The Research Of Start-up Of ASBBBR Anammox Process Ond Microbial Community Structure

Abstract: Anaerobic ammonia oxidation (Anammox) is an economical and efficientbiological nitrogen removal technology. For the features of high nitrogen removalefficiency, low sludge production, needing no dissolved oxygen and additional organiccarbon source, etc., Anammox has got extensive attention among research communities.With the further study of Anammox, Anammox process has been developed rapidly.While the growth cycle of anaerobic ammonium oxidation bacteria is long and thebacteria requires rigorous reaction conditons, ammonium oxidation activated sludge israre, as well as the long start-up time make the technology seldom applying in practice.To solve series of problems, this study investigated the starting process of ASSBRAnammox process; the influence of two kinds of inoculated sludge on the start-up ofASBR Anammox reactor; the influence of reaction conditions on the nitrogen removalperformance of the reactor and the microbial diversity within the system at differenttimes.This study can support the applying of Anammox technology in practice, revealthe succession process of microbial communities within the reactor and has importantsignificance in the development of using this technology to remove ammonia in wastewater. The main results are as follows:Sludge which from aerobic biofilm reactor tank or anaerobic denitrification tankcan both start up anammox reactor successfully, while the reactor inoculated the aerobicsludge had a less start-up time. After4months running, the max TN volume loading andammonia volume loading of the reactor inoculated the aerobic sludge was1.074kg·m-3d-1and0.576kg·m-3d-1respectively, higher than the reactor inoculatedthe denitrification sludge in which the values were0.863kg·m-3d-1and0.453kg·m-3d-1respectively.Forming the characteristic structure of anaerobic ammonium oxidationbacteria—cauliflower—needs only three months in the reactor inoculated the aerobicsludge, which is shorter than the reactor inoculated anaerobic denitrification sludge toform a similar structure.Controlling influent NH4+-N and NO2--N concentration to be85mg/L and90mg/L respectively and pH at7.6~8.0, to investigate the nitrogen removalperformance of ASBBR reactor at three different temperatures. Results indicated thatwhen temperature was35±1℃the reactor got the best nitrogen removalperformance. While controlling influent NH4+-N and NO2--N concentration to be 85mg/L and90mg/L respectively and temperature at32±1℃, to investigate thenitrogen removal performance of ASBBR reactor at three different pH ranges. Resultsindicated that when pH range was7.6~8.0the reactor got the best nitrogen removalperformance. Increasing the influent NH4+-N and NO2--N concentration both from120mg/L to be200mg/L when pH was7.6~8.0and temperature was32±1℃toinvestigate the performance of the reactor. Results indicated that the influentNH4+-N concentration had a weak inhibition on the nitrogen removal performancewhile the nitrogen removal performance would be influenced and the the activity offlora would be inhibited when the influent NO2--N concentration have exceeded150mg/L.UPGMA cluster analysis indicated that the microorganisms in the same stageof R1reactor and R2reactor were classified to one category and microorganismsin the later stage of them were classified to another; the homology ofmicroorganisms in the later stage within the two reactors was high, among themthe homology reached92%.Shannon-wiener variation trends indicated that typesand quantity of microorganism in R1and R2both had a tendency of declining andthen rising after ASBBR anaerobic ammonia oxidation reactor start up. Themicroorganisms species of reduction in R2is higher than R1.Simpson index betweeneach sample was almost the same indicated that no outstanding domaint speciesexisting in the samples and each species was well distributed. The sequencingresults showed that Pseudomonas mendocina, Alcaligenes latus were the domaintspecies in R1and R2respectively, while Ammonium-oxidizing bactetium andAnaerobic ammonium-oxidizinng planctomycete became the domaint species ofASSBR after the successful start-up.