Demonstration of Mineral Traps to Passively Evaluate and Monitor In-Situ Reactive Minerals for Chlorinated Solvent Treatment
Abstract
The objective of this project is to field-validate the Min-Trap (registered trademark) technology, a new in-situ monitoring tool for collecting mineralogical data to evaluate and manage in-situ groundwater remediation programs. The Min-Trap is a sampling device consisting of a solid medium (e.g., silica sand, iron oxide sand, site soil) contained within a water permeable mesh that is deployed inside a monitoring well and allowed to incubate over time. The media serves as a carrier substrate upon which target minerals can form passively. Analysis of the medium through chemical, microscopic or spectroscopic means gives direct evidence of the formation of target minerals in-situ. The degradation of chlorinated volatile organic compounds via the reducing power stored in reactive minerals (e.g., iron sulfides; FeSx) is recognized as a very important process, and cost-effective tools to support field applications are needed. The demonstration occurred at Sites SS003 and SD015 at Vandenberg Space Force Base in Central California. Both sites are undergoing active remediation via enhanced reductive dechlorination and Min-Traps were deployed in multiple wells, many where reactive FeSx minerals were expected to be actively forming. MinTrap samples recovered after various incubation times ranging from 2 to 9 months were analyzed by a variety of analytical techniques, including total iron, Aqueous and Mineral Intrinsic Bioremediation Assessment (AMIBA), Scanning Electron Microscopy-Energy Dispersive X-Ray Spectroscopy (SEM-EDS), 14C-assay techniques (e.g., Mills et al. 2018), and microbiological characterization via Quant Array-Microbially Influenced Corrosion (MIC). In summary, Min-Traps samples were utilized to conclusively verify the formation of FeSx, measure reactivity of these minerals, and verify the presence of target microbiological communities.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 2022
- Accession Number
- AD1202914
Entities
People
- Craig Divine