\) c & \(0.60\pm 0.25\) b & n.d. \\ As & \(0.62\pm 0.09\) c & \(0.85\pm 0.14\) b\({}^{*}\) & \(6.98\pm 0.73\) c \\ Cd & \(0.08\pm 0.02\) d & \(0.11\pm 0.04\) c & n.d. \\ Cu & \(4\pm 0.54\) b & \(5.13\pm 0.75\) a & \(20.5\pm 1.31\) b \\ Ni & \(0.53\pm 0.15\) c & \(0.73\pm 0.17\) b & \(19.43\pm 0.25\) b \\ Pb & \(0.69\pm 0.28\) c & \(0.66\pm 0.38\) b & \(13.49\pm 6.155\) b \\ Hg & \(0.003\pm 0.001\) e & \(0.002\pm 0.001\) d & \(0.042\pm 0.003\) d \\ Se & \(0.45\pm 0.189\) d & \(0.29\pm 0.199\) b & n.d. \\ Zn & \(12.64\pm 3.34\) a & \(10.56\pm 6.06\) a & \(78.07\pm 5.09\) a \\ \hline \end{tabular} Data represent mean \(\pm\) standard deviation over at least 5 replications. Different letters indicate significant differences in the concentration of individual HMs in soil (ANOVA, \(p<0.05\), post hoc Tukey’s HSD test). Symbol \({}^{*}\) indicates significant differences between HM concentrations in shoots and roots (pair f-test, \(p<0.05\)). n.d. = not detected.  
\end{table} 
Table 1: Determination of selected PTEs in aerial biomass, underground biomass and in the soil (mg/kg). plants growing on landfills, in the landfill surroundings, or compost plants. The extent of PTE accumulation in _Cordus_ shoots was dependent on the location and on the distance from the source of pollution (surrounding the landfill). Therefore, there is an assumption that the model plant (_M. albus_) does not exhibit increased capacity for taking up and then transporting PTEs within its biomass.