Achieving Advanced Nitrogen Removal for Small Flow Wastewater using a Baffled Bioreactor (BBR) with Intermittent Aeration


Nitrogen discharge from decentralized and onsite wastewater treatment systems, such as recirculating sand filters, stabilization ponds, and septic tanks, is an important source of groundwater and surface water contamination. This study demonstrated a simple baffled bioreactor (BBR) technology, operated with an intermittent aeration mode, that effectively removed nearly all nitrogen for small flow wastewater treatment. The BBR is characterized by an aeration zone, followed by an integrated internal settler, which automatically retains a high biomass concentration of approximately 6 g/L without using a separate sludge return device. Long-term testing results indicated that this process had reduced the chemical oxygen demand and total nitrogen concentration to approximately 20 mg/L and less than 3 mg-N/L, respectively, under an operational temperature of 7.1 °C to 24.7 °C. The average effluent ammonia and nitrate concentrations were 0.75 and 0.61 mg-N/L, respectively, indicating that both nitrification and denitrification had been completed. In addition to nitrogen removal, this BBR had removed approximately 65% of the total phosphorus.


Civil, Architectural and Environmental Engineering


This research was funded by the Water Resource Science and Technology Innovation Program of Guangdong Province (201628), the Chinese National Natural Science Foundation (51608230), the Fundamental Research Funds for the Central Universities (21616335) and the Research Fund Program of Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology (2016K0001).

Keywords and Phrases

Ammonia; Nitrate; Nitrogen; Phosphorus; Aeration; Biomass; Bioreactor; Chemical oxygen demand; Concentration (composition); Denitrification; Discharge; Groundwater; Nitrogen; Phosphorus; Surface water; Temperature effect; Wastewater treatment; Article; Baffled bioreactor; Biomass; Bioreactor; Chemical oxygen demand; Constructed Wetland; Denitrification; Effluent; Nitrification; Nitrogen concentration; Sludge; Waste water; Waste water management; Sewage; Water management; Bioreactors; Waste Disposal; Fluid; Waste Water; Water Purification; Intermittent aeration; Nitrogen removal; Small-flow wastewater treatment

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Article - Journal

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Publication Date

01 Sep 2017

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