Abstract: | Shortcut nitrification-denitrification, anaerobic ammonium oxidation (ANAMMOX), and methanogenesis have been successfully
coupled in an Expanded Granular Sludge Bed-Biological Aerated Filter (EGSB-BAF) integrated system. As fed different synthetic
wastewater with chemical oxygen demand (COD) of 300–1200 mg·L−1 and NH4+-N of 30–120 mg·L−1 at the outer recycle ratio of 200%, the influence of influent on ANAMMOX in the integrated system was investigated in this
paper. The experimental results showed that higher COD concentration caused an increase in denitrification and methanogenesis
but a decrease in ANAMMOX; however, when an influent with the low concentration of COD was used, the opposite changes could
be observed. Higher influent NH4+-N concentration favored ANAMMOX when the COD concentration of influent was fixed. Therefore, low COD =NH4+-N ratio would decrease competition for nitrite between ANAMMOX and denitrification, which was favorable for reducing the
negative effect of organic COD on ANAMMOX. The good performance of the integrated system indicated that the bacterial community
of denitrification, ANAMMOX, and methanogenesis could be dynamically maintained in the sludge of EGSB reactor for a certain
range of influent. |