The Characteristics And Domestication Of Short-cut Nitrification Sludge At Normal Temperatures

As the nitrogen pollution in waters becoming increasingly serious，and thenitrogen index becoming increasingly strict, short-cut biological nitrogen removal isregarded for its advantages，such as saving energy and carbon resource，reducing theamount of sludge-discharging and shortening hydraulic residence time，and etc.The efficiently and steadily shout-cut nitrification was difficult to carry out,which is significant to the combined SHARON （Single Reactor High ActivityAmmonia Removal Over Nitrite）-ANAMMOX（Anaerobic Ammonium Oxidation）process. Now the research using of the difference between the ammonia-oxidizingbacteria （AOB） and the nitrite-oxidizing bacteria （NOB） in physiological functionshas already studied out the best control strategy, such as low oxygen （DO）, hightemperature and rich free amino nitrogen. But these control strategies will descreasethe biomass, the ammonia removal efficiency and the nitrite accumulation ratio. Itrusults in the actual enginerring of shout-cut nitrification process rarely succeed. Tosolve these problems, the research use the ways of sludge addtion and elutriation. Inorder to achieve the efficiently and steadily shout-cut nitrification the characteristicsof sludge also has been studied.Through real-time aeration duration control, short-cut nitrification process wascarried out in a lab-scale SBR for150days, at normal temperatures （15³0℃）, fedwith synthetic wastewater. This experiment is completed via three steps, thestarting-up partial nitrification stage, the enhancing the sludge capabity stage and thesteady operation stage. The SBR operated8hours a cycle with aerated (5h,DO:1.2¹.4mg·L^-1) and non-aerated （3h） periods. And the in fluent loading rate（NH₄⁺-N） could reach0.24kg/（m³·d）. The ammonia removal efficiency and the nitriteaccumulation ratio separately kept over80%and90%. It also solves the problem oflow sludge concentration and non-steady-state conditions by sludge addition andelutriation. Besides, by analyzing of the extracellular polymeric substances indicatethat the contribution in settleability by TB content appeared to be more significantthan that by LB. Meanwhile, the sludge was analyzed by zeta potential and othermeans. The results show that sludge after culture has better settling velocity than seedsludge. It indicates that the short-cut nitrification process is efficient and perfectlystable by the domesticated sludge. To summarize, by domestication of sludge and the characteristics of sludge the efficiently and steadily shout-cut nitrification has beencarried out.