Recovering Bioresources from Integrated Photo-Bioelectrochemical System

Abstract

Compared to traditional wastewater treatment technologies, the electricity generation is one of the most important advantages of bioelectrochemical systems (BES). However, due to its high cost and low energy production, BES technologies are still far away from feasible application. The main purpose of this work was to investigate ways to improve the electricity generation and reduce the cost of BES technologies. We focused on microbial fuel cells (MFCs) and microbial electrolysis cells (MECs) as two representative BES technologies. In order to improve the energy performance of MFCs, an accurate evaluation of the energy is necessary. However, the common evaluation methods of the energy performance in most MFC related studies prevent the meaningful comparison between different MFCs, and hence impede the further development of MFC technologies. So this study developed a new parameter, normalized energy recovery, to evaluate the energy performance of MFCs. Electrode materials are the main expense for the construction of BES and they have a significant effect on the performance of BES. Crumpled graphene and carbon/iron-based nanorod catalyst are relatively low-cost materials, so were applied in BES to improve their performance. Also, a novel system, integrated photo-bioelectrochemical (IPB) system, was developed to integrate algal technology and MFCs. The IPB system can efficiently remove the organics and nutrients in the wastewater and produce electricity and biomass.