Study On Rapid Granulation And Stability Of Aerobic Granular Sludge At Low Temperature

Aerobic granular sludge formed as a unique microbial biofilm from flocculation, which has characteristics of the compact structure, the rules of appearance, the rich internal microbial species. many people have taked widespread attention to it in recent years.However, aerobic granular sludge reactor startup and stable operation is still the key issues constraining its engineering applications. Because microbial activity is inhibited at low temperature, so startup and operation of the reactor is more prominent. It is great significance for the development of its theory and engineering applications to the low-temperature startup and stable operation of aerobic granular sludge. In this paper,the formation process, the removal efficiency for pollutants and operating stability of aerobic granules were investigated, which formed in the SBARs under the same conditions, using three different training methods.Investigation showed that adding Ca2+(R1), bone glue(R3) or some aerobic granular sludge and activated sludge mixture (R2) which all can be cultivated aerobic granular sludge at low temperature (10℃±1) . but, the required time for R3 training is to be shorter than the others, at least to shorten more than 10d. The average particle size and wet sludge density of the aerobic granular sludge in the R1,R2,R3 was 1.8mm, 1.032g/ml; 2.5mm, 1.022g/ml; 2.0mm, 1.03g/ml respectively. They have a strong handle on the effects of pollutants, COD removal rate is above 90%; the ammonia nitrogen removal efficiency of R2, R3 is above 95%, higher than R1, similarly, TP of R2, R3 also higher than the R1, were 70% and 75%. This indicates that the aerobic granular sludge is to have good at physical and chemical properties of particles and sludge treatment capacity in R3. It is important for low-temperature rapid culture method of aerobic granular sludge. Monitoring the control parameters such as DO, pH, ORP are to clearly understand the sludge of the environment and biological activity, in order to further provide the basis for explaining the removal of nitrogen and phosphorus.It has greatly destructive on aerobic granular sludge by adding ammonia nitrogen concentration in influent water, filamentous bacteria multiply on the granular sludge surface, and the structure of granular sludge is loosed. removal efficiency of nitrogen and phosphorous is very poor, Ammonia nitrogen removal rate decreased from 95% to 50% and total phosphorus from 90% to 60%. Reducing the dissolved oxygen concentration can increase the total nitrogen removal efficiency in theory, however, the result of the removal of COD and total nitrogen have not been affected, the total phosphorus removal has greatly been inhibited, and the structure stability of aerobic granular sludge is hazarded. So maintaining the concentration of dissolved oxygen in water is beneficial to the stability of aerobic granular sludge and the treatment effect.