Evaluation of organic load measurement techniques in a sewage and waste stabilisation pond

Abstract

Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) are the major parameters used as routine surrogate tests for measuring the load of organic carbon into the environment. In this context, an evaluation of possible replacement of BOD and COD for Dissolved Organic Carbon (DOC) measurements are presented for different wastewaters. For anaerobic pond effluent, the following correlations were obtained: COD = 1.08 DOC + 79 and BOD = 0.82 DOC + 12. For facultative pond effluent, COD = -0.29DOC + 109 and BOD = 0.14DOC + 26. For raw sewage COD = 4.18DOC - 2 and BOD = 0.46COD + 5. For aerated pond effluent COD = 3.57DOC + 6 and BOD = 0.27COD + 3. For sedimentation pond effluent, COD = -1.34DOC + 138 and BOD = 0.73DOC + 16.5. Determination of COD was not appropriate for substituting classical alternatives in tested samples in despite of the limitations of the samples.