# Metal Recovery from Wastes: A Review of Recent Advances in the Use of Bioelectrochemical Systems
## 2 Bioelectrochemical Systems for Metal Recovery
** \\ \hline  & & Analybe: 1.0 g/ L CH\({}_{3}\)COONa, & & -Zn\({}^{+}\) removal: 96\% for synthetic and \\  & & System: Half-cell MPC & 3.0 g/ L NaCl (\(\gamma\sim 7\times 2\) cm\({}^{3}\) working & -Zn\({}^{+}\) removal: 96\% for synthetic and \\  & & & volume) & industrial samples (\(<\)2.0 mM Zn\({}^{2+}\)) in \\ Removal of zinc from industrial & & Anode: Plain carbon felt (3 \(\times\) 3 cm\({}^{2}\)) & & 22 h \\ effluents using MFCs & & Cathode: Plain carbon felt (3 \(\times\) 3 cm\({}^{2}\)) & Cathode: 1.9 mM ZnCl\({}_{3}\), 30 g/ L & -Cathode recovery: 83\% (synthetic), [90] \\  & & Membrane: Anion exchange membrane & & 46\% (industrial) \\  & & (Fab-PK-130, Funnet) & & -Electrodeposition predominated \\  & & Rest: 10 \(\Omega\) & -over chemical deposition \\  & & Temperature: 22 \(\pm\) 3 \({}^{\circ}\)C & & over chemical deposition \\ \hline  & & & MPC mode: & \\ Recovery of metals (Fe, Cu, Sn, & & & -Fe\({}^{+}\) reduced to Fe\({}^{+}\) within 1 day \\  & & & & -Ca\({}^{+}\) to Ca\({}^{+}\) recovery: 100\% in \\ Recovery of metals (Fe, Cu, Sn, & & & -Ca\({}^{+}\) to Ca\({}^{+}\) recovery: 100\% in \\ NiO) from synthetic AMI using & & Cathode: C 1.1 synthetic AMD (Fe\({}^{+}\), & MEC mode: & \\  & & Cathode: Copper (MFC), Titanium (MFC) & - & -At 0.7 \(\times\) Si\({}^{2+}\) recovery: \(>\)80\% in \\ BES in MFC and MEC modes & Membrane: Bipolar membrane (Fumasep\({}^{2}\)) & & 50 mg/ L, Si\({}^{+}\) 50 mg/ L, pH 2.5) & 0.3 days \\  & & Rest: 120 \(\Omega\) & -After 2\(\pm\) h: Ni\({}^{2+}\): 77\%, Fe\({}^{+}\): 60\% \\  & & Temperature: 25 \({}^{\circ}\)C & -BES required 0.5 V, significantly less \\  & & & than the 1.8 reduced in the abiotic \\  & & & blank system & \\ Synchronized recovery of & & System: Triple-chamber MPC (two cathode chambers flanking the anode chamber) & -Recovery in 50 h: Fe: 80\% as \\ high-purity Fe and S from & & Anode: Pretreated carbon felt (7.1 cm\({}^{2}\)) & -Fer0(H), S: 22.1\% as S\({}^{0}\) \\ sulfide tailings using & & Cathode: 28 mM (Na;S\({}_{20}\): O: 67 g, & -Parities: Fe(OH)\({}_{3}\): 93.1\%, S\({}^{0}\): 90.2\% \\  & & simulating ferrous- and sulfate-laden & -Facilitates simultaneous removal of \\ triple-chamber MFC & & Membranes: CEM (first cathode chamber) and & -Fer0(H) and sulfate ions, reducing waste \\  & & & Rest: 500 \(\Omega\) & -and enabling direct reuse of \\  & & & -BES required 0.5 V, significantly less \\  & & & -BES required 0.5 V, significantly less \\  & & & than the 1.8 reduced in the abiotic \\  & & & blank system & \\  & & & blank system & \\ \hline  & & & -Recovery in 50 h: Fe: 80\% as \\ Synchronized recovery of & & Analybe: 28 mM (25 g/ L sulfide & -Recovery in 50 h: Fe: 80\% as \\  & & tailing model, 1 g/ LNLMoO) & -Fer0(H), S: 22.1\% as S\({}^{0}  
\begin{table}
\begin{tabular}{l l l l l} \hline
**Objective** & **Reactor Setup** & **Operational Conditions** & **Milestones** & **Ref. ** \\ \hline \multirow{6}{*}{Modeling and validating metal removal efficiencies and energy consumption in BES vs. conventional techniques} & Model: “Grey-box” combining Monod kinetics (MFC) and Butler-Volinear equations (MEC), predicting concentration profiles, current generation, and metal recovery. & Analytic: 0.1 L (Cu\({}^{2+}\); 500 mg/L, and “MEC”), predicting concentration profiles & \multirow{6}{*}{Anolyte: 0.1 L (Cu\({}^{2+}\); 500 mg/L, and “MEC”), “MEC”: - MEC Mode: Complete Cu\({}^{2+}\) and “MEC”: - MEC Mode: Complete Cu\({}^{2+}\) and “MEC”: - MEC Mode: Complete Cu\({}^{2+}\) and “MEC”: - MEC Mode: Complete Cu\({}^{2+}\) and “MEC”: - MEC Mode: Optimized Fraction (MEC): - MEC Mode: “80% Sn” recovery in 1 day; Ni\({}^{2+}\) (15 mg/L) and Fe\({}^{+}\) (30 mg/L) recovered over 4 days & \\  & & & \\ \cline{1-1} \cline{3-4}  & System: Dual-chamber MFC glucose, pH \(\delta\) = 0.01 & \multirow{2}{*}{ \begin{tabular}{l} - Highest 5\(\%\) recovery, 26.4\% in \\ BES-Sec with 73.6\% selenium \\ removal from ethoside \\ cathode: A dual-chamber BES \\ \end{tabular}  } \\  & & & \\ \cline{1-1} \cline{3-4}  & Membrane: Nafion 117 (4 \(\times\) 4 cm) & & \\ \cline