PERFORMANCE OF BOD SENSOR UNDER DIFFERENT ENVIRONMENTAL-CONDITIONS

Microbe coupled amperometric biosensor for the estimation of biochemical oxygen demand (BOD) has been developed. The working range of the sensor is 3-60 ppm and the life period of the immobilized biocatalyst is-over 45 days. The sensor performs well in the pH range of 6.0 to 8.0, temperature range 298-308k and salinity range to up 1.5% for longer durations. Further, the sensor is found to work satisfactorily for a short duration (30 -60m) even in the DH range of 5.0 or 9.0 and temperature of 283 or 313k and salinity of 2.5%. Presence of heavy metals, viz., Cu2+, Sr2+, Pb-2+,Pb- Ni2+, Cd2+, Cr2+ over 5 ppm, Hg over 2 ppm as well as 30 ppm of nutrient metal ions viz., Fe2+, Zn2+ and Mg (2+) in the analyte does not influence the sensor performance considerably.