On the Estimation of Biological Oxygen Demand of collected Water Samples with Special Reference to that of the Ganges Water

Polymer Science Unit, Department of Biological Chemistry, Indian Association for the Cultivation of science, Jadavpur, Calcutta-700 032 Manuscript received 30 November 1994, accepted 2 February 1995 A procedure for measuring BOD of collected water samples using a Karube type microbial BOD sensor is described. BOD of water samples collected from the Ganges at Calcutta, decreases on standing. This phenomenon has been attributed to consumption of the organic matter present in the collected sample due to microbial growth and cut-off the source of the organic matter from the sample. The water samples should therefore be sterilised at collection point so that BOD can be measured later on in test laboratories either by the 5-day BOD or by the 30-minute sensor method