碳酸化水和醇混合注入调控下孔隙尺度DNAPLs的迁移演化规律

密度大于水的重非水相液体有机污染物（DNAPLs）的有效修复是当前地下水污染防治的重点和难点。目前常用的表面活性剂和助溶剂冲洗技术，通过增溶、增流来大幅度提高冲洗效率的同时,增加了DNAPLs向下迁移而扩大污染范围的风险。饱含CO2的碳酸化水与醇混合注入，能够有效调控DNAPL与冲洗液的相对密度、增加浮力，从而降低污染物向下迁移的风险。本研究拟在透明孔隙介质中模拟碳酸化水和醇混合注入淋洗DNAPLs的过程，用共聚焦拉曼成像技术同时采集孔隙网络中不混溶相边界变化和醇、CO2、DNAPL的含量变化两组信息，分析碳酸化水和醇与DNAPL相互作用而发生的多相流动行为，通过采用不同孔渗结构和润湿性的介质、调控冲洗液的初始组成、注入压力和抽提速率来观测重力、毛细力、粘滞力协同影响下DNAPL的迁移和分布，总结其迁移演化的规律。本研究有助于优化DNAPL修复方案、降低原位冲洗风险、提高去除效率。

Remedation of dense nonaqueous phase liquids(DNAPLs) is difficult and important in prevention of groudwater contamination. The current common remedation methods are flushing with surfactants and cosolvents. The flushing efficiency is improved by increasing solubility and mobility of DNAPLs,which will resut to the risk of downwards migration of DNAPLs and incresing contamination. Carbonated water saturated with CO2 can reduce such risks and prevent the downward migration, by controling the relative density of DNAPL to flushing solution and increase the buoyant effect. The study is going to experimentally simulation DNAPL flushing processes of co-inject of carbonated water and alcohols in the transparent micro-model, to monitor the changes of imiscible phase interface and CO2,alcohol and DNAPL concentrations in each phase simultaneonsly with Raman spectroscopic imaging method. We will study the migration and distribution of DNAPL under the different kinds of flow morphology controlled by capillary,gravity and viscous forces. The study will help to reduce the risk of site flushing,optimize the DNAPL remedation techologies and improve the DNAPL removal efficiency.