简易垃圾填埋场LFG迁移规律研究
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。
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.
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。
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.
引文
[1]张文杰.城市生活垃圾填埋场中水分运移规律研究: [博士学位论文].浙江:浙江大学图书馆, 2007
[2]李红,高平.城市生活垃圾污染危害防治及利用.黑龙江环境通报, 2005, 29(2): 81～82
[3]逢磊,倪桂才,闫光绪.城市生活垃圾的危害及污染综合防止对策.环境科学动态, 2004(2): 15～16
[4] Eldon D. Enger, Bradley F. Smith. Environmental Science(A Study of Interrelationships). McGraw - Hill publisher, 2000, 31(1)
[5]胡中雄.土力学与环境土工学.上海:同济大学出版社, 1997.
[6]赵欣,田宇,汤建化等.我国生活垃圾处理现状分析与技术发展方向研究.广西轻工业, 2008(7): 85～87
[7]廖利,陈朱蕾,李道圣等.垃圾填埋气体横向迁移测试研究.武汉城市建设学院学报, 1999, 16(2): 15～19
[8]蒋建国,郑安平.城市垃圾堆放场排气补救措施刍议.环境卫生工程, 1996(4):29～32
[9]廖利.南方雨季对LFG横向迁移影响的实验研究.环境与开发, 1999, 14(3): 7～9
[10] Bendz D, V P Singh, M Akesson. Accumulation of water and generatin in a young landfill. Hydrol. , 1997, 203: 1～10
[11] Pohland F G, A Al Yousfi. Design and operation of landfills for optimum stabilization and biogas production. Water Sci. and Technol. , 1991, 30(12): 117～124
[12] Aitkenhead N, Williams G. M. Geological Evidence to the Public Inqyiry into Gas Explosion at Loscoe. British Geological Survey. Report NO. FP/8T/8/83AS. 79～82
[13]周北海,松藤康司.中国垃圾填埋场的问题与改善方法.环境科学研究, 1998, 11(3): 2～29
[14] Houshang Esmaili. Control of Gas Flow from Landfill . Sanitary. J. Envir. Engrg. , 1975, 101(EE4): 555～566
[15] Douglas E. Metcalfe , Grahame J. Farquhar. Modeling Gas Migration Through Unsaturated Soils from Waste Disposal Sites. Water、Air and Soil Pollution, 1987(32): 247～259
[16] Tjalfe G. Poulsen . Modeling Lateral Gas Transport in Soil Adjacent to Old Landfill. J. Environ. Eng. , 2001, 127(2): 145～153
[17]吴学龙,廖利.深圳市玉龙坑垃圾填埋场气体横向迁移的测试研究.环境卫生工程, 1998, 6(3): 94～98
[18]刘元元,王里奥,黄川等.非规范生活垃圾填埋场填埋气横向迁移规律及控制.环境工程学报, 2007, 1(2): 124～129
[19]邹春,廖利.垃圾填埋场气体横向迁移数序模型.环境卫生工程, 1998, 6(3): 85～88
[20] TOUMA J, VAUCLIN M. Experimental and numerical analysis of two-phase infiltration in a partially saturated soil. Transport in Porous Media, 1986(1): 27～55
[21] WEIR G J, KISSLING W M. The influence of airflow on the vertical infiltration of water into soil. Water Resour Res, 1992, 28: 2765～2772
[22] WANG Z, FEYEN J, NIELSEN D R. Two-phase flow infiltration equations accounting for air entrapment effects. Water Resour Res, 1997, 33: 2759～2767
[23] Zhi Wang , Jan Feyen, M. van Genuchten, D. R. Nielsen. Air entrapment effects on infiltration rate and flow instability. Water Resource Research, 1998, 34(2): 213～222
[24]骆祖江,付延玲.非饱和带水-气二相渗流动力学模型.煤田地质与勘探, 1999, 27(5): 43～47
[25]孙冬梅,朱岳明,张明进.非饱和带水气二相数值模拟研究.岩土工程学报, 2007, 29(4): 560～568
[26]陈家军,彭胜,王金生等.非饱和带水-气二相流动参数确定实验研究.水科学进展, 2001, 12(4): 467～473
[27]刘建国,聂永丰,王洪涛.填埋场水分运移模拟实验研究.清华大学学报(自然科学版), 2001, 41(4/5): 244～247
[28]黄文雄.垃圾填埋气产生过程与产气量预测模型的研究: [硕士学位论文].重庆:重庆大学, 2002
[29] George Tchobanoglous, Hilary Theisen, Samuel Vigil. Integrated Solid Waste Management: Engineering Principles and Management Issues.北京:清华大学出版社, 2000: 381～416
[30]房怀阳,吴长振.城市生活垃圾填埋场甲烷气资源的产量估算及其利用.资源开发与市场, 1999, 15(6): 330～331
[31]张文杰,陈云敏,詹良通.垃圾填埋场内的渗流和稳定分析.第二届全国岩土与工程学术大会论文集. 881～889
[32]菀莲菊,李振栓,武胜忠等.工程渗流力学及应用,北京:中国建材工业出版社
[33] R. einhartDR, Townsend T G. Landfill bioreaetor design and operation. Florida: CRCPress, 1998
[34]沈东升,何若,刘宏远.生活垃圾填埋生物处理技术.北京:化学工业出版社, 2003
[35]钱学德,郭志平.城市固体废弃物的工程特性.岩土工程学报, 1998, 20(5): 1～5
[36]冉龙.城市生活垃圾的压缩和渗透特性及填埋场水力特性研究: [硕士学位论文].成都:西南交通大学, 2005
[37] M. Th. Van Genucheten. A close form equation for predicting the hydraulic conductivity of unsaturated soil. Soil Sci. Soc. Am, 1980, 44: 892～898
[38]王洪涛.多孔介质污染物迁移动力学.北京:高等教育出版社, 2008. 21～22
[39]杨青,廖利,王松林.填埋场渗滤液水力学研究进展.环境卫生工程, 2003, 11(3): 119～122
[40]刘磊,梁冰,薛强.水相作用下填埋气体迁移数值仿真及参数灵敏性研究.系统仿真学报, 2008, 20(22): 6114～6117
[41]陈家军,王红旗,王金生.填埋场释放气体运移数值模型及应用.环境科学学报, 2000, 20(3): 327～331
[42]彭绪亚,余毅,刘国涛.垃圾填埋场竖井抽气条件下的填埋气压力分布.重庆大学学报, 2003, 26(1): 92～95
[43]冯向明,蒋建国,张唱.老垃圾填埋场渗滤液回灌工艺参数研究.工业安全与环保, 2009, 35(1): 30～32
[44]薛强,梁冰,刘晓丽.填埋场中气体运移的非稳定耦合渗流数学模型.岩土力学, 2002, 23(2): 191～195
[45]瞿贤,何品晶,邵立明.城市生活垃圾填埋场渗滤液粘度研究.环境工程, 2005, 23(1): 82～85
[46] An-Hua Lu , Charles O. Kunz. Gas-Flow Model to Determine Methane Production at Sanitary Landfills. J. Envir. Sci. &Tech. , 1981, 15(4): 436～440
[47]余毅.填埋垃圾体气体渗透特性及填埋气迁移过程模拟研究: [硕士学位论文].重庆:重庆大学图书馆, 2002.
[48]王君连.工程地下水计算.北京:中国水利水电出版社, 2004: 93～109
[2]李红,高平.城市生活垃圾污染危害防治及利用.黑龙江环境通报, 2005, 29(2): 81～82
[3]逢磊,倪桂才,闫光绪.城市生活垃圾的危害及污染综合防止对策.环境科学动态, 2004(2): 15～16
[4] Eldon D. Enger, Bradley F. Smith. Environmental Science(A Study of Interrelationships). McGraw - Hill publisher, 2000, 31(1)
[5]胡中雄.土力学与环境土工学.上海:同济大学出版社, 1997.
[6]赵欣,田宇,汤建化等.我国生活垃圾处理现状分析与技术发展方向研究.广西轻工业, 2008(7): 85～87
[7]廖利,陈朱蕾,李道圣等.垃圾填埋气体横向迁移测试研究.武汉城市建设学院学报, 1999, 16(2): 15～19
[8]蒋建国,郑安平.城市垃圾堆放场排气补救措施刍议.环境卫生工程, 1996(4):29～32
[9]廖利.南方雨季对LFG横向迁移影响的实验研究.环境与开发, 1999, 14(3): 7～9
[10] Bendz D, V P Singh, M Akesson. Accumulation of water and generatin in a young landfill. Hydrol. , 1997, 203: 1～10
[11] Pohland F G, A Al Yousfi. Design and operation of landfills for optimum stabilization and biogas production. Water Sci. and Technol. , 1991, 30(12): 117～124
[12] Aitkenhead N, Williams G. M. Geological Evidence to the Public Inqyiry into Gas Explosion at Loscoe. British Geological Survey. Report NO. FP/8T/8/83AS. 79～82
[13]周北海,松藤康司.中国垃圾填埋场的问题与改善方法.环境科学研究, 1998, 11(3): 2～29
[14] Houshang Esmaili. Control of Gas Flow from Landfill . Sanitary. J. Envir. Engrg. , 1975, 101(EE4): 555～566
[15] Douglas E. Metcalfe , Grahame J. Farquhar. Modeling Gas Migration Through Unsaturated Soils from Waste Disposal Sites. Water、Air and Soil Pollution, 1987(32): 247～259
[16] Tjalfe G. Poulsen . Modeling Lateral Gas Transport in Soil Adjacent to Old Landfill. J. Environ. Eng. , 2001, 127(2): 145～153
[17]吴学龙,廖利.深圳市玉龙坑垃圾填埋场气体横向迁移的测试研究.环境卫生工程, 1998, 6(3): 94～98
[18]刘元元,王里奥,黄川等.非规范生活垃圾填埋场填埋气横向迁移规律及控制.环境工程学报, 2007, 1(2): 124～129
[19]邹春,廖利.垃圾填埋场气体横向迁移数序模型.环境卫生工程, 1998, 6(3): 85～88
[20] TOUMA J, VAUCLIN M. Experimental and numerical analysis of two-phase infiltration in a partially saturated soil. Transport in Porous Media, 1986(1): 27～55
[21] WEIR G J, KISSLING W M. The influence of airflow on the vertical infiltration of water into soil. Water Resour Res, 1992, 28: 2765～2772
[22] WANG Z, FEYEN J, NIELSEN D R. Two-phase flow infiltration equations accounting for air entrapment effects. Water Resour Res, 1997, 33: 2759～2767
[23] Zhi Wang , Jan Feyen, M. van Genuchten, D. R. Nielsen. Air entrapment effects on infiltration rate and flow instability. Water Resource Research, 1998, 34(2): 213～222
[24]骆祖江,付延玲.非饱和带水-气二相渗流动力学模型.煤田地质与勘探, 1999, 27(5): 43～47
[25]孙冬梅,朱岳明,张明进.非饱和带水气二相数值模拟研究.岩土工程学报, 2007, 29(4): 560～568
[26]陈家军,彭胜,王金生等.非饱和带水-气二相流动参数确定实验研究.水科学进展, 2001, 12(4): 467～473
[27]刘建国,聂永丰,王洪涛.填埋场水分运移模拟实验研究.清华大学学报(自然科学版), 2001, 41(4/5): 244～247
[28]黄文雄.垃圾填埋气产生过程与产气量预测模型的研究: [硕士学位论文].重庆:重庆大学, 2002
[29] George Tchobanoglous, Hilary Theisen, Samuel Vigil. Integrated Solid Waste Management: Engineering Principles and Management Issues.北京:清华大学出版社, 2000: 381～416
[30]房怀阳,吴长振.城市生活垃圾填埋场甲烷气资源的产量估算及其利用.资源开发与市场, 1999, 15(6): 330～331
[31]张文杰,陈云敏,詹良通.垃圾填埋场内的渗流和稳定分析.第二届全国岩土与工程学术大会论文集. 881～889
[32]菀莲菊,李振栓,武胜忠等.工程渗流力学及应用,北京:中国建材工业出版社
[33] R. einhartDR, Townsend T G. Landfill bioreaetor design and operation. Florida: CRCPress, 1998
[34]沈东升,何若,刘宏远.生活垃圾填埋生物处理技术.北京:化学工业出版社, 2003
[35]钱学德,郭志平.城市固体废弃物的工程特性.岩土工程学报, 1998, 20(5): 1～5
[36]冉龙.城市生活垃圾的压缩和渗透特性及填埋场水力特性研究: [硕士学位论文].成都:西南交通大学, 2005
[37] M. Th. Van Genucheten. A close form equation for predicting the hydraulic conductivity of unsaturated soil. Soil Sci. Soc. Am, 1980, 44: 892～898
[38]王洪涛.多孔介质污染物迁移动力学.北京:高等教育出版社, 2008. 21～22
[39]杨青,廖利,王松林.填埋场渗滤液水力学研究进展.环境卫生工程, 2003, 11(3): 119～122
[40]刘磊,梁冰,薛强.水相作用下填埋气体迁移数值仿真及参数灵敏性研究.系统仿真学报, 2008, 20(22): 6114～6117
[41]陈家军,王红旗,王金生.填埋场释放气体运移数值模型及应用.环境科学学报, 2000, 20(3): 327～331
[42]彭绪亚,余毅,刘国涛.垃圾填埋场竖井抽气条件下的填埋气压力分布.重庆大学学报, 2003, 26(1): 92～95
[43]冯向明,蒋建国,张唱.老垃圾填埋场渗滤液回灌工艺参数研究.工业安全与环保, 2009, 35(1): 30～32
[44]薛强,梁冰,刘晓丽.填埋场中气体运移的非稳定耦合渗流数学模型.岩土力学, 2002, 23(2): 191～195
[45]瞿贤,何品晶,邵立明.城市生活垃圾填埋场渗滤液粘度研究.环境工程, 2005, 23(1): 82～85
[46] An-Hua Lu , Charles O. Kunz. Gas-Flow Model to Determine Methane Production at Sanitary Landfills. J. Envir. Sci. &Tech. , 1981, 15(4): 436～440
[47]余毅.填埋垃圾体气体渗透特性及填埋气迁移过程模拟研究: [硕士学位论文].重庆:重庆大学图书馆, 2002.
[48]王君连.工程地下水计算.北京:中国水利水电出版社, 2004: 93～109