Development of a microbial fuel cell for digestate treatment and energy generation

Abstract

The microbial fuel cell (MFC) presents itself as a promising technology, as it has the ability to generate clean electricity from wastewater treatment. However, this technology has challenges and limitations. Therefore, this project aims to develop an efficient and low-cost electrode to be applied in the treatment of digestate from anaerobic digesters and thus overcome some technological limitations. Dual-chamber continuous-flow MFCs will be evaluated with different modifications to the granular activated carbon (GAC) electrode. The electrodes will be chemically modified from a conductive solution. Initially, the anode chamber will be fed with 5 gCOD L-1 and the cathode chamber will be fed with nitrate wastewater to promote autotrophic denitrification. After inoculation and stabilization, the system will be fed with the incorporation of digestate and will have 3 experimental phases. Inoculation and adaptation; Effect of digestate incorporation and reactor coupling. The efficiency of the system for the treatment will be evaluated from the monitoring of the physical-chemical parameters. Electric power generation and electrochemical characteristics will be evaluated from the system voltage, which makes it possible to find the maximum power density, characterize the reactions and the occurrence of redox mediators and evaluate the performance of the electrode. The extraction of DNA from the biofilm of the electrodes and subsequent sequencing will allow the evaluation of the microbial community for the elucidation and optimization of bioelectrochemical processes. After the development of the project, positive results are expected that lead to the improvement of the system, in order to take advantage of the energy resources contained in the digestate before its final destination, contributing to sustainable development in sanitation and energy. (AU)