Simultaneous Nitrification-Denitrification Influence Factor In SBBR

At present, for more and more pollutant containing nitrogen was discharged to water body, and eutrophication became more and more serious, it was important to control the nitrogen contamination of water effectively. Present studies, principals and the research direction in the future of SND (simultaneous nitrification and denitrification) were introduced. Meanwhile, it was pointing out that, SBBR (Sequencing Batch Biofilm Reactor) developed from the SBR, was an improved technology with the advantages of SBR process and biofilm process and had good effects of SND. Artificial domestic wastewater was used as the water resource and the spherical filler was used as the biofilm carrier. Biofilm formation, start-up and factors affecting the simultaneous nitrification-denitrification of SBBR process such as aeration, C/N ratio, were investigated in this research, and the optimal period and the optimal aeration time of SBBR process were also determined.Experimental results indicated that,(1) After 26-day intermittent operation, the biofilm formed successfully with variety microbial. On the biofilm formation stage, COD and NH4+-N removal rate increased gradually, and at last, were kept at the level of higher than 85% and 95% respectively. Higher COD and NH4+-N load was conducive for biofilm formation.(2) Different aeration times and COD concentration of influent did not have significant influence on COD removal efficiency. COD degradation processes were similar under different aeration conditions. Most of COD's degradation occurred in the first 60 minutes of aeration, and COD concentration decreased rapidly at this stage. When aeration rate were 25L/h,50L/h,60L/h,70L/h respectively, the COD removal efficiency were 90.8%,89.8%, 89.9%,89.9%, respectively, which demonstrated that SBBR process had higher capacity of the COD load.(3) SND phenomenon occurred under different aeration rates, and when the aeration rate was 25L/h, the highest TN removal efficiency,53.7%, could be achieved.(4) When the influent COD concentration was 500mg/L and with C/N ratio was 10, the system had higher nitrogen removal efficiency, which was 60.7%.(5) When the aeration time was 308 minutes, higher nitrogen removal could be obtained under the condition of the cycle time of SBBR system was 6 hours, and the effluent quality could be satisfied the B class of the first discharge standard.