Rapid Starting-up Of An Anammox Biofilm Reactor And Its Influencing

ANAMMOX has shown us a broad application prospects through its features of energy-saving and high-efficient. But the ANAMMOX bacteria were mesophilic bacteria, its features of long generation time, low cell yield, small volume, easy lost, and sensitive to the environment made it hard to enrich the microorganism and run the reactor in very short time which hinder the application of this technology.Therefore, the nonwovens were used as carriers in the paper to run the ANAMMOX in traditional anaerobic sequencing batch reactor, vaccinating the preserved ANAMMOX sludge which was filtered before, in order to study the regular pattern and feature of the starting of ANAMMOX in anaerobic membrane bioreactor, and the effect factors during the process to optimize the working condition and parameters. The major contents were as follows:1) The ASBBR studied in this paper can raise the N romoval rate from 0.05 kg N·m^-3·d^-1 to 2.06 kg N·m^-3·d^-1, keep the removal rate of NH₄⁺-N and NO2—N over 98%. The result of different substration concentration and filling ratio showed that the N removal ability was stable, the proportion of NH₄⁺-N and NO₂^--N removal to the NO₃^-N production was 1.00:1.30:0.25 It showed that the fabrics were good carriers of ANAMMOX, which were benificial to the improvement of the N removal ability of ANAMMOX.2) The result of increasing the influent substration concentration and shortening HRT of the ASBBR whose N removal rate had already reached 2.11 kg N·m^-3·d^-1 showed that, after running 60days, the N load of the former increased to 6.44kg N·m^-3·d^-1, and the N removal rate increased to 4.50 kg N·m^-3·d^-1. The N load of the latter increased 10.75 kg N·m^-3·d^-1 after 55days running, and the N removal rate increased to 7.50kg N·m^-3·d^-1. When they reached the same N removal rate, the NH₄⁺-N and NO₂^--N effluent concentration was much lower than that of the way increasin the influent substration concentration, which showed increasing substration concentration was a better way than shortening HRT.3) In the process of starting-up the ANAMMOX reactor, PH would increased sharply with the increasing of infulent substration concentration and N removal rate. PH didn't have great impact due to the higher filling ratio in SBR and the large range of pH concentration in a period. The substration refresh rate in continous flow reactor was low, FA and FNA would increased with the increasing of pH. It would lead the restriction of the activity of ANAMMOX bacterium which went against the ANAMMOX bacterium generation and the stability of N removal ability.4) The study of starting-up the reactor by high substration concentration and infulent with DO had also been done, according to the features of the biofilm of ANAMMOX reactor. The results showed that 130 mg·L^-1 of NO₂^--N didn't restrict the reaction of ANAMMOX due to the concentration gradient of biofilm. The increasing of N load would lead the increasing of PH, which was difficult to the increasing of N removal rate. When using the raw water whose DO hadn't been eliminated,after 100days'starting-up, the highest N removal rate reached 1.090 kg N·m^-3·d^-1,which showed that there would turn out to be DO concentration gradient after the form of biofilm which would offer a great environment for ANAMMOX reaction. Even the DO in the raw water hadn't been eliminated, it was still able to start up the reactor. Compared to the way of eliminatin DO, the increasing rate of N removal rate was lower. The further study of the degradation of reactor substration, the ANAMMOX reaction would slow down if DO in the raw water hadn't been eliminated.