| China's water eutrophication phenomenon is serious.A lot of discharge of nitrogen and phosphorus is the main reason to cause this phenomenon.Therefore,sewage nitrogen and phosphorus removal has become a focus problem.Urban domestic sewage discharged the implementation of China's "City sewage treatment plant pollutant discharge standard"(GB18918-2002)in an A standards.SBBR as a new biofilm reactor has the advantages of good settlement performance,less residual sludge,high efficiency,good effect of the nitrogen and phosphorus removal.Therefore it has received attention in the field of water treatment.In this experiment,through the analysis and research on operation effect of SBBR adding polypropylene filler,it provides theoretical reference and practical technology of urban sewage nitrogen and phosphorus removal.Experimental study on object is simulated domestic wastewater,SBBR reactor is made of organic glass,and suspended filler cast polypropylene reactor.Experimental study on SBBR startup,optimize the system working condition time,studies the main factors of influence on system operation effect,study on the aerobic stage effects of five kinds of aeration on the treatment effect of SBBR system.In the startup of the SBBR reactor,the effect of polypropylene filled suspended filler startup is better than non polypropylene filler cast traditional activated sludge process.The results show that,in the same starting time,non polypropylene filler reactor is faster in the initial startup with higher initial removal rate.But as the operation continued,removal effect of reactor with fillers gradually becomes better than that in the reactor without adding the filler.The final results of the device showed that,the treatment effect is better in reaction adding polypropylene filler,so subsequently experimental study completes on thus reactor.The optimum conditions of SBBR were determined by testing,namely the anaerobic stirring(including inlet time)(2h),aeration(4h),precipitation(30min),drainage(lOmin)and idle(80min).The optimization system is stable,the average COD effluent concentration was 34.3mg/L,the average removal rate was 84.03%,the average effluent concentration of TP was 0.82mg/L,the average effluent concentration of TN was 15.03 mg/L,the average removal rate was 56.03%.The existence of simultaneous nitrification and denitrification(SND)in SBBR reactor is good.At the temperature of 25 ?,C/N value in the range of 4.7?13.7,C/P is greater than 42(C/N values greater than 6 conditions),DO to 3.5mg/L,the system performance is better,SND phenomenon is the most obvious.But the system nitrogen removal ability can be further promoted,the effluent concentration of TP did not reach "City sewage treatment plant pollutant discharge standards" standards A.In order to further improve the effluent indexes of nitrogen and phosphorus,the test will change aeration mode to intermittent aeration oxygen,research and analyse fIA and AF effect on nitrogen and phosphorus removal.Five different conditions were:aeration 60min/non aeration stirring 60min,frequency of fIA is 2,namely(60min/60min)2;aeration 30min/non aeration stirring 30min,fIA is 4,namely(30min/30min)4;aeration 25min/non aeration stirring 5min,fIA is 8,namely(25min/5min)8;aeration 15min/non aeration stirring 5min,fIA is 12,namely(15min/5min)12;aeration 5min/non aeration stirring 5min,fIA is 24,namely(5min/5min)24.The results show that,under the same AF,the higher the fIA value is,the more conducive is the denitrification,simultaneous nitrification and denitrification phenomenon is more obvious.Smaller AF is more conducive to the removal of nitrogen and phosphorus.Water indicators eventually meet "City sewage treatment plant pollutant discharge standard" class A standards.Through the study on operating conditions and effects of the suspended carrier biofilm system SBBR,it can provide some technical support for the practical application of SBBR,and provide reference for further research of a similar process. |
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