BENTONITE BARRIER COMPOSITIONS AND RELATED GEOSYNTHETIC CLAY LINERS FOR USE IN CONTAINMENT APPLICATIONS

1 . A geosynthetic clay liner comprising:

at least one geosynthetic layer; and

a bentonite barrier composition comprising: bentonite and a polyanionic low molecular weight polymer.

2 . The geosynthetic clay liner of claim 1 wherein the geosynthetic layer is a geotextile or a geomembrane.

3 . The geosynthetic clay liner of claim 1 wherein the geosynthetic layer comprises a structure selected from the group consisting of: a nonwoven structure, a woven structure, and any combination thereof.

4 . The geosynthetic clay liner of claim 1 wherein the geosynthetic layer is laminated with a geofilm or coated with a coating.

5 . The geosynthetic clay liner of claim 1 wherein the bentonite barrier composition is adhered to the geosynthetic layer by an adhesive and/or by a mechanical means.

6 . The geosynthetic clay liner of claim 1 further comprising a second geosynthetic layer that is a geotextile, a geofilm, or a geomembrane.

7 . The geosynthetic clay liner of claim 1 wherein the bentonite barrier composition is present in an amount of about 0.25 to about 3 lb/ft 2 of the geosynthetic clay liner.

8 . The geosynthetic clay liner of claim 1 wherein the polyanionic low molecular weight polymer comprises a polymer selected from the group consisting of: a guar, a hydrolyzed low molecular weight acrylamide, a polyacrylate, a polyanionic cellulose, poly(sodium styrene sulfonate), polyacrylic acid, pectin, carrageenan, an alginate, polyvinylpyrrolidone, and any combination of these.

9 . The geosynthetic clay liner of claim 1 wherein the geosynthetic clay liner has a retained permeability of about 1×10 −8 cm/s or lower.

10 . The geosynthetic clay liner of claim 1 wherein the geosynthetic clay liner has a retained permeability of about 1×10 −9 cm/s or lower.

11 . A sandwich geosynthetic clay liner comprising:

a first geosynthetic layer;

at least a second geosynthetic layer; and

a bentonite barrier composition that is sandwiched between the first geosynthetic layer and the second geosynthetic layer comprising: bentonite and a polyanionic low molecular weight polymer.

12 . The sandwich geosynthetic clay liner of claim 11 wherein the first geosynthetic layer or the second geosynthetic layer is a geotextile or a geomembrane.

13 . The sandwich geosynthetic clay liner of claim 11 wherein at least one of the first geosynthetic layer or the second geosynthetic layer comprises a structure selected from the group consisting of: a nonwoven structure, a woven structure, and any combination thereof.

14 . The sandwich geosynthetic clay liner of claim 11 wherein at least one of the first geosynthetic layer or the second geosynthetic layer is laminated with a geofilm or coated with a coating.

15 . The sandwich geosynthetic clay liner of claim 1 wherein the bentonite barrier composition is adhered to at least one of the first geosynthetic layer or the second geosynthetic layer by an adhesive and/or a mechanical means.

16 . The sandwich geosynthetic clay liner of claim 11 wherein the bentonite barrier composition is present in an amount of about 0.25 to about 3 lb/ft 2 of the sandwich geosynthetic clay liner.

17 . The sandwich geosynthetic clay liner of claim 11 wherein the thickness of sandwiched bentonite barrier composition is about 0.01 inch to about 2 inches.

18 . A geosynthetic clay liner comprising:

at least a first geosynthetic layer;

a bentonite barrier composition comprising: bentonite and a polyanionic low molecular weight polymer; and

an adhesive that at least partially bonds the bentonite barrier composition to the first geosynthetic layer.

19 . The geosynthetic clay liner of claim 18 wherein the adhesive may comprise an acrylic polymer, polyvinyl acetate, waterborne polyurethane dispersions, or combination thereof.

20 . The geosynthetic clay liner of claim 16 wherein the adhesive is present in an amount of about 2% to about 25% by weight of the bentonite.