Municipal wastewater treatment plants coupled with electrochemical, biological and bio-electrochemical technologies: Opportunities and challenge toward energy self-sufficiency.

Municipal wastewater treatment plants (WWTPs) will face challenges in the coming decades including reducing energy consumption and decreasing carbon emissions. These challenges can be addressed by combining electrochemical, biological, and bio-electrochemical technologies within existing WWTPs. The results from this review indicate that electrochemical technology is an effective advanced treatment method for WWTPs. However, electrochemical technology is not yet economically suitable as a stand-alone unit for treating wastewater because it consumes energy in the operation process. Electricity generation from biological and bio-electrochemical technologies can provide the power supply needed for WWTP electrochemical processes while reducing greenhouse gas emissions. WWTPs coupled with electrochemical, biological, and bio-electrochemical technologies can increase electricity recovery in WWTPs, impart energy self-sufficiency to the WWTPs, and decrease greenhouse gas emissions.