| In the research, a Sequential UBF-ABR/contact oxidation process was used to treatlandfill leachate. The purpose was to chang the biodegradability of leachate to reduceprocessing difficulty and simplify the process through the two levels of anaerobic andbackflow. The research used biological method to degradate a lot of organics, ammonianitrogen, total nitrogen of the landfill leachate. Finally the research could reduce thedifficulty of the deeping processing of the landfill leachate treatment.This research included the following contents: the design and installation of the reactor,the inoculation and acclimation of the sludge, startup operation and debugging of the reactor,orthogonal experiment, the verification tests of the best operation conditions and engineeringdesign.The experimental results showed that:(1) The experiment used the mixture of leachate and sewage to culture sludge, whichshortenned the inoculation and culture time effectively by increasing landfill leachate intakeratio. The actived sludge with good settlement performance and rich biological communitieswas cultivated after15d s domestication and cultivation.(2)The experiment used high-load starting mode.During the startup period of the system,the volume load range of UBF, ABR and contact oxidation tank were1.01~2.49kg/m3.d,2.99~4.85kg/m3.d and1.29~2.11kg/m3.d.During the startup period, the phenomenon that theeffluent contained a small amount of sludge and the biomenbrane of filler falls off appeared.Added activated carbon into UBF reactor and ABR reactor can help the formation ofgranular sludge, improved the sedimentation of sludge, reduced the amount of sludge ofeffluent. By reducing oxygen of contact oxidation ponds could slow biomenbrane falls offeffectively. After the startup of50days, the phenomenon of sludge outflow and membranefalls off disappeared, the system adapted to the high load inffluent. After the system was in astable stage, the removal rate of CODCr, BOD5, NH4+-N were85%,94%,80%, and thebiodegradability of leachate improved obviously. The biodegradability of effluent of UBF and ABR could keep in0.39and0.33. The startup of the experiment showed that thisprocess can adapt to the high-load inffluent in short time to realize the system s quick start.(3) The research designed16sets of experiments through orthogonal test. Screened twolevel combinations through the level effect and analysis of range:(a) recirculationratio of2,backflow position and proportion is a: b=1:1, hydraulic retention time of70.4h;(b),recirculationratio of4, backflow position and proportion is a, hydraulic retention time of48.5h. After variance analysis, it concludeed that hydraulic retention time worked significantinfluence on CODCrremoval, recirculation ratio woked significant effects for NH4+-N andTN remove.The influence of backflow position for the removal rate of the three kinds ofindex was not obvious.(4) The experiment choosed the level combination for4reflux ratio, backflow positionand ratio for a, hydraulic retention time of48.5h as best operation level and test. During the30d s process of this level,the removal efficiency of CODCrcould stay above94%; NH4+-N removal rate could stay above95%, TN removal rate stayed above91%. The operationpurpose achieved the expected effects and the effect of operation was stable. Compared withthe first DTRO process, this system had better removal efficiency and did not produce aconcentrated liquid, the running cost was less than the first DTRO processingtechnology.The experiment provided a theoretical basis for the practical application and hadsome reference value. |
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