TECHNICAL FIELD

The invention relates generally to geocomposites.

BACKGROUND A geocomposite incorporates two or more geosynthetic materials in a single device to satisfy multiple engineering functions. For example, a geogrid sandwiched between two geotextile fabrics, or filters, can be combined to provide both high strength and water drainage. Such drainage geocomposites have a porous yet high strength core that prevents crushing/collapse of the internal porosity that is sandwiched between two geotextile fabrics. One-sided drainage geocomposites have an impermeable membrane on one side, and a geotextile fabric on the other. Common drainage applications include the vertical attachment of pre-fabricated thin-layer drainage boards, or mats, to foundation walls and the horizontal placement of thin-layer drainage geocomposites on top of soft soils prior to their consolidation.

These applications are designed to facilitate water movement on, around, and beneath the ground. Such engineering applications allow for passive cross and in-plane fluid flow (relative to the plane of the geocomposite mat). However, these applications are designed for fluid conveyance and do not include any materials for treatment of water sources flowing into and out of the geocomposites.

Common passive water treatment includes the use of constructed vertical trenches or horizontal blankets or permeable sediment capping systems which typically combine porous solids (sand/gravels) with reactive and/or sorptive media to treat impacted surface or ground waters. These reactions and processes are well known in the environmental treatment industry. Most current passive environmental treatment systems are not pre-fabricated, and the currently available pre-fabricated thin layer geosynthetic systems only allow for cross- plane flow, not in-plane fluid flow. Exemplary of such thin layer geosynthetic systems providing for cross-plane flow are CETCO® reactive core mats sold by Minerals Technologies Inc. of NY, NY.

Accordingly, there is a need for a reactive geocomposite mat or board that provides passive treatment of fluids in both the cross-plane and in-plane directions when positioned in a vertical, horizontal and/or sloped direction where the treated fluids may be aqueous, nonaqueous, gaseous, or a combination thereof. There is a need in the industry to remove contaminants from distressed fluids proximal to and in some cases underneath man-made structures such as concrete slabs, foundation walls, green roofs, plaza decks, retaining walls, underground parking garage floors and walls, exterior planters, sediment basins, storm water or other water flow management systems, and the like. Further, there is a need to deliver compounds that are beneficial for plant growth to living plants planted in soil proximal to, including on top of, man-made structures.

There is a need in the industry to provide devices and articles to accomplish such goals with ease of manufacturing. There is a need in the industry to provide such devices and articles with an array of reactive media tailored to one or more expected fluid treatment challenges to be encountered. There is a need in the industry to provide such devices and articles that can be easily installed during construction of man-made structures without the need for added steps, additional fixtures or any other adjustment in the construction procedure. There is a need in the industry to provide such devices and articles that avoid, limit, or delay the need for excavation of, within, surrounding, or proximal to man-made structures to address the challenges of distressed fluids.

SUMMARY

Disclosed herein is a reactive geocomposite mat comprising first and second geosynthetic layers and a reactive flow layer disposed between the geosynthetic layers, the reactive flow layer comprising a nonwoven core and a reactive particulate, wherein the mat facilitates a flow of fluid therethrough, further wherein the flow of fluid causes contact of at least a portion of the fluid with the reactive particulate while substantially retaining the reactive particulate within the mat.

Also disclosed herein is a method for treating a fluid, the method comprising causing the fluid to flow into the reactive layer of the geocomposite mat described above and collecting the treated fluid, wherein the treated fluid includes less of one or more fluid components, one or more additional components, or a combination thereof. The fluid is a gas, a liquid, or a combination thereof. In embodiments the fluid is a distressed fluid. In embodiments the fluid is a distressed water source. In embodiments the fluid flow into the reactive layer is substantially coplanar with the reactive geocomposite mat. In other embodiments the fluid flow into the reactive layer is substantially perpendicular to the plane of the reactive geocomposite mat. In still other embodiments the fluid flow into the reactive layer is both coplanar with and perpendicular to the plane of the reactive geocomposite mat. In embodiments the dispensing is substantially coplanar with the reactive geocomposite mat. In other embodiments the dispensing is substantially perpendicular to the plane of the reactive geocomposite mat. In still other embodiments the dispensing is both coplanar with and perpendicular to the plane of the reactive geocomposite mat.

Where the fluid is a distressed water source, the method further comprises operably disposing the reactive geocomposite mat in contact with the earth that causes the distressed water source to flow into the reactive geocomposite mat. In embodiments, the flow is a passive flow. The applying in such embodiments is applying a distressed water source, wherein the applied distressed water source contacts the reactive particulate for a period of time sufficient to form a treated water source; and the dispensing is dispensing the treated water source from the reactive geocomposite mat.

Where the fluid is a water source that optionally is a distressed water source, the method further comprises operably disposing the reactive geocomposite mat in contact with the earth that causes the water source to flow into the reactive geocomposite mat. In embodiments, the flow is a passive flow. The applying in such embodiments is applying a water source to the reactive geocomposite mat, wherein the applied water source contacts the reactive particulate for a period of time sufficient to form an eluate; and the dispensing is dispensing the eluate from the reactive geocomposite mat.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 A is a schematic drawing of a reactive geocomposite mat of the invention.

FIG. IB is a close-up view of a portion of the reactive geocomposite mat of FIG. 1A.

FIG. 2 is a schematic drawing of one method of manufacturing of the reactive geocomposite mat of the invention.

FIG. 3 is an exploded schematic representation of a reactive geocomposite test mat assembly for testing vertical flow therethrough.

FIG. 4 is a schematic representation of a test setup for testing vertical flow through the reactive geocomposite test mat assembly of FIG. 3.

FIG. 5 is a plot of pH as a function of liquid/solid ratio for various hydraulic residence times as reported in Example 1. FIG. 6A is a plot of orthophosphate concentration as a function of liquid/solid ratio for various hydraulic residence times as reported in Example 1.

FIG. 6B is a plot of percent orthophosphate removed as a function of liquid/solid ratio for various hydraulic residence times as reported in Example 1.

FIG. 7 is a plot of total dissolved solids (TDS) as a function of liquid/solid ratio for various hydraulic residence times as reported in Example 1.

FIG. 8 is a plot of total suspended solids (TSS) as a function of liquid/solid ratio for various hydraulic residence times as reported in Example 1.

FIG. 9 is a schematic representation of a tank for testing horizontal flow through a reactive geocomposite mat.

DETAILED DESCRIPTION

Although the present disclosure provides references to preferred embodiments, persons skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. Various embodiments will be described in detail with reference to the drawings, wherein like reference numerals represent like parts and assemblies throughout the several views. Reference to various embodiments does not limit the scope of the claims attached hereto. Additionally, any examples set forth in this specification are not intended to be limiting and merely set forth some of the many possible embodiments for the appended claims.

Definitions

As used herein, the term "geosynthetic" refers to a manmade article used to stabilize terranean and subterranean environments. In embodiments, a geosynthetic is a geotextile, a geogrid, a geonet, a geomembrane, a geofilter, a geosynthetic liner, a geofoam, or a geocell. As used herein, the term "geosynthetic layer" means geosynthetic article present as a layer within, or present as a portion of a geocomposite.

As used herein, the term "geotextile" means a generally planar, generally flexible web-based fabric, material, or layer designed and adapted for use as a geofilter or geomembrane. As used herein, the term "geofilter" means a geotextile that prevents passage of macroscopic or particulate matter while allowing a fluid to pass therethrough. As used herein, the term "geomembrane" means a geotextile that does not allow the passage of a fluid therethrough.

As used herein, "geocomposite" means a generally planar, generally flexible web- based article or device, in some embodiments referred to as a "mat", that includes at least a combination of one or more geosynthetic layers and one or more additional layers, wherein the one or more additional layers differ from the one or more geosynthetic layers by composition, porosity, compression strength, functionality, or two or more thereof.

As used herein, "flexible" refers to a substantially planar device or article that is capable of being wound into a roll type format, whether or not it is actually provided in such format; alternatively, "flexible" refers to a substantially planar device or article that is capable of conforming to an irregular or undulating surface, where such surfaces may include natural or compacted soil layers, sloping portions of the earth, and the like.

As used herein, "fluid" or "fluid flow" refers generally to the flow of aqueous liquids, non-aqueous liquids, and gases, or more specifically to one or more thereof as determined by context. In embodiments, the fluid is a water source.

As used herein, "distressed fluid" means a fluid, that is, a gas, a liquid, or a combination thereof comprising one or more contaminants dissolved, dispersed, or distributed therein.

As used herein, "contaminant" means a material, species, compound, element, or ion that is dissolved, dispersed, or distributed in a fluid that is undesirably present according to one or more humans (e.g. for reasons of governmental regulation, toxicity, or excess concentration). In some embodiments, the contaminant is present in the fluid as a result of human activity, animal activity, insect activity, or microbial activity.

As used herein, "water source" means water, water containing one or more dissolved liquids, gases, or solids; water containing undissolved (dispersed or emulsified) liquids or solids, or water containing both such dissolved and undissolved materials. Water sources include groundwaters, surface waters, process waters, and aqueous runoff from industrial or agricultural processes. In some embodiments, a water source is a distressed water source.

As used herein, "distressed water source " means a water source comprising one or more contaminants dissolved or dispersed therein. Contaminants commonly associated with water sources include, but are not limited to, phosphorus species including orthophosphates, polyphosphates, metaphosphates; inorganic gases such as ammonia or hydrogen sulfide gas; synthetic volatile or semi-volatile organic compounds; and heavy and/or toxic metals in various oxidation states. Contaminants include mixtures of two or more of these.

As used herein, "reactive particulate" means a discrete solid particulate material capable of causing a chemical reaction with one or more components of a fluid, capable of removing one or more components of a fluid, capable of adding (in embodiments, "eluting") one or more compounds into a fluid, or a combination of two or more thereof.

As used herein, the terms "comprise^)," "include^) " "having " "has " "can," "contain^) " and variants thereof, as used herein, are intended to be open-ended transitional phrases, terms, or words that do not preclude the possibility of additional acts or structures. The singular forms "a," "and" and "the" include plural references unless the context clearly dictates otherwise.

As used herein, the term "consisting essentially of means that the methods and compositions described may include additional steps, components, ingredients or the like, but only if the additional steps, components and/or ingredients do not materially alter the basic and novel characteristics of the claimed methods and compositions. The present disclosure contemplates that all embodiments described herein may comprise, consist of, or consisting essentially of the recited embodiments or elements presented herein, whether explicitly set forth or not below.

As used herein, the term "optional" or "optionally" means that the subsequently described event or circumstance may but need not occur, and that the description includes instances where the event or circumstance occurs and instances in which it does not.

As used herein, the term "about" modifying, for example, the quantity of an ingredient in a composition, concentration, volume, process temperature, process time, yield, flow rate, pressure, and like values, and ranges thereof, employed in describing the embodiments of the disclosure, refers to variation in the numerical quantity that can occur, for example, through typical measuring and handling procedures used for making compounds, compositions, concentrates or use formulations; through inadvertent error in these procedures; through differences in the manufacture, source, or purity of starting materials or ingredients used to carry out the methods, and like proximate considerations. The term "about" also encompasses amounts that differ due to aging of a formulation with a particular initial concentration or mixture, and amounts that differ due to mixing or processing a formulation with a particular initial concentration or mixture. Where modified by the term "about" the claims appended hereto include equivalents to these quantities. Further, where "about" is employed to describe a range of values, for example "about 1 to 5" the recitation means "1 to 5", "about 1 to about 5", "1 to about 5" and "about 1 to 5" unless specifically limited by context.

As used herein, the term "substantially" modifying, for example, the type or quantity of an ingredient in a composition, a property, a measurable quantity, a method, a position, a value, or a range, employed in describing the embodiments of the disclosure, refers to a variation that does not affect the overall recited composition, property, quantity, method, position, value, or range thereof in a manner that negates an intended composition, property, quantity, method, position, value, or range. Examples of intended properties include, solely by way of non-limiting examples thereof, flexibility, partition coefficient, rate, solubility, temperature, compression strength, fluid conductivity, and the like; intended values include thickness, yield, weight, concentration, length, width, and the like. The effect on methods that are modified by "substantially" include the effects caused by variations in type or amount of materials used in a process, variability in machine settings, the effects of ambient conditions on a process, and the like wherein the manner or degree of the effect does not negate one or more intended properties or results; and like proximate considerations. Where modified by the term "substantially" the claims appended hereto include equivalents to these types and amounts of materials.

Discussion

Disclosed herein is a reactive geocomposite mat comprising, consisting essentially of, or consisting of first and second geosynthetic layers and a reactive layer disposed between the geosynthetic layers, the reactive flow layer comprising, consisting essentially of, or consisting of a nonwoven core and a reactive particulate, wherein the mat facilitates a flow of fluid therethrough, further wherein the flow of fluid causes contact of at least a portion of the fluid with the reactive particulate while substantially retaining the reactive particulate within the mat. The reactive geocomposite mat is a substantially planar layered web construction having first and second major mat sides defining a mat thickness of about 5 mm to 50 mm (5 cm). In embodiments, the mat is flexible and can be wound on a roll or on itself and/or is capable of conforming to irregular or uneven surfaces on which it is placed in otherwise substantially planar form. In embodiments, a flow of fluid within the mat is cross plane fluid flow (that is, perpendicular to the plane of the mat). In embodiments, a flow of fluid within the mat is in-plane fluid flow (parallel to the plane of the mat), In embodiments, a flow of fluid within the mat is a combination of in-plane and cross-plane flow.

In embodiments, the first and second geosynthetic layers are formed from the same or substantially the same material and have the same or substantially the same properties. In other embodiments first and second geosynthetic layers are formed from different materials and/or have one or more differentiable properties such as composition, basis weight, weight per unit area, average fiber diameter, average fiber length, compression strength in a selected direction, chemical resistance, fluid permeability, elongation in a selected direction, tensile strength in a selected direction, and the like. In some embodiments a geosynthetic layer is woven; in some embodiments a geosynthetic layer is nonwoven. In some embodiments a geosynthetic layer includes, consists essentially of, or consists of a polyolefin homopolymer or copolymer. In some embodiments a geosynthetic layer has an average thickness of about 25 um to 3 mm. In embodiments, a needle punched nonwoven geotextile composed of synthetic fibers, such Mirafi®1120N (polypropylene nonwoven geotextile obtained from Koninklijke Ten Cate nv.) is employed as both the first and second geosynthetic layers.

In some embodiments, one or more geosynthetic layers are geotextile layers. In some embodiments one or more geosynthetic layers are geomembrane layers. In some embodiments, one or more of the geosynthetic layers are geofilter layers. In some embodiments, one or more of the geosynthetic layers are geomembrane layers. In embodiments where one geosynthetic layer is a geomembrane layer and one geosynthetic layer is a geofilter layer, hydraulic cutoff of fluid flow is enabled, while still allowing fluids to enter the reactive geocomposite mat and contact the reactive particulate by flowing substantially in the in-plane direction.

The reactive geocomposite mat includes a reactive flow layer comprising, consisting essentially of, or consisting of a nonwoven core and a reactive particulate. The nonwoven core of the reactive flow layer is a three-dimensional matrix of fibers irregularly looped and intermingled, as will be familiar to one of skill in the art of nonwoven fiber assemblies in general. The nonwoven core comprises, consists essentially of, or consists of a thermoplastic polymer or a blend of two or more thermoplastic polymers. In embodiments, the thermoplastic polymer comprises, consists essentially of, or consists of a polyolefin, a polyamide, or a blend of two or more thereof. In some embodiments one or more thermoplastic polymers comprises, consists essentially of, or consists of recycled content. The nonwoven core has weight per unit area of about 400 g/m ² to about 1,000 g/m ² . The nonwoven core has a layer thickness of about 1 mm to 45 mm. The nonwoven core is formed from fibers having an average fiber thickness of about 0.1 mm to 3 mm. The nonwoven core has compressive strength of about 500 kN/m ² to 3,000 kN/m ² perpendicular to the plane of the mat, which in conventional geosynthetic parlance may be taken to mean that the nonwoven core is "crush resistant". The nonwoven core comprises a pore size, or fiber-to- fiber spacing, of about 0.1 mm to 1 cm. Such effective pore sizes are more than sufficient for one or more fluids having a dynamic viscosity of less than about 20 cP, or less than about 10 cP, under temperature and shear conditions within the mat, to flow both in-plane and cross-plane within the mat.

In embodiments, the nonwoven core is thermally bonded or welded. By "thermally bonded" or "welded" it is meant that where e.g. two fibers of the nonwoven core contact each other, the contact point is welded by melting or partially melting at least a portion of at least one of the fibers at the contact point. Welding imparts increased compression strength to the nonwoven core, for example in the cross-plane direction (perpendicular to the plane of the nonwoven core). Thus, in embodiments, the reactive layer of the reactive geotextile mat comprises a thermally bonded nonwoven core. In some embodiments the thermally bonded nonwoven core comprises a blend of fibers with different melting points, a bicomponent thermoplastic binder fiber, or a combination thereof. Such nonwoven cores optionally include secondary fibers and/or other additive materials such as particulate fillers including but not limited to titanium dioxide, carbon black, and the like; or fibrous fillers including but not limited to glass fibers, cellulose fibers, and the like. These components are suitably combined to form a nonwoven core having high compressive strength, that is at least 500 kN/m , in at least the cross-plane direction in addition to a flow capacity sufficient to allow flow of a fluid therethrough. The nonwoven core is capable of facilitating flow-through of liquids when the reactive geocomposite mat is subjected to substantial compression for at least one year, and at least up to a specified or designated industry lifetime expectation, such as 3 years, 5 years, 10 years, 20 years, 30 years, 40 years, 50 years, 60 years, 70 years, 80 years, or even longer when placed in one or more geographical installations.

In embodiments, the nonwoven core is formed from or includes one or more bicomponent fibers. Nonwoven fabrics made from bicomponent or sheath-core type fibers are disclosed in, for example, Wincklhofer et al., U.S. Pat. No. 3,616,160; Sanders, U.S. Pat. No. 3,639,195; Perrotta, U.S. Pat. No. 4,210,540; Gessner, U.S. Pat. No. 5,108,827; Nielsen et al, U.S. Pat. No. 5,167,764; Nielsen et al., U.S. Pat. No. 5,167,765; Powers et al., U.S. Pat. No. 5,580,459; Berger, U.S. Pat. No. 5,620,641; Berger, U.S. Pat. No. 6,174,603; Hollingsworth et al., U.S. Pat. No. 6,146,436; Dong, U.S. Pat. No. 6,251,224; Sovari et al., U.S. Pat. No. 6,355,079; Hunter, U.S. Pat. No. 6,419,721; Cox et al, U.S. Pat. No. 6,419,839; Stokes et al, U.S. Pat. No. 6,528,439; Amsler, U.S. Pat. No. H2,086 and Amsler, U.S. Pat. No. 6,267,252. Such nonwoven cores have been made by both air laid and wet laid processing and have been used in both air and liquid filtration applications with some degree of success. The principle of operation of bicomponent fibers in forming thermally bonded, or welded, nonwoven cores is well understood.

In some embodiments, the nonwoven core is formed by melt extrusion of thermoplastic fibers through an orifice situated to extrude thermoplastic in a substantially vertical direction, further wherein the orifice is designed and adapted to jet molten thermoplastic from the orifice and onto a first, moving geosynthetic layer. In some embodiments, the thermoplastic is jetted onto a moving surface having a profile. A profile surface is one bearing a three-dimensional structure, as opposed to a substantially flat/planar and featureless substrate surface such as a standard film, felt, wire, and the like.

In embodiments, the nonwoven core is a patterned nonwoven core. That is, in embodiments the nonwoven core includes an embossed pattern. The patterned nonwoven core is formed by methods similar to those used to thermally emboss thermoplastic materials, which are well understood in the art. One such method is melt spinning fibers onto a moving surface having a profile, as described above. In some embodiments the embossed pattern includes wells, i.e. cavities or concave regions, wherein the dimensions of the wells are suitable for disposing and/or entrapping one or more particulate materials therein. The wells or cavities provide an open, porous assembly or arrangement of fibers that is suitable for unimpeded fluid flow into and out of the cavities, provided that the fluid has a dynamic viscosity of about 20 cP or less or about 10 cP or less under conditions of temperature and shear within the reactive layer. In some embodiments, the patterned nonwoven core includes a pattern having a generally recognizable description to many people, for example an "egg carton" type pattern, or a "corrugated" pattern, or a "waffle" pattern.

The dimensions of the embossed pattern are suitable for retaining particulate materials disposed therein even under conditions of fluid flow, such as a water source flowing into, out of, around, or through the wells, cavities, or concave regions having particulate materials disposed within. In some embodiments, the embossed pattern effectively provides both convex and concave features from the perspective of a major side of the nonwoven core. In some embodiments, the embossed pattern constitutes a series of wells or cavities on both major sides of the nonwoven core. The embossed pattern includes wells or cavities on at least one major side thereof that have at least one average dimension that is greater than the average size of the openings between fibers of the nonwoven. Thus, reactive particles of a size intermediate between an average cavity/well size, on the upper end, and an average fiber- to-fiber spacing, on the lower end, are retained within the wells or cavities of the nonwoven core and do not leave the wells or cavities via fiber-to-fiber openings. An average size of a reactive particulate is selected by the user, for example by comminution followed by sieving or another method conventionally used in the industry to select a size range of particulate materials, to be greater than an average opening size between fibers of the nonwoven core but smaller than an overall dimension of the patterned cavities or wells. Such reactive particles are suitably disposed within a well or cavity and are retained therein within the reactive geocomposite mat during flow of a fluid therein.

Additionally, the dimensions of the embossed pattern are suitable for retaining particulate materials disposed within the nonwoven core of the reactive geocomposite mat regardless of the orientation of the mat relative to the earth and regardless of fluid present and/or flowing therein. It is a feature of the reactive geocomposite mat that the reactive layer is secure e.g. when the mat is "dry" (that is, no liquids are flowing within the mat), and the reactive layer remains substantially in place within the embossed pattern of the nonwoven core during movement and changes in orientation.

Referring to the embodiment of FIG. 1A, web-type mat device 100 first major side 10 and second major side 50 comprising layers 20, 30, 40, 60 may suitably be cut, manipulated, placed, situated, or oriented in any direction including substantially horizontally, substantially vertically, and positions between these, without limitation; further, orientation of device 100 may be substantially flat, or may be irregular, curved, or angled, for example even rolled into a cylindrical shape such as indicated by 80 in FIG. 1A. During installation in anticipation of use, device 100 may be wrapped around an article, may be placed contiguous to an article such that the mat overall conforms to the article, and the like without limitation. Such movement or placement is common, for example, during selection of a mat portion and cutting the portion from the web in anticipation of terranean or subterranean placement; or during placement of a reactive geocomposite mat portion within a terranean or subterranean environment. Even further, flow of a liquid into, out of, or within device 100, described above in reference to FIG. 1 A and three dimensional space x, y, z, occurs regardless of the orientation of the reactive geocomposite mat during the flow. During flow of a liquid into, out of, or within device 100, the reactive layer remains substantially secure and placed as shown in 100(B) of FIG. IB. The fluid flow direction can change as a result of orientation of the reactive geocomposite mat, but the flow occurs while the mat is oriented in any direction while the reactive layer remains substantially fixed within the nonwoven core.

The nonwoven core is bonded to the first and second geosynthetic layers by chemical (adhesive) or thermal bonding (welding). In some embodiments, the substrate onto which a nonwoven core is formed, such as by use of a process described above, is the first geosynthetic layer, and adhesion of the nonwoven core to the geotextile is incurred by thermal bonding or welding contemporaneously with the process of fiber and fabric formation. In other embodiments, the nonwoven core is thermally bonded, or welded, to a first geosynthetic layer contemporaneously with embossing a pattern onto the nonwoven core. In one such non-limiting example, a nonwoven core is formed using one of the techniques or methods described herein; then the nonwoven core is passed through a patterned nip that is heated sufficiently to melt or partially melt the fibers to achieve bonding or welding, while also causing pressurized contact at the nip of some portion of the nonwoven core with the first geosynthetic layer. The patterned nip includes a nip roll having protrusions extending away from the nip roll, the protrusions having a generally parallelepiped, cube corner, cylindrical, or conical shape. In embodiments the shape is a truncated pyramid, truncated cube corner, or truncated conical shape. As used herein in context, the term "top" of the shape means the portion of the shape extending furthest away from the nip roll. In some embodiments, the shape is a truncated pyramidal shape, wherein the top of the shape is generally square or rectangular and wherein at least one dimension of the square or rectangle, i.e. a "length" or a "width", is about 1 mm to 2 cm. The nip roll is heated to a temperature sufficient to melt at least a portion of the thermoplastic present in the nonwoven fibers. As the nonwoven core and the first geosynthetic layer are passed through the heated nip, the nonwoven fibers contacting the top of each truncated pyramid of the nip roll are pressed into contact with the geotextile first layer while becoming at least partially melted, thereby forming a weld-type bond with the geotextile. The embossing and contemporaneous welding further result in a truncated pyramidal cavity shape imparted to the nonwoven core layer, the general shape of which is substantially the inverse of the pattern present on the nip roll.

Nonwoven fabrics and patterned nonwoven cores similar to those described herein, or methods useful for making the nonwoven cores or patterned nonwoven cores described herein, are disclosed, for example, in Stapp, U.S. Pat. No. 4,012,249; Rasen et al., U.S. Pat.

No. 4,177,312; Vollbrecht et al., U.S. Pat. No. 4,212,915; Bronner, U.S. Pat. No. 4,324,749;

Bronner, U.S. Pat. No. 4,329,392; Van Vliet, EP No. 0 526 848; Meijer et al., Intl. Pub. No.

WO 2007/147562; Bronner et al., GB Pat. Appln. No. 2 064 607; Wingfield, Intl. Pub. No.

2010/026510; and Daimler et al, U.S. Pat. No. 3,934,421; the teachings of which are incorporated herein by reference in their entirety and for all purposes.

The cavities, wells, or concave portions of the patterned nonwoven core have spaces between fibers that vary, given the random patterns inherent in the formation of nonwoven cores. However, fiber-to-fiber spaces in the patterned nonwoven core generally range from about 0.1 mm to 2 cm in at least one direction and may have an average fiber-to-fiber spacing of about 1 mm to 1 cm as determined by optical methods.

The following exemplary ranges and scenarios are provided for illustrative purposes only and are not intended to be limiting. In some embodiments, an average fiber-to-fiber spacing of a nonwoven core is about 5 mm. In embodiments, a patterned nip roll includes truncated pyramidal shaped protrusions. The top portions of the protrusions are squares spaced about 2.5 cm from center to center on the nip roll. Each protrusion extends away from the patterned nip roll a distance of about 2 cm. The inverse of this pattern is imparted to the nonwoven core while also welding the nonwoven core to a first geosynthetic layer. This is accomplished by moving the geotextile and the nonwoven core together through a heated nip including the patterned nip roll, wherein pressurized contact of the top portions of the protrusions of the patterned nip roll with the nonwoven core melts at least a portion of some of the fibers of the nonwoven core and contemporaneously welds the molten thermoplastic (from the molten fibers) to the first geosynthetic layer.

The cavities or wells of the patterned nonwoven core are filled with a reactive particulate having an intermediate particle size, as described above. Then a second geosynthetic layer is applied to the nonwoven core such that the nonwoven core, containing the reactive particulate, is disposed between the first and second geosynthetic layers. The second geosynthetic layer is bonded chemically, such as by use of an adhesive, or thermally, such as by heating the second geosynthetic layer, some portion of fibers of the nonwoven core, or both sufficiently to at least partially melt some fibers of the nonwoven mat and provide a thermal weld. Where thermal welding is desirably carried out, it is advantageous that one or more polymers used in the first, second, or both geosynthetic layers has a melting point that is within 10 °C, or within 5 °C, or within 3 °C, or less of 3 °C of one or more polymers present in the nonwoven core. In some such embodiments, one or more polymers used in the first, second, or both geosynthetic layers is the same or is substantially the same as one or more polymers present in the nonwoven core.

The reactive particulate is any particulate material that reacts with a fluid, reacts with a component of the fluid, or elutes a compound into the fluid. In some embodiments where the fluid is a water source, the reactive particulate is selected by the user based on the need to treat the water source and how water flow will be encountered by the mat; in some embodiments the selection is also based on the availability of particle sizes useful as described above. In some embodiments, the reactive particulate includes a selected average particle size that is sufficiently large to substantially prevent the particulate from moving between fibers of the nonwoven core. In some embodiments, the reactive particulate includes a selected particle size that is intermediate between a dimension of an embossed well or cavity, and a fiber-to-fiber dimension of the nonwoven core. An average particle size, minimum particle size, or maximum particle size, combination thereof is selected by the user for the reactive particulate employed.

Reactive particulates useful in the reactive geocomposite mats are particulate materials as formed or as provided by one or more comminution processes. In some embodiments, a reactive particulate includes a blend of two or more average size particles. In embodiments an average particle size, or a maximum particle size, or particle size range as determined by methods such as sieving, is about 1 mm to 15 cm, or about 2 mm to 15 cm, or about 3 mm to 15 cm, or about 100 μιη to 10 cm, or about 100 μπι to 8 cm, or about 100 μπι to 6 cm, or about 100 μπι to 4 cm, or about 100 μιη to 2 cm, or about 100 μηι to 1 cm, or about 100 μπι to 8 mm, or about 100 μιη to 6 mm, or about 100 μπι to 4 mm, or about 1 mm to 1 cm, or about 1 mm to 6 mm. The reactive particle size, average particle size, maximum particle size, and particle size distribution is selected by one of skill to meet the particular needs of the user and also meet the particular needs and requirements set forth above for particle size of the reactive particulate. Factors such as desired overall mat thickness, particle size availability; availability of comminution equipment, expected rate of fluid flow into, within, or out of the reactive geocomposite mat, conductivity or permeability of the particles themselves; and reaction rate, elution rate, or removal rate of one or more compounds facilitated by the particles also affect the decision of the user with regard to reactive particle selection.

In one useful but non-limiting example, an optically determined average pore size, i.e. fiber-to-fiber spacing of a patterned nonwoven core, is about 5 mm; about 90% of the fiber- to-fiber spacing is less than 1 cm. The patterned nonwoven core includes truncated pyramidal shaped cavities about 2 cm deep. The reactive particulate is selected to have an average particle size of about 2 cm or less, in embodiments about 1 cm average particle size, and in some embodiments a minimum particle size of about 1 cm, a maximum particle size of about 1.5 cm, or both in order to provide an average particle size suitable for filling one or more cavities one or more both sides of the patterned nonwoven core while then preventing the particulate from simply falling through the nonwoven fibers or being washed therefrom by the movement of fluids therethrough.

The reactive particulate is added to the nonwoven core prior to, contemporaneously with, or after imparting the pattern to the nonwoven core and/or bonding or welding the nonwoven core to the geotextile first layer. Then a second geosynthetic layer is applied to the patterned nonwoven core having the reactive particulate disposed therein. The second geosynthetic layer is applied contemporaneously with, or after adding the reactive particulate to the nonwoven core. The second geosynthetic layer is bonded or welded, e.g. with adhesive or by thermal welding, to some portion of the fibers of the nonwoven core to substantially enclose the reactive particulate within the confines of the nonwoven core and form the reactive geocomposite mat.

The finished reactive geocomposite mat comprises, consists essentially of, or consists of two geosynthetic layers having a reactive layer disposed therebetween. The reactive layer comprises, consists essentially of, or consists of a nonwoven core and a reactive particulate. The reactive particulate is substantially trapped within the geocomposite mat: that is, fluid flow into and out of the reactive layer does not substantially cause the reactive particulate to become dislodged from the mat or to be conveyed within the mat. The reactive geocomposite mat allows the flow of a fluid both into and out of the reactive layer, wherein the fluid exiting the reactive layer has a lower concentration of a contaminant, has a compound dissolved in the fluid that is added to the fluid when the fluid contacts the reactive particulate, or both. FIG. 1A is a schematic representation of one exemplary embodiment of a reactive geocomposite mat. Web-type mat device 100 has first major side 10 comprising first geosynthetic layer 20 and second major side 50 comprising second geosynthetic layer 60; disposed between layers 20, 50 is reactive layer 30 comprising a nonwoven core 40 and reactive particulate (not shown). The first geosynthetic layer 20, second geosynthetic layer 60, and reactive layer 30 together define thickness 70 of device 100. Also shown in FIG. 1A is the web-based nature of device 100: the manufacturing of the device, and flow of a fluid into, out of, or within device 100 is described by three dimensional space x, y, z wherein x is generally also the "machine direction" for purposes of manufacturing and thus also may be used to describe the "length" of device 100. The y direction is thus width with respect to manufacturing. The x and y directions are indicative of the direction of "in-plane flow" of a fluid into, out of, through, or within device 100. Device 100 may be manufactured in roll form 80 as shown, wherein movement of the web in the x direction allows for windup in roll form 80. The z direction indicates thickness 70 of device 100 and also indicates the direction of "cross-plane flow" of a fluid into, out of, or within device 100.

FIG. IB is a close-up view of device 100 at area B of FIG. 1A. Shown in FIG. IB is first geosynthetic layer 20, second geosynthetic layer 60, and reactive layer 30 defining thickness 70 of device 100. Reactive layer 30 includes nonwoven core 40 having a pattern 42, and further comprising reactive particulate 46. Reactive layer 30 may also be referred to as a "drainage layer" since without the reactive particulate, layer 30 would function to allow drainage of a fluid therethrough.

The benefits, utility, and uses of providing reactive particulate within a nonwoven core that allows substantially free flow of fluid therethrough include at least the following, where those of skill will recognize that other benefits may also be associated with the reactive geocomposite mat designs and adaptations described herein and apparent upon such description. In one example of such a benefit, in some embodiments the reactive geocomposite mat is an elution device, wherein the eluant flows actively or passively into the reactive layer to contact the reactive particulate and form an eluate. The eluate then is dispensed from the mat. In some embodiments, the eluate is a fluid that includes the eluant plus one or more compounds added thereto from the reactive particulate. In other embodiments, the eluate is a fluid that includes the eluant minus one or more compounds removed therefrom by the reactive particulate. In another example of such a benefit, in some embodiments the reactive geocomposite mat is a filtration device to capture one or more contaminants by reacting with them to form a precipitate that is substantially trapped within the mat reactive layer. In yet another example of such a benefit, in some embodiments, an eluate includes both compounds added to the eluant, and compounds removed from the eluant: that is, one or more compounds are added to the eluant, and one or more compounds removed from the eluant when the eluant contacts the reactive particulate as it flows within the mat and is eventually dispensed as eluate.

The fluid flows into the reactive layer either from the edges of the mat - thus, in a direction substantially coplanar with the mat - or by traversing the first or second geosynthetic layer in a direction substantially perpendicular to the mat. In some embodiments the fluid flow is a passive fluid flow, and the reactive geocomposite mat is positioned to intercept at least a portion of the expected flow. In other embodiments the fluid flow is caused to occur, such as by action of a pump or another engineered structure, device, or apparatus designed and adapted to modify the flow of a fluid. A treated fluid then flows out of the mat in a direction substantially coplanar with the mat or by traversing the first or second geosynthetic layer in a direction substantially perpendicular to the mat.

It is a feature of the invention that the geocomposite mat has both high compressive strength and high porosity. These features work together to provide the observed performance attributes reported herein. As recited above, the compressive strength of the nonwoven core itself is about 500 kN/m ² to 3,000 kN/m ² . The addition of the reactive particulate does not decrease, and in some embodiments increases the effective compression strength of the reactive layer and thereby also the overall compressive strength of the reactive geocomposite mat.

The high porosity of the reactive geocomposite mat will be appreciated by one skill upon a reading of Malasavage, N.E., Jagupilla, S.C., Grubb, D.G., Wazne, M., and Coon, W.P., J. Geotech. Geonenviron. Eng., 138(8), 981-991 (2012). Malasavage et al. reported that the hydraulic conductivity (per ASTM D2434) of compacted steel slag fines (<9.5 mm fraction) to a minimum of 95% relative compaction of the maximum dry unit weight per ASTM D1557 was on the order of 6.12E-03 cm/s. In embodiments, the reactive geocomposite mat includes a reactive particulate, for example steel slag fines, corresponding to about 20% to 80% relative compaction of the maximum dry unit wright of steel slag fines, for example about 25% to 80%, or about 35% to 80%, or about 40% to 80%, or about 45% to 80%, or about 50% to 80%, or about 20% to 75%, or about 20% to 70%, or about 20% to 65%, or about 20% to 60%, or about 20% to 55%, or about 20% to 50%, or about 30% to 70%, or about 30% to 60%, or about 40% to 70%, or about 40% to 60%. The loading is selected by the operator during manufacturing of the reactive geocomposite mat. Selecting 50% relative compaction in an exemplary reactive geocomposite mat, taken together with "SP soil" type as determined by the Unified Soil Classification System (also referred to as poorly graded sand), results in a calculated hydraulic conductivity of the steel slag fines as loaded within the reactive geocomposite mat on the order of 1E-02 to lE-01 cm/s (Freeze, R.A., and Cherry, J.A., 1979, Groundwater, Prentice Hall, Englewood Cliffs, NJ, p. 604). Adopting the value of 5E-01 cm/s for illustration purposes is approximately an order of magnitude greater than the compacted value (6.12E-03 cm/s), which is consistent with a relatively loose, open, or porous matrix.

This open matrix structure and high compression strength of the reactive geocomposite mat enables fluid flow into, out of, and within the reactive layer even where the reactive geocomposite mat is placed under pressure conditions. Pressure conditions include subterranean placement and placement within, underneath, or proximal to man-made structures including buildings, walls or containments to deflect, hold, or move water sources, and the like.

FIG. 2 is a schematic depiction of one method of manufacture of device 100. Web- based manufacturing device 1000 includes feed hopper 200 having external guider flanges 210 and internal guider flanges 220 for applying a reactive particulate 46 to patterned nonwoven core 40 to form a reactive layer 30. The feed hopper 200 includes a weight metering system (not shown) to meter an amount of reactive particulate to be applied to nonwoven core 40. Nonwoven core 40 is fed into manufacturing device 1000 in a substantially vertical disposition. This arrangement provides a substantially even distribution of particles 46, including particles having a range of particle sizes, compositions, and the like applied to both sides of the patterned nonwoven core 40.

It is also possible to add a first reactive particulate to a first major side of the patterned nonwoven core while the core is disposed substantially horizontally, followed by welding or bonding the first geosynthetic layer to the first major side; then turn the web over and apply a second reactive particulate, or a second amount of the first particulate, to the second major side of the patterned nonwoven core while the core is disposed substantially horizontally, followed by welding or bonding the second geosynthetic layer to the second major side of the mat. Further, it is possible to fill only one of the first and second major sides of the nonwoven core, for example to allow for greater fluid flow capacity, even where cavities or wells are available to fill with reactive particulate on both major sides of the patterned nonwoven core.

First and second geotextiles 20, 60 are also fed into device 1000 as shown, and after reactive particulate 46 is applied to nonwoven core 40 to form reactive layer 30. Reactive layer 30 is contacted and compressed with geotextiles 20, 60 with assistance of rollers 300 at nip 301. In some embodiments, the width of the geotextiles 20, 60 is greater than the width of nonwoven core 40 to allow for side flaps (not shown) which may be used to create sealed edges of finished device 100.

With the assistance of web guides 400 and additional rollers 300, reactive layer 30 is urged toward first bonding device 500. Bonding device 500 is situated such that reactive layer 30 and geosynthetic layers 20, 60 are substantially horizontally situated. Bonding device 500 includes at least first lifting shoe 510, first cleaning battens 520, and first heat source 530 in that order as reactive layer 30 is urged in web direction (x direction indicated in FIG. 1A). Lifting shoe 510 separates geosynthetic layer 60 from contact with reactive layer 30, and cleaning battens 520 wipe or otherwise clean the surface of the geosynthetic layer 60 to be bonded or welded to the nonwoven core 40. After cleaning, heat source 530 heats geosynthetic layer 60, reactive layer 30, or both sufficiently to melt at least some portion of one thereof and cause thermal welding of layers 30, 60. Reactive layer 30, now bonded to geosynthetic layer 60, proceeds to second bonding device 501. Bonding device 501 includes at least second lifting shoe 511, second cleaning battens 521, and second heat source 531. Lifting shoe 511 separates geosynthetic layer 20 from contact with reactive layer 30, and cleaning battens 521. After cleaning, heat source 531 heats geosynthetic layer 20, reactive layer 30, or both sufficiently to melt at least some portion of one thereof and cause thermal welding of layers 20, 30. An optional system of cleaning battens (instead of 520, 521) that operate in the transverse direction to the web direction (that is, the y-direction) can be used to remove any excess reactive particulate, fines and/or debris from the web edges.

Once the second thermal welding is accomplished, device 100 may be rolled up and stored for future use. In some embodiments the side edges of device 100 indicated by the y direction shown in FIG. 1A are trimmed or sealed prior to storage or use. For example, a series of standard edge filling, heatbonding and trimming of the excess side flap materials can be likewise undertaken (not shown) before feeding the finished device 100 to the production roll. Referring to FIG. 1A, edges of device 100 in width direction y are not shown in FIG. IB. Edges on the width direction of web-based device 100 may be chemically bonded or thermally welded together, or to another woven/non-woven geotextile to provide cross-flow filtering capability. Typical woven and non-woven geotextile weights where the primary function is filtering and particle separation are on the order of 4 to 16 oz per square yard.

In such web-based manufacturing methods, typical roll lengths (x-direction, or the direction of movement of the mat e.g. through a nip) are about 15 to 100 meters, but this is not in any way limiting of embodiments where longer mats are required. Web length is selected by the user. Web width is also selected by the user. However, in the geotextile industry drainage geocomposites may have a web width of about 15 cm to 50 cm for edge drain applications, whereas board or mat type applications demand a web width of about 1 meter to 5 meters.

In embodiments, the reactive particulate is present in the reactive geocomposite mat at about 1 kg m ² to 50 kg/m ² , for example about 2 kg/m ² to 20 kg/m ² . The reactive particulate is one or more of: biologically-active, thermochemically reactive, capable of e luting a compound, capable of adsorbing a compound, surface-active, and strongly pH buffering. In embodiments the reactive particulate is or two or more thereof. In embodiments, mixtures of two or more different particulates are employed as the reactive particulate, wherein the two or more particulates differ in one or more of composition, porosity, particle size, surface area, particle circularity, average aspect ratio, wherein property differences including porosity, particle size, surface area, circularity, and aspect ratio are compared as averages, minimums, or maximums according to a selected method published by ASTM International of West Conshohocken, PA. In embodiments, the particulate is in the form of, or resembles, fibers, for example wherein an average aspect ratio is more than 5 in a direction.

In embodiments, suitable reactive particulate materials include porous particulates, alumina-silicate materials, soil-like minerals, amo hous/clystalline reagents, colloidal media, coatings, composite materials, industrial byproducts, recycled materials, iron-rich solids and mixtures thereof. Non-limiting examples of specific types of useful reactive particulates include wood mulch, wood sawdust, soil, manure, granular activated carbon, organoclay granules, zero valent iron, apatite, AQUABLOK® particles, manufactured by AquaBlok, Ltd. Of Swanton, OH) slow release oxidants/reductants, and others.

In some embodiments, an industrial byproduct useful as the reactive particulate is a steel slag particulate. "Slag" is an industrial term of art for solid byproducts formed during a metal refining process, such as the smelting of various ores of copper, zinc, lead, etc. Examples of suitable slag sources include but are not limited to blast furnace (BF) slags, basic oxygen furnace (BOF) slags, electric arc furnace (EAF) slags, and related ladle slags. In some embodiments, a steel slag is a blend of slags obtained from two or more slag sources. In some such embodiments, the two or more slag sources differ in terms of chemical composition, average particle size, or both. In some embodiments, a steel slag is a blend of slags having two or more average particle sizes. In some embodiments, a steel slag is a blend of slags obtained from two or more sources such as BF, BOF, EAF, or ladle sources. It is an advantage of the methods and articles of the invention that any blend of slags from various slag sources are easily employed within the reactive geocomposite mats of the invention.

It is known to employ the aqueous eluate of steel slag for the purpose of fertilizing plants. See, e.g. U.S. Pat. No. 6,748,698. Above-ground elution devices packed with steel slag are described by Grubb, Appl. No. PCT US2016/042249, wherein e.g. rainwater may enter the elution device to form an aqueous steel slag eluate, and the eluate is then applied to the ground to react with and cause precipitation of e.g. waterborne phosphates that are the culprit in agricultural fertilizer runoff, or it may itself be applied to fertilize plants. It is also known to employ steel slag in a filtration device or within the ground, where it is placed in the path of a source of distressed water, such as a polluted ground water or surface water. The slag causes an immobilizing reaction with certain harmful chemicals dissolved therein. Thus, for example, Hilton Jr. et al., U.S. Patent No. 6,893,570 disclose in-ground pond-type structures loaded with steel slag to capture mine drainage wastes, wherein the slag components) react with the drainage waste to produce manganese species that precipitate and can be recovered. The pond is situated at an elevation wherein manganese-bearing waste water can flow into the pond. Further, Drizo et al., Environ. Sci. Technol. 2002, 36, 4642- 4648; Pratt et al., Environ. Sci. Technol. 2007, 41, 6585-6590; Drizo et al., Environ. Sci. Technol. 2008, 42, 6191-6197; Bowden et al., Environ. Sci. Technol. 2009, 43, 2476-2481; Eveborn et al., Environ. Sci. Technol. 2009, 43, 6515-6521; Claveau-Mallet et al., Environ. Sci. Technol. 2012, 46, 1465-1470; Barca et al, Environ. Sci. Technol. 2013, 47, 549-556; Claveau-Mallet et al., Environ. Sci. Technol. 2014, 48, 7486-7493; Grubb et al., J. Hazard. Toxic Radioact. Waste 2014.18; Blowes et al, U.S. Patent No. 5,876,606; Phifer et al., U.S. Patent No. 6,254,785; Smith, U.S. Patent No. 6,602,421, Drizo et al., U.S. Patent Pubs. 2008/0078720 and 2013/0032544 and U.S. Patent No. 8,721,885; and others have proposed, optimized, or studied passive or active immobilization of waterborne phosphates by applying the phosphate-containing water source to a filtration media and/or device packed with particulate steel slag. As the phosphate-containing water is passed through the filtration device, the phosphorus is precipitated and retained within the filtration device, and the resulting purified water is allowed to pass through. The filtration devices are situated in the path of polluted water that is passively or actively applied steel slags useful in the elution devices of the invention are the alumina-siliceous byproducts of iron making or steelmaking processes wherein iron ore, scrap metal, and/or alloys are melted in combination with one or more calcium-rich compounds or materials.

In some embodiments, the reactive particulate is a blend thereof to achieve a particular treatment of a fluid. It is a feature of the reactive geocomposite mats of the invention that a particulate blend may be suitably tailored to address a specific treatment of a distressed fluid. To that end, particular treatments may include adding blends of two or more reactive particulates to the reactive geocomposite mat. For example, blends of wood mulch, industrial steel slag, and porous carbon added to the reactive layer of the reactive

geocomposite mat at particular ratios based on treatability studies may be used to remove or reduce the amount of certain phosphorus, nitrogen, sulfur and heavy metal species simultaneously from a distressed water.

In some embodiments, the reactive geocomposite mat provides the ability to form an eluate by the contact of a fluid source with the reactive layer of the reactive geocomposite mat, followed by egress of the eluate from the mat wherein the eluate is the treated fluid. Such methods and uses are termed "elution uses" and similar terms. In some embodiments the fluid source is a distressed fluid source. Aqueous fluids moving into the mat may be termed "water source" whereas the aqueous fluid leaving the mat may be termed "treated water source". In some embodiments, a water source is rainwater, surface water, fresh water, ground water, connate, or another solution of water and one or more solid compounds dissolved therein. In some embodiments the water source is a distressed water source.

The reactive geocomposite mat is also contemplated to allow immobilization of certain undesirable chemical species, or "contaminants", present in fluid sources proximal to the reactive geocomposite mat and able to flow passively or caused to flow into the mat. Fluid sources including one or more contaminants may be referred to herein as a "distressed fluid source" or "distressed fluid". As discussed above, aqueous fluids moving into the mat may be termed "water source" and aqueous fluids leaving the mat may be termed "treated water source". Where the fluid source includes one or more compounds that are not present in the treated fluid source, associated methods and uses may be termed "filtration uses" "reactive filtration", "filter use" and like terms.

In embodiments, reactive filtration of a water source causes formation of a precipitate and a treated water source, wherein the treated water source has a reduced concentration of at least one contaminant compared to the water source as it entered the mat. In a non-limiting example of a reactive filtration method, a water source having a phosphate dissolved therein flows into the reactive geocomposite mat and contacts a slag particulate therein, whereupon the phosphate reacts with the slag to form a precipitate and a treated water source; and the treated water source flows out of the mat while the precipitate remains within the mat. In some embodiments, a reduced concentration of a contaminant is a concentration that is sufficiently low that it cannot be measured using conventional means to measure the concentration of the species in the fluid.

In embodiments, the reactive geocomposite mat employs both elution and filtration type use mechanisms, wherein one or more compounds are removed and one or more different compounds are added to the treated fluid. Stated differently, a treated fluid can include both a reduced amount of one or more compounds, and an increased amount of one or more different compounds. In embodiments, the reduced amount is or is substantially zero, with regard to the ability of the ordinary skilled artisan to measure the amount of the compound.

In embodiments, the fluid comprises, consists essentially of, or consists of a gas. A gas may include a mixture of two or more gases. In embodiments the gas is a distressed gas or a distressed gas source; that is, the gas comprises a contaminant distributed therein. In embodiments the contaminant is ammonia, methane, hydrogen sulfide, a volatile organic compound (VOC), a semi-volatile organic compound (SVOC), or a mixture of two or more thereof. Thus, disclosed herein is a method for treating a distressed gas, the method comprising operably disposing the reactive geocomposite mat described above in contact with the earth, foundation wall/floor, tunnel liner, etc.; applying a distressed gas source to the reactive geocomposite mat, wherein the applied distressed gaseous source contacts the reactive particulate for a period of time sufficient to form a treated gaseous source; and dispensing the treated gaseous source from the reactive geocomposite mat.

In embodiments, the reactive geocomposite mat is operably applied in contact with the earth, in some embodiments in subterranean disposition, wherein the fluid contacting the mat is a water source. The orientation of the reactive geocomposite mat with respect to the earth is not limited. With regard to the plane of the geocomposite mat, the geocomposite mat may be installed on top of or underneath the ground in substantially horizontal disposition, substantially vertical disposition, or a position between horizontal and vertical. The egress of a water source into or out of the reactive geocomposite mat, as well as the flow of a water source within the nonwoven core, is facilitated by the placement of the mat with respect to the ground in combination with the particular makeup of the geosynthetic layers (i.e. geofilter vs. geomembrane properties). The reactive geocomposite mat is suitably placed by the user to enable a filtration-type use, an elution-type use, or both. One of skill in the art of using geotextiles for drainage applications will understand how to place the reactive geocomposite mat for maximum utility in a selected geographic area.

Subterranean placement of the reactive geocomposite mat gives rise to an interior mat volume comprising the reactive particulate, wherein a water source applied through a geosynthetic layer or applied at the edge of the mat flows into the interior mat volume, wherein said flow causes contact of the water source with the reactive particulate to form an eluate, a treated water source, or a treated eluate. Subterranean placement of the reactive geocomposite mat and the subsequent pressure normally applied to the mat therein does not cause undue compression of the mat, due at least to the high compressive strength of the nonwoven core therein; and flow of aqueous fluids (water source, eluate, treated water source, or treated eluate) can be as high as 20.2 gallons/minute/foot at 250 psf and a gradient of 1.0. Even at pressures as high as 8,000 psf, flow rate through the reactive geocomposite mat is as high as 1.7 gallons/minute/foot for a 1.0 gradient.

Thus, in embodiments, disclosed herein is a method for treating a distressed water source, the method comprising operably disposing a reactive geocomposite mat in contact with the earth; and applying a water source to the interior volume of the geocomposite mat, wherein the water source flows into the interior volume of the mat and into contact with the reactive particulate for a period of time sufficient to form an eluate, a treated water source, or a treated eluate; and dispensing the eluate, treated water source, or treated eluate from the reactive geocomposite mat such that it contacts the earth proximal to the mat. In embodiments the dispensing is proximal to a distressed water source, wherein contact of an eluate or treated eluate with the distressed water source causes formation of a treated water source exterior to the reactive geocomposite mat. In some embodiments, a water source has a first pH and the treated water source, eluate, or treated eluate has a second pH. In some embodiments the first pH is about -1 to 8 and the second pH is about 9 to 13. In some embodiments, the water source comprises one or more of distilled water, deionized water, rain water, tap water, a treated water source, surface water, or groundwater. In some embodiments, the period of time is about 10 seconds to 10 days. In some embodiments, the eluate, treated water source, or treated eluate comprises about 1 mM to 1000 mM calcium hydroxide.

Also disclosed herein is a method for treating a distressed water source, the method comprising operably disposing the reactive geocomposite mat in contact with the earth; applying the distressed water source to the interior volume of the geocomposite mat, wherein the applied distressed water source flows into contact with the reactive particulate for a period of time sufficient to form a treated water source; and dispensing the treated water source from the reactive geocomposite mat. In embodiments, the applying in such methods is caused by natural forces: that is, the method is a passive method. In some such embodiments, the interior volume of the mat retains a precipitate that is the reaction product of a compound present in the reactive particulate and a compound present in the distressed water source. In some embodiments, the distressed water comprises a phosphate compound. In some embodiments, the contact with the reactive particulate causes one or more phosphate compounds to form a precipitate comprising calcium and phosphorus. In such embodiments, the precipitate is retained in the geocomposite mat; in other embodiments, the precipitate is carried along with the flow of aqueous fluid through the reactive geocomposite mat out of and away from the mat interior volume.

Additional advantages and novel features of the invention will be set forth in part by the foregoing, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned through routine experimentation upon practice of the invention.

Experimental Section

Example 1. vertical ("cross-plane") challenge of a reactive geocomposite mat with a "distressed" water.

A sample of steel slag was collected from a steel mill; the slag as received is shown as 46 in FIG. 3. The slag particles were homogenized to provide a particle size upper limit of less than 9.5 mm A subsample of the homogenized slag particles having a representative particle-size distribution was collected for analysis of moisture content and loss on ignition (LOI) by ASTM D2974. A moisture content of 6.33% and LOI of 2.39% was measured for the subsample. The subsample was loaded at 4 lb/ft ² into a polypropylene nonwoven core layer, shown as 41 in FIG. 3, having a square grid or waffle pattern defining a total nonwoven layer thickness of about 20 mm.

A 1 mg/L phosphate solution was made in 75-L batches using dechlorinated tap water and sodium phosphate dibasic heptahydrate (Na ₂ HP0 ₄ ^■ 7H ₂ 0, ACS grade). The P0 ₄ solution was analyzed for total P0 and ori&o-P0 ₄ using USEPA methods 365.4 and 365.1, respectively. This solution was employed in the test described below as

representative of a "distressed water source".

A flow-through column was constructed to test a reactive geocomposite mat vertical flow (flow through the mat thickness) and resulting treatment efficacy when challenged with a distressed water source. The individual layers assembled to form a geocomposite mat in the test column is shown in FIG. 3. FIG. 3 shows first geosynthetic layer 61 having basis weight of 4 oz, second geosynthetic layer 62 which is the same material as geosynthetic layer 61, and polypropylene nonwoven core layer 41 having a square grid or waffle pattern 43 defining a total nonwoven layer 41 thickness of about 20 mm. Layers 61, 62, 41 were cut to a circular 10 inch diameter configuration. Reactive particulate 46 is also shown as a discrete batch of particles; the particulate 46 was packed on both sides and of layer 41 and further within the "wells" of the waffle pattern 43 of layer 41 to form geocomposite mat construction 101. When assembled, the geocomposite mat construction 101 was 25.4 cm in diameter and 20 mm thick, comprising a total volume of 1,013.4 cm ³ or 1.013 L with a measured pore volume of 0.4 L, making the calculated porosity 0.39.

Referring to FIG. 4, a test column was constructed by securing perforated PVC endcap A (also shown in FIG. 3) to a corresponding PVC pipe K having a 10 inch inner diameter. A geogrid support B (also shown in FIG. 3), was placed over endcap A, followed in order by: geosynthetic layer 61, nonwoven core 41 packed with reactive particulate 46 on both sides thereof, and geosynthetic layer 62, to form geocomposite test mat 101. Then, polypropylene beads C were placed on top of geosynthetic layer 62 in a layer about 1 inch thick in order to uniformly secure the placement of the constituents of geocomposite test mat 101. An enlarged view of assembly A, B, C, 101 including details of assembled layers 61, 41/46, 62 is also shown in FIG. 4. PVC pipe K is secured to base M; base M includes a valve N and drain tube P leading to collection flask R. To test the geocomposite test mat, a test solution D is transferred at a metered rate to PVC pipe K through transfer tubes E, F by action of pump G. Test solution D is applied to the top of the PVC pipe K by spray head H to impact geocomposite test mat 101. Valve N controls the hydrostatic head created by placing pipe K/base M above the level of collection flask R. Further placing the apex of drain tube P level with the uppermost layer of geocomposite test mat 101 mitigates "channeling" of applied fluid between the mat 101 and the inner surface of the tube P by maintaining a saturated condition within the mat.

Using the test setup shown in FIG. 4, a total of 225 L of aqueous fluids were delivered to the top of pipe K via spray head H. The first fluid was 25 L was tap water, while the remaining fluid was the 1 mg/L PO ₄ fluid described above. The fluids were delivered at various hydraulic residence times (HRT), including 30 seconds (25 L of tap water followed by 50 L of impacted water), 60 seconds (100 L impacted water), and 20 seconds (50 L impacted water), which correspond to flow rates of 0.8, 0.4, and 1.2 L/minute, respectively. Effluent samples, each sample being 500 mL, were collected in collection flask R for every 5 L of fluid eluted from the column.

The effluent samples were analyzed for pH, dissolved (ortho-) PO ₄ , total dissolved solids (TDS), and total suspended solids (TSS). The pH, TSS, and TDS measurement samples were not filtered prior to submission for analysis, while ori/zo-P0 ₄ samples were filtered through a 0.45 μπι syringe filter. The pH of a fluid was measured immediately after collection using a Thermo Scientific Orion 3 Star pH benchtop meter. Ortho-VO^ was analyzed via USEPA method 365.1. TSS and TDS were measured following Standard Method 2540 D and C, respectively.

Results of sample measurement are shown in FIGS. 5-8. FIG. 5 is a plot of effluent pH as a function of liquid/solid (L/S) ratio, for the various HRT reported above. FIG. 6A is a plot of effluent ort/zo-phosphate concentration as a function of L/S ratio. FIG. 6B is as plot of percent ort 70-phosphate removed from the 1 mg/L test "challenge" solution as a function of L/S ratio. FIG. 7 is a plot of effluent TDS as a function of L/S ratio. And FIG. 8 is a plot of effluent TSS as a function of L/S ratio.

Example 2: horizontal ("transverse") challenge of a reactive geocomposite mat with a "distressed" water.

The geocomposite mat construction of Example 1 may be tested for horizontal-only flow, based on an estimated hydraulic conductivity of 5E-01 cm s (or 5E-03 m/s) given the size parameters and porosity as reported above. FIG. 9 shows geocomposite mat 102 (same constructions as mat 101) disposed at the bottom of a tank for passive treatment of impacted water as it flows through the mat positioned at the bottom of the apparatus between two reservoirs having different static water levels. The mat is in contact with each reservoir to facilitate horizontal, or in-plane, flow from the reservoir with greater hydraulic head containing environmentally impacted water to that reservoir with a lower hydraulic head having treated water. The annular space above the mat is comprised of a dense, inert solid block which snugly fits into the central chamber to prevent water flow to areas above the mat.

Measurements made in Example 1 indicate that for a mat 102 that is 1 meter in length, challenged with distressed water requiring greater than 90% removal of orthophosphate, a hydraulic residence time of 30 seconds would be needed. To ensure this, the maximum allowable gradient (head difference) between the reservoirs containing impacted and treated waters by Darcy's Law would be i = length /(porosity * K * time) or 1 m / (0.39 * 5E-03 m/s * 30 s) = 16.89. Additionally, total PO4 was measured for the effluent samples of Example 1, and these measurements indicate that to ensure more than 50% removal of total PO4, a hydraulic residence time of approximately 60 s is required. In this case, the maximum allowable gradient is approximately 8.45.

Using the equipment described herein and shown in FIG. 9, further applying the same aqueous fluids employed in Example 1, both orthophosphate and total phosphate are removed in amounts reflecting these expected results.