# Simultaneous Electrochemical Removal of Selenium and Strontium from Aqueous Solution
## Appendix A
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Source**} & \multicolumn{2}{c}{**Sum of**} & \multirow{2}{*}{**df**} & \multicolumn{2}{c}{**Mean**} & \multirow{2}{*}{**F-Value**} & \multirow{2}{*}{**\(p\)-Value**} \\  & & **Squares** & & & & \\ \hline C\({}^{2}\) & 228.22 & 1 & 228.22 & 48.10 & \(<\)0.0001 \\ ABD & 0.5459 & 1 & 0.5459 & 0.1151 & 0.7357 \\ ACD & 115.56 & 1 & 115.56 & 24.36 & \(<\)0.0001 \\ BCD & 30.82 & 1 & 30.82 & 6.50 & 0.0135 \\ BDE & 0.7698 & 2 & 0.3849 & 0.0811 & 0.9222 \\ CDE & 46.45 & 2 & 23.22 & 4.89 & 0.0109 \\ A\({}^{2}\)D & 27.95 & 1 & 27.95 & 5.89 & 0.0184 \\ AB\({}^{2}\) & 134.46 & 1 & 134.46 & 28.34 & \(<\)0.0001 \\ B\({}^{2}\)C & 104.01 & 1 & 104.01 & 21.92 & \(<\)0.0001 \\ B\({}^{2}\)D & 1.27 & 1 & 1.27 & 0.2686 & 0.6063 \\ B\({}^{2}\)E & 15.78 & 2 & 7.89 & 1.66 & 0.1986 \\ C\({}^{2}\)D & 220.05 & 1 & 220.05 & 46.38 & \(<\)0.0001 \\ C\({}^{2}\)E & 11.28 & 2 & 5.64 & 1.19 & 0.3122 \\ AB\({}^{2}\)D & 55.88 & 1 & 55.88 & 11.78 & 0.0011 \\ B\({}^{2}\)DE & 59.45 & 2 & 29.73 & 6.27 & 0.0035 \\ C\({}^{2}\)DE & 72.63 & 2 & 36.31 & 7.65 & 0.0011 \\ Residual & 270.43 & 57 & 4.74 & & & \\ Lack of fit & 176.12 & 33 & 5.34 & 1.36 & 0.2201 \\ Pure error & 94.31 & 24 & 3.93 & & & \\ Cor total & 5417.51 & 101 & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Coefficients for model equations. \begin{table} \begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Term**} & \multirow{2}{*}{**No pH Adjustment**} & \multicolumn{2}{c}{**Selenium**} & \multicolumn{2}{c}{**Fe**} & \multirow{2}{*}{**Maximum Range**} \\  & & **Al** & & & & \\  & **Middle Range** & **Maximum Range** & **No pH Adjustment** & **Middle Range** & **Maximum Range** \\ \hline Intercept & 102.59322 & 152.30846 & 167.46964 & 158.47179 & 128.98206 & 147.96128 \\ I & \(-\)1.78133 & \(-\)1.99085 & \(-\)2.08221 & 0.174781 & \(-\)0.034732 & \(-\)0.126099 \\ N & \(-\)28.45478 & \(-\)40.88607 & \(-\)43.61474 & \(-\)26.02535 & \(-\)18.24464 & \(-\)21.90023 \\ t & 2.5182 & 1.48845 & 0.922576 & \(-\)2.77511 & \(-\)1.14904 & \(-\)1.89877 \\ I\({}^{*}\)N & 1.61783 & 1.61783 & 1.61783 & 0.338102 & 0.338102 & 0.338102 \\ I\({}^{*}\)I \(\times\) t & \(-\)0.072632 & \(-\)0.072632 & \(-\)0.072632 & \(-\)0.028747 & \(-\)0.028747 & \(-\)0.028747 \\ N \(\times\) t & 0.789865 & 0.789865 & 0.789865 & 0.903191 & 0.903191 & 0.903191 \\ I\({}^{2}\) & \(-\)0.027952 & \(-\)0.027952 & \(-\)0.027952 & \(-\)0.006915 & \(-\)0.006915 \\ N\({}^{2}\) & 2.54475 & 3.6074 & 3.81977 & 2.12081 & 1.52026 & 1.81221 \\ t\({}^{2}\) & \(-\)0.080611 & \(-\)0.055081 & \(-\)0.043016 & 0.026132 & \(-\)0.023444 & \(-\)0.004316 \\ I\({}^{*}\)N \({}^{2}\) & \(-\)0.137635 & \(-\)0.137635 & \(-\)0.137635 & \(-\)0.029734 & \(-\)0.029734 & \(-\)0.029734 \\ N\({}^{2}\)\(\times\) t & \(-\)0.0736 & \(-\)0.0736 & \(-\)0.0736 & \(-\)0.0736 & \(-\)0.0736 & \(-\)0.0736 \\ \hline \hline \end{tabular} 
\begin{tabular}{c c c c c} \hline \hline \multicolumn{4}{c}{**Strontium**} \\
**Term** & **No pH adjustment** & **Middle range** & **Maximum range** & **No pH adjustment** & **Middle range** & **Maximum range** \\ \hline Intercept & \(-\)73.48373158 & 55.1166486 & 41.86531447 & \(-\)87.71007808 & 134.9277131 & 103.0776063 \\ I & \(-\)0.192039389 & 2.450689256 & 0.94349502 & 4.44940244 & 1.459543068 & 0.660441204 \\ N & 22.79774267 & \(-\)8.014730563 & 4.418370306 & 12.26260226 & \(-\)26.82815325 & \(-\)11.75994274 \\ t & 7.182069021 &