Chapter 20 Algae-based Bioelectrochemical Systems

Bioelectrochemical systems (BES) are a technology under development that utilizes microorganisms to convert chemical energy to electrical energy or vice versa. BES have been used for applications in wastewater treatment, production of electricity, and material recovery. Microbial fuel cells (MFCs), the most common type of BES, have been widely tested for producing electricity from wastewater treatment. Conventionally, the cathodic part of an MFC is abiotic but recent research has been exploring the use of microalgae because of their ability to naturally produce oxygen, which is required for the cathodic reactions in an MFC. In this chapter, we provide a review on the status of the algae-based MFC technology. We discuss the main components used in this technology as well as the results of microalgae tested systems. As it is common for anodic biofilms to improve the performance of microbial fuel cells, a case has been made for the influence of cathodic biofilms on the performance of the system. Therefore, we discuss the possibility of immobilizing microalgae in the cathodic compartment of microbial fuel cell, highlighting the electrode surface immobilization techniques such as entrapment, adsorption and affinity immobilization. Finally, the prospects of adapting other forms of microalgae immobilization used in other technologies, into microbial fuel cell systems, have been highlighted.