| Sewage treatment plants mostly use the activated sludge process, and the removal effectof its nitrogen,phosphorus is not high effective. The application of A/O process causes theeffect of nitrogen removal enhanced, but this process have many shortcomings,such as highcost of construction,operating and needing circumfluence of nitrifying liquid. Moving bedbiofilm reactor (MBBR) has good effect for nitrogen and phosphorus removal, and it maydevelop well in the future.This paper compares the effect of organic matter and nitrogen removal by MBBR andA/O process.The results show that:Under the condition of influent COD and NH4+-N concentration of 1000 mg/L and 25mg/L respectively,varying HRT and fred out that when HRT is 8 h, the removal rate of CODand TN in MBBR reaches 92％and 94％, respectively, and those in A/O are 78％and 82％,respectively.MBBR has better resistant to organic shock loads than that of A/O. When HRT is 8 hand influent COD concentration is 500 mg/L, COD removing rate of MBBB and A/Oachieves 95％and 92％respectively. When influent COD concentration is between 200 mg/L～1000 mg/L, NH4+-N removing rate of MBBR stabilizes about 97％; When influent CODconcentration is 600 mg/L, TN removing rate of MBBR and A/O is 95％and 84％respectively. With influent COD concentration increased, the removing rate of NH4+-N ofA/O increases all along, that disobeys the traditional theory. So we conjecture that the actionof heterotrophic nitrobacteria occurres in the A/O process.When influent NH4+-N concentration is between 20 mg/L～80 mg/L, NH4+-N removingrate ofMBBR maintens above 90％; TN removing rate falls from 95％to 78％. NH4+-Nremoving rate is 53％in A/O reactor when influent NH4+-N concentration is 60 mg/L,and isonly 43％when influent NH4+-N concentration is 80 mg/L.The microbiology phase of two processes under different COD concentration is inspectedin this paper. The results show that the organism in MBBR is extremely rich. With influentCOD concentration increased, the biomembrane concentration maintains about 2400 mg/L inMBBR, but in the reactor the aerosol organism gradually increases, that makes the effluentwater quality become wores. The sludge concentration of A/O process maitaines 2500 mg/Lthrough sludge backflow and the row of putty control. Because of suddenly elevating of temperature, A/O process has had a sludge expanding in the beginning of May, the inflationtendency is controlled through changing continuous running to batch operation.At last, the experiment compares the treatment effect of organic matter and nitrogen tothe actual city life sewage between MBBR and A/O process. The results indicate that WhenHRT is 6 h, their COD removing rate are 81％and 79％respectively. Bio-denitrification isrestrained in low concentration municipal wastewater, where TN removal is only 10％and17％, respectively. Along with exterior carbon source being added, nitrification and denitrifi-cation in wastewater increased. When COD concentration reaches 300～400 mg/L in the feed,TN removal in MBBR is obviously higher than that in A/O. At that time, TN removalincreases to 83％and 64％respectively. |
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