# Metal Recovery from Wastes: A Review of Recent Advances in the Use of Bioelectrochemical Systems
## 2 Bioelectrochemical Systems for Metal Recovery
\begin{table}
\begin{tabular}{l l l l} \hline
**Objective** & **Reactor Setup** & **Operational Conditions** & **Milestones** & **Ref.** \\ \hline  & & & \begin{tabular}{l} Analye: Activated sludge and \\ municipal wastewater \\ Middle Chamber: Synthetic Cu\({}^{2+}\) and \\ Zn\({}^{2+}\) \\ Cathode: Carbon graphite \\ Membrane: Polyester-based CEM (Fumase) \\ FTCM-E) and AEM (Fumase) \\ \end{tabular} & \begin{tabular}{l} Analye: Activated sludge and \\ municipal wastewater \\ Middle Chamber: Synthetic Cu\({}^{2+}\) and \\ Zn\({}^{2+}\) solution (100 mg/L) at pH 7 \\ \end{tabular} & \begin{tabular}{l} - Removal efficiency: Cu\({}^{2+}\): 79.7\%, \\ Zn\({}^{2+}\): 79.6\% (synthetic samples) \\ - Voltage: 0.9 V (Cu\({}^{2+}\)), 0.8 V (Zn\({}^{2+}\)) \\ - Removal efficiency: 2.1 \% \\ - Removal efficiency: 1.01 m/phosphate buffer \\ - Removal efficiency: 2.1 \% \\ - Removal efficiency: 0.87\%, Zn\({}^{2+}\): 70.64\% \\ - Maximum removal at mesophilic \\ - Temperature: 26 \% (C mesophilic \\ - conditions) \\ \end{tabular} & \begin{tabular}{l} - Removal efficiency: Cu\({}^{2+}\): 79.7\%, \\ Zn\({}^{2+}\): 79.6\% (synthetic samples) \\ - Voltage: 0.9 V (Cu\({}^{2+}\)), 0.8 V (Zn\({}^{2+}\)) \\ - Removal efficiency: 0.86\%, Zn\({}^{2+}\): 70.64\% \\ - Maximum removal at mesophilic \\ - Temperature: 26 \% (C mesophilic \\ - conditions) \\ \end{tabular} & \begin{tabular}{l} [56] \\ - Maximum removal at mesophilic \\ phase: 4.4 mg / L \\ retention time \\ - \\ \end{tabular} \\ \hline  & & \begin{tabular}{l} System: Dual-chamber MDC-ED \\ (electrodialysis) integrated system \\ \end{tabular} & \begin{tabular}{l} 1 g/ L CH\({}_{3}\)CONA (pH 7) \\ Cathode: Cu\({}^{2+}\) solution (100 mg/L, \\ pH 2) \\ \end{tabular} & \begin{tabular}{l} - Cu recovery efficiency: 88\% \\ - Salt removal efficiency: 47\% \\ - Energy-efficient desalination with \\ simultaneous Cu\({}^{2+}\) recovery \\ - Current density: 2.1 A/m\({}^{2}\) \\ \end{tabular} \\ \hline  & & \begin{tabular}{l} System: Four-chamber MDC (FMDC) \\ Anode: Carbon felt \\ Cathode: Carbon felt \\ Membrane: AEM and CEM \\ \end{tabular} & \begin{tabular}{l} Analye: Synthetic Cu wasetwater \\ (100-800 mg/L, Cu\({}^{2+}\) pH 7) \\ Desalination chamber: 5 g/ L NaCl \\ - Temperature: Room temperature \\ \end{tabular} & \begin{tabular}{l} - 94\% Cu recovery \\ - 43\% salt removal in desalination \\ - Electricity generation with \\ maximum current density: 2.0 A/m\({}^{2}\) \\ \end{tabular} \\ \hline  & & \begin{tabular}{l} System: Dual-chamber MDC \\ Anode: Carbon felt \\ Cathode: Carbon felt \\ Membrane: AEM and CEM \\ \end{tabular} & \
\begin{tabular}{l} Analye: Acetate solution (1 g/L) \\ (pH 7) \\ Cathode: Cu\({}^{2+}\) solution \\ - Temperature: Room temperature \\ \end{tabular} &
\begin{tabular}{l} - Cu removal efficiency increased to \\ 292 mg/g due to ZIF-8 membrane \\ adsorption capacity \\ - Desalination efficiency of 56\% \\ achieved \\ - Significant biofouling prevention \\ due to reduced microbial adhesion on the ZIF-8 surface \\ \end{tabular} \\ \hline \end{tabular}
\end{table} 
Table 2: _Cont._ \begin{table}
\begin{tabular}{l l l l l} \hline
**Objective** & **Reactor Setup** & **Operational Conditions** & **Milestones** & **Ref.** \\ \hline \multirow{6}{*}{Coupling MDC-MEC for Pb recovery} & System: MDC-MEC integrated system & MDC and MEC Anolyte: Synthetic & MDC: Carbon brush anode, carbon cloth & wastewater (acettite, pH7) & - Lead recovery: 96\% in 48 h \\  & MDC: Catholyte and middle & - Energy generated by MDC stored in [50] \\  & MDC: Carbon brush anode, carbon cloth & - Energy generated by MDC stored in [50] \\  & & & \\  & cathode for Pb reduction & - MEC Catholyte: Pb(NO)\({}_{2}\) solution (pH7) & capacitors to power MEC \\ \hline \end{tabular}
\end{table} 
Table 2: _Cont._