Demonstration of an Energy Neutral, Off-Grid Microbial Fuel Cell System for Decentralized Wastewater Treatment

Abstract

Water and energy are main priorities for much of the world as increasing demands on the world’s resources forces nations to make sustainable choices. Microbial fuel cells emerged as a promising technology to provide energy efficient wastewater treatment at significant cost savings compared to conventional treatment processes. They have an even greater benefit in those areas that are difficult to connect to municipal sewage treatment networks. We discuss here a pilot scale demonstration at a rural Naval training camp in Warner Springs, CA. The system is a 100 gallon system outfitted with a solar energy system that allows full system operation in an energy neutral configuration. The system configuration here was previously tested in the laboratory using wastewater in semi-batch operation at both the 40 gallon scale and 100 gallon scale. Laboratory studies indicated that a 7-day batch treatment time would result in high removal of biological oxygen demand. Effluent quality was also good with more than 99% removal of suspended solids, turbidity, and nitrogen. Before deployment to the field, the system was rebuilt using lessons learned from the laboratory studies and other large scale demonstrations. Considerations for size, portability, ease of use, and operations were considered here and will be discussed. The overall goal for the field-deployed system was to demonstrate continuous treatment at rate of 20 gallon per day. Initial results from the startup phase operating in semi-batch mode show promising results, decreasing the COD content more than 80% over a 7-day treatment time. Results from the ongoing demonstration will also be discussed here. The system here represents a significant move towards providing decentralized wastewater treatment. We examine the feasibility of applying this technology in an off-grid application to meet a real-world requirement. We will also examine lessons learned from the demonstration and possible improvements to incorporate into the next iterations of these types of systems.

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Identifiers

DOI

10.1149/ma2016-02/44/3246

Journal

ECS Meeting Abstracts

Year

2016