SEQUENCING BATCH REACTOR - A TOOL FOR WASTE-WATER CHARACTERIZATION FOR THE IAWPRC MODEL

The use of a sequencing batch reactor (SBR) for wastewater characteriz ation requires the interpretation of the total respirometric response obtained in batch culture with primary settled water. In a first step and with the aim of understanding this total response, the water was d ivided by filtration into three fractions,the respirometric responses of which were analysed separately. This paper presents the results of the study of the biodegradability and of the specific respirometric re sponses of the soluble and colloidal fractions of an urban wastewater during batch cultures with a high concentration in preacclimatized act ivated sludges (low So/Xo ratio). For the water studied, the soluble f raction could be divided in two fractions of equal size : a readily bi odegradable fraction and an inert fraction Ultrafiltration of the solu ble fraction during the cultures allowed stating the specific evolutio n of the soluble organic compounds according to their Molecular Weight . For the colloidal fraction, the observed behaviour was totaly differ ent. Indeed, the colloidal organic matter disappeared very quickly fro m the Liquid phase according to a physical phenomenon but without any important biological oxidation during the first 5 hours of a batch cul ture. Latest work concerns the study of the particulate organic matter and the interpretation of the total respirometric response knowing th e specific response of the three fractions.