Storing of exoelectrogenic anolyte for efficient microbial fuel cell recovery. Issue 11 (12th May 2019)

• Record Type: Journal Article
• Authors: Haavisto, Johanna M.; Lakaniemi, Aino-Maija; Puhakka, Jaakko A.
• Is Part Of: Environmental technology. Volume 40:Issue 11(2019)
• Page Start: 1467
• Page End: 1475
• Publication Date: 2019-05-12
• Subjects: Exoelectrogenic culture -- mixed culture storage -- freezing -- refrigerating -- process recovery; Environmental engineering -- Periodicals; Environmental protection -- Periodicals; 628.05
• DOI: 10.1080/09593330.2017.1423395
• Languages: English
• ISSNs: 0959-3330

Abstract

ABSTRACT: Starting up a microbial fuel cell (MFC) requires often a long-term culture enrichment period, which is a challenge after process upsets. The purpose of this study was to develop low-cost storage for MFC enrichment culture to enable prompt process recovery after upsets. Anolyte of an operating xylose-fed MFC was stored at different temperatures and for different time periods. Storing the anolyte for 1 week or 1 month at +4°C did not significantly affect power production, but the lag time for power production was increased from 2 days to 3 or 5 days, respectively. One month storing at –20°C increased the lag time to 7 days. The average power density in these MFCs varied between 1.2 and 1.7 W/m 3 . The share of dead cells (measured by live/dead staining) increased with storing time. After 6-month storage, the power production was insignificant. However, xylose removal remained similar in all cultures (99–100%) while volatile fatty acids production varied. The results indicate that fermentative organisms tolerated the long storage better than the exoelectrogens. As storing at +4°C is less energy intensive compared to freezing, anolyte storage at +4°C for a maximum of 1 month is recommended as start-up seed for MFC after process failure to enable efficient process recovery.