Bench Scale Studies of Novel In-situ Aquifer Remediation of Recalcitrant Fluorinated Organic Compounds at Superfund Sites

项目摘要/摘要：土壤和地下水中的多氟烷基和全氟烷基物质（PFAS）是 目前通过提取受污染的地下水，通过吸附进行异地处理来进行补救 颗粒活性炭（GAC）或其他吸附剂，仅将污染物转移到另一个 媒体还需要治疗。这是一个非常长期和昂贵的过程，因为1）它需要 通过地下水泵和处理（P&T）提取土壤上吸附的PFAS需要几十年，以及2） 碳必须经常更换和3）处理（通过高温再生或焚烧） 是昂贵的。此外，P&T技术可能永远不会达到EPA健康咨询浓度， 含水层PFAS是美国环保局和全球卫生组织 已被确定为有毒，持久性，生物累积性和高度不稳定性， 水解、光解和生物降解。PFAS用于许多产品，包括水性膜- 形成泡沫来扑灭化学火灾。在军事和民用消防训练中使用这些泡沫 这些地区是PFAS对环境的共同来源。它们在地表被发现 沃茨在使用后多年仍存在于地下水中，并在地下移动的， 并威胁饮用水供应。截至2014年，仅美国国防部 仅确定了664个火灾/坠机/训练场地可能存在PFAS污染。因此，有一个 迫切需要一种更具成本效益的就地补救方法来补救PFAS 在未来几年中，污染的场地只会增加。我们的团队将进一步发展和 展示一种创新的原位/非原位结合技术，以具有成本效益的方式加快处理 在超级基金的网站上。所提出的处理系列结合1）无毒的环状糖（CS）， 从原位土壤中冲洗吸附的PFAS，2）用地下水提取CS-PFAS复合物， 在高效（99+ %去除）的非原位反应器中处理，该反应器同时降解，去除， 并浓缩（100-1000倍）PFAS，3）通过碱性臭氧化进行最终现场销毁 (99+%去除），和4）将具有低浓度CS修正物的处理水返回注入 威尔斯继续冲洗。非原位处理反应器也可以用作对现有的非原位处理反应器的预处理。 GAC。实验室规模试验将用于评估优化PFAS所需的参数 从土壤中解吸，在异位反应器中破坏提取的CS-PFAS复合物， 通过碱性臭氧化破坏PFAS浓缩物。批量土柱和小规模多功能 计划进行分阶段扩散气体反应器实验。测试条件包括改变CS和氧化剂 浓度、流速、pH、停留时间和PFAS去除速率。特定场地场地的设计 将准备PFAS处理的试点试验，并估计费用。 1

Project Summary/Abstract: Poly- and perfluoroalkyl substances (PFAS) in soil and groundwater are currently remediated by extracting the contaminated groundwater for ex-situ treatment via adsorption onto granular activated carbon (GAC) or other sorbents which only transfers contaminants to another media that still needs to be treated. This is a very long-term and expensive process because 1) it takes decades for the sorbed PFAS on soil to be extracted via groundwater pump and treat (P&T), and 2) the carbon must be changed frequently and 3) treatment (by high temperature regeneration or incineration) is costly. In addition, P&T technology may never achieve EPA Health Advisory concentrations in the aquifer. PFAS are fluorinated anthropogenic pollutants that the USEPA and global health organizations have identified as toxic, persistent, bioaccumulative and highly recalcitrant, being largely resistant to hydrolysis, photolysis, and biodegradation. PFAS were used in many products, including aqueous film- forming foams to combat chemical fires. The use of these foams at military and civilian fire training areas represents a common source of PFAS to the environment. They have been identified in surface waters and they persist in groundwater years after use and are mobile in the subsurface, contaminating and threatening drinking water supplies. As of 2014, the U.S. Department of Defense alone has identified 664 fire/crash/training sites alone that potentially have PFAS contamination. Thus, there is a critical need for a more cost-effective and in-situ remediation approach for remediating PFAS contaminated sites that will only increase in the coming years. Our team will further develop and demonstrate an innovative combined in-situ / ex-situ technology to cost-effectively expedite treatment of PFAS at Superfund sites. The proposed treatment train combines 1) a non-toxic cyclic sugar (CS) to flush sorbed PFAS from the in-situ soil, 2) extraction of the CS-PFAS complex with groundwater and treatment in a high efficiency (99+ % removal) ex-situ reactor that simultaneously degrades, removes, and concentrates (100-1000 times) the PFAS, 3) ultimate on-site destruction by alkaline ozonation (99+% removal), and 4) returns the treated water with low concentration CS amendment to injection wells for continued flushing. The ex-situ treatment reactor can also be used as pre-treatment to existing GAC. Bench scale tests will be used to evaluate those parameters needed to optimize PFAS desorption from soil, destruction of the extracted CS-PFAS complex in the ex-situ reactor, and ultimate destruction of the PFAS concentrate by alkaline ozonation. Batch soil column and small scale multi- staged diffused gas reactor experiments are planned. Test conditions include varying CS and oxidant concentrations, flowrates, pH, residence time, and PFAS removal rates. Design of a site-specific field pilot test for PFAS treatment with estimated costs will be prepared. 1