Single chamber air-cathode microbial fuel cells as biosensors for determination of biodegradable organics

Biotechnol Lett. 2019 May;41(4-5):555-563. doi: 10.1007/s10529-019-02668-4. Epub 2019 Apr 3.

Abstract

Objectives: Single chamber air cathode microbial fuel cells (MFCs) were investigated with sodium-acetate and peptone as test substrates to assess the potential for application as biosensor to determine the concentration of biodegradable organics in water/wastewater samples.

Results: MFCs provided well-reproducible performance at high (> 2000 mg COD l-1-Chemical Oxygen Demand) acetate concentration values. Current in the cells proved to be steady from 25 to 35 °C, significant decrease was, however, revealed in the current below 20 °C. Direct calculation of non-toxic biodegradable substrate concentration in water/wastewater from the current in MFCs is possible only in the non-saturated substrate concentration range due to the Monod-like dependence of the current. This range was determined by a fitted and verified Monod-based kinetic model. Half saturation constant (KS) values were calculated at 30 °C applying different external resistance values (100 Ω, 600 Ω and 1000 Ω, respectively). In each case KS remained below 10 mg COD l-1.

Conclusions: Biosensors with this particular MFC design and operation are potentially applicable for detecting as low as 5 mg COD l-1 readily biodegradable substrates, and measuring the concentration of these substances up to ~ 50-70 mg COD l-1.

Keywords: Air cathode; Biodegradation kinetics; Biosensor; Microbial fuel cell.

MeSH terms

  • Air*
  • Biodegradable Plastics / analysis*
  • Bioelectric Energy Sources / microbiology*
  • Biosensing Techniques / methods*
  • Electricity*
  • Electrodes*
  • Organic Chemicals / analysis*
  • Peptones / analysis
  • Reproducibility of Results
  • Sodium Acetate / analysis
  • Temperature

Substances

  • Biodegradable Plastics
  • Organic Chemicals
  • Peptones
  • Sodium Acetate