Original scientific paper

https://doi.org/10.15255/KUI.2024.057

Nitrogen and Phosphorus Removal from Low Carbon/Nitrogen Wastewater in an Anaerobic/Oxic/Anoxic Process with Endogenous Denitrification at Different DO Concentrations

Tea Štefanac ; University of Zagreb, Faculty of Food Technology and Biotechnology, Pierottijeva 6, 10 000 Zagreb, Croatia
Dijana Grgas ; University of Zagreb, Faculty of Food Technology and Biotechnology, Pierottijeva 6, 10 000 Zagreb, Croatia *
Irena Landeka Jurčević ; University of Zagreb, Faculty of Food Technology and Biotechnology, Pierottijeva 6, 10 000 Zagreb, Croatia
Sanja Radman ; University of Split, Faculty of Chemistry and Technology, Ruđera Boškovića 35, 21 000 Split, Croatia
Mirna Habuda-Stanić ; Josip Juraj Strossmayer University of Osijek, Faculty of Food Technology Osijek, Franje Kuhača 18, 31 000 Osijek, Croatia
Tibela Landeka Dragičević ; University of Zagreb, Faculty of Food Technology and Biotechnology, Pierottijeva 6, 10 000 Zagreb, Croatia

* Corresponding author.

Abstract

The effect of selected dissolved oxygen (DO) concentrations (DO ≥ 2 mg l−1 and DO ≈ 1 mg l−1) on nitrogen (N) and phosphorus (P) removal was investigated in the treatment of wastewater with a low C/N ratio using an anaerobic/oxic/anoxic (A/O/A) process with endogenous denitrification. The selected DO significantly influenced the efficiency and rate of N removal. The N loss of 43 and 71 %, due to simultaneous nitrification and denitrification in the oxic phase of the A/O/A process, were observed at ≥ 2 mg DO l−1 and ≈ 1 mg DO l−1, respectively. The NH₄-N removal rate of 11.2 mg NH₄-N lh−1 and the PO₄-P uptake rate of 9 mg PO₄-P lh−1, and NH₄-N removal rate of 9.4 mg NH₄-N lh−1 and PO₄-P uptake rate of 9.4 mg PO₄-P lh−1 at ≥ 2 mg DO l−1 and ≈ 1 mg DO l−1, were determined. P removal of 78.5 % and N removal of 76.6 % (in the A/O/A process at DO ≥ 2 mg l−1), and P removal of 77.9 % and N removal of 95.3 % (in the A/O/A process at DO ≈ 1 mg l−1) were achieved.

Keywords

nitrification; denitrification; phosphorus removal; endogenous denitrification; dissolved oxygen; wastewater with low C/N ratio

Hrčak ID:

331180

URI

https://hrcak.srce.hr/331180

Publication date:

17.7.2025.

Article data in other languages: croatian

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