[Start-Up and Regional Characteristics of a Pilot-scale Integrated PN-ANAMMOX Reactor]

The start-up and regional characteristics of a pilot scale integrated PN-ANAMMOX reactor was studied. The results show that inoculated nitrosation suspension filler in the anaerobic zone, ANAMMOX sludge, and common anaerobic sludge in the anaerobic zone can start the reactor quickly. The PN-ANAMMOX reactor was successfully started at 74 days. The removal rate of total nitrogen increased from 0.02 kg·(m³·d)^-1 to 0.48 kg·(m³·d)^-1. The analysis of the nitrogen conversion characteristics in two regions showed that the AOB had been in a dominant position in the aerobic zone, and the NOB was inhibited by DO and the matrix, NPR_a increased from 0.22 kg·(m³·d)^-1 to 0.58 kg·(m³·d)^-1, and NAP_a could reach 95% with the increase in anaerobic denitrification capacity. The anaerobic zone was a critical region of the integrated PN-ANAMMOX reactor, and NRR_ana increased from 0.02 kg·(m³·d)^-1 to 4.7 kg·(m³·d)^-1. During the start-up period (temperature decreased from 32℃ to 27℃), the changes first affected the anaerobic zone, NRR_ana decreased to 3.7 kg·(m³·d)^-1 (about 21%), with little effect on the aerobic zone. The two regions can achieve a large ANAMMOX bacteria enrichment, as, during this time, the aerobic zone also has a certain denitrification capacity, while the anaerobic zone featured enhanced denitrification.