ES1278154U - SYSTEM FOR THE FORMATION OF ARTIFICIAL MARINE REEFS AND UNDERWATER STRUCTURES WITH CALCARE COATING INDUCED BY ELECTROLYSIS - Google Patents

Abstract

System for the formation of artificial marine reefs and submarine structures with calcareous coating induced by electrolysis that comprises at least two electrodes, where one is a metallic cathode, which once the electrolysis is finished constitutes the modular unit element (EUM), and another at least one iron anode, where the electrodes are in a concentric or parallel arrangement, and with a fixed and equidistant separation between them, without any contact occurring between them. (Machine-translation by Google Translate, not legally binding)

Description

DESCRIPTION

SYSTEM FOR THE FORMATION OF ARTIFICIAL MARINE REEFS AND

UNDERWATER STRUCTURES WITH INDUCED CALCAREOUS COATING

BY ELECTROLYSIS

System for the formation of artificial marine reefs and submarine structures with calcareous coating induced by electrolysis.

Field of the invention

The present invention belongs to the fields of marine biology and the mitigation of impacts and sustainable exploitation of coastal areas and the maritime strip near the coast. In the field of marine biology, reference is made to the field of restoring marine ecosystems, for example, through the construction of artificial reefs, as well as the mitigation of impacts such as those derived from waste from fattening cages in industrial aquaculture farms. In the field of sustainable exploitation of the maritime strip, reference is made to the construction of structures such as bio-filters of organic matter and for recreational diving activities.

State of the art

There are devices or systems that are similar, or that bear a certain relation to that described in the present invention, which reflect the state of the art with regard to the applications mentioned in the previous section. The following is the reference to several of them.

Regarding elements that can be stacked or can form artificial reefs (manufactured without the use of electrolysis):

Document EP0134855A1 refers to the use of concrete blocks of specific geometry, curved and flat, and with the possibility of joining between them. These blocks usually contain steel reinforcement. Its purpose is to create surfaces on which marine organisms can adhere and develop. One of its problems is the high pH of the solution existing in the concrete pore network, due to its high concentration of alkalis and hydroxide ion. To counteract this high alkalinity, iron sulfate is incorporated into the concrete. These blocks of elevated weight, which are manufactured on land, must be deposited on the seabed, a fact that makes their transport, anchoring and placement much more complicated and more expensive than those corresponding to the present invention. The colonization times of concrete surfaces are much higher than those of the present invention, as they are not covered with calcareous films, similar to those excreted by corals.

Patent US20030138296A1 is based on the use of concrete modular elements with silica fume and reinforcing fiberglass bars, whose main objective is the stability of the anchored structure, against currents and tides, putting said property before manufacturing cost and location and the interaction of the structure with the environment and with marine organisms. The main disadvantages of this type of structures compared to the present invention lie in the fact that they cannot be manufactured in situ and also provide a much greater weight, so their transport and handling become more complex.

Documents US5588538 and US6042300 try to alleviate the environmental impact of used tire waste, reusing it to form geometric structures with the help of skeletons made of various materials. These structures, deposited on the seabed, can form artificial reefs. Of course, it represents a form of reuse of wastes from the automotive industry, however, they are unnatural elements in the marine environment. The physico-chemical nature of the surfaces of these structures cannot be considered the most suitable for the fixation and growth of marine organisms.

It is also possible to find in the bibliography publications that refer to the use of various plastic materials, such as polyvinyl chloride (PVC), for the manufacture of artificial reefs, however, PVC does not represent a suitable surface for the fixation of organisms. marine, since their physicochemical characteristics are very different from those of natural rocks or carbonate layers excreted by corals; Furthermore, the degradation of these elements implies a gradual contamination of the marine environment by microplastics.

On systems that pursue the formation of calcareous deposits by electrolysis:

Document ES2729315T3 refers to a method to fix, on metallic elements, a calcareous deposit that serves as the basis for the generation of marine reefs. However, the description does not cover the possibility of forming stackable elements in the form of mesh cylinders, lighter and more effective for the fixation of biofilters, which allow the composition of larger structures, minimizing, among other factors, transportation costs of large structures and allowing greater interaction of marine species through the gaps in the mesh size.

Document US5543034 uses the method of electrolysis for the formation of calcareous substances on a structure for the creation of artificial reefs in saline solutions or in sea water, using direct, pulsed or intermittent current. It does not consider the geometry of the anodes or their relationship with the formed deposit. In said patent, the electrodes are located close to the cathode or in a position higher than it, without surrounding it. It does analyze the importance of keeping the anode close, but warns of the acidification problems of the medium due to the formation of hydrochloric acid in the vicinity of the anode. The patent does not, in any case, delve into the material that makes up the anode, so it does not take into consideration the possibility of avoiding or minimizing the effect of acidification using iron anodes. Due to the same fact, the document does not consider the benefit of using this type of anodes whose corrosion products favor phytoplankton (Geider & La Roche, 1994) being, therefore, a non-harmful element, as well as an added value in the end. last of the present model.

Document US4623433 refers to the formation of deposits on a metal base or skeleton, with the desired shape, which acts as a cathode, and a metal or metal alloy anode, more electronegative than the metal used for the cathode. In this case, both electrodes are connected in a marine environment and it is necessary that the anode / cathode surface ratio is between 1/30 and 2/1. The document suggests the use of aluminum, zinc or magnesium anodes and a ferrous element as a cathode. Said patent does not use external current in the electrolysis of seawater as an accelerator method of the process, which makes it impossible to control, or regulate, the intensity of current or voltage applied. Not using current sources to control the electrolytic process prevents the use of the same material for anode and cathode, for this reason it does not offer the option of using iron as anode, because the coating system is based on the concept of anode of sacrifice. The patent referred to uses iron only as a cathode. On the other hand, the material of the anodes used does not constitute an added value to the process, being able, in some cases, to generate substances that are harmful to the environment (release of heavy metal ions).

For the aforementioned reasons, derived from the problem that, in general, affects the case at hand, there is therefore the need to provide a system that allows the formation of marine reefs, solving the problems indicated above and respecting the environment, both the habitat of the species as the species themselves, for which the said system must be as innocuous as possible and not alter the ecosystem to be restored.

Description

The inventors have developed a lightweight element, called Modular Unitary Element (EUM), based on a metallic substrate, covered with a layer of calcareous stone or calco-magnesian material similar to that excreted by corals. The coating is obtained by an electrolysis process, for which it is necessary to build a basic electrolytic cell that we will call the Electrolytic Unit (UE).

By grouping several EUMs with the appropriate shape and size, any more complex structure that is necessary for applications such as biofilter systems (restoration of marine ecosystems), artificial reefs, structures for recreational diving, can be built in a modular way, etc. The EUM can be grouped by assembly, welding, fixing with joining elements or stacking, to obtain the final structure, which can have any geometric shape and dimensions, and which we will call Reciphal Structure (ER).

The calcareous, or calco-magnesian coating, is carried out by electrolysis in seawater or saline medium, both in swimming pools and in large volumes of water with continuous movement and agitation of the liquid (open sea, ports, salt flats, etc.).

The main advantages of the present invention with respect to other existing systems with similar purposes are the following:

a) EUM are characterized by their low weight, since they are made of metallic mesh on which the electrolysis is carried out.

b) EUMs can adopt any geometric shape that later allows the construction of more complex subsea structures. c) EUMs can be manufactured on-site at their final location, or they can be manufactured in more controlled environments, such as swimming pools, port areas, salt flats or industrial premises. The latter facilitates a more exhaustive control of your manufacturing process. Once the EUMs are prefabricated, These can be easily transported due to their reduced weight, and the final structure can be assembled in situ by assembling, welding, fixing with connecting elements or stacking the necessary modular elements. d) The particularities of the designed electrolysis process make it possible to avoid, or at least reduce, certain possible impacts that occur with other systems and, at the same time, generate chemical species that are considered beneficial for living organisms in the marine environment. The use of carbon steel or iron anodes prevents the generation of chlorine gas in the manufacturing area, as well as partially reduces the acidification of the liquid medium in the vicinity of the electrolysis area. These two circumstances contribute to the minimization of risks in the manufacturing process. The products of the anodic electrochemical reaction, which are iron ions (Fe2 + and Fe3 +), have been recognized as species that favor the development of phytoplankton (Geider & La Roche, 1994). This last advantage is particularly relevant for cases where the manufacturing process is in situ in the marine environment itself. e) In the electrolysis process, they work with elements with a large mesh size that allow maintaining a greater homogeneity of the current lines, favoring the homogeneous growth of the calco-magnesian coating. In this way, they obtain a double utility of using the same ferrous element in both electrodes, which allows the oxidation of the anode, releasing positive ions (cations) from the iron and forming corrosion products of said chemical element. Iron cations have been found to favor phytoplankton (Geider & La Roche, 1994), being, therefore, a non-harmful element, as well as an added value to the ultimate purpose of the present invention.

The present invention solves the problems described in the state of the art since it provides a system formed from modular elements obtained with a reduced weight of the structure, ease of transport and placement, or anchoring, and a favorable interaction with the marine environment. by facilitating the adhesion of species to the structure, and the free access and movement of aquatic animals through it, generating spaces that allow the protection and development of numerous living species.

Thus, in a first aspect, the present invention refers to a UE as a system that comprises at least two electrodes, where one is a metallic cathode, which once the electrolysis is finished will constitute the EUM, and an anode or several anodes of iron, where the electrodes are in a concentric or parallel arrangement, and with a fixed and equidistant separation between them, without contact at any time between them, where separating elements of non-conductive material can be used that allow these restrictions in the event that the EU is not totally rigid on its own.

In a preferred embodiment, the separation between electrodes is at least 1 cm, provided that ionic flow between electrodes is guaranteed.

In a preferred embodiment, the separation between electrodes is at least 5 cm.

EUM is a metallic element, which can adopt any geometric shape, on which a hard coating of a layer of calcium carbonate and magnesium hydroxide is obtained, with an irregular surface and porous nature, which favors the adhesion of sessile marine benthos organisms ( mainly suspensivores) that act as biofilters.

In a preferred embodiment, the preferred substrate for the manufacture of the EUM is an electrowelded mesh of bars of small diameter and with a mesh size of the order of 10 to 15 cm. Said electrowelded mesh is shaped to obtain any geometry, shape and dimensions that may be the most suitable for the final application.

In a preferred embodiment, the preferred substrate for manufacturing EUM is carbon steel.

In a preferred embodiment, the substrate for the EUM is made up of any other basic metal element or structure, such as metal bars (or groupings of welded or bolted bars), metal sheets or plates, beam-type structures, etc.

By grouping several EUMs with the appropriate shape and size, any more complex structure that is necessary for applications such as biofilter systems (restoration of marine ecosystems), artificial reefs, structures for recreational diving, can be built in a modular way, etc.

Separate electrical wiring is soldered for the anode (s) and for the cathode, in order to be able to establish a flow of continuous electrical current between the elements when they are immersed in a conductive medium.

The supply of direct current to the EU can be by transforming the network conventional, by photovoltaic panels directly or through the use of accumulators of electrical energy or batteries.

The EU is submerged in the sea, or in a saline environment, and is connected to the current.

Electrolysis is carried out at low current densities, that is, below 2 mA / cm2. The applied intensity is determined taking into account the cathode surface area (EUM).

The thickness of the deposit layer of the calcareous or calco-magnesian material has a linear relationship with the time of application of the current.

The formation time of the calcareous or calco-magnesian deposit is variable, depending on the needs of subsequent use of the EUM, with a minimum of about 30 days onwards.

During the electrolysis time, the anode (s) partially dissolve in the form of iron cations that serve as food for the phytoplankton and form corrosion products of said chemical element, said species being harmless to the marine environment.

After the formation of the calcareous or calco-magnesian deposit, the UE is extracted from the saline medium, the wiring, the anode (s) and the separating elements are removed, obtaining the EUM coated and ready for use, either individually or in combination or grouping of other EUMs, leading to ER.

Brief description of the drawings

To complement the description that is being made and in order to help a better understanding of the characteristics of the invention, a set of figures is attached as an integral part of said description, which, with an illustrative and non-limiting nature, represent the process of manufacture of a cylindrical EUM:

Figure 1 .- UE containing the elements of the invention formed by the internal and external anodes, the cathode (EUM without calcareous deposit) and the non-conductive elements that maintain the concentric structures. Perspective and plan views. Three-electrode UE: External anode 1, Internal anode 3, EUM 2 without reservoir and separator elements 4.

Figure 2 .- Electrical connections of the elements of the UE of three electrodes: external anode 1 and internal anode 3 to the positive pole of the power supply 8 through the lead wires 5 and 7, and cathode or EUM 2 without reservoir to the negative pole of the power supply 8 through the electrical wiring 6.

Figure 3 .- UE of three electrodes immersed in sea or saline water, during the calcareous or calco-magnesian coating process.

Figure 4.- UE of three electrodes with the EUM coated with a calcareous or calco-magnesian deposit. The elements of the invention appear formed by the external 1 and internal 3 anodes, the coated EUM 2 and the non-conductive separating elements 4 that maintain the concentric structures. Perspective and plan views.

Figure 5 .- EUM 2, covered by the calcareous or calco-magnesian deposit, devoid of external and internal anodes and non-conductive elements.

Figure 6 .- Recreation of a grouping of six EUM 2 of cylindrical shape, in their final arrangement as ER. After being coated the ER surfaces by sessile marine benthos organisms, the structure could be used as a biofiltration system.

Figure 7 .- Examples of ER with different geometries.

Detailed description of the invention

In this section, and in view of the figures shown above, the preferred embodiment of the invention is described for the case of a cylindrical EUM manufactured from carbon steel mesh. The case of using two anodes is described in detail, one with a diameter greater than the EUM 2 which would be the external anode 1, and the other with a smaller diameter than the EUM 2 which would be the internal anode 3. However, it should be noted that it is It is possible to manufacture this type of EUM using only a single anode, in which case the internal anode 3 is not used.

For the EU manufacture, the electrodes, made from steel mesh with a mesh size of 15 cm and a bar diameter of 0.5 cm, are molded into cylinders of 60 cm (anode with the largest diameter), 50 cm ( EUM 2) and 40 cm in diameter (anode of smaller diameter), respectively, with a height of 105 cm, in the three cases. The three electrodes are arranged concentrically, with the first anode being the smallest cylinder (40 cm in diameter), concentric to it the cathode (50 cm in diameter) and the outermost, a second anode (60 cm in diameter). The minimum separation between electrodes is 1 cm, specifically it is 5 cm.

The three cylindrical elements that make up the EU have been manufactured, as separating elements 4 PVC pipe crosses are used to make the structure more rigid and prevent the three cylinders from touching each other due to the action of sea currents or accidental blows. (Figure 1).

Shielded and insulated current cables are welded to each of the cylinders (Figure 2). The external 1 and internal 3 anodes are connected to the positive pole of the power supply by electrical wiring 5 and 7 and the cathode or uncoated EUM 2 is connected to the negative pole of the power supply by electrical wiring 6.

The DU is immersed in seawater or in a saline liquid medium (Figure 3).

Set a working current density below 1 mA / cm2 in the EUM. The intensity set in the power supply is calculated based on the current density that circulates through the EUM, taking into account its surface area, calculated based on the nominal diameter of the bars and wires that make it up.

The coating time is set at two months, the depositing speed being constant. The thickness of the coating to be obtained is approximately 3 mm. The composition of the coating obtained has a calcite: aragonite ratio of 1: 1, which improves the properties of the deposit and its hardness. In addition, it does not usually contain magnesium hydroxide.

Once the time established for the formation of the deposit has concluded, the DU is extracted with the EUM 2 coated, on which the calcareous deposit can be observed (Figure 4).

The anodes 1 and 3 and the PVC pipe crossings are removed, leaving only the coated EUM 2.

The final ER (Figure 6) is assembled on-site by assembling or joining the required EUMs.

Example 1

A study experience has been carried out in the fixation of sessile macro-biofouling (biofiltrators) in the Port of Alicante, on carbonated mesh treated by electrolysis and untreated metallic mesh (control), with three replications. The conclusions obtained In the first three months of funding (October-January) they have been:

1. A total of 37 different taxa have been found, with 94.6% (35 taxa) appearing in the carbonate substrates, and only 40.5% (15 taxa) in the controls, highlighting Bryozoa with 11 species.

2. All species, with the exception of Conopeum seurati and Bugulina fulva, have appeared in the carbonate substrate; and 22 species have only appeared in this one.

3. The carbonate substrate has presented greater biodiversity and a more developed successional stage (higher Shannon indices and Pielou equitability).

4. Greater abundances have been found in the carbonate substrate, but no significant differences have been observed for coverage.

5. Sponges and sea squirts, and most bivalves (all filter feeders), have only appeared in the carbonate substrate, which is a suitable material to build biofilters.

6. These first results lead to a positive evaluation of carbonate electrolytic structures, since they can be substrates with great potential as a material for the construction of artificial reefs. They have presented a greater diversity and recruitment of species compared to untreated iron.

Claims (9)

1. System for the formation of artificial marine reefs and submarine structures with calcareous coating induced by electrolysis that comprises at least two electrodes, where one is a metallic cathode, which once the electrolysis is finished constitutes the modular unit element (EUM), and another at least one iron anode, where the electrodes are in a concentric or parallel arrangement, and with a fixed and equidistant separation between them, without contact at any time between them. 2. System for the formation of artificial marine reefs and underwater structures with calcareous coating induced by electrolysis according to claim 1, wherein it comprises separating elements of non-conductive material placed between the electrodes to avoid contact. 3. System for the formation of artificial marine reefs and underwater structures with calcareous coating induced by electrolysis according to claim 1 where the separation between electrodes is at least 1 cm, provided that the ionic flow between electrodes is guaranteed. 4. System for the formation of artificial marine reefs and underwater structures with calcareous coating induced by electrolysis according to claim 3, where the separation between electrodes is at least 5 cm. 5. System for the formation of artificial marine reefs and submarine structures with calcareous coating induced by electrolysis according to claim 1 where the preferred substrate for the manufacture of EUM is an electrowelded mesh of small diameter bars with a mesh size of the order of 10 to 15 cm, where said electrowelded mesh is shaped to obtain any geometry, shape and dimensions. 6. System for the formation of artificial marine reefs and submarine structures with calcareous coating induced by electrolysis according to claim 1 where the preferred substrate for the manufacture of EUM is carbon steel. 7. System for the formation of artificial marine reefs and submarine structures with calcareous coating induced by electrolysis according to claim 1 where the substrate for the EUM comprises basic metal elements, preferably metal bars, groups of welded or screwed bars, sheets or metal plates or beam-type structures. 8. System for the formation of artificial marine reefs and submarine structures with calcareous coating induced by electrolysis according to claim 1, wherein it comprises independent welded electrical wiring for the anode (s) and for the cathode, as well as a power source, in order to power establish a flow of continuous electric current between the elements when they are immersed in a conductive medium. 9. System for the formation of artificial marine reefs and underwater structures with calcareous coating induced by electrolysis according to claim 8, where the current density has values below 2 mA / cm2 for at least 30 days.