On the other hand, energy production from salinity gradient
can be a popular trend in the near future. Energy can be produced
from a reverse electrodialysis (RED) due to the salinity gradient
[71]. It is reported that electrical potential of 0.1–0.2 V per pair of
membrane can be produced from seawater and freshwater (ortreated wastewater) through pairs of ion-exchange membranes in
a RED. Globally, up to 980 GW of power could be generated from
salinity gradient energy where freshwater flows into the sea .
A RED stack can be placed between the anode and cathode
chambers of an MFC or microbial electrolysis cell (MEC), creating a
hybrid technology called a microbial reverse electrodialysis
cell (MRC).