JP4746362B2 - Water purification facility using wave energy - Google Patents

Description

  The present invention relates to a technique for purifying water quality in water areas such as the ocean, lakes, and ponds.

Traditionally, as a technology to purify the water quality in the ocean, lakes, ponds and other water areas,
(1) Purification method using natural purification ability by creating tidal flats and securing vegetation
(2) A dredging method that removes pollutants by pouring contaminated bottom mud
(3) Sand cover method that covers the surface layer of the bottom mud with sea sand, river sand, mountain sand, etc. that does not contain pollutants, suppresses the elution of pollutants, and reduces the oxygen digestion rate of the bottom mud.
(4) A method of purifying water quality by installing a water purification facility and a purification device and forcibly generating a circulating flow with a pump to purify the water quality.

  Among these, a number of purification methods using the natural purification ability by the creation of tidal flats and vegetation of (1) have been proposed in recent years (see, for example, Patent Documents 1 and 2). This purification technology utilizes the ability of animals and plants to absorb nutrient salts and decompose organic matter, and because it does not use energy such as electricity or chemical substances, it has a low secondary environmental impact, and it is necessary to solve environmental problems. It is an excellent method.

  However, since there is no function for forcibly supplying unpurified water or draining the purified water outside the facility, even if there is room for purification capacity, natural water exchange alone cannot fully demonstrate that capacity. Cases are also conceivable. In addition, since the tidal flat is a landform that repeats drying due to tides, the problem is that the installation location is limited to the vicinity of the coast.

  In addition, according to the purification method using dredging (2) (see, for example, Patent Document 3), it is difficult to secure a disposal site for dredged bottom mud, and the bottom mud is transported and treated (dehydration, chemical solidification, etc.). There is a problem that requires high technology and enormous processing costs. In addition, the formation of depressions in the ruins makes it easier for pollutants to accumulate, makes it difficult for water to be exchanged, and tends to lower the dissolved oxygen concentration in the bottom layer, making it difficult for organisms to inhabit, There is also a problem that nutrients are easily eluted from substances.

  In addition, in the sand-capping method (3) (see, for example, Patent Documents 4 and 5), when waste such as coal ash is used as sand-capping, it is low-cost but not natural, There are concerns about the adverse effects of

  Furthermore, the purification method (4) (see, for example, Patent Documents 6 and 7) uses a pump to pump or stir the circulated flow to the purification device in order to supply unpurified water and discharge the purified water. In order to generate this, it is pointed out that there is a problem that it requires electric power as well as equipment installation costs and maintenance inspection management costs.

JP 2003-001285 A JP 2003-268745 A JP-A-7-313996 JP-A-2004-305971 JP2004-113858A JP2004-181440 JP 2003-175394 A

  The present invention has been made in view of the above problems, and its technical problem is to induce a forced circulation flow that passes through the purification means without using artificial energy such as electric power, and to improve the water quality. The object is to provide a water purification facility that can efficiently purify water.

As means for effectively solving the technical problem described above, the water purification facility using wave energy according to the invention of claim 1 generates an overflow in the wave traveling direction by breaking the incident wave. A submerged dike and a water purification means installed on the wave traveling direction side of the submerged dike, and the submerged bank has a predetermined interval with respect to the wave traveling direction and the shallower water depth is closer to the wave traveling direction side. It is a multi-stage installation . According to this configuration, by installing the submarine in a water area where wave energy is likely to be generated, for example, waves incident from the offshore side are broken, and the wave energy is converted into flow energy by breaking waves, and the It induces overflow on the bank in the direction of wave travel (for example, on the shore side). In addition, since the submerged dike is installed in a plurality of stages at a predetermined interval with respect to the wave traveling direction and so that the water depth at the top end becomes shallower toward the wave traveling direction side, the flow in the wave traveling direction can be caused over a wide area. . As a result, the dead water area is eliminated, the water level of the submerged dike is increased (for example, on the shore side), and the flow through the water purification means is generated by the difference in water level. Can help. Furthermore, a quiet area can be created in the facility.

The water purification facility using wave energy according to the invention of claim 2 is the structure according to claim 1, wherein the water purification means has water permeability and has a function of removing contaminants by filtration, sedimentation or adsorption. The submerged dike consists of this water purification structure.

The water purification facility using wave energy according to the invention of claim 3 is the structure according to claim 2 , wherein the water purification structure includes gravel, crushed stone, shells, or crushed shells in a cage or net. It has a packed porous structure. According to this configuration, phosphorus, ammonia nitrogen, sulfide ions, or heavy metals using the nutrient absorption ability and organic matter decomposition ability of living organisms attached to gravel and crushed stone, or by shells or crushed shells The ability to adsorb water can effectively filter, adsorb or settle suspended substances and pollutants in water.

According to the water purification facility using wave energy according to the first to third aspects of the invention, the purification structure can be obtained by converting the wave energy into the flow energy without using artificial energy or chemical substances such as electric power. Therefore, the purification structure can efficiently purify the water quality and circulate the water quality. Moreover, since air is taken into the water by breaking waves, a purification action by the aeration effect can be expected. In addition, since the calm water area can be created by the wave-dissipating function of the submerged dike, water quality purification by sedimentation of suspended matter can be expected.

  Hereinafter, a preferred embodiment of a water purification facility using wave energy according to the present invention will be described with reference to the drawings. FIG. 1 is a plan view of a water purification facility according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along II-II in FIG. 1, and FIG. FIG. 4 is a cross-sectional view showing a state at a high water level cut along the line II-II in FIG. 1.

First, in FIGS. 1 and 2, reference numeral G is a bottom ground of a water area, and reference numerals 1 and 2 (2 ₁ to 2 ₄ ) are submerged banks installed on the bottom ground G. In these submerged dikes 1 and 2 (2 ₁ to 2 ₄ ), the height of the top is lower than the water surface when the water level becomes the lowest in the normal fluctuation of the water level.

Of the submerged dikes 1 and 2 (2 _{1 to} 2 ₄ ), the most submerged submerged dike 1 (hereinafter referred to as the overflow dike) is preferably made of masonry, a snakecage, or a concrete structure. The wave W moving from the offshore side is forced to break the wave W ₁ , and the wave energy is converted into the flow energy to generate a shore-facing overflow Fa ₁ on the overflow submerged dike 1 Have the effect of

  Here, as shown in FIG. 3 (B), when the levee body 1 ′ having no water permeability and the top end exposed on the water surface is installed on the offshore side where the wave W is the largest, the wave W is completely removed. Since it is reflected, the impact is large, and there is a risk that it will become unstable due to scouring H in the ground on the front side of the levee body 1 ′, but the overflow dike 1 is shown in FIG. As shown in the figure, the wave W is not completely reflected but allowed to overflow and / or penetrate into the facility, so that the wave force acting on the facility is reduced and scouring is performed. It is possible to suppress.

As shown in FIG. 1 and FIG. 2, the submerged dikes 2 ₁ to 2 ₄ (hereinafter referred to as the first purification submerged dike) are located on the shore side of the overflow dike 1 and have a predetermined interval toward the shore side. A plurality of stages are provided. Of these, the first purification latent bank 2 of _the most offshore (first stage) is shallower than the depth of the depth of the top end crest of overflow latent bank 1, first two-stage purification latent Tsutsumi 2 ₂ the depth of the top end shallower than depth of the first purification latent Tsutsumi 2 ₁ of the top end of the first stage, the more those same hereinafter, positioned relatively shore side, depth of the top end is shallower. Then, Sentsutsumi 2 ₄ most downstream of the first purification latent crest _{21 to 24} has a height of a normal still water surface WL substantially equal indicated by a chain line in FIG.

The first purification submersibles 2 ₁ to 2 ₄ are composed of a purification structure having a porous structure in which gravel, crushed stone, shells, or crushed shells are packed in a cage or net, Utilizing the ability to absorb nutrients and decompose organic matter of living organisms that adhere to them, or the ability to adsorb phosphorus, ammonia nitrogen, sulfide ions, or heavy metals by shells or shell crushed materials, It has the function of effectively filtering, adsorbing or sedimenting pollutants.

Between the first purification latent crest ₂₁ to _24, a plurality of second purification latent Tsutsumi 3 extending in a direction perpendicular to these first purification latent crest ₂₁ to ₂₄ it is installed. Similarly to the first purification submersibles 2 ₁ to 2 ₄ , the second purification submersible 3 is composed of a purification structure having a porous structure in which gravel, crushed stones, shells, or crushed shells are packed in a cage or net. a is, depth of the top end, corresponding to the first purification latent crest ₂₁ to _24, is gradually shallower toward the shore side.

On the shore side of the installation area of the first purification submersibles 2 ₁ to 2 ₄ and the second purification submersible 3, a bank body 4 is installed. This dam body 4 also has a porous purification structure in which gravel, crushed stone, shells, or crushed shells are packed in a cage or net in the same manner as the first purification submersibles 2 ₁ to 2 ₄ and the second purification submersible 3. It consists of a body, and its top edge is always exposed from the surface of the water. Further, as shown in FIG. 1, the dam body 4 is constructed such that both ends thereof are opposed to or continuous with both ends of the overflow overflow dike 1.

Furthermore, the overflow latent bank 1, between the first purification latent Tsutsumi 2 ₁ of the first stage behind it, Kutsugaesuna for suppressing contaminants eluted from hoisting prevention and bottom mud sediment material 5 Is laid. This sand-capping material 5 is constructed by laying sea sand, river sand, mountain sand, crushed shells or the like on the bottom ground G so as to cover the sand with an appropriate layer thickness.

As mentioned above, the overflow overflow dike 1 is basically made of masonry, snake basket, concrete structure, etc., but stability against impact at the time of wave W collision is ensured. If possible, a purification structure having a porous structure in which gravels, crushed stones, shells, or crushed shells are packed in a cage or net in the same manner as the first purification submersibles 2 ₁ to 2 ₄ , the second purification submersible 3 and the bank 4 It may be composed of a body. Preferably, a futon basket 6 for preventing scouring of bottom mud due to reflected waves is installed in the lower part of the front surface of the overflow dike 1 that receives the greatest wave energy. The futon basket 6 is a metal basket filled with gravel or crushed stone.

According to the thus constructed water purification facilities as described above, as shown in FIG. 2, the overflow latent bank 1 receives the greatest wave energy, the wave breaking W ₁ to the energy of a part flow of the waves energy As a result of the conversion, the wave energy is attenuated and a shore-facing overflow Fa _{1 on} the overflow dike ₁ is generated. Further, since the first purification submerged dike 21 having a shallower depth than the overflow dike ₁ is installed on the shore side of the overflow dike 1, it is attenuated to some extent by the overflow dike 1. and waves are again breaking W ₂ in the first purification latent Tsutsumi 2 _1. Therefore, part of the wave energy is also converted into flow energy here, and a shore-facing overflow Fa ₂ is generated. By the first purifying latent Tsutsumi 2 ₂ 21 to _24, even the same effects of a subsequent stage, generating a overflow Fa shore direction.

In addition, when the hydrostatic surface WL becomes higher than the level shown in FIG. 2 due to tides in the case of ocean or rain in the case of lakes, the water depth at the top of the overflow dike 1 becomes deep. In this overflow dike 1, no significant breaking waves occur, but the depth of the top edge of the first purification dike 2 ₂ to 2 ₄ behind it is relatively shallower as it is located on the shore side. because there, as shown in FIG. 4, the wave breaking W ₁ at what stage overflow Fa ₁ shore direction occurs here. And a subsequent stage, if still water depth of the top end there is a shallow latent Tsutsumi, again is breaking W ₂ again generates an overflow Fa ₂ shore direction.

For this reason, since the breaking wave as described above is repeated, a continuous flow toward the shore is generated in the vicinity of the water surface, and the flow to return to the offshore side is restrained. still water surface WL is Kakusentsutsumi _{1,2 1, 2} 2, rises in the shore side of ... is higher than the first purification latent Tsutsumi _{2 4} most subsequent stage. And by such a water level rise, the flow Fb which permeate | transmits each submerged dike ₁ , 2 ₁ , 2 ₂ ... Toward the low water level side (offshore side) is generated.

  On the other hand, in the water area where the facility is not installed, the waves W are hardly attenuated, so that the water level does not rise and the shoreward flow does not occur. Therefore, since a water level difference ΔWL also occurs between the inside of the facility and the outside of the facility, as shown in FIGS. 1 and 2, the dam body 4 and the submerged levee in the vicinity thereof are directed toward the shore side. A permeating flow Fc is generated.

With the above operation, water is exchanged between the inside of the facility and the outside of the facility. Moreover, in the course of such a flow, water permeates through the first purification submergence 2 ₂ to 2 ₄ , the second purification submergence dike 3 and the levee body ₄ , so that living organisms attached to gravel and crushed stones have Water quality is effectively purified by the ability to absorb nutrients and decompose organic substances, or by the ability to adsorb phosphorus, ammonia nitrogen, sulfide ions, or heavy metals by shells or shells. Since the purified water is discharged (flow Fc) toward the shore side, the water quality can be circulated (exchanged) without using artificial energy such as electric power.

In addition, since these overflow submerged dike 1, first purification submerged dike 2 ₂ to 2 ₄ , second purification submerged dike 3 and embankment body 4 have a wave-dissipating function like offshore dikes and artificial reefs, In addition, a quiet area can be created behind the facility, and water purification by sedimentation of suspended matter can be expected.

Note first purification latent crest ₂₁ to _24, the second purification latent Tsutsumi 3, the cleaning structure constituting the dam body 4, gravel as described in the above-described embodiment, crushed stone, shell, or shell pulverized to It is not limited to a porous structure packed in a cage or net, and may be replaced with other purification means such as vegetation floating islands or masonry.

  In general, since waves enter from the offshore side on the coast of the sea, it is basically preferable to configure as illustrated, but the present invention is not limited to this. That is, since the traveling direction of the waves varies depending on the wind direction, when the traveling of the waves is dominant in a direction other than the shore direction, the submerged dike and the water quality purification means may be installed corresponding to the dominant direction.

  FIG. 5 is a plan view showing an embodiment in which the present invention is applied to a polluted pond having a water depth of about 1.3 m, FIG. 6 is a sectional view taken along line VI-VI in FIG. 5, and FIG. It is explanatory drawing which shows a result.

In this embodiment, as shown in FIG. 5 and FIG. 6, in the adjustment pond, in the region of the total length L ₁ = 31 m and the width L ₂ = 10 m, the most upstream overflow dike 1 and the second stage A purification facility comprising a single submersible dike 2, a shore body 4 on the most shore side, a crossover submerged dike 1, a first submersible dike 2 and a second submersible dike 3 between both widthwise ends of the dike body 4 installed. The overflow overflow dike 1, the first purification submersible 2, the second purification submersible 3, and the bank 4 were all constructed by oyster shell filters in which oyster shells were packed in a metal cage.

The thickness of the overflow latent bank 1 t _{1 =} 3m, the thickness of the first purification latent Tsutsumi 2 t _{2 =} 1 m, overflow latent bank 1, and the installation interval P = 10 m of the first purification latent bank 2 and dam 4 did. The top edge of the overflow dike 1 was set to a water depth D ₁ = 0.2 m from the still water surface WL, and the incident waves were forced to break. In addition, a futon basket 6 was laid in an area of about 5 m in front of it.

The top end of the first purification submerged dike 2 placed behind the overflow submerged dike 1 has a water depth D ₁ = 0.1 m from the still water surface WL. By making it shallow, even if the wave height is attenuated, the wave breaks continuously. Furthermore, the top end of the second first submersible dike 2 arranged behind it is the same height as the still water surface WL (1.3 m from the bottom ground G). Added support for rising water levels due to breaking waves and overflow. Further, the most shore-side dam body 4 has a protruding height h of 0.3 m from the still water surface WL.

  As described above, the overflow submerged dike 1, the first and second first submersible submerged dike 2 and the dike body 4 were provided with steps so as to be higher toward the shore side. In this example, the wave period was 2 seconds and the wave height was 0.3 m. As a result, it was confirmed that there was a water level rise of about 5 cm in the purification facility, and a water flow as shown in FIG. 7 was generated.

It is a plane layout view showing a preferred embodiment of a water purification facility using wave energy according to the present invention. It is sectional drawing cut | disconnected and shown by the II-II line | wire in FIG. It is explanatory drawing which shows the effect | action of the overflow dike 1 in FIG. 2 compared with the bank body 1 'higher than a water surface. It is sectional drawing which shows the effect | action at the time of a high water level cut | disconnected by the II-II line | wire in FIG. It is a top view which shows the Example which applied this invention to the polluted adjustment pond with a water depth of about 1.3 m. It is sectional drawing cut | disconnected and shown by the VI-VI line in FIG. It is explanatory drawing which shows the analysis result by an Example.

Explanation of symbols

1 Overflow dike (submarine)
2 (2 _{1 to} 2 ₄ ) First purification submerged dike (submerged dike)
3 Second purification submarine 3 (submarine)
4 Dyke body 5 Sand covering material 6 Duvet basket

Claims (3)

A submerged levee that generates an overflow in the wave traveling direction by breaking the incident wave, and water purification means installed on the wave traveling direction side of the submerged dam, the submerged dam in the wave traveling direction. On the other hand, a water purification facility using wave energy, characterized in that it is installed in a plurality of stages so that the water depth at the top edge becomes shallower at a predetermined interval and toward the wave traveling direction side . The water quality purification means is a water quality purification structure having water permeability and a function of removing contaminants by filtration, sedimentation or adsorption action, and the submerged dike consists of this water quality purification structure. A water purification facility using wave energy as described in 1. The water purification facility using wave energy according to claim 2 , wherein the water purification structure has a porous structure in which gravel, crushed stone, shells, or crushed shells are packed in a basket or net .

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