1. In-situ fermentation coupling with partial-denitrification/anammox process for enhanced nitrogen removal in an integrated three-stage anoxic/oxic (A/O) biofilm reactor treating low COD/N real wastewater
- Author
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Shujun Zhang, Wenlong Liu, Shufeng Hao, Jun Li, and Bin Ma
- Subjects
Environmental Engineering ,Denitrification ,Nitrogen ,Population ,Bioengineering ,Wastewater ,Anaerobic Ammonia Oxidation ,chemistry.chemical_compound ,Bioreactors ,Ammonium Compounds ,Nitrite ,education ,Waste Management and Disposal ,Effluent ,education.field_of_study ,Sewage ,Renewable Energy, Sustainability and the Environment ,General Medicine ,Anoxic waters ,chemistry ,Anammox ,Biofilms ,Environmental chemistry ,Fermentation ,Oxidation-Reduction - Abstract
Mainstream partial-denitrification with anammox (PD-anammox) process faced the challenge of complex organics involved in real sewage. Herein, PD-anammox coupled with in-situ fermentation was successfully achieved in a full biofilm system formed by three-stage anoxic/oxic reactor to treat real wastewater with low COD/N of 3.6. The total nitrogen (TN) removal efficiency was enhanced to 78.4% ± 3.6% with average TN and ammonium concentrations in effluent of 10.6 and 0.5 mg N/L, respectively. Batch tests confirmed that partial-denitrification was the major nitrite provider for anammox in the anoxic biofilm, while in-situ fermentation could decompose the complex organics to readily-biodegradable organics for full- or partial-denitrification. Additionally, a significant anammox bacteria (Candidatus Brocadia) population was detected in the second (3.53%) and third (4.46%) anoxic zones, while denitrifiers and fermentative bacteria were mainly enriched in the first anoxic zone. This study presents a feasible approach for PD-anammox process in practical application under mainstream condition.
- Published
- 2022
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