New Dilution Technique for BOD Estimation in Brackish and Sea Waters

Abstract

Biochemical oxygen demand (BOD) of estuarine and coastal waters was studied by employing techniques like incubating the samples as such (direct method), dilution with buffer, APHA (American Public Health Association) dilution technique, distilled water dilution and synthetic seawater dilution. Rate and extent of oxidation of organic matter were calculated for each method. Relatively higher rate (1.44 mg.l-1) and extent of oxidation (14.439 mg.l-1) were found in the case of synthetic sea water dilution technique. The most reliable method of analysing BOD in estuarine and coastal waters would be the dilution of the sample with synthetic sea water of same salinity. The increased rate and extent of oxidation due to dilution were tested by studying the effect of dilution on BOD through an assessment of bacterial population.