Decay Experiments of Effective N-Removing Microbial Communities in Sequencing Batch Reactors

Abstract

The temporal changes in the compositions of effective N-removing bacterial communities and the decay coefficients of Anammox were studied within the 120-day decay period under anaerobic or aerobic conditions at 25 ∘ C. The maximum nitrogen production rate (MNPR) was determined by measuring the temperature, pH, volatile suspended solids (VSSs), and nitrogen-removal efficiency of the microbial communities during the decay period. The decay coefficients under anaerobic and aerobic conditions at 25 ∘ C were determined through equation-based fitting to be 0.031 d −1 and 0.070 d −1 , respectively. Through molecular biological means and together with quantitative polymerase chain reaction (qPCR), the proportions of AnAOB in the microbial communities dropped from 48.70% to 3.69% under anaerobic condition and from 48.70% to 1.98% under aerobic condition during the decay period.