Kinetic Research On SBR Process Of Sludge Transfer

The Sludge-Shifting SBR process as a new type of EBPR process,and has resolved the problems of the low utilization of the working volume of the reactor,insufficient stability of phosphorus removal in the traditional SBR.Through transferring the sludge between the main reactor and the biological selector,which can enrich phosphorus accumulating organisms successfully,the phosphorus removal efficiency is well.In this paper,the Sludge-Shifting SBR process as the research object,mainly investigates the effect of SRT,sludge cycling ratios,C/P,temperature and pH value on phosphorus removal efficiency.At the same time,having established the phosphorus release and uptake kinetic equation about sludge cycling ratios,so as to guide the design,optimization and operation of reactor.The experiment results show that:(1)The kinetic parameters of sludge growth was Y=0.402 kg MLVSS/(kg COD·d),Kd=0.054d-1 and the kinetic equation of sludge growth was: dX/dt=0.402dS/dt-0.054 X.Sludge production could be expressed as ?X=0.402Q(S0-Se)-0.054 XV.The optimum sludge age was 14 d while the COD removal rate was about 90%,the removal rate of NH4+-N was 89.66%~94.39%,the removal rate of TN was 71.45%~74.25%,the removal rate of PO43-was 86.88%~92.40%,the efficiency of nitrogen and phosphorus removal was well.(2)In the range of 0%~50%,the kinetics equation of phosphorus release was:dP/dt=ake-kt,a=1.14+2×(3.6+29.4R-41R2),k=1.5+0.17×(3.6+29.4R-41R2)and the kinetic model equation of uptake phosphorus was dP/dt=-ake-kt,a=4.7+1.9×(4.6+31.5R-43.5R2),k=0.7+0.11×(4.6+31.5R-43.5R2)in the range of0%~50%.(3)In the short period,the temperature of 12~30?,release(uptake)phosphorus kinetic parameters were increased with the increase of the temperature.In the long period,the lower the culture temperature,the bigger release(uptake)phosphorus kinetic parameters at the same temperature.In the treatment of domestic sewage,the influent pH should be controlled at 7~8 and DO control condition was 3~4mg/L,while the release(uptake)phosphorus kinetic parameters were high,and the sludge had a good ability to uptake phosphorus.(4)When the C/P was controlled from 45 to 96,the specific phosphorus release,the synthetic quantity of PHB and phosphorus release amount were rather high,also,the removal of phosphorus was above 90.82%,the effluent of the average concentration of phosphorus was below 0.5mg/L.