## 3 Results and Discussion
### Effect of Revegation on Metal(loid) Content in Mining Areas  
The contents of metal(loid)s in smelting slag and tailings after revegetation are shown in Figure 2. The contents of As, Cd, Hg, Cu, Ni, Pb, Sb, and Zn in the remediated smelting slag heap and tailings piles were significantly lower than those in the unremediated US and UT. Compared to the unremediated US, the average contents of As, Cd, Hg, Ni, Pb, Sb, Zn, and Cu in the RS5 area decreased by 75.09%, 91.12%, 49.17%, 62.15%, 88.89%, 63.15%, 69.76%, and 61.35%, respectively, and the average contents of As, Cd, Hg, Ni, Pb, Sb, Zn, and Cu in the RS10 area decreased by 93.18%, 92.00%, 73.39%, 53.85%, 89.50%, 89.87%, 62.99%, and 62.68%, respectively. Similarly, the average content of As, Cd, Hg, Ni, Pb, Sb, Zn, and Cu decreased by 88.72%, 60.45%, 83.30%, 22.71%, 23.26%, 93.47%, 23.04%, and 14.54%, respectively, in the RT10 area compared to the UT. \begin{table}
\begin{tabular}{l c c c c c c c c c c c} \hline \hline  & **pH** & **TN (g/kg)** & **TP (g/kg)** & **Corg(\%)** & **Al\({}_{2}\)O\({}_{3}\)(\%)** & **CaO(\%)** & **Fe\({}_{2}\)O\({}_{3}\)(\%)** & **SiO\({}_{2}\)(\%)** & **MgO(\%)** & **Na\({}_{2}\)O(\%)** & **k\({}_{2}\)O(\%)** \\ \hline
**BS** & 5.51 \(\pm\) 0.03 & 1.21 \(\pm\) 0.10 & 0.415 \(\pm\) 0.04 & 1.53 \(\pm\) 0.38 & 14.86 \(\pm\) 1.24 & 0.10 \(\pm\) 0.03 & 5.42 \(\pm\) 0.63 & 66.50 \(\pm\) 2.69 & 0.44 \(\pm\) 0.02 & 0.21 \(\pm\) 0.03 & 1.33 \(\pm\) 0.11 \\
**US** & 8.88 \(\pm\) 1.71 & 0.38 \(\pm\) 0.01 & 0.177 \(\pm\) 0.03 & 1.94 \(\pm\) 0.51 & 11.86 \(\pm\) 2.05 & 2.98 \(\pm\) 1.51 & 4.28 \(\pm\) 0.25 & 65.93 \(\pm\) 1.37 & 0.61 \(\pm\) 0.12 & 0.67 \(\pm\) 0.08 & 1.30 \(\pm\) 0.28 \\
**RSS** & 6.68 \(\pm\) 1.33 & 0.76 \(\pm\) 0.14 & 0.243 \(\pm\) 0.01 & 0.24 \(\pm\) 0.06 & 8.47 \(\pm\) 0.59 & 0.28 \(\pm\) 0.10 & 3.64 \(\pm\) 0.23 & 82.13 \(\pm\Results showed that revegetation could effectively control the metal(oid) pollution problem of smelting slag heaps and tailings piles, which exhibited a tendency of gradual reduction of metal(loid) content with the prolongation of revegetation time. [PERSON] [48] researched the effect of revegetation on Mn, Zn, Pb, and Cd in manganese mine wasteland and also found that the metal content of the soil was significantly reduced after revegetation compared to the unremediated mine waste sites, and it gradually decreased with the increase in the time of revegetation, and after 9 years of revegetation, the metal content was 85.29% lower than that of the unremediated plots. [PERSON]'s research [40] also found that after 7 years of revegetation, As and Sb concentrations in Pb-Zn smelting slags were significantly lower than in unremediated control slags. This may be due to the influence of plant root exudates and microbial activities on the chemical formation and adsorption-resolution behavior of metal(loid)s in the waste slag, which promotes the transport and transformation of metal(loid)s [49]. Related studies have reported that root exudates of _Miscanthus_ can promote metal uptake by releasing organic acids, chelating agents, and other compounds [31]. [PERSON] et al. [32,50] found that the enrichment concentration of As and Sb in the root system of _Miscanthus_ could reach 38.53 and 177.29 mg/kg. Similarly, [PERSON] et al. [43] found that the shoot of _Miscanthus_ contained 63.41, 360.53, and 158.5 mg/kg of Cu, Zn, and Pb, respectively, and the Pb and Zn content in the roots reached 1449.09 and 1114.33 mg/kg, respectively. The results of the above-related studies all indicated that _Miscanthus_ has the potential to absorb metal(loid)s. In addition, with the increase in the vegetation restoration time, the rhizosphere organic matter and nutrient elements accumulated continuously, which effectively improved the soil quality, and the vegetation  
Figure 2: Total metal(loid) concentrations in the BS, US, RS5, RS10, UT, and RT10 sites. Panels show As (**a**), Cd (**b**), Hg (**c**), Ni (**d**), Pb (**e**), Sb (**f**), Zn (**g**), Cu (**h**), and Cr (**i**).