危险废物填埋场复合衬层渗漏分析与污染物运移预测
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摘要
以我国危险废物填埋场次防渗层采用1 mm高密度聚乙烯(HDPE)土工膜和0.5 m压实粘土衬垫(CCL)组成的复合衬层为研究对象,采用经验公式以及解析方法计算了不同缺陷条件下复合衬层的渗漏率.在此基础上,采用一维污染物对流扩散运移方程对重金属Cd~(2+)、Zn~(2+)、Cu~(2+)、Pb~(2+)击穿复合衬层的时间进行了计算和分析.结果表明:复合衬层渗漏率主要受到复合衬垫界面接触条件,渗滤液水位以及缺陷类型的影响;当复合衬层的漏洞密度为20个·hm~(-2)时,半径为5.64 mm的圆孔型缺陷其最大渗漏率为22.7 m~3·a~(-1)·hm~(-2);当单位面积裂缝长度为200m·hm~(-2)时,宽度为2 mm长度为1 m的裂缝型缺陷其最大渗漏率为42.5 m~3·a~(-1)·hm~(-2);Cd~(2+)可作为重金属污染物击穿复合衬层的指示性污染物,其击穿时间最长为2.74 a,最短为1.38 a;通过改变土工膜下伏土壤衬层的性能或增加土壤衬层厚度可延缓污染物击穿时间.
Composite liners consisting of a 1 mm thick HDPE geomembrane overlaying a 0.5 m thick compacted clay liner( CCL) are commonly used in the secondary barrier system of hazardous waste landfill in China. By taking the typical composite liners as the research object,leakage through composite liners with different defects was analysed using existing empirical equations and analytical solutions.,the breakthrough time of composite liners for contaminant Cd~(2+),Zn~(2+),Cu~(2+)and Pb~(2+)was calculated using one-dimensional convection-diffusion equation. The results show that the leakage rate may be influenced by the interface properties,the leachate level and the defect types. When the hole density of composite liners is 20 holes·hm~(-2),the maximum leakage rate through composite liners with circle defect having a radius of 5.6 mm is 22.7 m~3·a~(-1)·hm~(-2)When the length of defective seam on unit area is 200 m·hm~(-2),the maximum leakage rate through composite liners with defective seam is 42.5 m~3·a~(-1)·hm~(-2). The longest and shortest breakthrough time of composite liners with defects for Cd~(2+),which is taken as contaminantion indicator of heavy metal,are 2.74 a and 1.38 a respectively. By changing the properties of the underlying soil layer or increasing the thickness of the soil layer,the breakthrough time of contaminant can be delayed.
Composite liners consisting of a 1 mm thick HDPE geomembrane overlaying a 0.5 m thick compacted clay liner( CCL) are commonly used in the secondary barrier system of hazardous waste landfill in China. By taking the typical composite liners as the research object,leakage through composite liners with different defects was analysed using existing empirical equations and analytical solutions.,the breakthrough time of composite liners for contaminant Cd~(2+),Zn~(2+),Cu~(2+)and Pb~(2+)was calculated using one-dimensional convection-diffusion equation. The results show that the leakage rate may be influenced by the interface properties,the leachate level and the defect types. When the hole density of composite liners is 20 holes·hm~(-2),the maximum leakage rate through composite liners with circle defect having a radius of 5.6 mm is 22.7 m~3·a~(-1)·hm~(-2)When the length of defective seam on unit area is 200 m·hm~(-2),the maximum leakage rate through composite liners with defective seam is 42.5 m~3·a~(-1)·hm~(-2). The longest and shortest breakthrough time of composite liners with defects for Cd~(2+),which is taken as contaminantion indicator of heavy metal,are 2.74 a and 1.38 a respectively. By changing the properties of the underlying soil layer or increasing the thickness of the soil layer,the breakthrough time of contaminant can be delayed.
引文
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何俊,何世秀,胡其志.2009.有机污染物在完好复合衬垫中的迁移分析[J].岩土力学,30(6):1653-1657
何小松,姜永海,李敏,等.2012.危险废物填埋优先控制污染物类别的识别与鉴定[J].环境工程技术学报,2(5):433-440
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Rowe R K.1998.Geosynthetics and the Minimization of Contaminant Migration through Barrier Systems Beneath Solid Waste[C].Proceedings of the 6th International Conference on Geosynthetics,Industrial Fabric Association International.Atlanta,USA
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沈阳环境科学研究院.2005.(HJ/T176-2005)《危险废物安全填埋处置工程建设技术要求》[S].北京:中国标准出版社
谢海建,柯瀚,陈云敏.2006.浓度变化时复合衬层中有机污染物的一维扩散分析[J].环境科学学报,26(6):930-935
谢海建.2008.成层介质污染物的运移机理及衬垫系统防污性能研究[D].浙江:浙江大学
谢海建,詹良通,陈云敏,等.2011.我国四类衬垫系统防污性能的比较分析[J].土木工程学报,44(7):134-141
徐亚,能昌信,刘玉强,等.2015.垃圾填埋场HDPE膜漏洞密度及其影响因素的统计分析[J].环境工程学报,9(9):4558-4564
中国环境科学研究院固体废物污染控制技术研究所.2001.(GB18598-2001)《危险废物填埋污染控制标准》.北京:中国标准出版社
詹良通,刘伟,陈云敏,等.2001.某简易垃圾填埋场渗滤液在场底天然土层迁移模拟与长期预测[J].环境科学学报,31(8):1714-1723
张文杰,陈云敏,詹良通.2008.垃圾填埋场渗滤液穿过垂直防渗帷幕的渗漏分析[J].环境科学学报,28(5):925-929
中国科学院武汉岩土力学研究所.2013.《生活垃圾卫生填埋处理技术规范》(GB50869-2013,2013)[S].北京:中国建筑工业出版社
朱伟,舒实,王升位,等.2016.垃圾填埋场渗沥液击穿防渗系统的指示污染物研究[J].岩土工程学报,38(4):619-625
Colucci P,Lavagnolo M C.1995.Threeyears field experience in electrica control of synthetic landfill liners[C].Proc.5th Int.Landfill Symp Cagliari:437-452
陈云敏,谢海建,张春华.2016.污染物击穿防污屏障与地下水土污染防控研究进展[J].水利水电科技进展,36(1):1-10
El Zein A,Rowe R K.2008.Impact on groundwater of concurrent leakag and diffusion of dichloromethane through geomembranes in landfill liners[J].Geosynthetics International,15(1):55-71
Foose G J.1997.Leakage rates and chemical transport through composite landfill liners[D].Madison:University of Wisconsin
Foose G J,Benson C H,Edil T B.2001.Predicting leakage through composite landfill liners[J].Journal of Geotechnical and Geoenvironmental Engineering,127(6):510-520
Foose G J.2010.A steady-state approach for evaluating the impact of solute transport through composite liners on groundwater quality[J].Waste Management,30(8):1577-1586
何俊,何世秀,胡其志.2009.有机污染物在完好复合衬垫中的迁移分析[J].岩土力学,30(6):1653-1657
何小松,姜永海,李敏,等.2012.危险废物填埋优先控制污染物类别的识别与鉴定[J].环境工程技术学报,2(5):433-440
李梅玲,张锡根,闫葆瑞,等.1993.GB/T14848-93《地下水质量标准》[S].北京:中国标准出版社
Rowe R K.1998.Geosynthetics and the Minimization of Contaminant Migration through Barrier Systems Beneath Solid Waste[C].Proceedings of the 6th International Conference on Geosynthetics,Industrial Fabric Association International.Atlanta,USA
Rowe R K,Quigley R M,Branchman R W,et al.2004.Barrier systems for waste disposal[M].London and New York,Spon Press
Rowe R K.2005.Long-term performance of contaminant barrier systems[J].Geotechnique,55(9):631-678
沈阳环境科学研究院.2005.(HJ/T176-2005)《危险废物安全填埋处置工程建设技术要求》[S].北京:中国标准出版社
谢海建,柯瀚,陈云敏.2006.浓度变化时复合衬层中有机污染物的一维扩散分析[J].环境科学学报,26(6):930-935
谢海建.2008.成层介质污染物的运移机理及衬垫系统防污性能研究[D].浙江:浙江大学
谢海建,詹良通,陈云敏,等.2011.我国四类衬垫系统防污性能的比较分析[J].土木工程学报,44(7):134-141
徐亚,能昌信,刘玉强,等.2015.垃圾填埋场HDPE膜漏洞密度及其影响因素的统计分析[J].环境工程学报,9(9):4558-4564
中国环境科学研究院固体废物污染控制技术研究所.2001.(GB18598-2001)《危险废物填埋污染控制标准》.北京:中国标准出版社
詹良通,刘伟,陈云敏,等.2001.某简易垃圾填埋场渗滤液在场底天然土层迁移模拟与长期预测[J].环境科学学报,31(8):1714-1723
张文杰,陈云敏,詹良通.2008.垃圾填埋场渗滤液穿过垂直防渗帷幕的渗漏分析[J].环境科学学报,28(5):925-929
中国科学院武汉岩土力学研究所.2013.《生活垃圾卫生填埋处理技术规范》(GB50869-2013,2013)[S].北京:中国建筑工业出版社
朱伟,舒实,王升位,等.2016.垃圾填埋场渗沥液击穿防渗系统的指示污染物研究[J].岩土工程学报,38(4):619-625