Annual Report submitted on the PNNL portion of EMSP Project No. 86729

Riley, Robert ; Amonette, James ; Peyton, Brent

Pacific Northwest National Laboratory (U.S.)

关键词: Decision Making;    Attenuation;    Sediments;    Source Terms;    Closures;   

DOI  :  10.2172/835419
RP-ID  :  EMSP-86729-2003
RP-ID  :  FG07-02ER63503
RP-ID  :  835419

美国|英语

来源: UNT Digital Library

【 摘 要 】

A migration-resistant fraction (MRF) is a portion of a polluted sediment's contaminant inventory that exhibits slow release. Slow release is a key process that controls organic contaminant transport and fate in a plume long after the major portion of the contaminant inventory of a source term has been depleted or removed. Slow release rates are not well understood nor are they commonly accounted for in subsurface numerical transport models. In this project, we propose to study the accumulation and slow-release behavior of carbon tetrachloride (CCl4) MRF as a function of time, contaminant concentration and different physicochemical properties of sediments. Both model materials that mimic the physical/chemical properties of sediments and natural sediments will be used in project studies. Experiments will be conducted at macro- and microscopic scales under both unsaturated (Washington State University-WSU) and saturated conditions (Pacific Northwest National Laboratory-PNNL). The results will be used to (1) develop a mechanistic description of slow release of CCl4 in the subsurface environment and (2) lay the groundwork for improving the robustness of numerical models that predict organic contaminant transport and fate under natural conditions. The outcomes of this study are expected to improve the conceptual model of CCl4 subsurface transport and fate at different physical scales and have an impact on remediation and site closure decision-making at Department of Energy (DOE) sites, especially in situations involving the potential application of natural attenuation. This report summarizes work performed on the PNNL component of the project after the first 8 months of a three-year project. Progress on the WSU component of the project is addressed under a separate annual report submission.