【作者】 刘欢欢；

【导师】 廖利；

【作者基本信息】 华中科技大学 ， 环境工程， 2009， 硕士

【摘要】 随着我国社会经济发展,城市生活垃圾产量逐年增加。目前,我国城市生活垃圾处理的主要方式是填埋。而在众多垃圾填埋场中,简易垃圾填埋场占据大部分。简易垃圾填埋场由于环保措施考虑不周,会产生高浓度渗滤液以及填埋气体横向迁移问题,尤其是填埋气体横向迁移造成爆炸的安全事故屡有发生。因此研究填埋气体横向迁移规律并提出有效的控制措施十分必要。目前对填埋气体横向迁移的研究分为两个方面:理论研究和现场实验。理论研究即建立填埋气体横向迁移模型并进行数值模拟。一般主要研究填埋气体在场内的的气压分布及速度场分布,很少涉及场外。而且多假设填埋场为无限边界或零通量边界,与简易垃圾填埋场实际情况不符;实验研究即在垃圾填埋场周边设置监测井,实地检测甲烷浓度值,借以证实存在填埋气体横向迁移现象。或者是填埋气体横向迁移过程中相关参数的实验测定。本文以多孔介质渗透力学为理论基础建立水-气两相迁移模型,模拟简易垃圾填埋场气体从场内迁移到场外的过程,从理论上探索了填埋气体横向迁移规律。通过模拟得出:垃圾空隙度、垃圾固有渗透率以及中间覆盖层均会对填埋气体横向迁移产生影响。增加垃圾空隙度、降低垃圾固有渗透率以及增设中间覆盖层,均会减弱填埋气体横向迁移作用,但是场外气相压力值降低幅度较小。另外,通过渗滤液环场回灌增加垃圾堆体含水率,可以有效阻止填埋气体横向迁移,场外气相压力值降低一个数量级。更多还原

【Abstract】 With the development of social and economic in China,municipal solid waste production has increased year by year.At present,the main disposal method of MSW is landfill.In many landfill sites,simple landfill occupy the majority.And generally speaking, simple landfill is lack of environmental protection measures,so it will generate leachate with high concentratins,as well as lateral migration issues of LFG,in particular the lateral migration of LFG caused frequently safety incidents.So research on the lateral migration of LFG and come up with effective control measures are necessary.At present,research on lateral migration of LFG include two areas:theoretical study and field experiment. Theoretical study means the establishment of models of lateral migration of LFG and numerical simulation.Mainly the gas pressure distribution and velocity field distribution in the field of landfill , rarely involved in outside of landfill.Generally the model base on the assumption that the boundary of landfill is the infinite or zero flux boundary,which inconsistent with the actual situation. Experimental study means setting monitoring wells around landfill to detect the concentration of methane,to confirm the existence of lateral migration of LFG. Or the experimental determination of relevant parameters which used in the model.The results show that porosity、intrinsic permeability of waste and intermediate covers will have an impact on lateral migration of LFG.Increasing the value of rubbish porosity,decreasing permeability and laying the intermediate covers will weaken lateral migration of LFG.However,the change scale of gas pressure off-site are small.In addition,leachate recirculation along landfill will increase moisture content of landfill body,which can prevent the lateral migration of LFG effectively. The gas pressure off-site decrease one order of magnitude.更多还原