https://doi.org/10.15255/KUI.2022.034
Published: Kem. Ind. 72 (1-2) (2023) 25–32
Paper reference number: KUI-34/2022
Paper type: Original scientific paper
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Nitrogen Removal with Aerobic Granules – Effect of Dissolved Oxygen and Carbon/Nitrogen Ratio

M. Galant, D. Grgas, T. Štefanac, M. Habuda-Stanić and T. Landeka Dragičević

Abstract

Nitrogen removal efficiency related to the dissolved oxygen (DO) concentration (DO 1–7 mg l^–1), carbon/nitrogen ratio (COD/N 1–14), and the effect of airflow (0.4–2.9 l min^–1) related to the granule size were investigated. The average chemical oxygen demand (COD) removal of ≥ 90 % was achieved at COD/N ≥ 11, but the satisfactory N values in effluent for discharge into the surface waters were almost achieved at COD/N 14. DO of 2 mg l^–1 is recommended for efficient removal of N and COD with mature granules. The size (diameter) of the granules decreases with increased airflow.

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Keywords

aerobic granules, COD removal, N removal, sodium acetate, synthetic wastewater