Pilot-scale Research of Novel Amendment Delivery for in-situ Sediment Remediation

描述（由申请人提供）： 与沉积物中存在的化学品有关的人类健康风险来自于直接接触沉积物或食用从沉积物中积累化学品的鱼类和贝类。我们小组和其他人的新兴实验室规模的研究表明，污染物的传输途径和生物利用度可以通过修改和增强天然沉积物的结合和污染物同化能力来中断。这是通过添加吸附剂改良剂来实现的，例如用于结合持久性有机污染物的活性炭和用于结合沉积物中有毒金属的天然矿物，例如磷灰石、沸石或铝土矿。采用这种就地补救办法的关键障碍是，是否有有效的方法对受影响的沉积物进行修正，以及是否了解控制技术有效性的实地物理和生物过程。该研究项目的主要目的是通过旨在解决技术进步中的关键障碍的试点调查来开发原位修复技术。该实地研究项目将在两个受多氯联苯/滴滴涕影响的敏感湿地进行。研究设计将涉及在每个地点四分之一英亩的地块上应用该技术，并制定监测计划，以了解多氯联苯/滴滴涕在湿地环境中的命运和运输过程如何受到吸附剂修正物的影响。生物监测将包括在实地接触室和实验室微生态系统中对淡水寡毛纲动物的多氯联苯/滴滴涕生物吸收情况进行测量。物理化学监测将包括水分配和沉积物的解吸率，这两项措施确定了沉积物结合污染物的生物利用度过程。对多氯联苯/滴滴涕归宿和迁移过程的了解将用于评估该技术在皮肤吸收模型和食物链模型基础上带来的人类健康风险惠益。与沉积物有关的污染物，如多氯联苯和滴滴涕，通过污染食物链和直接接触，对公众健康构成威胁。这项实地研究将评估一种新方法的有效性，以改变沉积物的结合能力，减少人类接触这些污染物。

DESCRIPTION (provided by applicant): Human health risks associated with the presence of chemicals in sediments arise from either direct contact with the sediments or by eating fish and shellfish that have accumulated chemicals from the sediments. Emerging laboratory-scale research by our group and others has shown that contaminant transport pathways and bioavailability can be interrupted by modifying and enhancing the binding and contaminant assimilation capacity of natural sediments. This is achieved by adding sorbent amendments such as activated carbon for binding persistent organic pollutants and natural minerals such as apatite, zeolites, or bauxite for the binding of toxic metals in sediments. Critical barriers in the adoption of this in-situ remediation approach is the availability of efficient delivery methods for amendments to impacted sediments and understanding of physical and biological processes in field sites that control technology effectiveness. The main aim of this research project is to develop the in-situ remediation technology through a pilot-scale investigation aimed at addressing the critical barriers in the advancement of the technology. This field research project will be carried out at two PCB/DDT-impacted sensitive wetland sites. The research design will involve application of the technology in a quarter acre plot in each site and a monitoring plan to understand how the fate and transport processes of PCB/DDT in the wetland environment is impacted by the application of the sorbent amendments. Biological monitoring will include PCB/DDT bio-uptake measurements in a freshwater oligochaete carried out in field exposure chambers and also in laboratory microcosms. The physicochemical monitoring will include aqueous partitioning and desorption rate from sediment, two measures that define the bioavailability processes of sediment bound contaminants. The PCB/DDT fate and transport process understanding will be used to assess human health risk benefit from the technology based on a dermal uptake model and a food-chain model. Sediment-bound contaminants such as PCBs and DDT pose a public health risk through contamination of the food chain and through direct exposure. This field research will evaluate the effectiveness of a novel approach to alter the binding capacity of sediments to reduce human exposure to such contaminants.