Different Operating Conditions’ Influence On Pollutant-removing Efficiency And Characteristics Of The Aerobic Granular Sludge.

Microorganism in the activated sludge have the adaptive-phase and the log-phase and the stable phase during the whole microbial growth.Adding coagulant(PAC) to the Sequencing Batch Reactor(SBR) during the adaptive-phase and the log-phase of the microbial growth respectively,and the other condition was SBR with no coagulant which become a contrasted one,so these constitute three different operating conditions for training aerobic particle sludge and studied the three kinds of particle sludge on growing process, properties,and the pollutant-removing efficiency.The results shows that:(1) Adding coagulant during the adaptive-phase(0~7d) of the microbial growth,whose particle sludge become ripe use 28 days, when it was the 14 th day, littel particle got taking the shape.Adding coagulant during the log-phase(8~14d) of the microbial growth,who use the shortest time to become mature.Particles can be seen at the 12 nd day, and took about 21 days for all the sludge becoming particle shape,shorter than the sludge which added coagulant during the log-phase for 7 days, and sludge with no coagulant took 35 days to get mature.(2) The aerobic particle sludge which adding coagulant during the adaptive-phase and the log-phase whose water containing rate are not very high,and the integrity coefficient are high,too,characteristics of sludge are better.Aerobic sludge which adding coagulant during the adaptive-phase whose particle diameter, water containing rate and proportion gravity were 94.02%, 97.68% and 1.038.Particle sludge formed by adding coagulant during the log-phase whose article diameter, water containing rate and proportion gravity were 92.76%, 98.53% and 1.059.The contrasted particle sludge whose water containing rate and proportion gravity were 94.38%, 97.26%, 1.016.The integrity coefficient of the former tow group were0.42% and 1.27% higher than the contrasted group, water contain rate 1.21% and 1.48% lower than the contrasted group and proportion gravity 2.16% and 4.23%’s higher.(3) The mature aerobic particle sludge which adding coagulant during the adaptive-phase and the log-phase whose removal rates of COD were all beyond 93% in average, they were 93.31% and 94.03%, the contrasted group with no coagulant was 91.53%, the former two were 1.78% and 2.5% higher. The NH4+–N’s average removal rates of three of them were 80.85%, 90.22% and 88.19%, The removal rates of TP are85.35%,91.38% and 87.47% respectively, the data shows that R2 which was added coagulant during the log-phase of microbial growth,the removal efficiency of the pollutant is the best.(4)The aerobic granular sludge which grown up by adding coagulant(PAC) to the Sequencing Batch Reactor(SBR) during the adaptive-phase of the microbial growth has a small biomass within the particle,so the simultaneous and nitrification and denitrification(SND) reaction was very weak, but the aerobic sludge without any coagulant whose nitrification reacted very obviously, NO2-–N and NO3-–N’s concentration were 3.39mg/ and 3.211mg/L, which were higher than the others, denitrification reaction was weak. Aerobic granular sludge which grown up by adding coagulant during the adaptive-phase of the microbial growth whose NO2-–N and NO3-–N’s concentration rose very fast, and simultaneous and nitrification and NO3-–N’s concentration was falling.Proves that when nitrification began accompany with denitrification.