The Effects Of Waste Tyres Reinforcement On The Stability Of Bioreactor Landfills

Treatment of the municipal solid waste(MSW)has become a worldwide problem,and the modern land filling is a primary way of disposal of the MSW.The newly proposed bioreactor landfill can utilize the landfill gas to generate electricity and operate the filling space more efficiently,which conforms to the concept of the sustainable management of waste.This paper proposes a new method which construct a spatial net consisted of bonded whole tyres in the municipal waste during landfill filling to improve the anti-landslide capacity of landfills and leachate recirculation efficiency;And a series of studies were carried out by means of theoretical analysis and numerical simulation.The main conclusions are summarized as follows:(1)Based on the idea of using tyres to form the spatial reinforcement network in bioreactor landfill,the dual permeability subsurface flows model,solid mechanics momentum balance equation and the slope stability analysis model are coupled to compute the leachate flow in filling body and the slope stability.Additionally,the simulation approach using the FEM software COMSOL is developed.(2)Based on the established calculation model,the leachate recirculation in bioreactor landfill having horizontal trench is simulated numerically.The results show that the reinforced waste during continuous leachate recirculation can raise the flow rate and improve the distribution of leachate,so as to promote the biochemical reaction;Moreover,the slope stability analysis of the landfill shows that the stability of reinforced slope has been significantly improved.(3)Considering that the intermittent leachate recirculation allows higher injection pressure,this paper studies the effect of reinforced waste during intermittent leachate recirculation.The results show that the existence of tire network can reduce the number of horizontal trenches and improve the slope stability of landfill site under the condition of similar pervious efficiency;At the same time,the reinforcement can further improve the injection pressure.(4)In the practice of landfill,the vertical wells can also be used to channeled theleachate,so this paper simulates the effect of reinforced waste on leachate recirculation by vertical wells and evaluates the effect the heterogeneous and anisotropic nature of the waste,and the geometric configuration of vertical wells.The results show that the heterogeneous and anisotropic nature of the waste can accelerate the migration of leachate,improve the uniformity of leachate distribution,and use the combination of shallow wells and deep wells to optimize the arrangement.Therefore,the tyre reinforced has a good application prospects,and the research results of this paper provide technical reference for the design of bioreactor landfill in the future.