Different calibration methods of a microbial BOD sensor for analysis of municipal wastewaters

On the base of diffusion limited amperometric oxygen sensor (the Clark-type oxygen sensor) a microbial BOD sensor was constructed and the dependence of output signal of device on wastewater biochemical oxygen demand (BOD) was studied. Calibration of BOD sensor was performed in steady-state and dynamic regime of measurements in OECD synthetic wastewater solutions. Results showed broader detection area (up to 230 mg BOD7 L−1) as well as shorter response and regeneration times in dynamic regime of analysis of output signal. The data acquired by steady-state method showed better repeatability, especially in the estimation of BOD7 of real wastewaters. After calibration the BOD sensor was used for quick BOD estimations of municipal wastewaters.