Contaminant-reactive geocomposite mat and method of manufacture and use

Abstract

Reactive geocomposite mats, and their method of manufacture, for treating contaminants in soil or water that allow the passage of essentially non-contaminated water therethrough. The geocomposite mat includes a pre-formed woven or non-woven geotextile, having a thickness of about 6 mm to about 200 mm, and having, a porosity sufficient to receive a powdered or granular contaminant-reactive material, contaminant-sorptive material, or a contaminant-neutralizing material (hereinafter collectively referred to as “contaminant-reactant material” or “contaminant-reactive material”) throughout its thickness, or in any portion of the thickness across its entire major surface(s). The powdered or granular contaminant-reactive material is disposed within the pores of the previously formed, high loft geotextile mat to surround the fibers, e.g., by vacuum or vibrating the high loft mat while in contact with the contaminant-reactive material to allow the powdered or granular contaminant-reactive material to flow by gravity into the pores of the previously formed geotextile and vibrational forces. Liquid-permeable cover sheets are adhered to the upper and lower major surfaces of the filled geotextile to prevent the powdered or granular material from escaping from the geotextile during transportation and installation.

Description

FIELD OF THE INVENTION [0001] The present invention is directed to a reactive geocomposite for controlling or preventing the further spread of contaminants in soil or water. More particularly, the geocomposite described herein includes a reactive core formed from a high loft geotextile that is filled with a powdered or granular reactive material, such as activated carbon, coke breeze, peat moss, polymeric ion exchange resins, polymeric adsorbing resins; zero-valent iron, apatite, organophilic clay, zeolite, diatomaceous earth or mixtures thereof and having a liquid-permeable cover sheet attached to the upper and lower major surfaces of the filled geotextile. BACKGROUND AND PRIOR ART [0002] The prior art is replete with methods and articles used to confine or store a wide variety of environmental contaminants ranging from completely capping, in-situ, contaminated sediments that are left in-place in underwater environments; terrestrial landfills wherein dredged or otherwise collected ...

AI Technical Summary

Benefits of technology

[0008] The method of manufacture permits the manufacture of a geocomposite article that includes a contaminant-reactant material that is structurally secure, without lateral movement, and contains contaminant-reactant material uniformly disposed throughout the thickness, or throughout a desired upper and / or lower portion of the thickness of the geocomposite. The geocomposite can be manufactured to provide either a flexible or a rigid geocomposite material, and permits the manufacture of various modified geocomposites; geocomposite articles that include a contaminant-reactant material, such as a zeolite or an organophilic clay with or without a water-absorbent material for treatment of contaminants in water, in an organic liquid, or in a mixture of water and an organic liquid; a minimum of leakage of powdered or granular materials held by the pre-formed mat; the application of layer(s) of liquid-permeable films or sheets of material over both major surfaces of the article to confine the granular or powdered material in place within the pre-formed geotextile; the application of solid or liquid adhesive materials or compositions to one or both major surfaces and / or to any of the edges of the geocomposite article for complete retention of essentially all powdered and / or granular materials; the capability of inserting one or more rigidifying materials into, or onto, the geocomposite article during manufacture, such as a sheet of perforated fiberglass; rope; cardboard; relatively rigid, liquid-permeable corrugated materials, e.g., corrugated cardboard, and the like at some point at or between the top and bottom major surfaces of the geocomposite article to provide various degrees of flexibility or rigidity; the capability of manufacturing the geocomposite articles without the necessity of a consolidation step; and providing various sizes, shapes and weights of pre-formed, high loft geotextiles to achieve the benefits of each. If a water-absorbent, water-swellable material, such as sodium bentonite is included with the contaminant-reactive material, it should be included in an amount less than about 20 lb / ft3, preferably 0 to about 10 lb / ft3, more preferably 0 to about 5 lb / ft3 so that, upon swelling, it does not prevent the flow of contaminated water through the geocomposite mat.

Problems solved by technology

One of the major problems encountered with the use of reactive mats for controlling or confining contaminated materials, or in controlling or preventing leaching of contaminants from sediments and preventing the contaminants from entering ground water supplies or from traversing through a lake or ocean soil interface into the lake or ocean, is in the ability to provide a transportable mat having a sufficient volume or thickness of reactive material so that the mat provides very long term protection without the necessity of periodic replacement.

Another issue with the '945 and '166 mats is that when water swellable sodium bentonite clay is utilized, with or without the reactive material, when the sodium bentonite clay swells, the resulting swell pressure restricts the aqueous flow through the mat.

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