Nitrogen removal in an oxidation ditch

The aim of this study is to obtain a good description of nitrogen removal in a full scale oxidation ditch of 1300 m³ for later optimization. Different Data are collected and exploitation chart of this WWTP are used to analyze the working conditions. An intensive measuring campaign was investigated to describe the dynamic behavior. Different concentrations of nitrogen component are measured in the inlet and outlet of WWTP with a step sampling of an hour during 8 hours of working. In the same time and with the same frequency, soluble COD is measured at inlet and outlet. To observe gradient concentrations in the ditch, 10 samples were done at various point of the ditch. Ammonia, nitrate, nitrite and dissolved oxygen are measured. ASM1 model is used to describe biological removal of organic and nitrogen removal. Data collection is necessary, for parameter implementation in the model for simulating oxidation ditch working and for calibration and validation of this model. Inert soluble Si and soluble fraction of influent COD was calculated from data collected. Soluble COD is about 35% of total COD and Si was quantified to 29% of soluble COD.