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Title: Linking deposit morphology and clogging in subsurface remediation: Final Technical Report

Groundwater is a crucial resource for water supply, especially in arid and semiarid areas of the United States west of the 100th meridian. Accordingly, remediation of contaminated groundwater is an important application of science and technology, particularly for the U.S. Department of Energy (DOE), which oversees a number of groundwater remediation sites from Cold War era mining. Groundwater remediation is complex, because it depends on identifying, locating, and treating contaminants in the subsurface, where remediation reactions depend on interacting geological, hydrological, geochemical, and microbiological factors. Within this context, permeability is a fundamental concept, because it controls the rates and pathways of groundwater flow. Colloid science is intimately related to permeability, because when colloids are present (particles with equivalent diameters between 1 nanometer and 10 micrometers), changes in hydrological or geochemical conditions can trigger a detrimental reduction in permeability called clogging. Accordingly, clogging is a major concern in groundwater remediation. Several lines of evidence suggest that clogging by colloids depends on (1) colloid deposition, and (2) deposit morphology, that is, the structure of colloid deposits, which can be quantified as a fractal dimension. This report describes research, performed under a 2-year, exploratory grant from the DOE’s Subsurface Biogeochemical Research (SBR) program.more » This research employed a novel laboratory technique to simultaneously measure flow, colloid deposition, deposit morphology, and permeability in a flow cell, and also collected field samples from wells at the DOE’s Old Rifle remediation site. Field results indicate that suspended solids at the Old Rifle site have fractal structures. Laboratory results indicate that clogging is associated with colloid deposits with smaller fractal dimensions, in accordance with previous studies on initially clean granular media. Preliminary modeling has identified the deposit radius of gyration as a candidate variable to account for clogging as a function of (1) colloid accumulation and (2) deposit morphology.« less
  1. University of Colorado Denver
Publication Date:
OSTI Identifier:
Report Number(s):
DOE Contract Number:
Resource Type:
Technical Report
Research Org:
University of Colorado Denver
Sponsoring Org:
USDOE SC Office of Biological and Environmental Research (SC-23)
Contributing Orgs:
University of Colorado Denver
Country of Publication:
United States
58 GEOSCIENCES; 54 ENVIRONMENTAL SCIENCES groundwater, remediation, permeability, clogging, colloids, fractal