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Updated: Mar 27, 2026

A Novel Bioreactor for High Density Cultivation of Diverse Microbial Communities
Published on: December 25, 2015
Comparison and Optimization of Intermittent Aeration/Interval Aeration for Enhancing Nitrogen Removal in Continuous
Ruochen Hu1, Zeming An1, Yuanqi Gu1
1National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China.
Abstract:
The anaerobic/oxic/anoxic (AOA) process is superior for advanced nitrogen removal; however, loss of carbon source in the aerobic zone is unavoidable. In order to utilise the organic carbon in raw wastewater more effectively, a comparative study was conducted using real domestic wastewater under three aeration modes in the aerobic zone: continuous, intermittent and interval. The results showed that continuous aeration resulted in a significant loss of both internal and external carbon sources. Intermittent aeration improved external carbon utilization. The optimal configuration was found to be an anaerobic/oxic/anoxic functional volume ratio of 1:4:3 with an aeration/rest ratio of 20 min:20 min. This resulted in a total inorganic nitrogen (TIN) removal efficiency of 77.6%. Nevertheless, repeated on/off aeration cycles within the same zone led to dissolved oxygen accumulation and accelerated depletion of internally stored carbon. In contrast, interval aeration minimises residual dissolved oxygen carryover into the anoxic phase. This better preserves internal carbon sources while maintaining efficient utilisation of external carbon. This mechanistic advantage enabled interval aeration to achieve a TIN removal efficiency of 77.9%, demonstrating clear operational and metabolic benefits over continuous and intermittent aeration modes. In conclusion, this study provides valuable insights and reference data for optimising aeration strategies in AOA systems, contributing to enhanced nitrogen removal from wastewater and more rational utilisation of resources.
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