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

项目总结 多氯联苯是最具问题的遗留污染物之一。持久和移动接入 在环境方面，多氯联苯在工业区水系的沉积沉积物中普遍存在。 美国的。它们相对较高的毒性和生物蓄积潜力导致两者的风险增加 人类和生态受体。因此，多氯联苯往往是超级基金沉淀点的主要风险驱动因素。 修复受多氯联苯影响的沉积物的常见做法成本高昂，通常涉及物理清除 受污染的沉积物和在密闭垃圾填埋场中处置沉积物，和/或安装多层 在受污染的沉积物上盖上工程盖子。 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正的活化 碳(AC)，它使用接种了丰富的多氯联苯降解微生物培养的AC颗粒。联席- 这项拟议研究的调查人员已经进行了使用生物... 修正了用于修复沉积物中多氯联苯的AC，并获得了商业上可行的种植方法的专利， 接种，并将生物修饰的AC颗粒输送到沉积物中。之前的第一阶段项目，协作 大学科学家和RemBac环境公司之间的合作，解决了限制该技术现成使用的两个因素 大型、多英亩场地的技术：1)厌氧多氯联苯的大规模生长、储存和运输 降解菌；2)大规模接种和部署生物修饰AC颗粒的方法。这个 在实验室规模的生物反应器中成功地将多氯联苯的卤素呼吸厌氧菌放大到最大密度， 开发了冷冻干燥保存细胞的方法，并成功地测试了两种方法 连续、均匀地接种大量AC颗粒，接种降解多氯联苯的微生物。 这项拟议的研究将通过展示 在第一阶段开发的方法，用于扩大商业设施的生产，并进行中试 在新贝德福德港超级基金网站(NBHSS)展示这项技术。印刷电路板的退化 微生物的数量将扩大到足以处理1英亩以上的土地，并将接种AC颗粒 现场使用第一阶段开发的方法来评估潮汐沼泽应用方法的效果。 沉积物和水中的多氯联苯水平将在一年后进行检测，以1)评估有效性和 2)用潮汐活动度评估治疗的稳定性。最后，一个 对整个过程进行成本分析，以评估生物修饰AC的商业可行性，作为成本- 多氯联苯受影响部位的有效治疗。拟议的研究预计将导致直接转移到 这项技术通过与美国的积极合作，从中试规模到完全的商业可行性。 环境保护局(USEPA)、美国陆军工程兵团(USACE)、工程顾问、 和超级基金网站的利益相关者。

PROJECT SUMMARY Polychlorinated biphenyls (PCBs) are one of the most problematic of legacy pollutants. 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 Superfund sediment sites. Common practices for remediating PCB-impacted sediments are costly, often involving the physical removal of contaminated sediments and disposal of the sediments in a confined landfill, and/or installation of a multi-layered engineered cap over the contaminated sediments. An emerging strategy for effectively removing PCBs from sediments in situ is the use of bio-amended activated carbon (AC), which employs AC pellets inoculated with enriched cultures of PCB-degrading microbes. The co- investigators of this proposed research have performed the fundamental research behind the use of bio- amended AC for remediation of PCBs in sediment and have patented commercially-viable methods for growing, inoculating, and delivering the bioamended AC pellets to sediments. The prior Phase I project, a collaboration between university scientists and RemBac Environmental, addressed two factors that limit the ready use of this technology for large, multi-acre sites: 1) the large-scale growth, storage, and transport of anaerobic PCB degrading bacteria, and; 2) large-scale methods for inoculating and deploying the bioamended AC pellets. The PCB halorespiring anaerobe was successfully scaled up to the maximum density in a bench-scale bioreactor, methods were developed for storage of cells by lyophilization and two approaches were successfully tested for the continuous, uniform inoculation of high volumes of AC pellets with the PCB-degrading microorganisms. The proposed research will advance the technology towards commercialization by demonstrating the efficacy of the methods developed in Phase I for scaled up production at a commercial facility, and perform a pilot-scale demonstration of the technology at the New Bedford Harbor Superfund Site (NBHSS). PCB degrading microorganisms will be scaled up to cell numbers sufficient to treat over 1 acre, and AC pellets will be inoculated on-site using methods developed in Phase I to assess the efficacy of the application methods in a tidal marsh. PCB levels in sediment and water will be assayed after one year to 1) assess the effectiveness and environmental impact of the treatment, and 2) assess the stability of the treatment with tidal activity. Finally, a cost analysis conducted for the entire process to assess the commercial viability of bio-amended AC as a cost- effective treatment for PCB impacted sites. The proposed research is anticipated to result in a direct transfer of this technology from pilot-scale to full commercial viability through an active collaboration with the U.S. Environmental Protection Agency (USEPA), U.S. Army Corps of Engineers (USACE), engineering consultants, and Superfund site stakeholders.