| Dairy waste water mainly contain organic matter,such as sugar,fat,protein.In addition is with a high content of organic nitrogen,good biodegradability,easy to expand of sludge and other characters.Improperly handling can cause certain harm to the environment.Multi-Stage Active Biological Process of Hybrid Anaerobic Baffled Reactor has a high efficiency,high impact resistance,small amount of mud produced and low cost.It is considered as an effective treatment for high concentration organic waste water and nitrogen containing waste water.In this paper,simulation waste water of dairy was studied as object by the combination of HABR and MSABP.Firstly,the system was constructed on the basis of the design and research of previous reactor,and the experiment was carried out to simulate and configure the dairy waste water.The HABR reactor and the MSABP reactor were independently started-up and graded trained,and the degradation ability,pH lower limit,protein,ammonia nitrogen and other index changes were studied respectively.After the success of the single reactor starting-up,jointly setting up system and starting to run up,the relationship and the processing efficiency of the whole efficiency,alkalinity,pH and Volatile Fatty acids(Volatile Fatty Acid,VFA)was explored.Single start-up we can find that dairy waste water is extremely easy to acidified,needing to monitor the system acidity;The MSABP reactor has an advantage in dealing with low-concentration dairy waste water.During the Jointly process of starting up,when the water in-let load is 8 kg COD/(m3·d),the temperature is 30?,hydraulic retention time(Hydraulic Retention Time,HRT)is for 24 h.The removal rate of HABR reactor was 90.44%,and the removal rate of the MSABP reactor was 98.76%.The reactor was started up successfully and stably operation.In the anaerobic environment,the protein in the waste water of dairy will decompose and produce a large amount of ammonia nitrogen,which causes the concentration of waste water to rise,and the too high concentration of organic material will inhibit the removal and transformation of NH4+-N.Secondly,the influence of temperature,HRT and pH on the single factor of the system was studied.When the temperature is 30?,HRT is for 24 h,pH is 6-7,COD removal rate of HABR reactor is steadily at around 86.38%,removal rate of NH4+-N is approximately 98.81%.It is proved that the system is efficient in treating high concentration of waste water of dairy,and HABR reactor has some advantages in treating high concentration waste water of dairy.In a certain temperature range,the increase of temperature will promote the degradation of organic matter.The longer the HRT is,the more organic matter will be degraded,and the effect of the pH on the system will be relatively small compared with the previous two factors.According to the parameters optimization of design principle of center combination experimental to reactor,optimal operation parameters of reactor is T=32.5?,HRT?17.4 h,pH=6.71,under the condition of the removal rate of COD is 81.29%,removal rate of NH4+-N is 75.71%,removal rate of TN is 60.08%.Then,high-throughput sequencing technologies was used to analyze the microbial community structure in sludge of different compartments under the same water in-let condition,to explore the made up of microbial community structure in compartment no.1?4?7 of HABR reactor,l?4?6?8 compartment of MSABP reactor,and the bacterial structure changes in the hydrolysis stage of compartment no.7 of HABR and MSABP,when anaerobic processes transferring into oxygen-sensitive processes.The research results show that in HABR reactor,is mainly containing bacteroidetes and thick wall fungus with degradation effect,etc.Deformation bacteria and spirillum has been added in back-end MSABP reactor compartment,and with a higher percentage.The differences in the composition of microbial communities in each compartment will be caused by the difference of water inlet concentration.The difference of anaerobic and aerobic environment can also result in the change of community structure.The experimental results show that the HABR reactor mainly have the function of degradation of large molecular organics,continues the degradation of the organic matter in the front end of the MSABP reactor,and the degradation and transformation of NH4+-N in the posterior compartment.Finally,the sludge morphology and sediment yield of each compartment are studied and the amount of sludge is analyzed from view of carbon balance.From the scanning picture of electron microscope of each compartment,we can see that microflora in the system was rich in morphology,including bacillus,coccus and filamentous bacteria,which showed that the system was started up successfully and was in good condition.After the operation is stable,the sludge in each compartment will decrease progressively as the water passes,the final effluent SS is at 0.5-5 mg/L,the water is clear,it proves that the system has its own sludge reduction function,with a small amount of sludge production. |
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