Surfactant Flushing Technique for the Removal of Residual NAPL from the Heterogeneous Subsurface Media

用于去除非均质地下介质中残留 NAPL 的表面活性剂冲洗技术

基本信息

批准号：
10555171
负责人：
INOUE Yasushi
金额：
$ 6.46万
依托单位：
Nagoya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 2000
项目状态：
已结题

项目摘要

Once non-aqueous phase liquid remains behind into the soil pores as a small droplet after filtrating into the ground, it becomes extremely difficult to remove. Aims of this study are the development of the innovative technology that reduces interfacial tension between water and residual NAPL by injecting the surfactant solution into the ground, and that remove it by solubilizing and dispersing into aqueous phase as a micellar, or mobilizing NAPL phase itself. Researches were conducted to establish the formulation on the optimum surfactant solution for enhancement of NAPL mobilization, and to demonstrate the efficiency by applying the formulation to the model porous media.Results were obtained as follows :1. Mobilization of NAPL was dependent on the hydrophobic group length of surfactant. It is very important to have enough carbon chain length in the surfactant for forming the micell. And the existence of alcohol and sodium chloride is effective for enhancing the NAPL mobility. Qualitative description on the relationship between those concentration and interfacial tension was found.2. The formulation for deciding the optimum salinity, which minimizes interfacial tension, was constructed by examining the relationship between alcohol concentration and carbon number of the NAPL, surfactant type and concentration, temperature. And the examination was carried out on NAPL saturation (NAPL content), which was the important parameter that shows present state of NAPL in the porous media, as the result, optimization level of the formulation was developed.3. Applying the formulation to soil column test and two-dimensional soil tank test, it was shown that more than 95% of the residual NAPL could be mobilized and removed. And, using the image analysis that is non-contact and non-disturbing method, it was explained that the mobilization mechanism of NAPL largely depended on its residual situation, and the factor, which affects the optimization, was considered.

一旦非水相液体在过滤到地面后将其留在土壤孔中，它就变得极其难以去除。这项研究的目的是开发创新技术，该技术通过将表面活性剂溶液注入地面来降低水和残留的NAPL之间的界面张力，并通过将其溶解并分散到水相中，或动员NAPL相本身来消除它。进行了研究，以建立最佳表面活性剂溶液的制定，以增强NAPL动员，并通过将配方应用于模型多孔介质来证明效率。结果如下：1。 NAPL的动员取决于表面活性剂的疏水群长度。在表面活性剂中具有足够的碳链长度来形成胶束非常重要。酒精和氯化钠的存在可有效增强NAPL迁移率。关于这些浓度和界面张力之间关系的定性描述。2。通过检查酒精浓度与NAPL，表面活性剂类型和浓度，温度的碳数之间的关系来构建最小化界面张力的最佳盐度的配方。检查是在NAPL饱和度（NAPL含量）上进行的，该参数是显示多孔介质中NAPL当前状态的重要参数，结果是开发了配方的优化水平。3。将公式应用于土壤柱测试和二维土壤罐测试，结果表明，可以动员和去除超过95％的残留NAPL。而且，使用非接触和非扰动方法的图像分析，解释说，NAPL的动员机制在很大程度上取决于其残留情况，并且考虑了影响优化的因素。