Chemical oxygen demand (COD) is a measure of the ability of chemical reactions to oxidise matter in aqueous system. The results are expressed in terms of oxygen so that they can be compared directly to the results of biochemical oxygen demand (BOD) testing. The test is performed by adding the oxidising solution to a sample, [...]
The BOD test is an indirect measure of the biodegradable organic matter in an aqueous sample. The test is indirect because oxygen used by microbes as they degrade organic matter is measured. Generally the test is performed over a 5 day period (BOD5) of 20°C in 300 ml bottles incubated in the dark to prevent [...]
Ecology means the study of living organisms in relation to their environment. The world has been derived from the Greek word Oikos. On the way of cultural evolution man has created an environment of his own. Industries are built, Green Revolution is geared and natural balance is disturbed, as a result he himself has become [...]
Dr. Amlan Kumar Mitra, Biology Guide Since 2009
