Start-up And Operating Performance Of Anammox Granular Sludge

The granulation process and operation performance of anaerobic ammonium oxidation microorganism in a reactor seeding with anaerobic granular sludge was investigated. The reactor had an inner diameter of 70 mm with a working volume of 9 L. The bioreactor was fed with artificial wastewater which composed of ammonium and nitrite. Results showed that ANAMMOX process was achieved successfully with nitrogen removal rate up to 0.18 Kg/(m~3.d) under nitrogen loading rate of 0.23 Kg/(m~3.d) after 100 day's operation. Furthermore, the color of seed sludge turned from black to brown, yellow and finally red. On the basis of ANAMMOX being started-up , the nitrogen loading rate further increased from 0.46 Kg/(m~3.d) to 1.39 Kg/(m~3.d) during 100th to 240th day, and the highest nitrogen removal rate reached 1.22 Kg/(m~3.d). Sludge was floated and the ef?uent ammonium and nitrite concentrations were gradually increased to 42.14 mg L-1 and 46.60 mg L-1 ,respectively.The extracellular polymers incresde from 82.75 mg·(g VSS)-1to 192.12 mg·(g VSS)-1 with the increase remove rate of influent nitrogen.The collection of ?oating granules, breaking them into small pieces and then returning to the anammox reactor proved an effective method for preventing sludge washout, and the removed nitrogen loading rate finally reached 1.22 kg N m-3 d-1 .Influence of pH ,IC,organic substance,mmonium and nitrite concentrations on ANAMMOX activity was investigate after the ANAMMOX being started-up.Results indicated that the biological activity reached maximum of 1.439mmol/(gVS.d) when the optimal pH was about 7.5.The theoretical pH value was 7.483; The optimal concentration of IC was 60 mg/L. There was substrata competition between the heterotrophic denitrification bacteria and ANAMMOX bacteria when organics existing in the influent. The relationship between anaerobic ammonia oxidation rate and the ef?uent ammonium and nitrite concentrations could be described by Haldane mode and both were showed inhibited type curves.Combination of a nitritation process and ANAMMOX process for treating of landfill leachate was evaluated. The anmonia and nitrite removal efficiency was stable at 90% and 96% rseperately.The maximum COD removal efficiency was 89%. Therefore it was feasible to treat landfill leachate through Nitrosation-Anaerobic Ammoxidation Process. Low nitrogen removal efficiency for the treatment of low concentration landfll leachate was caused mainly by pH variation.Nitorgen removal efficiency could be increased by regulating pH.