Performance and sludge characteristics of anammox process at moderate and low temperatures

摘要

A sequencing batch reactor (SBR) was used to investigate the performance and sludge characteristics of anammox process at moderate and low temperatures. The initial pH was 7.5 and hydraulic retention time (HRT) was 3 h. When temperature was 25-35 A degrees C, nitrogen removal rate (NRR) fluctuated from 1.67 to 1.82 kg/m(3)center dot d. However, when temperature dropped to 15 A degrees C, NRR suddenly decreased by 0.48 kg/m(3)center dot d. Larger activation energy was acquired at lower temperature, and it was difficult to achieve efficient nitrogen removal under low temperature. When temperature declined to 10 A degrees C, Delta NO (2) (-) -N/Delta NH (4) (+) -N and Delta NO (3) (-) -N/Delta NH (4) (+) -N reached 1.02 and 0.27, respectively. Inhibition resulting from low temperature on anammox activity was recoverable, and the modified Boltzmann model was appropriate to analyze recovery feature of anammox process. Low temperature not only led to poor nitrogen removal, but also affected sludge size and feature.