Development of an innovative approach for in situ treatment of PCB impacted sediments by microbial bioremediation

项目摘要 多氯联苯是最具问题的遗留污染物之一。 多氯联苯在环境中具有持久性和移动性，广泛存在于 美国工业区的水上系统。它们相对较高的毒性和 生物蓄积潜力会对人类和生态受体造成更高的风险。因此， 多氯联苯往往是受影响沉积物地点的主要风险驱动因素。常见的做法是 修复受多氯联苯影响的沉积物成本高昂，通常涉及物理清除表面 沉积物，覆盖沉积物或用多层工程盖子疏浚凹陷，以及 在密闭垃圾填埋场处置受污染的沉积物。 一种新出现的从沉积物中就地有效去除多氯联苯的策略是使用生物修饰的 活性碳(AC)，用降解多氯联苯的浓缩培养物接种AC颗粒 微生物。这项拟议研究的联合调查员已经进行了基础研究 使用生物修饰的AC修复沉积物中的多氯联苯，并已开发和 获得专利的商业可行方法，用于种植、接种和输送接种的AC 从小球到沉积物。然而，在使用生物改良的中试研究期间 AC，有两个因素会限制这项技术在大型、多英亩土地上的现成使用 鉴定：1)厌氧多氯联苯降解菌的大规模生长、储存和运输， 以及2)大规模接种AC球团的方法。拟议的研究 旨在解决这些限制。 这项拟议的研究将测试利用时间释放生长培养这些微生物的方法。 介质，并开发和测试存储容器，以保持最佳环境条件 厌氧生物的长期生存能力。这些进步最终将使交付成为可能 为大型项目提供大量的多氯联苯降解微生物。拟议的研究 还将开发和测试连续、均匀接种大量AC的方法 使用降解多氯联苯的微生物的颗粒，这将允许在 多英亩受多氯联苯影响的地点。结合在一起，拟议的研究预计将导致 直接将这项技术从中试规模转移到完全的商业可行性。 1

Project Summary Polychlorinated biphenyls (PCBs) are one of the most problematic of legacy contaminants. Persistent and mobile in the environment, PCBs are largely ubiquitous in depositional sediments of aquatic systems in industrial regions of the United States. Their relatively high toxicity and bioaccumulation potential cause elevated risk to both human and ecological receptors. As such, PCBs are often the primary risk driver at impacted sediment sites. Common practices for remediating PCB-impacted sediments are costly, often involving the physical removal of surficial sediments, capping the sediments or dredge depression with a multi-layered engineered cap, and disposal of the contaminated sediments in a confined landfill. An emerging strategy for effectively removing PCBs from sediments in-situ is the use of bioamended activated carbon (AC), which inoculates AC pellets with enriched cultures of PCB-degrading microbes. The co-investigators of this proposed research have performed the fundamental research behind the use of bioamended AC for remediation of PCBs from sediment and have developed and patented commercially-viable methods for growing, inoculating, and delivering the inoculated AC pellets to sediments. However, during the performance of pilot-scale studies using the bioamended AC, two factors that would limit the ready use of this technology for large, multi-acre sites were identified: 1) the large-scale growth, storage, and transport of anaerobic PCB degrading bacteria, and; 2) large-scale methods for inoculating AC pellets during application. The proposed research aims to address these limitations. The proposed research will test methods of culturing these organisms using time-release growth media, and develop and test storage vessels that maintain optimal environmental conditions for the long-term viability of the anaerobic organisms. These advances will ultimately allow for the delivery of large volumes of PCB degrading microorganisms for large-scale projects. The proposed research will also develop and test methods for the continuous, uniform inoculation of high volumes of AC pellets with the PCB-degrading microorganisms, which will allow for cost-effective application at multi-acre PCB-impacted sites. Coupled together, the proposed research is anticipated to result in a direct transfer of this technology from pilot-scale to full commercial viability. 1