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物质有关的人类健康风险来自与沉积物的直接接触或食用从沉积物中积累化学物质的鱼类和贝类。我们小组和其他人新出现的实验室规模的研究表明，通过改变和加强天然沉积物的结合和污染物同化能力，可以中断污染物的传输途径和生物有效性。这是通过添加吸附改良剂来实现的，例如用于结合持久性有机污染物的活性碳和用于结合沉积物中的有毒金属的天然矿物，如磷灰石、沸石或铝土矿。采用这种就地修复办法的关键障碍是，是否有有效的方法对受影响的沉积物进行修正，并了解控制技术有效性的实地物理和生物过程。这一研究项目的主要目的是通过一项旨在解决技术进步中的关键障碍的试点调查，开发就地修复技术。这项实地研究项目将在两个受到多氯联苯/滴滴涕影响的敏感湿地地点进行。研究设计将涉及在每个地点的四分之一英亩土地上应用该技术，并制定监测计划，以了解吸附剂改良剂的应用如何影响多氯联苯/滴滴涕在湿地环境中的去向和运输过程。生物监测将包括在实地曝光室和实验室微观世界中对淡水寡毛类进行的多氯联苯/滴滴涕生物吸收测量。物理化学监测将包括沉积物中水的分配和解吸率，这两个衡量标准定义了沉积物结合污染物的生物可利用性过程。将利用对多氯联苯/滴滴涕去向和运输过程的了解来评估基于皮肤吸收模型和食物链模型的这项技术对人类健康风险的益处。与沉积物结合的污染物，如多氯联苯和滴滴涕，通过污染食物链和直接暴露，构成公共健康风险。这项实地研究将评估一种改变沉积物结合能力的新方法的有效性，以减少人类接触此类污染物。

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.