Bioaugmentation of sidestream nitrifying-denitrifying phosphorus-accumulating granules in a low-SRT activated sludge system at low temperature

摘要: Sidestream granular activated sludge grown on anaerobic digester dewatering centrate was bioaugmented and selectively retained to enable high nitrification performance of a 2.5-day aerobic SRT non-nitrifying flocculent system at 12 °C. Sidestream-grown granules performed enhanced biological phosphorus removal (EBPR) short-cut nitrogen via nitrite. After bioaugmentation, EBPR continued in the mainstream but ammonia oxidation eventually nitrate. Low effluent NH3-N concentrations from 0.6 1.7 mg/L were achieved with solely by granules, thus enabling denitrification removal. Molecular microbial analyses flocs also suggested that nitrifying organisms persisted minimal nitrifier loss flocs. Mainstream granule mass end bioaugmentation testing 1.7 times amount sidestream added, indicating growth. Nitrite nitrate availability during unaerated feeding period encouraged significant growth ordinary heterotrophs nevertheless capacity sustained.