Biochemical Oxygen Demand and Carbonaceous Oxygen Demand of the Covenant University Sewage Oxidation Pond

Biochemical Oxygen Demand (BOD) is a measure of the dissolved oxygen consumed by microorganisms during the oxidation of reduced substances in waters and wastewaters. It is often used ambiguously in relation to Carbonaceous Oxygen Demand (CBOD) which is the oxygen consumed during the oxidation of carbonaceous compounds to carbon dioxide (CO2) and other oxidized end product. BOD is actually the sum of CBOD and NBOD where NBOD is the Nitrogenous Oxygen Demand which is the oxygen consumed during the oxidation of nitrogenous compounds (mainly NH3) to nitrates with nitrites being an unstable intermediate. The major difference between CBOD and NBOD is that there are two classes of bacteria believed to be responsible for the oxidation of reduced nitrogen. The BOD5 value of Sewage samples collected from Covenant University oxidation pond was therefore measured and the samples examined for the presence of Escherichia coli. The sewage samples collected from four points (starting point (A), two middle points (B, C), and end point (D) were inoculated on an Eosin Methylene Blue agar plates and the presence of E. coli was confirmed by the appearance of greenish metallic sheen colonies on the agar plates and biochemical Tests. The BOD of the effluent at the different points (A, B, C, D) respectively showed a reduction in microbial load. The ultimate CBOD was also estimated based on the BOD5 value which is based upon the exponential (first-order) nature of oxygen demand. This research describes the formulations of CBOD breakdown using simplified oxidation kinetics