This study presented a method to upgrade existing aeration tanks to remove total nitrogen (TN). Bioplates carrying entrapped biomass were installed in an aeration basin to create anoxic/anaerobic zones where denitrification can proceed. In a reactor that coupled bioplates containing entrapped biomass (equivalent to as high as 7,500 mg/L of biomass) and an activated sludge suspension (at mixed liquor suspended solids of 1,300–2,400 mg/L), nitrification efficiency exceeded 95% for an influent wastewater containing 21–54 mg/L of NH3-N. In all cases amended with alkalinity and with or without added methanol as an electron source, TN removal was between 60 and 70%. The results demonstrated anoxic/oxic or anaerobic/anoxic/oxic processes could be incorporated in a conventional aeration basin, requiring no substantial modifications of the vessel and operation, and thus providing improved treatment in terms of nitrogen removal in the conventional suspended-growth process.
Improving total nitrogen removal in aeration basin retrofitted with entrapped biomass
Yeong-Nan Chao, Jui-Hsien Lin, Kok-Kwang Ng, Chung-Hsin Wu, Pui-Kwan Andy Hong, Cheng-Fang Lin; Improving total nitrogen removal in aeration basin retrofitted with entrapped biomass. Water Sci Technol 1 April 2014; 69 (7): 1558–1564. doi: https://doi.org/10.2166/wst.2014.053
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