Assessment of an Oxidation Ditch's Performance via COD and Nitrogen Fractionation Analysis

Abstract

The rapid population growth in the southern part of Quito, driven by the pursuit of material prosperity, has increased the production of wastewater, leading to discharges into water bodies and impacting water quality. In this context, characterizing wastewater is crucial for reliable operational decisions. This research evaluates the Quitumbe Wastewater Treatment Plant's bioreactor in relation to the fractionation of COD and nitrogen, considering the sludge age as a controlled variable. Wastewater samples were collected in March at the inlet and outlet points of the bioreactor, and a physicochemical method was used for COD fractionation. The results indicate a predominance of slowly biodegradable COD (XS) and removal rates of 95% for biodegradable COD and 93% for ammonia nitrogen, demonstrating biodegradation capacity. Incomplete nitrification was confirmed, along with a cellular retention time of 20 days. This study provides a solid foundation for improving the operational management of the Quitumbe Wastewater Treatment Plant.