Environmentally friendly low-cost membranes for micro and meso-scale bioelectrochemical systems

CORTÓN, EDUARDO; GONZALEZ PABON MARIA JESUS; MARTINEZ CASILLAS DIANA CRISTINA; FIGEREDO, FEDERICO

Ciudad de Néxico

Congreso; VIII International Congress of the Mexican Hydrogen Society; 2018

Mexican Hydrogen Society

Microbial fuel cells (MFCs) and microbial electrolysis cells (MECs) are well known bio-electrochemical systems (BESs) that can be used to produce electricity, and hydrogen respectively, by means of microbial metabolic activity. Nonetheless, new strategies for constructions, start up, operation and maintenance are required to improve BESs efficiency and commercial feasibility. At that point, BESs manufacturing materials (electrodes and membranes) represent the main bottleneck for industrial use and scalable real-world applications. Then, one of the challenges to make MFCs and MECs a viable technology is to obtain low cost and environmentally sound materials to fabricate them. In this work we synthesized membranes by a simple procedure: using solution casting and solvent evaporation technique, involving low price and biodegradable materials such as poly (vinylalcohol) (PVA), chitosan (CS) and PVA:CS, all cross-linked with sulfuric acid. The synthesized membranes were characterized by SEM and EIS, as well as their water uptake, oxygen diffusion and MFC performance, and compared to Nafion® 117, as our reference/control membrane. Conductivity values of the three synthesized membranes were lower than Nafion® 117. However, PVA and PVA:CS show lower oxygen permeability in comparison to Nafion® 117 membranes, a strong advantage in order to maintain anaerobic conditions in the anodic compartment of MFCs. Membranes were first studied in a typical meso-scale H-Type MFCs with LB medium containing E.coli (OD = 1). Our results show that CS membrane has the best current output performance (76.1 ± 11.9 mA/m2).On the other hand, PVA:CS membranes outperform Nafion® 4 times (power production, 20.8 ± 2.9 mW/m2) while being 75 times more economic. Furthermore, the best membrane in terms ofpower generation (PVA:CS) were used to made disposables paper-based micro-scale devices (16 µL), were power production was 10.5 ± 0.7 µW/cm3. PVA:CS membranes presented here can be useful to fabricate miniaturized and biodegradable MFC, for analytical uses as biosensors, and meso-systems capable to produce energy in a sustainable mode