基于Visual Modflow的重庆某垃圾填埋场封场后地下水污染物运移模拟研究  

SIMULATION ON TRANSPORT OF GROUNDWATER POLLUTANTS AFTER CLOSURE OF A LANDFILL IN CHONGQING BASED ON VISUAL MODFLOW

作　　者：杨延梅[1] 夏铜 张赟[2,3] 敖亮 YANG Yanmei;XIA Tong;ZHANG Yun;AO Liang(Hehai College,Chongqing Jiaotong University,Chongqing 400074,China;Southwest Branch of Chinese Research Academy of Environmental Sciences,Chongqing 401147,China;Chongqing Academy of Environmental and EcologicalScience,Chongqing 401147,China)

机构地区：[1]重庆交通大学河海学院,重庆400074 [2]中国环境科学研究院西南分院,重庆401147 [3]重庆市生态环境科学研究院,重庆401147

出　　处：《环境工程》2024年第4期40-47,共8页Environmental Engineering

摘　　要：垃圾填埋场作为潜在的地下水污染源,在封场后渗滤液仍可能泄漏对周边地下水造成极大的污染风险,因此,研究填埋场渗滤液泄漏后污染物运移规律对于填埋场封场后的管理和地下水污染监测具有重要意义。基于Visual Modflow软件建立水流和溶质运移模型,仅考虑填埋区底部长期连续泄漏这一非正常工况,对生活填埋场典型污染物(COD)的运移扩散规律进行预测。结果表明:研究区地下水流向从北向南流动,COD泄漏后向下游方向运移;填埋区底部长期连续泄漏使污染羽的扩散范围、距离、最大浓度不断增大,到3650 d时已经超出研究区边界,对右侧的CY河造成污染,因此发现泄漏后一定要及时采取有效措施,如气相抽提、PRB技术等,避免污染物继续运移扩散;必须加强填埋场及其周边地下水的监测工作,定期检查维护地下水监测井,建立合理的应急响应机制。As a potential source of groundwater pollution,landfill sites may still cause significant pollution risks to surrounding groundwater due to leachate leakage after closure.Therefore,studying the pollutant transport patterns after leachate leakage in landfill sites is of great significance for managing landfill sites after closure and monitoring groundwater pollution.In this paper,we established a water flow and solute transport model based on Visual Modflow,considering only the abnormal condition of long-term continuous leakage at the bottom of a landfill site,to predict the transport and diffusion laws of typical pollutants(COD)in domestic landfills.The research results indicate that the groundwater flow in the study area flows from north to south,and COD leaks and then migrates downstream;the long-term continuous leakage at the bottom of the landfill area continuously increases the diffusion range,distance,and maximum concentration of the pollution plume.By the 3650th day,it has exceeded the boundary of the research area,causing pollution to the CY River on the right side.Therefore,after discovering the leakage,it is necessary to take effective measures promptly,such as gas phase extraction,PRB technology,etc.,to avoid the continued migration and diffusion of pollutants;it is necessary to strengthen the monitoring of groundwater in the landfill and its surrounding areas,regularly inspect and maintain groundwater monitoring wells,and establish a reasonable emergency response mechanism.

关 键 词：生活垃圾填埋场 地下水 Visual Modflow 数值模拟 COD 

分 类 号：X523[环境科学与工程—环境工程]