## 3 Results
### Mercury Environmental Speciation
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline  & **E1** & **E2** & **E3** & **E4** & **F1** & **F2** & **F3** & **HgT** \\ \hline MBC & \(\mathbf{-0.90}\) & \(\mathbf{-0.84}\) & \(\mathbf{-0.26}\) & \(\mathbf{0.84}\) & \(\mathbf{-0.93}\) & \(\mathbf{-0.60}\) & \(\mathbf{-0.83}\) & \(\mathbf{0.92}\) \\ DH & \(\mathbf{-0.89}\) & \(\mathbf{-0.78}\) & \(\mathbf{-0.37}\) & \(\mathbf{0.85}\) & \(\mathbf{-0.93}\) & \(\mathbf{-0.59}\) & \(\mathbf{-0.81}\) & \(\mathbf{0.93}\) \\ Bglu & \(\mathbf{-0.89}\) & \(\mathbf{-0.79}\) & \(\mathbf{-0.39}\) & \(\mathbf{0.86}\) & \(\mathbf{-0.93}\) & \(\mathbf{-0.59}\) & \(\mathbf{-0.81}\) & \(\mathbf{0.93}\) \\ Urease & \(\mathbf{-0.90}\) & \(\mathbf{-0.84}\) & \(\mathbf{-0.35}\) & \(\mathbf{0.88}\) & \(\mathbf{-0.93}\) & \(\mathbf{-0.62}\) & \(\mathbf{-0.82}\) & \(\mathbf{0.93}\) \\ P5 & \(\mathbf{-0.91}\) & \(\mathbf{-0.64}\) & \(\mathbf{-0.42}\) & \(\mathbf{0.79}\) & \(\mathbf{-0.94}\) & \(\mathbf{-0.51}\) & \(\mathbf{-0.87}\) & \(\mathbf{0.91}\) \\ P9 & \(0.09\) & \(\mathbf{0.45}\) & \(0.14\) & \(\mathbf{-0.37}\) & \(0.09\) & \(\mathbf{0.72}\) & \(\mathbf{-0.05}\) & \(\mathbf{-0.31}\) \\ Aryl & \(\mathbf{-0.88}\) & \(\mathbf{-0.81}\) & \(\mathbf{-0.40}\) & \(\mathbf{0.88}\) & \(\mathbf{-0.91}\) & \(\mathbf{-0.63}\) & \(\mathbf{-0.79}\) & \(\mathbf{0.94}\) \\ FDA & \(\mathbf{-0.92}\) & \(\mathbf{-0.84}\) & \(\mathbf{-0.45}\) & \(\mathbf{0.93}\) & \(\mathbf{-0.94}\) & \(\mathbf{-0.72}\) & \(\mathbf{-0.83}\) & \(\mathbf{0.97}\) \\ Clay & \(\mathbf{0.94}\) & \(\mathbf{0.59}\) & \(\mathbf{0.69}\) & \(\mathbf{-0.90}\) & \(\mathbf{0.92}\) & \(\mathbf{0.75}\) & \(\mathbf{0.94}\) & \(\mathbf{-0.86}\) \\ TOC & \(\mathbf{-0.90}\) & \(\mathbf{-0.86}\) & \(\mathbf{-0.30}\) & \(\mathbf{0.87}\) & \(\mathbf{-0.93}\) & \(\mathbf{-0.60}\) & \(\mathbf{-0.83}\) & \(\mathbf{0.92}\) \\ Al & \(\mathbf{0.68}\) & \(\mathbf{0.70}\) & \(\mathbf{0.43}\) & \(\mathbf{-0.79}\) & \(\mathbf{0.66}\) & \(\mathbf{0.92}\) & \(\mathbf{0.60}\) & \(\mathbf{-0.75}\) \\ Fe & \(\mathbf{-0.46}\) & \(\mathbf{-0.12}\) & \(\mathbf{-0.10}\) & \(\mathbf{0.22}\) & \(\mathbf{-0.48}\) & \(\mathbf{-0.22}\) & \(\mathbf{-0.44}\) & \(\mathbf{0.47}\) \\ pH & \(\mathbf{0.70}\) & \(\mathbf{0.83}\) & \(\mathbf{-0.08}\) & \(\mathbf{-0.62}\) & \(\mathbf{0.73}\) & \(\mathbf{0.20}\) & \(\mathbf{0.70}\) & \(\mathbf{-0.58}\) \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Pearson correlation coefficients (\(n=30\)) between enzymes activities, soil parameters and mercury mobility; bold values are significant at the \(p<0.05\). Figure 2: Mercury environmental speciation for the six sites as a percentage of each fraction relative to total mercury. (**a**) Focus on the most mobile fractions of mercury. F1: H\({}_{2}\)O soluble mercury, F2: CaCl\({}_{2}\) exchangeable mercury, F3: EDTA bioavailability mercury. (**b**) Focus on the main extractions of mercury. E1: Extraction of highly mobile mercury, E2: Extraction of mobile and toxic mer cury, E3: Extraction of semi mobile mercury, and E4: Non-mobile mercury. * Total non-mobile mercury species  
The restored Yao3 site showed that mercury was most immobilized with 54% non-mobile mercury. The two non-restored Yaoni sites Yao1 and Yao2 had significantly lower levels of non-mobile mercury than the other sites with 4.4% and 9.9%, respectively. The two non-restored sites Bel1 and Bel2 had more mercury, 50.3% and 30.9%, respectively, than the restored site Bel3 with 19.7%. The correlation between non-mobile mercury and the dataset followed exactly the same pattern as the total mercury content.