In order to develop communities in a sustainable manner it is necessary to think about how to provide basic and affordable services including sanitation and electricity. Wastewater has energy embedded in the form biodegradable organic matter, but most of the conventional systems use external energy to treat the wastewater instead of harvest its energy. Microbial fuel cells (MFCs) are unique systems that are capable of converting chemical energy of biodegradable substrates embedded in the waste materials into renewable electricity. Even though the technology showed great progress, the direct electrical energy output from MFC reactors is still very low and the electrical interface with microbial activities is not well understood.

In this work, I investigated the development and deployment of energy management systems to improve energy harvesting of microbial fuel cells during wastewater treatment. The specific studies presented in this dissertation consist of the first AC power generation from microbial fuel cells, the development of harvesting strategies to maximize microbial fuel cell performance in different conditions, and the understanding of microbial community and activities under different harvesting conditions. To enable the application of MFC technology for treating actual wastewaters and providing net electricity output, I also investigated the integration of AC-powered electrocoagulation with granular biochar to treat hydraulic fracturing water, and I used the electricity generated by MFCs to directly power electrocoagulation for oily wastewater treatment, achieving energy positive wastewater treatment for distributed applications. System scale up and integration will be next steps for technology development.