The changes of nitrogen content during sewage treatment : A study of a two-stages wastewater treatment plant

The paper relates to the changes in the content of various nitrogen forms, i.e. total nitrogen (TN), Kjeldahl nitrogen (TKN), ammonium nitrogen (NH4-N), nitrite nitrogen (NO2-N), nitrate nitrogen (NO3-N) and organic nitrogen (ON) at the subsequent operation stages of a mechanical-biological wastewater treatment plant (WWTP). The obtained results indicate the correctness of nitrogen compounds transformations at the subsequent stages of sewage treatment; they are considered as typical for two-stages WWTPs, operating in the activated sludge technology. The analysis of multi-year data and the analysis for particular months show that nitrogen compounds in the form of NO3-N and NO2-N, were characterised by the greatest variability. Both the classical analysis of the nitrogen compounds content in each month of the year and the analysis using control cards prove that in the months characterised by a low temperature or by the impact of meltwater or rainwater, disturbances in the nitrification and denitrification processes can be expected, and thus, lower efficiency of nitrogen removal (winter months, the period between winter and spring, summer months). Knowledge on the transformation of nitrogen compounds at the subsequent stages of treatment can be useful both to improve the efficiency of the currently used processes and to model new solutions, which is particularly important in the case of biogenic compounds reduction.

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Opracowanie rekordu ze środków MNiSW, umowa nr POPUL/SP/0154/2024/02 w ramach programu "Społeczna odpowiedzialność nauki II" - moduł: Popularyzacja nauki (2025).