## Permeate
### Integration of MFC with MDC  
Desalination is another approach for the treatment of contaminated water and potable water production. Distillation, electrodialysis, and reverse osmosis are the methods used in desalination [75]. It is believed that desalination is not applicable in all circumstances due to the high energy requirements and maintenance cost [42]. MFCs have the potential to be integrated into desalination cells due to their advantages in the synthesis of renewable energy, such as CH\({}_{4}\), H\({}_{2}\), and electric power. In 2009, [PERSON] along with his co-workers [76] described a new type of desalination system known as microbial desalination cell, which is based on the movement of ions from water in accordance to the electron supplied by microbes. A desalination cell MFC with three chambers was constructed (as shown in Figure 5. An anion exchange and cation exchange membrane, as well as a central compartment, were included in the three-chambered DS-MFCs. In the anode chamber,  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Sr. No**} & \multirow{2}{*}{**Reactor Type**} & \multirow{2}{*}{**Substrate**} & **COD,** & \multirow{2}{*}{**Cathode**} & \multirow{2}{*}{**Anode**} & **Power** & \multirow{2}{*}{**Reference**} \\  & & & **P\(\mathbf{H}\)** & & & **(W/m\({}^{3}\))** & \\ \hline \multirow{2}{*}{1.} & Sediment MFC, 350 L & Synthetic & \multirow{2}{*}{-} & Activated & \multirow{2}{*}{C mesh} & \multirow{2}{*}{0.0064} & [70] \\  & & wastewater & & & & & \\ \hline \multirow{2}{*}{2.} & Sediment MFC, 195 L & River & 13.5 mS/m & Activated carbon/stainless steel & \multirow{2}{*}{C mesh} & \multirow{2}{*}{0.0415} & [71] \\  & & sediment & pH 6.8–7.4 & & & & \\ \hline \multirow{3}{*}{3.} & Self-stratifying & \multirow{2}{*}{Urine} & 5.6–6.8 g/L & Microporous carbon & \multirow{2}{*}{C veil fibers} & \multirow{2}{*}{7.3–9.9} & [72] \\  & & 19.2–57.6 L & & & & & \\ \hline \multirow{3}{*}{4.} & Sediment MFC, & \multirow{2}{*}{72 units, 72 L} & River & 890 g/L & \multirow{2}{*}{Zinc} & \multirow{2}{*}{Copper} & \multirow{2}{*}{0.0019} & [73] \\  & & sediment & sediment & & & & \\ \cline{1-1} \cline{2-5}  & Sediment MFC, & \multirow{2}{*}{water} & \multirow{2}{*}{pH 8} & & & 0.0069 & [74] \\ \cline{1-1} \cline{2-5}  & & 35 units, 35 L & & & & & \\ \hline \hline \end{tabular}
\end{table}
Table 2: Several studies demonstrating the performance of sediment MFC.  
bacteria decompose contaminants and yield power, while negatively charged ions pass through a membrane from the central chamber to the anodic chamber. The cathode utilizes protons in the same way as that in typical MFCs, and a positive charge from the central compartment is transferred to the cathodic compartment. As a result, water in the central compartment is desalinated, and contaminated water is treated at the same time [77].  
For synthetic wastewater and saline sewage treatment, [PERSON] and [PERSON] [78] devised an osmotic MFC with an FO membrane coupled with a microbial desalination cell (MDC). The research achieved an energy output of 0.160 kW h/m\({}^{3}\) and an electrical conductance decline of 95.9%. Due to dilution and desalination, the system was demonstrated to be an excellent technology for salt elimination. [PERSON] and [PERSON] [78] used 105 L MDC to test the scaling up of the system. The research revealed that several feeding inlets could improve the current production. The current production improved from 670 to 2000 mA with a salt elimination of 3.7 to 9.2 kg/h when external power was applied (m\({}^{3}\) day). [PERSON] and [PERSON] [79] employed organics from petroleum effluent for an MFC and used osmotic MFCs with up-flow microbial desalination cell for marine treatment. According to their research, the integrated system can eliminate up to 93% COD from saltwater while also removing 48% salt.