BOD Test for Tropical Countries

Abstract

This paper presents results of a study undertaken to rationalize the incubation time and temperature in biochemical oxygen demand (BOD) tests with respect to higher ambient temperature conditions in tropical countries. The experimental protocol comprised two phases. In the first phase studies were concurrently conducted at the laboratories of the National Environmental Engineering Research Institute (NEERI) at Nagpur, Bombay, Hyderabad, Kanpur, and Madras to estimate progressive BOD values. They also estimated the reaction kinetics for each of the 110 sets of samples at 20, 25, 30, and 35°C with acclimated seed. In phase 2, further studies were carried out at 27°C incubation temperature in five NEERI laboratories, along with laboratories of Jadhavpur University, Central Pollution Control Board (CPCB), and pollution control boards from 10 Indian states. The protocol included 17 replicates of six pure chemicals, sewage samples from respective cities, wastewaters from six types of industries, and surface water samples. Statistical analyses of data reveals that the BOD5,20 is equivalent to the BOD3,27 irrespective of the composition of test sample.