title: A small-scale air-cathode microbial fuel cell for on-line monitoring of water quality.
abstract: The heavy use of chemicals for agricultural, industrial and domestic purposes has increased the risk of freshwater contamination worldwide. Consequently, the demand for efficient new analytical tools for on-line and on-site water quality monitoring has become particularly urgent. In this study, a small-scale single chamber air-cathode microbial fuel cell (SCMFC), fabricated by rapid prototyping layer-by-layer 3D printing, was tested as a biosensor for continuous water quality monitoring. When acetate was fed as the rate-limiting substrate, the SCMFC acted as a sensor for chemical oxygen demand (COD) in water. The linear detection range was 3-164 ppm, with a sensitivity of 0.05 μA mM(-1) cm(-2) with respect to the anode total surface area. The response time was as fast as 2.8 min. At saturating acetate concentrations (COD>164 ppm), the miniature SCMFC could rapidly detect the presence of cadmium in water with high sensitivity (0.2 μg l(-1) cm(-2)) and a lower detection limit of only 1 μg l(-1). The biosensor dynamic range was 1-25 μg l(-1). Within this range of concentrations, cadmium affected only temporarily the electroactive biofilm at the anode. When the SCMFCs were again fed with fresh wastewater and no pollutant, the initial steady-state current was recovered within 12 min.
authors.affiliation: University of Bath, Department of Chemical Engineering, Bath BA2 7AY, UK. Electronic address: M.Di.Lorenzo@bath.ac.uk.
authors.forename: Mirella
authors.initials: M
authors.lastname: Di Lorenzo
authors.affiliation: University of Bath, Department of Chemical Engineering, Bath BA2 7AY, UK.
authors.forename: Alexander R
authors.initials: AR
authors.lastname: Thomson
authors.affiliation: University of Bath, Department of Chemistry, Bath BA2 7AY, UK.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Schneider
authors.affiliation: University of Bath, Department of Chemistry, Bath BA2 7AY, UK.
authors.forename: Petra J
authors.initials: PJ
authors.lastname: Cameron
authors.affiliation: Bristol Robotics Laboratory, University of the West of England, Bristol, UK.
authors.forename: Ioannis
authors.initials: I
authors.lastname: Ieropoulos
mesh_terms: D000388:Air; D001674:Bioelectric Energy Sources; D015374:Biosensing Techniques / Q000379:methods*; D002104:Cadmium / Q000032:analysis; D004566:Electrodes; D004867:Equipment Design; D005618:Fresh Water / Q000032:analysis*; D057230:Limit of Detection; D009862:Online Systems; D066330:Printing, Three-Dimensional; D014874:Water Pollutants, Chemical / Q000032:analysis*; D060753:Water Quality
chemical_list: D014874:Water Pollutants, Chemical; D002104:Cadmium
keywords: BOD; Biosensor; Cadmium; Microbial fuel cell; Water quality