title: Immobilised activated sludge based biosensor for biochemical oxygen demand measurement.
abstract: A biochemical oxygen demand (BOD) sensor, based on an immobilised mixed culture of microorganisms in combination with a dissolved oxygen electrode, has been developed for the purpose of on-line monitoring of the biological treatment process for waste and wastewater. The sensor was designed for easy replacement of the biomembrane, thereby making it suitable for short-term use. The drawbacks of activated sludge based sensor, such as short sensor lifetime, were thereby circumvented. The sensor BOD measurements were carried out in the kinetic mode using a flow injection system, resulting in 25 s for one measurement followed by 4-8 min recovery time. Based on the results of normalised sensor responses, the OECD synthetic wastewater was considered to be a more suitable calibration solution in comparison with the GGA solution. Good agreement was achieved between the results of the sensor BOD measurement and those obtained from BOD5 analysis of a wastewater sample from a food-processing factory. Reproducibility of responses using one sensor was below +/- 5.6%, standard deviation. Reproducibility of responses using different sensors was within acceptable bias limits, viz. +/- 15% standard deviation.
authors.affiliation: Department of Biotechnology, Centre for Chemistry and Chemical Engineering, Lund University, Sweden.
authors.forename: J
authors.initials: J
authors.lastname: Liu
authors.forename: L
authors.initials: L
authors.lastname: Björnsson
authors.forename: B
authors.initials: B
authors.lastname: Mattiasson
mesh_terms: D015374:Biosensing Techniques; D002138:Calibration; D010100:Oxygen / Q000032:analysis*; D015203:Reproducibility of Results; D012722:Sewage
chemical_list: D012722:Sewage; D010100:Oxygen