Concentrations and fate of sugars, proteins and lipids during domestic and agro-industrial aerobic treatment

摘要

This work investigates the composition and the fate of sugars, lipids, proteins, amino acids undernaerobic conditions for 13 domestic and 4 agro-industrial wastewaters, sampled before and afterntreatment. The rates of aerobic degradation were moreover studied with a 21-day continuousnaeration batch test. It is shown that the sum of the biochemical forms represented 50 to 85%nof the total chemical oxygen demand (COD). Lipids represented the half of the identified COD;nsugars and proteins correspond to a quarter of the identified COD. Aerobic processes providednan increase of the relative fractions for proteins, whereas the ones of lipids decreased and sugarsnfraction remains stable. For the wastewaters released from cheese dairy (lipid-rich) andnslaughterhouses (protein/lipid-rich), the dissolved phase after biological treatment is composednof proteins whereas the particulate one is composed of lipids. After the 21-day test, thenconcentration in proteins was nearby 10 mg/L. The results should be used for operations of WWTPnto detect when a dysfunction is about to occur. They can be used to predict the concentrationsnin the treated water when upgrading an existing municipal plant that will admit agro-industrialndischarge.