Selection of subsoils, saturated zone materials, and related sorbents for subsurface research. Rationale for selection of experimental materials for DOE research in subsoils and in groundwater: Subsurface Science Program.

摘要

This report describes reference subsoils and aquifer materials that support research in DOE's Subsurface Science Program. Research is being conducted on the geochemical behavior of co-contaminants in the subsurface, for example: (1) the mechanisms of organic contaminant sorption to mineral surfaces; (2) the rates and mechanisms of microbiological degradation of organic contaminants; (3) the flow physics of organic liquids in saturated and unsaturated porous media; (4) the identity and chemical reactivity of colloids in groundwater; and, (5) the physical and chemical nature of absorbed water on mineral surfaces and its role in contaminant binding to sorbent surfaces. Sorption and degradation experiments are performed at the laboratory and intermediate scale using a reference collection of subsurface materials and single phase components (e.g., clays, oxides, humic substances) which are described herein. This report describes how and why these particular materials were selected as research substrates; the report summarizes the properties of the reference materials as they relate to the vadose and saturated zones and how these materials are being used to understand organic contaminant reactions in the subsurface. The primary set of reference materials is being augmented with (1) samples of opportunity from deeper vadose and saturated zones, and (2) with pure phase organic and mineral solids for fundamental studies of contaminant sorption and degradation mechanisms.