Nontoxic chemical process for in situ permeability enhancement and accelerated decontamination of fine-grain subsurface sediments
The remediation of heterogeneous subsurfaces is extremely time consuming and expensive with current and developing technologies. Although such technologies can adequately remove contaminants in the high hydraulic conductivity, coarse-grained sediments, they cannot access the contaminated low hydraulic conductivity fine-grained sediments. The slow bleed of contaminants from the fine-grained sediments is the primary reason why subsurface remediation is so time-consuming and expensive. This invention addresses the problem of remediating contaminated fine-grained sediments. It is intended that, in the future, a heterogeneous site be treated by a hybrid process that first remediates the high hydraulic conductivity, coarse-grained sediments, to be followed by the process, described in this invention, to treat the contaminated low hydraulic conductivity fine-grained sediments. The invention uses cationic flocculants and organic solvents to collapse the swelling negative double layer surrounding water saturated clay particles, causing a flocculated, cracked clay structure. The modification of the clay fabric in fine-grained sediments dramatically increases the hydraulic conductivity of previously very tight clays many orders of magnitude. 8 figs.
- Issue Date:
- OSTI Identifier:
- 426631
- Assignee:
- Univ. of California, Oakland, CA (United States) PTO; SCA: 540220; PA: EDB-97:029018; SN: 97001724500
- Patent Number(s):
- US 5,593,248/A/
- Application Number:
- PAN: 8-495,294
- Contract Number:
- W-7405-ENG-48
- Resource Relation:
- Other Information: PBD: 14 Jan 1997
- Research Org:
- University of California
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 54 ENVIRONMENTAL SCIENCES; REMEDIAL ACTION; INTERSTITIAL WATER; SOILS; HYDRAULIC CONDUCTIVITY; PARTICLE SIZE; FLOCCULATION; COAGULANTS; WATER REMOVAL