Nontoxic chemical process for in situ permeability enhancement and accelerated decontamination of fine-grain subsurface sediments
US5593248A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 27, 1995 |
| Grant date | Jan 14, 1997 |
| Priority date | — |
| Expiry date | Jun 27, 2015 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB09C2101/00
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
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 flocculents 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 pre…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.