## 4 Conclusions  
In this study, soil contaminants were removed by applying PRB filled with eco-friendly FSA and the improved EK remediation technique to ground with multiple contaminations. A comparison between the previous and log-transformed adsorption isotherms showed that the characteristics of copper and phenanthrene adsorption were matched better with the adsorption isotherm model by [PERSON]. The overall adsorption isotherm might be confirmed using the semi-log transformation of those parts that were unidentifiable using a previous model. In addition, FSA, one of the by-products of food waste, was determined to be appropriate for use as a PRB filling material due to its highly efficient capacity to remove contaminants. Acetic acid and Brij30 were used to improve the movement of contaminants within the ground and, ultimately, to improve the efficacy of the EK technique to treat heavy metals and organic compounds. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Test No.**} & **Initial Amount of** & **Residual** & **PRB (FSA)** & **Amount** & \multicolumn{2}{c}{**Residual Amount in**} & \multirow{2}{*}{**Mass**} \\  & **Phenanthrene** & **in the Bed** & **(mg)** & **Removed by** & \multicolumn{2}{c}{**Reservoir (mg)**} & \\  & **(mg)** & **(mg)** & & **EOF (mg)** & **(+) Anode** & **(–) Cathode** & **(\%)** \\ \hline Exp. 2 & 288 & 3.86 & 0.00075 & N.D & N.D & N.D & 1.34 \\ Exp. 3 & 288 & 4.22 & 0.00025 & N.D & N.D & N.D & 1.47 \\ Exp. 4 & 288 & 6.65 & 0.00075 & N.D & N.D & N.D & 2.31 \\ Exp. 5 & 288 & 6.21 & 0.00175 & N.D & N.D & N.D & 2.16 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Mass balance of phenanthrene removed. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Test No.**} & **Initial** & **Residual** & **PRB (FSA)** & **Amount** & \multicolumn{2}{c}{**Residual Amount in**} & \multirow{2}{*}{**Mass**} \\  & **Amount of** & **in the Bed** & **(mg)** & **Removed by** & \multicolumn{2}{c}{**Reservoir (mg)**} & \\  & **Copper (mg)** & **(mg)** & & **EOF (mg)** & **(+) Anode** & **(–) Cathode** & **(\%)** \\ \hline Exp. 1 & 144 & 23.24 & 105.88 & 0.45 & 2.17 & 0.04 & 91.53 \\ Exp. 3 & 144 & 22.24 & 108.62 & 0.21 & 0.75 & 0.02 & 91.58 \\ Exp. 4 & 144 & 16.70 & 121.12 & 0.11 & 1.29 & 0.06 & 93.90 \\ Exp. 5 & 144 & 14.15 & 116.98 & 0.35 & 6.27 & 0.04 & 95.71 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Mass balance of copper removed. Figure 7: Mass Balance. (**a**) Copper; (**b**) Phenanthrene. The outflow increased as the initial value of the current increased and, thereafter, tended to decrease in a consistent degree over time. This indicates that the movement of the contaminants improved through the smooth introduction of the improver. If Brij30 with a high initial current density and responsiveness to the outflow was used after using the acetic acid, the heavy metal might be removed via selective purification involving the use of acetic acid as an improver after the purification of the initial organic contaminants. In addition, the water content of the post-experiment sample was maintained as the initial water contents, 60%, and the movement of the improver was determined to be smooth during the EK remediation. A substantial change in the current and outflow reaction of the ionized heavy metal copper suggested rapid heavy metal removal. The FSA adsorption was 105-212 mg after the experiment in the heavy metal copper-contaminated ground. The use of acetic acid as the improver was confirmed to be appropriate in Exp. 4 which used the acetic acid as an improver in the copper adsorbed to the FSA. Accordingly, acetic acid might be a safe and economical improver, maintaining the stability of current density while biodegradation. However, phenanthrene was hardly detected and was unidentifiable due to its low recovery rate in kaolinite. Therefore, pretreatment in the phenanthrene-contaminated kaolinite requires further study. All the authors contributed to this study. J.H.