TY - JOUR N2 - In this study, the dependence between volumetric exchange rate (n) in an SBR (Sequencing Batch Reactor) with a modified cycle and simultaneous nitrification and denitrification (SND) efficiency during the treatment of anaerobic sludge digester supernatant was determined. In the SBR cycle alternating three aeration phases (with limited dissolved oxygen (DO) concentration up to 0.7 mg O2/L) and two mixing phases were applied. The lengths of each aeration and mixing phases were 4 and 5.5 h, respectively. Independently of n, a total removal of ammonium was achieved. However, at n = 0.1 d-1 and n = 0.3 d-1 nitrates were the main product of nitrification, while at n = 0.5 d-1, both nitrates and nitrites occurred in the effluent. Under these operational conditions, despite low COD/N (ca. 4) ratio in the influent, denitrification in activated sludge was observed. A higher denitrification efficiency at n = 0.5 d-1 (51.3%) than at n = 0.1 d-1 (7.8%) indicated that n was a crucial factor influencing SND via nitrite and nitrate in the SBR with a low oxygen concentration in aeration phases. L1 - http://journals.pan.pl/Content/85807/PDF/10265-Volume39-Issue1-paper_08.pdf L2 - http://journals.pan.pl/Content/85807 PY - 2013 IS - No 1 DO - 10.2478/aep-2013-0008 KW - Anaerobic sludge digester supernatant KW - SBR KW - simultaneous nitrification and denitrification (SND) A1 - Bernat, Katarzyna PB - Polish Academy of Sciences VL - vol. 39 DA - 2013 T1 - Simultaneous Nitrification and Denitrification in an SBR with a Modified Cycle During Reject Water Treatment UR - http://journals.pan.pl/dlibra/publication/edition/85807 T2 - Archives of Environmental Protection ER -