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

项目摘要 多氯联苯（PCBs）是遗留污染物中最具问题的污染物之一。持久和移动的， 在环境方面，多氯联苯在工业区水生系统的沉积物中普遍存在 美国的其相对较高的毒性和生物累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积物场址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，通常涉及物理去除 受污染的沉积物和在封闭的垃圾填埋场处置沉积物，和/或安装多层 在受污染的沉积物上盖上工程帽。 一种新兴的有效去除沉积物中多氯联苯的策略是使用生物改良的活性 碳（AC），它采用AC颗粒接种与多氯联苯降解微生物的富集培养。该公司- 这项拟议研究的调查人员已经进行了使用生物技术背后的基础研究， 经修正的活性炭用于治理沉积物中的多氯联苯，并已获得商业上可行的种植方法专利， 将生物改良的AC颗粒输送到沉积物中。第一阶段的合作项目， 大学科学家和RemBac环境之间的合作，解决了两个限制这种现成使用的因素。 大型多英亩场地的技术：1）厌氧PCB的大规模生长，储存和运输 降解细菌，和; 2）大规模的方法，用于接种和部署生物改良的AC颗粒。的 在实验室规模的生物反应器中成功地将PCB halorespiring厌氧菌放大到最大密度， 开发了通过冻干储存细胞的方法，并成功地测试了两种方法， 用降解多氯联苯的微生物连续、均匀地接种大量的活性炭颗粒。 拟议的研究将通过证明以下方法的有效性，推动该技术走向商业化： 在第一阶段开发的方法，用于在商业设施中扩大生产，并进行中试规模 该技术在新贝德福德港超级基金现场（NBHSS）的演示。PCB降解 微生物将按比例增加到足以处理超过1英亩的细胞数量，并将接种AC颗粒 现场使用第一阶段开发的方法，以评估潮汐沼泽中应用方法的有效性。 一年后，将对沉积物和水中的多氯联苯含量进行检测，以1）评估效果， 处理的环境影响，以及2）评估具有潮汐活动的处理的稳定性。最后 对整个过程进行成本分析，以评估生物改良AC的商业可行性， 对受多氯联苯影响的地点进行有效处理。拟议的研究预计将导致直接转让 通过与美国的积极合作，将这项技术从中试规模发展到完全商业化。 环境保护署（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.