| The main disposal methods for municipal solid waste were compost, landfill, incineration, earthworm bed and heat degrading, and so on. With the low cost and no secondary pollution, landfill was a popular disposal methods for municipal solid waste in the world. And it would be used in the near future years in China, a developing country, widely.The existing landfilling method had some disadvantages: the municipal solid waste degraded slowly and landfill field needed long time to be stable; the leachate was difficult to be treated and its cost was high; it might be lead to explode, the methane couldn't be reused and led to air -polluted. The novel bio-reactor landfill with leachate recycle was benefit to increase the degrading rate of municipal solid waste, but the leachate direct recycle was led to production restrain, so it couldn't make full use of microorganism degradation for increasing the degrading rate of municipal solid waste. The experiments of the bio-reactor landfill(R3 ^ R4) and the bio-reactor landfill with inoculability (R5, R6) were carried out in this paper. The traditional landfill (Rl) and the landfill with leachate cycled directly (R2) were also carried out as the contrast experiments.The municipal solid waste degraded slowly in the traditional landfill (Rl), and it needed long time to be stable; the degraging rate for municipal solid waste in the landfill with direct recycling leachate (R2) was faster than Rl, but organic acid accumulated in the R2 landfill, especially in the initial stage when the flow of recycling leachate was large and the organic load was high, and the high pressure of H2 destoried the combined metabolizability of microorganism for degrading refuse, led to the ensiling . In R3 > R4, R5 and R6, because they all had reactor for producing methane, the leachate was treated in the reactor for producing methane, then circumfluenced to landfill, it solved the problem of organic acid accumulation; but in R3 and R5, the moisture of refuse was less than 45% ,because the leachate was recycled partly, the activity of microorganism restrained. While in R4 and R6, the moisture of refuse was about 60% because the leachate was recycled fully, theVIdegrading rate of refuse increaseing, and the landfill of R6 system was stable when 145d passed because it was inoculated with high effected strain of microorganism.In the study of stabilization mechanism of landfill, the distribution of molecular weight of leachate in landfill and the humic coefficient of organic substance in municipal solid waste were discussed. The result showed: the more the percent of high molecular weight of leachate in landfill, the more stabilization of landfill, and with the time passed, the percent of high molecular weight of leachate increase. By the analysis of humic coefficient of organic substance in municipal solid waste, the variation of CODcr couldn't described the humic process, but the humic coefficient. And the stabilization of landfill increased with the humic coefficient up. The experiment indicated : the humic coefficent in R6 landfill was the highest, R4 landfill followed, then of R2> R3 and R5 landfill, Rl landfill was the lowest, and the humic coefficents in R2> R3 , R5 landfill were almost the same.The data of sedimentation height of municipal solid waste suggested : the sedimentation height of refuse in R6 landfill is the highest, R4 landfill followed, then ofR2> R3 and R5 landfill, Rl landfill is the lowest, and the sedimentation height of R2^ R3 , R5 landfill were almost the same .And the data from the time 60d passed were dealt with logarithm regression. The regression equation showed : the sedimentation of R6 landfill finished,others were still proceeding.It was suggested that the CODcr degrading kinetic model 1 by average hydraulic retention time and the CODcr degrading kinetic model 2 by mathmatics somilation of R6 system. And the forecast data from models was almost the same as measured data. So the model could express the running situation of bio-reactor landfill...
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