Study of Chemical Oxygen Demand (COD) in Relation to Biochemical Oxygen Demand (BOD)

Abstract

This investigation has been conducted to Study Chemical Oxygen Demand (COD) in Relation to Biochemical Oxygen Demand (BOD).Three replicates samples were taken in Baghdad city from :1 - From the water upper part of Army Channel , 2 –Near Al-Talbaia Bridge on Army Channel , 3 - Anaerobic main holes effluent (Septic systems) near Vegetables Station in Gamelia City , 4 –From Dyalia river near Ristmaia , 5 - From the intersection between Tigris and Dyalia river southern Baghdad , 6 - From Tigris river Near Bab –Al –Matham Bridge , 7- From Tigris river Near Al – AL-Aiemah Bridge and 8 –Waste water from Ristmaia Station before treatment . Mean values of COD and BOD in the investigated locations show strong relation with high value of correlation coefficient (r = 0.9758 ) and describe by the equation :BOD= 6.1242 + 0.3142( COD ) + 0.0008 ( COD )² The above formula used to estimate BOD depending on COD . The COD test can be run in a couple of hours instead of five days to determine BOD .____________________________________________