COD and BOD correlation of organic compounds of known structure in water

Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) are the major parameters used for measuring the load of organic carbon into aquatic environment. In this context, this work deals with evaluation of correlation between COD and BOD values of water systems containing organic compounds of known structure. Water systems contained oxalic and benzoic acids. BOD parameter was obtained using instrumental technique with OxiTop® IS 6, Value of COD parameter depends on Mw and number C atoms within organic compound. Increase number of C atoms elevate value of COD parameter. Substances with the same or similar number of C atoms have different values of COD parameter if they have different Mw. There is linear correlation between COD and BOD for organic substances with simple structure. Obtained data for COD comprise 80% of BOD value. The significance of obtained data is that using this correlation of parameters, fast and rough estimation of organic matter content in water could be made. .