Biological Oxygen Demand (BOD) is a measure of the quantity of oxygen used by microorganisms (e.g., aerobic bacteria) in the oxidation of organic matter. Determining the BOD of the water body help in suggesting the quality of the water body. Presence of more organic waste increases the biological activity which uses up a large amount of oxygen and thus results in deficiency of oxygen. Thus the oxygen demand of the water body increases, high BOD value indicates that the water body has more organic wastes and microbial activity, indicating that the water body is polluted and it is poor in quality.
