In situ destruction of halogenated Superfund contaminants with persulfate-generated radicals

项目4：总结/摘要 经过40年的研究和实地经验， 场地仍然是一个重大挑战。在过去的三十年里， 在使用原位处理方法，如生物修复和渗透 反应性屏障。尽管如此，挖掘和场外处置仍然是最常见的 土壤和地下水抽取的补救办法（即，泵送和处理）系统仍然 在许多超级基金的网站上工作。在这些新兴的替代品中， 昂贵的方法，原位化学氧化（ISCO）已显示出巨大的潜力， 提供了一种有效的方法来补救各种污染物，包括三氯乙烯， 石油碳氢化合物尽管ISCO很受欢迎，但事实证明它很难在 疏水性化合物和表现出低反应性的化合物的处理 羟基自由基和硫酸根- 过氧化氢和过二硫酸盐的分解（即，过硫酸盐）。 我们建议的研究旨在开发新的原位化学修复技术， 处理超级基金污染物，往往需要昂贵的异地方法，（充分 卤化有机溶剂、多氯联苯、多溴联苯醚 多溴二苯醚（PBDEs）和全氟和多氟烷基物质（PFAS）） 根治性治疗（ART）。 在目标1中，我们建议开发和优化厌氧热活化过硫酸盐 脱卤化柠檬酸盐污染物的方法。我们将开发一个动力学模型， 考虑温度、pH值、氧化剂剂量、污染物浓度和氧气 浓度.在目标2中，我们将开发一种采用共溶剂冲洗的方法 在厌氧条件下，活化的过硫酸盐可以与醇反应， 以碳为中心的自由基能够降解污染物。我们还预测过硫酸盐 可以在较低的温度下在溶剂的存在下活化，这将允许更有效地 处理复杂的化学混合物。这包括使用的水性成膜泡沫（AFFF） 在被卤化溶剂污染的场地。目标3的重点是发现和命运的 在ART期间形成稳定的转化产品。与项目3合作，我们将 在微宇宙研究中调查转化产物的生物降解性。目标4： 利用计算毒性模型预测可能的毒性模式， 生物分子测定以及已建立的生物测定如艾姆斯试验。的结果 项目4可以为治理高卤化新兴工业提供新的方法 和遗留化合物，同时提供新的模型和方法， 最大限度地减少有毒转化产物。

PROJECT 4: SUMMARY/ABSTRACT After 40 years of research and field experience, the remediation of hazardous waste sites remains a substantial challenge. Over the past three decades, considerable progress has been made in the use of in situ treatment methods, such as bioremediation and permeable reactive barriers. Nonetheless, excavation and off-site disposal remains the most common remedial approach for soil and groundwater extraction (i.e., pump-and-treat) systems are still being employed at numerous Superfund sites. Among the emerging alternatives to these expensive approaches, in situ chemical oxidation (ISCO) has shown substantial potential for providing an effective means of remediating a variety of contaminants, including TCE and petroleum hydrocarbons. Despite its popularity, ISCO has proven difficult to use in the treatment of hydrophobic compounds and compounds that exhibit low reactivity towards hydroxyl radical and sulfate radical—the two strongest oxidants produced during the decomposition of hydrogen peroxide and peroxydisulfate (i.e., persulfate) in the subsurface. Our proposed research aims at developing new in situ chemical remediation techniques capable of treating Superfund contaminants that often require expensive ex-situ methods, (fully halogenated organic solvents, polychlorinated biphenyl (PCBs), polybrominated biphenyl ethers (PBDEs), and per- and polyfluorinated alkyl substances (PFAS)) by employing Anaerobic Radical Treatment (ART). In Aim 1, we propose to develop and optimize anaerobic thermally activated persulfate methods to dehalogenate recalcitrant contaminants. We will develop a kinetic model that will account for temperature, pH, oxidant dose, contaminant concentration, and oxygen concentration. In Aim 2, we will develop a method that employs the use of co-solvent flushing followed by ART. In anaerobic conditions, activated persulfate can react with alcohols to form carbon centered radicals that are able to degrade contaminants. We also predict that persulfate can activate at lower temperature in the presence of solvents, which will allow for more efficient treatment of complex chemical mixtures. This includes aqueous film-forming foams (AFFF) used at sites contaminated with halogenated solvents. Aim 3 is focused on the discovery and fate of stable transformation products formed during ART. In collaboration with Project 3, we will investigate biodegradability of transformation products in microcosm studies. Aim 4 focuses on predicting possible modes of toxicity by utilizing computational toxicity models, screening with biomolecule assays, as well as established bioassay such as the Ames test. The results of Project 4 could provide novel approaches for the remediation of highly halogenated emerging and legacy compounds in the environment, while providing new models and methods for minimizing toxic transformation products.