[Simultaneous chracterization of RBCOD and SBCOD in wastewater by hybrid respirometer]

Respirometry was made using wastewater and activated sludge from a WWTP of Chongqing through self-developed hybrid respirometer. And complete oxygen uptake rate (OUR) curves containing OUR of biodegradation process of RBCOD and SBCOD and endogenous process were obtained. A new method based on respirometry was proposed to characterize RBCOD and SBCOD in wastewater simultaneously, in which hydrolysis model was selected to analyze OUR curves of SBCOD according to the two-phases nature of exogenous OUR and trend-test method for endogens OUR. Compared with the traditional OUR-stages method, the new method reduces the man-made error and improves the accuracy of wastewater COD fractions characterization.