Correlation between BOD5 and COD – biodegradability indicator of wastewater

Biochemical Oxygen Demand (BOD5) and Chemical (COD) are the most commonly parameters for characterization of organic matter content water. Correlation between BOD5 COD different types water can provide relevant information about nature pollution, its level biodegradability. This correlation could also be used to assess quality effluent after treatment processes, improve performance wastewater plants (WWTPs) and/or monitor river into which discharged. The objective this study was degree biodegradability (influents effluents 3 important municipal WWTPs Romania, untreated discharged by economic units from Bucharest; 5 hospitals surface - natural receptors plants), based on ratios BOD5/COD. BOD5/COD ratio (also called Biodegradability Index) varied depending type investigated should periodically rechecked due variations in climatic conditions, industrial receptors, supply characteristics, availability. Index enable evaluation pollution wastewater, providing possibility estimation regarding biological treatability influent WWTP.