垃圾焚烧发电项目地下水环境影响数值模拟分析及PRB方案设计

发布时间：2018-03-14 05:21

本文选题：地下水　切入点：数值模拟　出处：《西南交通大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着改革开放的深入,我国现代化、城镇化进程加快,相伴而来的则是包括地下水环境质量不断恶化在内的各种环境问题。目前我国地下水污染程度已十分严重,但比起地表水污染及大气污染等易被关注的环境污染问题,在国内人们重视的程度还远远不够。由于地下水隐蔽性强,自身流速慢,自净能力差等特点,在现有的技术条件下使人们很难套用修复地表水的技术对地下水污染进行治理。本文以《巴中市某生活垃圾焚烧发电项目》为例,在收集、整理项目相关地质、水文地质资料的基础上,选取CODcr作为模拟因子,建立了研究区域地下水溶质运移模型,并利用Visual MODFLOW求解,采用数值模拟的方法研究污染物的迁移过程。最后,假设项目遭遇突发事故,垃圾渗滤液下渗到含水层中,利用模拟预测出的CODcr在地下水系统的运动规律,设计PRB方案来修复污染水体。获得的主要结论如下：1、通过分析研究目标区域的地质、水文地质相关资料数据,将研究区内北侧沟谷定义为河流边界条件；对研究区域内主要水文地质条件进行分析后,将其分为两层结构,第一层为第四系粉质粘土,第二层为中、强风化砂岩含水层组,建立地下水流数值模型,并对模型进行验证和识别。2、在地下水流数值模型基础上,选取CODCr作为模拟因子,建立溶质运移模型,并用Visual MODFLOW求解。从预测结果来看,污染物由模型的污染源位置向模型北侧沟谷运移扩散,CODcr污染羽面积随着时间推移而变大。十年模拟期后,整个CODcr污染羽已经扩散至模型北侧沟谷附近,其平均浓度已达到80mg/L,最大浓度为150mg/L。3、利用本文前面所模拟的污染羽状图及其项目相关的水文地质资料和数据,研究PRB技术修复方案。PRB反应介质采用石英砂、零价铁及改性煤渣组成的复合介质,墙体结构选用连续式渗透反应墙。墙体主要设计参数如下：墙体长度确定为40m,高度确定为5.7m,埋深确定为10.7m,厚度确定为0.6m；墙体与模型水平方向坐标轴之间的夹角为52°,反应层渗透系数为9.23×10-7m/s。最后,利用Visual MODFLOW软件概化相关条件,验证PRB系统对地下水水质修复效果。
[Abstract]:With the deepening of reform and opening up, the modernization of our country, the acceleration of urbanization process, accompanied by a variety of environmental problems, including the deterioration of groundwater environmental quality. At present, the degree of groundwater pollution in China has been very serious. However, compared with surface water pollution and air pollution and other environmental pollution problems that are easy to be concerned about, the degree of attention paid by people in China is far from enough. Because of the characteristics of strong concealment of groundwater, slow velocity of its own and poor self-purification ability, etc. Under the existing technical conditions, it is very difficult for people to apply the technology of surface water restoration to control the groundwater pollution. In this paper, taking the Project of Incineration and Power Generation of a Municipal solid waste in Bazhong City as an example, the relevant geology of the project is collected and sorted out. On the basis of hydrogeological data, CODcr is selected as the simulation factor, and the solute transport model of groundwater in the study area is established. The solution is solved by Visual MODFLOW, and the transport process of pollutants is studied by numerical simulation. If the project encounters a sudden accident, the landfill leachate seeps into the aquifer, and the movement law of CODcr in the groundwater system is predicted by the simulation. The main conclusions are as follows: 1. By analyzing the geological and hydrogeological data of the target area, the northern gully in the study area is defined as the river boundary condition. After analyzing the main hydrogeological conditions in the study area, it is divided into two layers: the first layer is quaternary silty clay, the second layer is medium and strong weathered sandstone aquifer group, and the numerical model of groundwater flow is established. The model is verified and identified. Based on the numerical model of groundwater flow, CODCr is selected as the simulation factor, and the solute transport model is established and solved by Visual MODFLOW. The pollution plume area of CODcr increased with the passage of time from the pollution source location of the model to the northern gully of the model. After a decade of simulation period, the whole CODcr pollution plume had spread to the north side of the model near the gully valley. The average concentration has reached 80 mg / L, and the maximum concentration is 150 mg / L. 3. Using the pollution plume map simulated in this paper and the hydrogeological data and data related to the project, the paper studies the remediation scheme of PRB technology. The reaction medium of PRB is quartz sand. A composite medium consisting of zero-valent iron and modified cinder, The main design parameters of the wall are as follows: the length of the wall is 40 m, the height is 5.7 m, the depth of the wall is 10.7 m, the thickness is 0.6 m, and the angle between the wall and the horizontal axis of the model is as follows. 52 掳, the permeation coefficient of the reaction layer is 9.23 脳 10 ~ (-7) m / s. Finally, Using Visual MODFLOW software to generalize the related conditions, the effect of PRB system on groundwater quality restoration is verified.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X523;X82

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