Recycled waste polypropylene composite ceramic membranes for extended lifetime of microbial fuel cells

Abstract

Increasing interest in sustainable electricity generation through microbial fuel cell technology reinforces the development of new and cost-effective materials for their manufacturing. Such a goal can be reached with inexpensive ceramic materials as separators. In this study, we present a new approach for increasing their lifetime, while dealing with problematic waste and thus using recycled polypropylene (PP) nonwoven fabric. Two approaches were applied, where PP was either reused as an additional layer placed over the ceramics, as well as recycled by coating on the surface of the ceramics. Two different ceramic materials (labelled as 468 and 373) were investigated in a single chamber air–cathode MFCs using acetate as a fuel. Among all studied membranes, the highest power, exceeding 0.2 mW was reached for PP/373 composite and was 92% higher than the unmodified 373. In the last stage of the long-term study (60–80 days), PP/373 remained at 190–600% higher level of power when compared to the unmodified 373 clay and 120–550% higher than 468 clay, suggesting strong antifouling effects of ceramic modification. The material characterisation indicated that the antifouling effect of the PP coating was dependent on the properties of the ceramic material. The proposed method of increasing the long-term efficiency of ceramic MFCs successfully employed recycling of polypropylene, which is the globally the least recycled plastic.