A low-cost microbial fuel cell based sensor for in-situ monitoring of dissolved oxygen for over half a year.

Abstract

In order to address the need for long-term, in-situ and inexpensive monitoring of dissolved oxygen (DO), a chitin-carrying microbial fuel cell (MFC) based DO sensor was developed using sediment anolyte, which had an extremely low cost of US$12.17 and comparable performance to certain commercial sensors. The MFC based DO sensor had a long lifetime of over half a year with chitin as the fuel, attributed to the syntrophic interactions between fermentative and exoelectrogenic microbes that were well developed for chitin degradation in anaerobic condition with sediment filling in the anode chamber. The use of sediment anolyte introduced hindered diffusion in the porous media, enabling the use of glass fiber as the separator to replace the ion exchange membrane and thus resulting in a much lower cost. Field tests of this MFC based DO sensor were conducted in fresh and saline waters respectively. Excellent performance was achieved with average deviations of <4.5% to three commercial methods of fiber optic sensor (HQ40d, HACH company, USA), Clark type sensor (Pro20i, YSI company, USA) and iodometry. This low-cost MFC sensor also showed a high reliability, with the same response of current generation to different DO levels in random 17-times tests, indicating its great market potentials for in-situ DO monitoring.

Key findings

• ▸The MFC based DO sensor had a low cost of US$12.17 and excellent performance in field tests.
• ▸The use of sediment anolyte and glass fiber as the separator resulted in a much lower cost compared to traditional ion exchange membranes.
• ▸The sensor showed a high reliability with an average deviation of <4.5% to three commercial methods.

Keywords

Identifiers

DOI

10.2139/ssrn.4229443

Journal

SSRN Electronic Journal

Year

2022