[Start-up Performance of ANAMMOX Enrichment with Different Inoculated Sludge in Anaerobic Baffled Reactor].

Two anaerobic baffled reactors (ABR) were compared for anaerobic ammonium oxidation (ANAMMOX) enrichment using synthetic wastewater with different inoculated sludge, the mixed anaerobic flocculent sludge/granular sludge (R1) and anaerobic activated sludge (R2). The research showed the ANAMMOX activity occurred in both reactors allowing continuous removal of ammonium and nitrite, in which the ammonia and nitrite nitrogen loading was about 54.5-68.0 g (m3 x d)(-1), when maintaining the temperature at 30-35 degrees C, pH at 7.5 +/- 0.5 and HRT at 26 h. However, the ANAMMOX reaction was successfully started after 120 d and 125 d, respectively. The removal rules of the two reactors were basically similar, and the enrichment processes occurred in both reactors could be divided into 4 phases, which were sluggish phase, expressive phase, enhanced phase and steady phase. In the steady phase, the average removal rates of NH4+ -N, NO2- -N were higher than 90%, and the average removal load achieved 57.3-67.9 g x (m3 x d)(-1). Moreover, the ammonium removal load in R1 was slightly higher than that in R2. Additionally, more than 90% of nitrogen was dramatically removed in the first compartment of ABR. Meanwhile, the color of sludge gradually changed from brown, litter bed brown to black along with the flow direction, which was similar to the removal rule of nitrogen. In a word, the results showed the different inoculated sludge did not cause obvious differences in the starting rule and the removal characteristics of ANAMMOX reactor.