Electrochemical cementation systems and methods for shoreline protection

Abstract

Methods and systems for the large-scale electrochemical cementation of soils for erosion protection are provided. The methods and systems use cathodes in natural environments to protect coastlines from damage and erosion, protect marine ecosystems, and / or restore marine habitats.

Description

Atty. Dkt. No. 00100-0420-PCTELECTROCHEMICAL CEMENTATION SYSTEMS AND METHODS FOR SHORELINE PROTECTION CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims priority to U.S. provisional patent application number 63 / 791,121 that was filed April 18, 2025, the entire contents of which are incorporated herein by reference.REFERENCE TO GOVERNMENT RIGHTS

[0002] This invention was made with government support under W911NF-22-1-0291 awarded by the Army Research Office. The government has certain rights in the invention.BACKGROUND

[0003] Coastal regions are some of the most densely populated and economically vital areas in the world, facing increasing environmental challenges due to more frequent extreme weather events and rising sea levels. Coastal erosion poses a severe threat, with natural accretion rarely occurring except in cases of environmental disturbances such as deforestation.

[0004] Traditional engineering solutions, such as concrete seawalls, grouting, and beach nourishment, have long been employed to combat erosion, but often offer only temporary relief and can disrupt marine ecosystems. Grouting is the injection of fluids that, once solidified, increases the strength of soils via cementation. However, grouting and other established ground improvement methods suffer from the customary need to inject fluids into the subsurface for cementation. As a result, these methods have several drawbacks, including high energy’ consumption, a significant carbon footprint, adverse environmental impacts, and limited applicability in remote areas.SUMMARY

[0005] Methods and systems for the large-scale electrochemical cementation of coastal soils for shoreline protection are provided.

[0006] One embodiment of a system for the large-scale electrochemical cementation of soils includes: a cathode sized to cover a 1 m2, or larger (e g, 2 m2or larger), area of soil; anAtty. Dkt. No. 00100-0420-PCTanode in electrical communication with the cathode; and a power supply connected to the cathode to apply a voltage or current to said cathode.

[0007] One embodiment of a method for electrochemically cementing soil particles that are in contact with water containing dissolved magnesium-based minerals and calcium-based minerals using a system for the large-scale electrochemical cementation of soils of a type disclosed herein includes the steps of: placing the cathode into or on top of the soil particles; and generating a current between the cathode and the anode to induce the electrodeposition of magnesium-based minerals and calcium-based minerals around and between the soil particles, whereby the electrodeposited magnesium-based minerals and calcium-based minerals and the soil particles form a cemented soil.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Illustrative embodiments of the invention will hereafter be described with reference to the accompanying drawings.

[0009] FIG. 1 A is a schematic diagram showing different mineral binder intrusion mechanisms in the oxidation reduction reaction (ORR) and water reduction reaction (WRR) regimes, with an image of cemented sand particles.

[0010] FIG. 1B shows a qualitative time-lapse progression of soil electrochemical cementation due to the application of an electrical stimulation.

[0011] FIG. 2A is a schematic diagram of an electrochemical cementation system that uses a wire mesh cathode.

[0012] FIG. 2B is a schematic diagram of a portion of a wire mesh cathode for use in the electrochemical cementation of marine soils.

[0013] FIGS. 3A and 3B illustrate the deployment of an electrochemical soil cementation system in an estuary using a single cathode and anode (FIG. 3A) or multiple cathodes and anodes (FIG. 3B).

[0014] FIG. 4 illustrates the deployment of an electrochemical soil cementation system submerged offshore in a seabed.

[0015] FIGS. 5A and 5B illustrate the deployment of an electrochemical soil cementation system along a shoreline using a single cathode and anode (FIG. 5A) or multiple cathodes and anodes (FIG. 5B).Atty. Dkt. No. 00100-0420-PCT

[0016] FIG. 6, panels (a) - (f) are schematic diagrams of the implementation of electrochemical soil cementation systems in various coastal areas.DETAILED DESCRIPTION

[0017] Methods and systems for the large-scale electrochemical cementation of coastal soils for shoreline protection are provided. The methods and systems deploy electrodes in marine environments to protect coastlines from damage and erosion, protect marine ecosystems, and / or restore marine habitats. The methods and systems do not require external fluid injections to cement the soils and can be carried out using low-tech hardware and mild amounts of electrical energy.

[0018] During the electrochemical cementation, calcium and magnesium minerals dissolved in water are converted into solid mineral binders around and within the pores of soil particles to cement soil particles and produce an erosion-resistant cemented soil. The precipitated minerals can form active and inactive bonds between soil particles. Active bonds result from the precipitation of mineral binders around and between soil particles, and result in particle-to-particle cementation upon curing. Inactive bonds result from the precipitation of mineral binders within the pores of soil particles. All these mineral binders, which precipitate when a difference in potential is applied and stop precipitating when the difference in potential is turned off, modify the structure of soils. As a result, the mineral binders also change the engineering properties of the soils, including permeability, stiffness, strength, thermal conductivity, density, volumetric heat capacity, and dilatancy.

[0019] The passing of an electric current in seawater, or other water containing dissolved calcium and magnesium minerals, can yield a variety of reduction and oxidation products depending on the electrochemical deposition parameters, particularly current density.Importantly, not all electrochemical cementation conditions are suitable for practical soil cementation applications; the electrodeposition conditions must be carefully controlled to provide the large-area cementation needed for real-world applications. In the methods and systems for electrochemical soil cementation described herein, the electrically mediated conversion of dissolved mineral salts into soil binders is designed to conduct electrochemical soil cementation at current densities that enable cementation of the soil over a large area while minimizing energy consumption.Atty. Dkt. No. 00100-0420-PCT

[0020] The area over which soil cementation takes place depends on the electrochemical growth processes for the precipitated calcium and magnesium mineral binders. These growth processes depend on whether the minerals are formed in a reaction regime favoring the oxygen reduction reaction (ORR), which favors CaCO3(s) formation, or a reaction regime favoring the water reduction reaction (WRR), which favors Mg(OH)2(s) formation. In both the ORR and WRR regimes, the electrodeposition relies on the generation of hydroxide ions at the cathode; however, the reduction reactions in the ORR and WRR regime require different electrochemical reaction potentials to proceed. At limited potentials,OH~ production is achieved via the ORR as:At larger potentials, selectivity of OH~ production shifts toward the WRR, evolving hydrogen gas:2H2O + 2e−⇌ H2(↑) + 2OH−In both regimes, the generation of OH~ ions leads to an increase in pH near the cathode, with two effects: (1) insoluble magnesium hydroxide Mg(OH−)2precipitates as follows:Mg2++ 2OH−→ Mg(OH)2(↓); and(2) the carbonate equilibrium shifts toward a higher concentration of carbonate ions (CO3~) CO2+ H2O ↔ H2CO3↔ H++ HCO3−↔ H++ CO32−OH−+ HCO3−→ H2O + CO32−Therefore, CaCO3can precipitate via either of the following pathways:Ca2++ CO32−→ CaCO3(↓)Ca2++ HCO3−+ OH−↔ H2O + CaCO3(↓).

[0021] As shown above, CaCO3and Mg(OH)2precipitate in either reaction regime. The CaCO3can precipitate in the form of calcite, aragonite, and vaterite; and the Mg(OH)2can precipitate in the form of brucite. Additionally, hydromagnesite (Mg5(CO3)4(OH)2) precipitates from magnesium, carbonate, hydroxide, and water under alkaline conditions in both regimes, as follows:5Mg2++ 4CO32−+ 2OH−+ 4H2O → Mg5(CO3)4(OH)2·4H2O↓Atty. Dkt. No. 00100-0420-PCT

[0022] Additional details regarding the characteristics of the ORR and WRR regimes can be found in Kwon, Yeong-Man, and Alessandro F. Rotta Loria. Applied Materials Today 38 (2024): 102235; and Landivar Macias et al., Communications Earth & Environment 5.1 (2024): 44, the contents of which pertaining to the ORR and WRR are incorporated herein by reference.

[0023] The current density, which is the electric current per unit area of a material (mA / cm2), used during the electrodeposition of the magnesium- and calcium-based minerals from water is a key parameter that governs the electrochemical reaction regime occurring at the cathode. At least some aspects of the methods and systems described herein are based on the inventors’ discovery that conducting electrochemical soil cementation using a current density window corresponding to a transition region between the ORR and WRR or in the lower potential region of the WRR results in cementation over large areas, as needed for real-world applications, without excessive energy expenditure (FIG. 1 A). This large-area cementation can be attributed, at least in part, to fast mineral formation in the bulk of the soil and / or on and around the cathode due to the formation of hydrogen gas bubbles when the reduction takes place in the transition region between the ORR and WRR or the low potential end of the WRR. These gas bubbles push the precipitating minerals into the soil network, thereby creating an extensive cement binder through and around soil particles (FIG. IB). As such, the methods and systems can be deployed efficiently in real-world marine settings. In contrast, in the ORR, the precipitated magnesium and calcium mineral binders remain confined close to the cathode surface and take too long to be grown for cementation purposes over large areas, thus requiring excessive energy even in these situations.

[0024] While the optimal range for the current density’ window may vary depending on the mineral composition of the water, the current density window generally covers the range from 0.1 mA / cm2to 20 mA / cm2, including the range from 1 mA / cm2to 15 mA / cm2, and further including the range from 5 mA / cm2to 10 mA / cm2. Lower current densities will result in minimal or localized precipitated minerals, while higher current densities will result in widely diffused minerals, but values of current density beyond the provided values will both require excessive energy consumption. The current density within the desired window can be maintained by operating the system in a constant current mode, whereby a constant current is reached over time, or in a constant voltage mode.Atty. Dkt. No. 00100-0420-PCT

[0025] Generally, lower values of current density within the range will result in the dominant precipitation of calcium-based minerals, such as CaCO3in the mineral forms of calcite and aragonite, whereas higher values of current density within the range will result in the dominant precipitation of magnesium-based minerals, such as Mg 0H)2, in the mineral form of brucite. Precipitating CaCO3in the specific polymorph calcite is generally preferable over Mg(0H)2because the calcite mineral is stronger and more stable in the long-term. Nevertheless, both of these minerals can, in any of their forms, serve as effective binders to cement soils.

[0026] The optimal normalized cell potentials, with respect to a standard Ag / AgCl reference electrode, at which the large-scale soil cementation can be carried out will vary' depending upon the nature of the water source. Generally, however, normalized cathodic potentials in the range from -3.00 VAg / Agci to 0 VAg / Agci are suitable, including the range from -1.58 VAg / Agci to -0.197 VAg / Agci. Accompanying normalized anodic potentials of 0 VAg / Agci to +3 VA / Agci are suitable, including the range from +0.204 V.vg / Agci to +2.44 VAg / Agci.

[0027] The electrochemical system includes a cathode and an anode connected to the cathode through an external circuit that includes a current source or a voltage source configured to induce current flow from the cathode to the anode. The cathode and anode can have a variety of geometrical forms and can be formed from a variety of electrically conductive materials, most commonly metals, including metal alloys. However, the cathode should be sized to cover or be inserted under a large area of submerged soil to achieve effective erosion protection. The system can, optionally, also include a pH probe to track the physicochemical conditions as the reactions proceed, as well as a water content sensor to track the humidity distribution in the soil. Large-area soil cementation covering areas with a coverage area of least 10 m2, at least 100 m2, at least 1000 m2, at least 10,000 m2can be achieved.

[0028] Upon the application of a potential across the anode and cathode, calcium and magnesium ions in the water undergo electrochemical reduction reactions at the cathode to form calcium and magnesium minerals that precipitate on, within the pores of, and around soil particles on or near the cathode, while other chemical species present in the water undergo electrochemical oxidation reactions at the anode. As the process continues, the precipitated minerals coalesce into a mineral cement that is resistant to damage and erosion.Atty. Dkt. No. 00100-0420-PCT

[0029] At the anode, complementary reactions are carried out to balance the reduction reactions at the cathode. Such reactions include, for example, oxygen evolution reactions and / or chlorine oxidation reactions. The material from which the anode is made will depend on the complementary reaction being carried out. By way of illustration, for oxygen evolution reactions, common oxygen evolution anodes, such as platinum, can be used.

[0030] Suitable materials for the electrodes (cathode and / or anode) further include, but are not limited to, 316 stainless steel, stainless steel 904L. duplex stainless steel 2205, super duplex stainless steel 2507, Inconel 625, titanium grade 2, and copper cladded carbon steel. Due to the presence of chloride ions in marine waters, preferred materials for the anode include platinum, platinum coated titanium, iridium coated titanium, and ruthenium-iridium coated titanium.

[0031] The methods and systems for electrochemical cementation of marine soils are well designed for use with soils in natural bodies of salinated water, such as oceans, seas, salt lakes, and estuaries, since these waters naturally contain dissolved minerals that can be converted into solid binders for soils. However, the methods and systems can be used for the cementation of soils in other natural or man-made bodies of water that contain dissolved magnesium and / or calcium salts. If these and other compounds capable of providing solid mineral depositions upon an electrical stimulation were not to be naturally present in sufficient quantities in the materials to be treated, they could be supplied through the injection of artificial solutions comprising said compounds.

[0032] The type of soil being cemented will depend on the body of water in which the electrochemical cementation takes place. Soils that are commonly found in natural marine waters include silica soils, calcareous soils, iron soils, or a mixture of two or more thereof. The soils include those containing course- and / or fine-grained sands. Descriptions of the compositions of soils can be found in the United Soil Classification System, as published by the Engineer Research and Development Center of the U. S. Army Corps of Engineers, as updated in 2014. Laboratory experiments demonstrate that electrodeposition is equally effective in silica, calcareous, and iron soils, and virtually any and all soil types.

[0033] A schematic diagram of one illustrative embodiment of a system for electrochemical cementation of coastal soils is shown in FIG. 2A. The system includes a cathode in the form of an electrically conductive wire mesh and an anode connected to the cathode through an external circuit. The wire mesh electrode that serves as a cathode is sizedAtty. Dkt. No. 00100-0420-PCTto cover a substantial surface area of soil along a submerged shoreline in a natural or manmade body of water. The optimal size and circumferential shape of the wire mesh electrode will depend on the size and shape of the shoreline being cemented. The system further includes a power supply (for example, photovoltaic (PV) solar panels, generators, DC power suppliers) connected to the anode and the cathode to apply a voltage or current therebetween. The system can, optionally, also include one or more pH probes and water content sensors.

[0034] The current density conditions and design of the wire mesh electrode used in the electrodeposition of minerals from marine waters described herein are tailored to facilitate large-scale deployment of the cementation modules in real-world environments under conditions of low electricity consumption and high mineral precipitation. The wire mesh electrodes, one embodiment of which is shown schematically in FIG. 2B, include electrically conductive wires laid out in a grid pattern. Apertures in the mesh are defined between the wires. While the wires can be made from a variety of electrically conductive materials, metal wires are a good choice due to their high electrical conductivity and pliability. Stainless steel, carbon steel, and copper cladded carbon steel wires are non-limiting examples. The grid pattern shown in FIG. 2B forms square apertures. However, the grid pattern can be designed to define apertures of various shapes, including circles or rectangles, triangles, hexagons, and other polygons. The wires may be, for example, woven, welded, or knitted.

[0035] Key parameters in the design of the wire mesh electrodes for large-area deployment in a marine environment include wire diameter, mesh aperture size, and the equivalent circular area of the mesh apertures. Although other cathode designs can be used, an advantage of a mesh electrode is the ability to control the location of the deposition of the mineral precipitates directly on the cathode or in the bulk soil by altering parameters of the wire mesh, such as aperture size and / or aperture spacing. For example, to precipitate the magnesium and calcium materials on the cathode and have the deposits form in a denser fashion, a mesh electrode having a smaller aperture size could be used, such that the electrodeposited minerals completely fill in the apertures of the wire mesh. By way of illustration, in beach slope stabilization, large wire mesh panels can be deployed along sandy beaches or conform along slopes to induce mineral precipitation in a distributed mesh pattern. When ecological sensitivity is of concern, wider aperture spacing can be utilized to allow native burrowing animals to move through the mesh without obstruction. Meanwhile, when higher structural reinforcement is of concern, closer aperture spacing can be used to encourage more continuous / dense deposits.Atty. Dkt. No. 00100-0420-PCT

[0036] In scenarios where naturally occurring seawater or other saline solutions containing dissolved magnesium- and calcium-based minerals are limited (insufficient) or non-existent in the vicinity of a soil to be cemented, a solution-distribution system allowing for the uptake and / or storage and distribution of such solutions onto the soil can be employed to enable consistent and controlled electrodeposition. This system may include a combination of pumps, storage tanks, piping (e.g., pipes or tubes), and / or emitters such as driplines or sprinklers, to uniformly wet soils intended for electrochemical cementation (FIG. 2A). In terrains with elevation changes or slopes, this system may be particularly useful. The system can operate such that seawater or other solution containing dissolved magnesium and calcium-based minerals is drawn from nearby sources either manually or via marine-grade, corrosion-resistant pumps; alternatively, the used solution may be brought to the desired site for the sake of treatment. In either case, these solutions may be stored in a tank or alternative reservoir in the vicinity of the cementation area. If a storage tank is used, water distribution from the tank can be carried out either through gravity or via an additional pump. Water distribution may resort to a network of piping / tubing, which can include specialized components such as filters / strainers, valves (pressure-regulating valves, air release valves, check valves, shut-off valves, flush valves), timers, and adapter fittings to control key engineering properties of the wetting fluid, such as chemical composition, temperature, and pH. A temperature and / or pH meter can be included in the system and configured to measure the temperature and / or pH, respectively of water or soil near or in contact with the cathode. Components can optimize the system by allowing for consistent flow, clogging prevention, and / or scheduled wetting, depending on the specific needs of a given treatment area. The solution may be delivered onto the soil to be cemented through emitters, which may include drip emitters (such as inline drip tubing), spray emitters (such as micro-sprinklers, misters, spray stakes), and bubbler emitters (such as micro-bubblers). The type of emitters used are contingent upon factors such as the site’s terrain, the depth of wetting required, the desired distribution and coverage pattern, and / or flow intensity, as different emitters are designed to deliver water in various modes. The versatility of this solution-distribution system enables it to be adapted across various coastal landscapes, even in areas where water may not be locally available. Thus, by carrying out targeted wetting to these areas, the system allows the cementation process to occur in areas that would have become vulnerable eventually, thereby proactively reinforcing these environments before further erosion, damage, or other unwanted effects can take place.Atty. Dkt. No. 00100-0420-PCT

[0037] The methods and systems using mesh cathodes (and other cathodes as described herein) can, optionally, include a layer of backfill material and a cover to protect the growing area of cemented soil as it is forming. In such embodiments, a vertical cross-section from bottom to top would include: the soil to be cemented, the mesh cathode (or other cathode), a layer of back-filled soil fully or partially covering the cathode, and atop cover, which may be made of biodegradable materials, such as a biodegradable coating, sheet, or film (for example, a biodegradable plastic coating, sheet, or film). This can be advantageous because the treatments will require time to be efficient and cement the soils. Therefore, using such a cover could support the cementation process by protecting the soil against waves and other actions while the soil particles get cemented. Biodegradable materials include naturally-occurring or synthetic organic polymers that are degraded in marine environments over periods in the range from three days to twelve months. Such materials include polymers that are degraded by naturally occurring microorganisms in marine water, such as polyhydroxyalkanoates (PHAs). Cellulose sheets are another example.

[0038] In some embodiments of mesh cathodes, the wire diameter of the wires used to form the mesh in the wire mesh cathodes is in the range from 0.1 mm to 10 mm, including in the range from 1 mm to 5 mm. Wire diameters in these ranges render the mesh flexible enough to adapt to diverse coastal terrains. Wire diameters of less than 0.1 mm limit the surface area available for electrochemical reactions, reducing precipitation efficiency and limiting the strength of the mesh. Wire diameters greater than 10 mm may make the wire mesh too rigid, and therefore unsuitable for coastal reinforcement, as it will not be able to flex and adapt to bumpy terrains.

[0039] In some embodiments, the aperture size of the wire mesh cathodes, as measured from wire center to wire center, is in the range from 1 cm to 35 cm, including in the range from 5 cm to 20 cm. Aperture size is the distance between two adjacent wires in the wire mesh. Apertures with sizes in the range from 1 cm to 35 cm facilitate effective soil cementation in a workable timeframe.

[0040] In some embodiments, the equivalent circular areas of the apertures in the wire mesh cathodes are in the range from 0.005 cm2to 1300 cm2(0.0057 cm2to 1225 cm2), including in the range from 0.1 cm2to 100 cm2. The equivalent circular area, defined as the area of a circle equal to the uncovered area within a non-circular mesh aperture (FIG. 2B),Atty. Dkt. No. 00100-0420-PCThas been calculated for aperture shapes such as squares, hexagons, and equilateral triangles. The range set above facilitates effective soil cementation in a workable timeframe.

[0041] Alternatives to wire mesh designs for the cathode include flat plates of various shapes (e.g., rectangular, square, disc), expanded meshes (cut and stretched metal sheets with apertures of different shapes), tubes, including solid and hollow cylinders, needles or thin rods (e.g., wires), electrically conductive geotextiles, ribbons (thin, strips), perforated plates (plates with through-holes), helices (e.g., coiled wires or ribbons), and linear cathodes (flexible cables embedded with cathode material).

[0042] The cathodes, including the wire mesh cathodes, may be a single continuous cathode unit or may be composed of smaller, electrically connected (e.g.. interlocking) cathode units (modules). The use of a modular cathode may be advantageous, as it allows for the tailoring of the size and shape of the cathode. The cathodes should be sufficiently mechanically flexible to allow them to conform to the contours of the soil surface on which they are deployed.

[0043] Plate cathodes take the form of flat sheets that can be laid on or just below the soil surface. Using these plates can be suitable for reinforcing coastal infrastructure like seawalls and piers through the in-situ mineral buildup.

[0044] Tubular cathodes are cylindrical electrodes that can be inserted into the ground either vertically or at an angle. These cathodes may be well suited for strengthening weak soil layers at depth, as tubes offer better penetration and control than flat plates or meshes, allowing for targeted deposition without disturbing the surface or requiring broad excavation. These metallic tubes could be foundation systems, or tubular systems deployed in the field to create barriers against wave action.

[0045] Needle cathodes are thin, pin-like electrodes which can be used for highly targeted electrodeposition in tight / irregular spaces. This can be particularly valuable in settings with weathered rocks or gaps between large coastal boulders, where inserting needles between cracks, fractures, etc. could allow minerals to precipitate directly inside these voids, effectively "healing'’ and strengthening them.

[0046] Cathodes in the form of electrically conductive geotextiles are fabric-like materials with conductive fibers such as carbon or stainless steel embedded within organic polymers. They can simultaneously serve as erosion control mats and cathodes, thus facilitating precipitation across broad areas while also reducing sediment loss due to wind orAtty. Dkt. No. 00100-0420-PCTwater action. Additionally, their flexibility allows them to conform to the terrain, making them suitable for remote or uneven sites where more rigid electrodes may be difficult to install.

[0047] The anodes need not have a large area; the types of anodes that can be used include the cathode designs recited above (i.e., mesh, plate, tube, etc.). While the electrodeposited mineral binders do not form on the anode, the anode facilitates essential oxidation reactions that balance the electrochemical system and play a role in the energy efficiency of the system.

[0048] Plate anodes may be a good choice when space allows for a flat, horizontal layout near the cathode, as their broad surface areas promote uniform current distribution, which can help minimize energy consumption or inefficient current paths. However, if the anode is placed above or too close to the cathode, the acidic environment generated by anodic reactions can diffuse towards the cathode and neutralize the elevated pH that facilitates precipitation at the cathode. Thus, placing these anodes below or lateral to the cathode helps prevent these acidic byproducts generated at the anode from migrating down onto the cathode.

[0049] Tubular anodes may be useful in space-limited environments such as narrow beach zones or nearshore areas. Because they have a compact footprint or can be driven vertically into soil, this form of anode can offer the necessary surface area for current generation without requiring as much plan area. This makes them ideal in settings where the cathode is deployed along a slope, with the anode being able to be located nearby but not directly overhead.

[0050] Wire mesh anodes provide a large surface area with relatively low material use and weight, making them great for shallow, uniform burial over broad areas. They can distribute current evenly, thus improving uniformity of deposition across the cathode.Additionally, the open structure helps encourage better ion flow through the soil, potentially enhancing reaction efficiency and could help reduce gas bubble accumulation.

[0051] As discussed above, the selection of electrode (cathode and / or anode) design and location will depend, at least in part, on the geometry (e.g., landscape) of the environment in which the system is being deployed. Examples of natural landscapes where the electrochemical soil cementation systems and methods can be deployed include estuaries, seabeds, and shorelines.Atty. Dkt. No. 00100-0420-PCT

[0052] Employing the systems and methods in an estuarine environment, specifically on the ocean-facing, saline water areas, allows for a sustainable way to reinforce the soil and reduce erosion in these coastal transition zones, as is depicted in FIGS. 3A and 3B. However, this will not only strengthen the soils but can additionally strengthen already existing erosion mitigators that are found in estuarine environments such as salt marshes, mangroves, and tidal flats. Thus, the electrodeposition systems and methods can aid in protecting and fostering estuarine developments, aquaculture zones, and ecological restoration projects.

[0053] In an offshore setting, the electrodeposition systems and methods can be utilized to solidify the seabed, as demonstrated in FIG. 4. This can further anchor and support offshore marine infrastructure such as marine platforms, wind turbines, subsea cables and pipelines, etc. Thus, instead of transporting heavy materials or using disruptive anchoring techniques, the electrodeposition systems can allow for in-situ hardening of the seafloor, reduce installation costs, minimize environmental disturbance, and support the sustainable expansion of marine industries.

[0054] The electrodeposition systems and methods can be used to cement soils on shorelines of various terrains. For instance, as conveyed in FIGS. 5A and 5B, the electrochemical setup can be deployed to reinforce a slope but could also simply be deployed flatly along the shoreline. Through this technique, infrastructure in coastal environments can be protected against erosion without the need for seawalls or constant beach nourishment, thus enhancing climate resilience while also preserving the natural appearance and function of the shore.

[0055] The locations in which the electrodes are deployed may be completely natural or may include man-made structures with which the electrodes can be integrated. This is illustrated schematically in FIG. 6, panels (a) - (f), which show: (a) cathodes inserted under the soil around bridge supports; (b) a cathode inserted in the soil below a submerged rock wall; (c) a cathode inserted in soil along a submerged natural embankment; (d) a cathode inserted in a man-made embankment; (e) cathodes inserted into a seafloor and anchored to a floating platform; and (f) a cathode inserted into soil above a water reservoir.

[0056] The word "illustrative" is used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as "illustrative" is not necessarily to be construed as preferred or advantageous over other aspects or designs. Further, for the purposes of this disclosure and unless otherwise specified, "a" or "an" means "one or more.”Atty. Dkt. No. 00100-0420-PCT

[0057] The foregoing description of illustrative embodiments of the invention has been presented for purposes of illustration and of description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. The embodiments were chosen and described in order to explain the principles of the invention and as practical applications of the invention to enable one skilled in the art to utilize the invention in various embodiments and with various modifications as suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents.

[0058] If not already included all numeric values of parameters in the present disclosure are proceeded by the term “about’' which means approximately. This encompasses those variations inherent to the measurement of the relevant parameter as understood by those of ordinary skill in the art. This also encompasses the exact value of the disclosed numeric value and values that round to the disclosed numeric value.

Claims

Atty. Dkt. No. 00100-0420-PCTWHAT IS CLAIMED IS:

1. A system for the electrochemical cementation of soils:a cathode sized to cover a 1 m2, or larger, area of soil;an anode in electrical communication with the cathode; anda power supply connected to the cathode to apply a voltage or current to said cathode.

2. The system of claim 1, wherein the cathode is sized to cover at least a 10 m2area of the soil.

3. The system of claim 1, wherein the cathode comprises a mesh.

4. The system of claim 3, wherein the mesh is a wire mesh comprising wires having diameters in the range from 0.1 mm to 10 mm and apertures with sizes, as measured from wire center to wire center, in the range from 1 cm to 35 cm.

5. The system of claim 4, wherein the apertures have equivalent circular areas in the range from 0.005 cm2to 1300 cm2.

6. The system of claim 1, wherein the cathode comprises a solid or perforated plate, a tube, or a helix.

7. The system of claim 1, wherein the cathode comprises an electrically conductive geotextile comprising electrically conductive fibers embedded within an organic polymer.

8. The system of claim 1, further comprising a solution-distribution system comprising a storage tank for holding water comprising dissolved magnesium-based minerals and / or calcium-based minerals and a pump and piping in fluid communication with the storage tank and configured to move the water contained in the storage tank from said storage tank to an area on or around the cathode.

9. A method for electrochemically cementing soil particles that are in contact with water comprising dissolved magnesium-based minerals and calcium-based minerals using the system of claim 1; the method comprising:placing the cathode into or on top of the soil particles; andAtty. Dkt. No. 00100-0420-PCTgenerating a current between the cathode and the anode to induce the electrodeposition of magnesium-based minerals and calcium-based minerals around and between the soil particles, whereby the electrodeposited magnesium-based minerals and calcium-based minerals and the soil particles form a cemented soil,wherein the electrodeposition of the magnesium-based minerals and calcium-based minerals is carried out at a current density in a range from 0.1 mA / cm2to 20 mA / cm2.

10. The method of claim 9, wherein the electrodeposition of the magnesium-based minerals and calcium-based minerals is carried out at a current density in a range from 1 mA / cm2to 15 mA / cm2.

11. The method of claim 9, wherein the electrodeposition of the magnesium-based minerals and calcium-based minerals is carried out at a current density in a range from 5 mA / cm2to 10 mA / cm2.

12. The method of claim 9, wherein the current density favors the electrodeposition of CaCO3over the electrodeposition of Mg(OH)2.

13. The method of claim 9, wherein the soil particles are in an ocean, a sea, a salt lake, or an estuary.

14. The method of claim 9, further comprising covering the cathode and any soil particles on the cathode with a biodegradable material, wherein the biodegradable material is characterized in that it degrades in a natural marine environment within a period of three days to twelve months.

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