Process to obtain (implement and maintain) water bodies larger than 15,000 m3 for recreational use with color, transparency and cleanness characteristics similar to swimming pools or tropical seas at low cost

(56) References cited:

EP-A1-0 352 487 EP-A1-0 483 470 WO-A1-03/010388 DE-A1- 19 860 568 FR-A1-2 685 374 JP-A- 5 261 395 US-A-3 406 416 US-A-4 176 058 US-A- 4 343 696 US-A- 5 039 427 US-A- 5 337 434

EP-A1-0 468 876 EP-A1-1 420 130 DE-A1-2 141 460 FR-A1-2 544 005 GB-A-2 243 151 US-A- 2 923 954 US-A- 3 470 091 US-A- 4 304 022 US-A- 4 652 378 US-A- 5 143 623

Note: Within nine months ofthe publication ofthe mention ofthe grant ofthe European patent in the European Patent Bulletin, any person may give notice to the European Patent Office of opposition to that patent, in accordance with the Implementing Regulations. Notice of opposition shall nőt be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).

Printed by Jouve, 75001 PARIS (FR)

ΕΡ 1 925 593 Β1

Description

FIELD OF THE INVENTION [0001] This invention discloses a process to obtain (i.e., to implement and maintain) large water bodies or volumes fór recreational use largerthan 15,000 m³, such as lakes or ponds with excellent color, high transparency and cleanness characteristics similar to swimming pools or tropical seas at low cost. A device to extract a particulate matéria! decanted from the water is provided. Furthermore, a structure to contain large water bodies or volumes, which is specially designed to carry out said process is disclosed. The decantation process together with the device to extract a decanted matéria! from the water, plus the arrangement of the large volume structure with its functional characteristics of water surface displacement, allow replacing traditional filtration as used in conventional swimming pools that would be very onerous and inefficient in systems having large bodies or volumes.

BACKGROUND OF THE INVENTION [0002] When a nutrient enters intő water, aerobic organisms consume dissolved oxygen as a result ofthe induced metabolic activity. Thus, the nutrient exerts a demand on dissolved oxygen availability, which is called biological oxygen demand (BŐD). If the amount of organic matéria! in the médium is very high, it can lead to a decrease in dissolved oxygen concentration. At low oxygen levels, aquatic environment promote the growth of anaerobic species.

[0003] Anaerobic metabolism is much slower than aerobic processes (typically more than one order of magnitude) have lower efficiency, and generates various intermediate organic compounds (e.g. organic acids, alcohols, methane). As a result of the lower rate of dissolved organic matter consumption, this will accumulate in the aquatic environment. [0004] If dissolved oxygen is consumed faster than it can be replenished, water starts to deoxygenate. No strictly aerobic organism, from microorganisms to fish, will survive in said water. Thus, organic contaminants will accumulate and further establish anaerobic conditions, which generate malodorous substances (e.g. sulfides and volatile amines) and partially oxidized organic compounds.

[0005] In addition to bad smell, anaerobic conditions can raise humán health issues, because many anaerobic bacteria are pathogenic (fór instance, tetanus, and botulism). When the water contains dissolved sulfates, reducing anaerobic bacteria produce H₂S (corrosive and poisonous).

[0006] The increase ofthe amount of nutrients required fór life in a water body is called eutrophication. Eutrophication is defined as the process of nutrient enrichment in a water body. It is a natural phenomenon in the ageing process of ponds and lakes (eutrophic lakes). On the contrary, a young water body, poor in nutrients required fór life, is called oligotrophic. The nutrient increase in the pond promotes a higher production of aquatic plants and animals. Said organic matter increase generates in its turn an increase of the organic content of sediments. Eutrophication can generate serious problems in superficial water bodies.

[0007] Photosynthesis implies the creation of organic matter from inorganic materials and therefore the production of large amounts of organic substances where there were only little amounts before. When algae/plants die, their components are transformed in organic nutrients that exert an oxygen demand.

[0008] During photosynthetic action, CO₂ is readily consumed, thus producing a rise in pH, which can attain a value over 10. During the night, the inverse reaction occurs, consuming oxygen and generating CO₂, with which pH tends to drop. Photosynthetic activity has a significant effect on the pH leve! ofthe water body, because it affects the reversible reaction.

HCO^3- + H+ <--------> CO₂ + H₂O [0009] Finally, the masses of algae deposited in the shore die and rotten, thus producing anaerobic conditions, which present health dangers (e.g. formation of Clostrídium botulinum, a strictly anaerobic pathogen microorganism). On the other hand, aquatic plánt ramifications retain organic solids that decompose, which exerts a concentrated oxygen demand.

[0010] Generally, nitrogén N and phosphorus P are the limiting factors. In microorganism growth, P is consumed as phosphate, while the major part of bacteria assimilate N under the form of NH₃, and only somé of them assimilate N as NO₃^_. Inversely, algae assimilate N as NO3^_ and very few use NH3. There are more bacteria able to use NO₃^_ as oxygen source than as N source. According to the approximate stoichiometry of photosynthesis in algae, N : P ratio is in the order of 7:1. According to the Liebig minimum law, an N : P ratio much higher than 7 in a water body indicates that P is the limiting nutrient; on the other hand, an N : P ratio value much lower than 7 implies an N limitation. Somé authors suggest that P and N concentrations higher than 0.015 and 0.3 mg/l, respectively, are enough to generate an excessive growth of algae in laké waters.

[0011] The main sources of organic N are proteins, amino acids and urea; on the other side, inorganic N is in the form

ΕΡ 1 925 593 Β1 of ΝΗ₃, ΝΟ₃, ΝΟ₂. Ammónia is a characteristic product of organic matterdecomposition, and it can be microbiologically oxidized to nitrites and nitrates by the action of nitrifying bacteria. These processes occur naturally in water and constitute a major contribution to the biological oxygen demand.

[0012] When artificial water bodies are formed, such as lakes or ponds, water quality deteriorates progressively. Depending on the nutrient contribution, it can be reached any state from equilibrium in which algae, aquatic plants, bacteria, insects and fish survive in stable condition to eutrophication processes in which the excessive contribution of nutrients produces a high proliferation of algae and aquatic plants. When these die, they are decomposed by bacteria in aerobic processes that consume the oxygen. When oxygen decreases, many organic remainders remain deposited in the bottom, thus increasing sediments and suffering processes that increase turbidity, bad smells are produced and the physicochemical and sanitary quality of the water is impaired, which reduces the possibilities of recreational use. [0013] To mitigate these effects different techniques are used, such as aeration systems to increase oxygen levels, algaecides and herbicides to control the excessive proliferation of algae and aquatic plants, the use of biological filters to decrease nutrient contribution, fish and zooplancton to reduce algae, nutrient capture by means of Chemicals, inoculation of bacteria to digest organic matter, colorants to improve the aesthetic appearance, mechanic removal of algae and aquatic plants, the use of dredges to decrease the amount of sediment, clarifying agents to decrease turbidity, etc. [0014] The characteristics and quality of the water of these ponds are very different to those of swimming pools. In thefirst case, an ecological equilibrium between different species must be attained, while in the second case the objective is the removal oforganisms and impurities. Therefore, very different turbidity, colorand physicochemical characteristics standards are accepted.

[0015] To keep swimming pool water transparent and apt fór bathing, filtration systems are used, mainly sand, diatomaceous earth and cartridge filtration systems. The entire water must be filtered every 4 to 12 hours, depending on the type of swimming pool.

[0016] In addition, organic matter oxidants, disinfectants, algaecides and eventually pH regulators and clarifiers must be used to keep aesthetic and sanitary conditions. Depending on each country’s regulation, swimming pools are required to keep minimál disinfectant residual concentrations or permanent redox potential (ORP) levels between 650 mV and 750 mV.

[0017] The application of the swimming pool technology to large water bodies to obtain optimál water quality is nőt possible due to the high cost ofthe installations and the involved operatíve costs.

[0018] To illustrate this situation, we can recall that if the water body to be filtered is the one described below in the application example of 250,000 m³, complying with the minimál regulations of Chilean Swimming Pools (T=2 en NCh 209, example country fór the application), 2,983 liters per second are required to be filtered, which corresponds to the water volume treated by a potable water plánt fór a city. An Olympic swimming pool has 2,500 m³ (50X25X2 m), which corresponds to 1% ofthe considered volume in the application example of this patent application.

[0019] The same is true when swimming pools Chemicals are to be applied to these volumes. The water volume of the application example of this invention corresponds to 4,000 10-meters-long swimming pools.

[0020] The control of disinfectants in swimming pools and spas by means ofthe measurement ofthe (ORP) has been used fór many years with good results. ORP measures the oxidizing power ofthe disinfectant or, in other words, its reál concentration-independent Chemical activity. Direct measurement of disinfectant concentration can lead toerror, because the activity can be decreased depending on pH and the presence of contaminants, even at high concentrations. In fact, studies have demonstrated that bacterial life in water is more dependent on ORP than on oxidant concentration. To remove undesired microorganisms in swimming pools, normally a ORP value between 650 mV and 750 mVis permanently maintained (public swimming pool regulations in developed countries require more than 700 mV permanently) at a normál pH between 7,2 and 7,6. This is nőt possible with large water bodies due to the high implied costs.

[0021] The previously exposed facts make maintaining large water bodies (over 15,000 m³) using filtration and disinfection technologies similar to those of swimming pools fór recreational use largely unviable.

[0022] Therefore, there are no large artificial ponds ordams with the aesthetic and sanitary characteristics of swimming pools or tropical seas that have clarity levels higher than 25 and even 40 meters.

[0023] The technical problem solved with the present invention is the achievement of these characteristics in large water bodies at low cost.

STATE OF THE ART [0024] Invention patents protecting treatment processes fór large volumes of water such as ponds and dams were found at world level. In what follows, an analysis of the most relevant documents and their relation with the technology to be protected is performed.

[0025] Invention patent applications JP4115008 and JP7310311 protect artificial ponds connected to the sea that have as objective the purification of sea water. The system allows the entrance of water to the pond, where it follows a path specially designed to remove contaminants or it is conducted to a purification facility to be subsequently returned to the

ΕΡ 1 925 593 Β1 sea. Clearly, the Japanese invention has no relation with the type of pond that is desired to protect in this application. [0026] The invention patent application FR2740493 protects a pool or artificial laké constructed with a flexible bottom comprising a textilé net and concrete. The invention includes a draining system and injectors around the bordér that allow the diffusion of a liquid to the draining system. The analyzed invention does nőt have relation with the artificial pond orthe process that is to be protected.

[0027] The invention patent application JP59222294 protects a purification process tor river and laké water to remove N, P, BŐD (biological oxygen demand), etc. that implies pumping the water through a bed fiiled with certain mineral. The Japanese invention allows cleaning pond water, bút based on water pumping through a packed bed, which is equivalent to filtering the liquid. Therefore, the Japanese invention does nőt have relation with the technology that is to be protected.

[0028] The invention patent application CN1256250 protects a water purification process that includes microflocculation with an inorganic flocculant with high molecular weight and direct deep bed filtration. The analyzed process corresponds to an assisted flocculation with faster and more efficient results, bút in no case it affects the novelty or the inventive level ofthe process ofthe present invention.

[0029] US 5,143,623 describes a method tor capturing descending particles in a water body. The method requires the use óta set of tűnnél shaped chambers which récéivé the descending particles, and afterwards, a system of pipes allows the collection of the descending particles. The present invention requires the use of a suctioning device which travels the bottom ofthe structure containing the water. Using a device such as the one described in US 5 143 623 in the present invention would nőt be suitable, since the recreational end of the body of water would nőt be maintained. Furthermore, document US 5 143 623 requires a few hours to allow receiving the descending particles, which is nőt comparable with the high speed at which the suctioning device ofthe present invention is operated.

[0030] US 3,470,091 describes a system and method to reduce pollution of streams, rivers or canals by applying aeration and flocculants to the water. The aeration system comprises gassing oxygen or air to the water, and providing different zones to apply the flocculants. The present invention uses oxidizing agents, such as özöne, sodium or potassium persulfate, chlorine derivatives, hydrogen peroxide, bromine derivatives or chlorine produced by electrochlorination, which are applied to an artificial lagoon. Nőne ofthe Chemicals used in the present invention are considered orsuggested by this publication.

[0031] EP 1420130 is addressed to the construction ofthe swimming pool bordér and the disposal of liner tor common swimming pools, it is nőt related to the construction of the whole structure, and there is no mention of walls and bottom of the swimming pool bút only to the bordér profile. Further, the publication mentions that The present invention is related generally to a swimming pool tiling profile, and more particularly, to a swimming pool tiling profile meant to constitute a peripheral bordér of a swimming pool (page 2, paragraph 1). Furthermore, there is no suggestion of a process similar to that of the present invention. And even further, there are no suggestions that a swimming pool should comprise a water inlet line and water inlet chambers through which water is extracted to feed the structure as defined in the present invention.

[0032] FR 2544005 is specially related to A method tor the construction of swimming pool characterized in the use of expendable form fiiled with concrete in situ. This document is addressed to a construction method of a swimming pool bút does nőt give any indication or suggestion to construct a structure suitable tor the process described in the present invention. Further, the resulting swimming pool constructed according to the method disclosed in this publication does nőt necessary suit the necessity to achieve the process described in the present invention. Furthermore, there is no suggestion that the swimming pool should comprise a water inlet line and water inlet chambers through which water is extracted to feed the structure as defined in the present invention.

[0033] DE 2141460 describes A method tor lining of swimming pool from concrete, cement, masonry with tensioned soft PVC foils . This document is addressed to a lining method of a swimming pool bút does nőt give any indication or suggestion to construct a structure suitable tor the process described in the present invention. Further, the resulting swimming pool constructed according to the method of DE 21 41 460 does nőt necessary suit the necessity to achieve the process ofthe present invention. Furthermore, there is no suggestion that the swimming pool should comprises a water inlet line and water inlet chambers through which water is extracted to feed the structure as defined in the present invention.

[0034] All these EP 1420130, FR 2544005 and DE 2141460 describe several alternatives of construction of swimming pools based on concrete, masonry or cement. The present invention uses materials which are nőt usual in the construction of swimming pools, such as bentonite orclay.

[0035] EP 0468876 defines an hydraulic sweeping device tor swimming pool and the like, in which a suctioning pump is provided to suction the pool water through a tűbe, comprising a housing open at its bottom, said housing is divided in two compartments with a partition defining the admission of a turbine wherein its rotors drives a shaft connected through a reduction and driving mechanism to support wheels. This device cannot be used in the process ofthe present invention, since a major modification would be required. The device should have to be modified to remove the turbine that drives the support wheels, so it may travel on the bottom of the structure at the necessary speed to cover the

ΕΡ 1 925 593 Β1 structure ofthe present invention. As itwill be disclosed in thespecification ofthe present invention, cleaning is performed in such a way that every sector of the laké is cleaned in time intervals no greater than 7 days, preferabíy every 4 days. With this step, togetherwith the use of skimmers, traditional filtering processes used in swimming pools are replaced. Since the device disclosed in the publication requires a major modification in order to achieve the process of claim 1 of the present invention, it should nőt be considered as state of the art fór the suctioning device described the present invention.

[0036] US 2,923,954 defines a submarine suction cleaner including a body adapted to be submerged beneath the liquid in a tank fór cleaning the bottom surface of the tank, which comprises, inter alia, a continuous suction pump on said body. This device cannot be used in the present invention, since a major modification would be required in order to allow it to travel the bottom of the structure at the necessary speed to cover the structure of the present invention. [0037] EP 0352487 defines an automatic, self-propelled swimming pool cleaner which comprises a hydraulic turbine motor fór one-way driving two oppositely located wheel locomotion member and at least one cam drive by the motor and associated with one ofsaid locomotion members to temporarily raise it while the other locomotion member is held in engagement. This device cannot work with the present invention, since a major modification would be required to remove the hydraulic turbine motor driving this device, in order to have it traveling the bottom of the structure at the necessary velocity to cover the structure of the present invention. Furthermore, the device described in EP 0352954 does nőt have the proper cleaning brushes which operating at high speed would lift the settled particles.

[0038] US 4,304,022 defines an apparátus fór cleaning a surface underwater and particularly the bottom of a swimming pool comprising, inter alia, the combination of a chassis, means fór moving the chassis across the surface to be cleaned, a rotatable cleaning brush carried by said chassis at an end thereof fór contacting the surface to be cleaned; a filter and a suction pump carried by said chassis fór causing flowof water and contaminants through said filter. This device includes a filter and a suction pump in the device itself, turning it unsuitable to travel the bottom ofthe structure at the necessary velocity to cover the structure of the present invention.

[0039] FR 2,685,374 defines a cleaning robot fór swimming pools, usable fór all kind of pools, bút most of all designed to cleaning swimming pool of médium or little dimensions, characterized in the combination of a suction robot equipped with a pump droved by an electric motor fed at low tension, said pump suctions the water through a tűbe leading forward the apparátus and delivering one part to a driving turbine acting upon a known propeller system, and another part in a venturi tűbe, or a suctioning turbine, creating a water flow assuring the suction of debris. On one hand, the device is designed to serve in a swimming pool of médium or small dimensions (abstract; page 1, paragraph 2 and claim 1). Therefore, this device is nőt suitable when a large body of water is considered, such as the case ofthe present invention where the smallest body of water considered is larger than 15,000 m3. On the other hand, said device includes a driving turbine and a propeller system which should be removed to allow its travel on the bottom ofthe structure at the necessary velocity to cover the structure of the present invention.

[0040] EP 0483470 defines an apparátus fór cleaning underwater substrates comprising, inter alia, a housing; drive means fór moving said housing; a motor mounted to said housing fór reversible motion of said drive means; a pump coupled to said motor. The presence of a motor and a pump coupled to the motor, turns this device unsuitable to cover the size of a structure as the one described in the present invention. This device would nőt be able to travel the bottom of the structure at the necessary velocity to cover the structure ofthe present invention.

[0041] US 5,337,434 discloses, inter alia, a directional control means fór an automatic swimming pool cleaner having a housing, with front and rear ends and two sides, a pair of motor driven cylindrical brushes rotatably mounted on the front and rear ends ofthe housing respectively fór propelling the cleaner along the bottom surface of a swimming pool. This device is unsuitable to be used in the present invention, since the presence of a motor would nőt allow its use to travel the bottom of the structure at the necessary velocity to cover the structure of the present invention.

[0042] From the analysis ofthe former documents, it is possible to conclude that there are no processes or artificial ponds similar to those to be protected, which allow obtaining water bodies larger than 15,000 m³ fór recreational use, with color, transparency and cleanness characteristics similar to swimming pools or tropical seas at low cost, because in the process ofthe present invention the traditional filtration step has been substituted by a suspended-solid flocculation step and subsequent cleaning with a suction device, designed fór said function, togetherwith the generation of a displacement of surface water that contains impurities and surface oils by means of injecting inlet water and evacuating said water through skimmers (surface slots and dumps) comprised in the structure, and disinfection has been achieved by the application of controlled oxidation pulses.

[0043] The present invention is related to a process to obtain large water bodies or volumes (wherein the term obtaining is meant to be understood as implementation and maintenance), wherein a structure is provided (having elements required fór water treatment and features that produce the desired results) to contain the water, and separation and flocculation (maintenance) processes of particles that make water cloudy and impure are performed, in such a way that flocculated matéria! is suctioned by a suction device once flocculation has taken piacé, and oily materials are removed through skimmers (surface slots or dumps) of the structure of the present invention, said structure having pipes that feed fresh water to fulfill the desired objective.

EP 1 925 593 Β1

DESCRIPTION OF THE FIGURES

Brief description of the figures.

[0044]

Figure 1 shows a side view ofthe suction device.

Figure 2 shows a top view of the structure of the suction device.

Figure 3a shows a front view of the structure of the suction device.

Figure 3b shows a front view of the structure of the suction device.

Figure 4a shows a right side view of the suction device.

Figure 4b shows a left side view of the suction device.

Figure 4c shows a rear view of the suction device.

Figure 5a shows a top view of the structure of the suction device.

Figure 5b shows a top view of the suction device.

Figure 6 shows a schematic view ofthe cleaning system with the suction device.

Figure 7 shows a detailed schematic view of the suction system with the suction device.

Figure 8 shows a schematic view ofthe suction device.

Figure 9 shows a schematic view of the structure of the suction device;

Figure 10 shows a top view ofthe structure ofthe water body ofthe present invention.

Detailed description of the figures.

[0045] Figure 1 shows the following components: moving direction (2) of the suction device, PVC pipe fór suction connection (8), bottom opening (14) in PVC pipe (27) fór bottom suction, sanitary T pipe (9), steel frame (10), autolubricated plastic wheels (12), supporting plate (19a) fór the axles ofthe wheels and rollers (19b), plastic-based brushes with synthetic bristles made of polyethylene or the like (20), steel platen with perforations or slots (21) to fasten the brushes (20) in a continuous line.

[0046] Figure 2 shows the moving direction (2); the frame (10) to which supporting plates (19a) are affixed to support wheels and rollers axles (19b) fór high density polyurethane rollers (11) that are intercalated with wheels (12), which are lined up and alsó supported by supporting plates (19a); a brush line (16) fastened to the perforated platen (21) provided with the structure; and the suction line (27) can be observed in the Central zone ofthe device, formed by a PVC tűbe with five rectangular bottom openings on wall (14), closed in both ends with a cap made ofthe same matéria! (17). [0047] In figures 3a and 3b the device structure is shown, wherein a supporting plate (1) can be observed fór the puliing tensors welded to the frame (10), a resin cover reinforced with fiberglass over a galvanized iron network (6), a lateral plastic membráné flap (7), rollers (11), wheels (12) and sanitary PVC pipes (8) having sanitary T pipes (9) at their bottom section, and a PVC suction pipe or line (27) attached to the open endings of said T pipes, said suction pipe or line (27) having openings wherein the opening area will be proportional to the installed suction capacity.

[0048] Figure 4a shows a lateral right view ofthe device with the moving direction (2), a supporting plate (1) fór the puliing tensors, whereas from the center a PVC suction pipe (8) emerges having a resin fiber collar attached at its base, said resin fiber collar being formed with fiberglass reinforcements (4) fór the fastening and sealing of suction tubes, handles (5) fór puliing, handling and lifting the device, the resin cover (6) and the lateral membráné flap (7). Figure 4b shows a left side view ofthe device indicating the moving direction (2) and the device cover (6). Figure 4c shows a rear view ofthe device indicating the device cover (6).

[0049] Figure 5a shows a top view of the device structure indicating the moving direction (2) and figure 5b shows a

ΕΡ 1 925 593 Β1 top view ofthe device indicating the moving direction (2).

[0050] Figure 6 shows the cleaning system with the suction device placed in the water body (41), wherein there is a pipe to draining chamber (28), plastic buoys (29) for floating a hőse (36), platform (30) for the steersman and the deck operator ofthe boát (31) for puliing with an incorporated four-stroke engine and protected propeller, a puliing tubular labeled galvanized-steel connecting rod (32) astern, a suction device (33), a connection hőse (34) from the boát (31) to the device (33), a connection piece (35) ofthe connection hőse (34) with the suction hőse (36), and a suction hőse (36) that connects the movable electric suction pump (37) at the lake’s shore with the boát (31).

[0051] Figure 7 shows a longitudinal section ofthe suction device in which the partial configuration ofthe structural frame (10), the puliing rod (32) that connects the device (33) (nőt shown in this figure) to the puliing boát, the set of symmetric suction pieces (38) that connect the suction pipes (27) of the cárt with the hőse (34) connecting the device to the boát is described. In this figure alsó appear the projections of wheels (12) and rollers (11).

[0052] Figure 8 shows a lateral view of the puliing boát (31), the suction device (33) placed in the bottom of the water body (41) ofthe laké, the piacement ofthe roofed platform (30) for the boát operator, the connecting rods (32) between the device (33) and the boát (31), the symmetrical suction elements (38), and the connecting hőse (34) with coupling pipe in the boát (35).

[0053] In figure 9, a rear view ofthe system is shown, indicating the connection hőse (34), the puliing rods (32), the set of coupling pieces (38) for symmetrical suction from all four device inlets toward the connecting hőse (34), the hőse (36) with floats (29) that connects the boát connector (35) with the suction pump on land (37), and the pipe that leads to the drainage (28).

[0054] In Figure 10, the following elements ofthe structure can be observed: recycle pipe (39) onto which injectors are arranged; injectors (40) arranged along all the perimeter ofthe water body; water body (41) contained bythe structure; skimmers (42) for removal of floating contaminants such as water with oils; water inlet line and chamber (43) where water is extracted tofeed the lagoon; zoneof restricted natural circulation (44); fresh waterfeeding point (45) to the lagoon.

DESCRIPTION OF THE INVENTION [0055] This invention comprises a process to implement and maintain artificial lakes and artificial lagoons for recreational use of water bodies [41] larger than 15,000 m³, with color, transparency and cleanness similarto swimming pools or tropical seas at low cost, comprising the following steps or stages:

a. - providing a structure with surface siót skimmers [42] able to contain a water body [41] larger than 15,000 m³;

b. - feeding the structure of step (a) with inlet water having írón and manganese levels lower than 1.5 ppm and turbidity lower than 5 NTU;

c. - measuring water pH, ideally it should be within a rangé lower than 7.8;

d. - adding an oxidizing agent to the water contained in the structure of step (a), with which a 600 mV minimál ORP is controlled in water for a minimál period of 4 hours and in maximai cycles of 48 hours, wherein the oxidizing agent is selected among özöne, sodium or potassium persulfate, chlorine derivatives, hydrogen peroxide, bromine derivatives or chlorine produced by electrochlorination;

e. - adding a flocculating agent in concentrations within 0.02 and 1 ppm with maximai frequencies of 6 days and cleaning the bottom of the structure of step (a) with a suction device to remove precipitated impurities from the bottom of said structure, together with the additional flocculants and;

f. - generating a displacement of surface water containing impurities and surface oils by the injection of inlet water according to step (b), which generates said displacement to remove said surface water by a system for impurities and surface oils removal arranged in the structure of step (a), which togetherwith step (e) replaces traditional filtering.

[0056] The process has agreat advantage over the previous art in that the desired characteristics are achieved without needing a filtration system or adding large amounts of Chemicals, which opens the possibility to implement and maintain large crystalline water bodies with no size limit.

[0057] It is worth mentioning that cleaning is performed in such a way that every sector ofthe structure is cleaned in time intervals no greater than 7 days.

[0058] In a preferred aspect, the disclosed structure or laké in step (a) maintains a minimál totál water renewal rate of 150 days, preferably 60 days, to avoid the accumulation of oxidation products (ageing).

[0059] Each step ofthe process to implement and maintain large water bodies is separately detailed in their preferred

EP 1 925 593 Β1 aspects below. In step (a), a structure or pond is provided to contain a large water body larger that 15,000 m³, with elements that allow water treatment and features required to obtain the desired aesthetic and sanitary results of having color, transparency and cleanness similar to swimming pools or tropical seas at low cost. The features ofthe structure provided to carry out steps (b) to (f) ofthe invention will be noted by the reader when the structure specially designed fór this invention is specifically described.

[0060] In step (b), and only in the case where it should be required, a water pre-filtering and treatment can be carried out on the water that is incorporated intő the laké, in the case wherein the water contains incrusting micro-mollusks or turbidity levels over 5 NTU. Nevertheless, water inlet should nőt include micro-mollusks and metals such as írón or magnesium in order to maintain the aforementioned ranges. In other words, low turbidity water is preferable because the process ofthe present invention does nőt have a traditional filtration process and the suction device and skimmers would be inefficient in case of receiving high levels of suspended particles, including both organic and inorganic contaminants.

[0061] If in step (c) the pH is higher than 7.8, it is necessary to add bromine salts such as sodium bromide, always keeping minimál bromide concentrations of 0.6 ppm. It is worth mentioning that in the case of sea water, in spite of having pH values higher that 7.8, it naturally contains high bromide levels, and therefore it is nőt necessary to add this element if the artificial pond or laké is fiiled with sea water.

[0062] In step (d), preferred maximai cycles are of 24 hours The amount of applied oxidant is controlled by permanent measurementof ORP during the application in such a way that it fulfills the minimál established requirements, i.e. oxidant is added up to achieve a minimál of 600 mV during a period of 4 hours.

[0063] The type of the oxidant chosen depends on the cost, among other factors. Hypochlorite produced by electrochlorination and özöne are economical because they are produced in situ, bút require high equipment investments. [0064] The applied amount depends on many factors that vary daily, such as, fór instance: temperature, solarradiation, environmental contamination, rain, storms, levels of use, etc. In short, the necessary oxidant amount is determined by ORP measurement.

[0065] Notwithstanding the foregoing and without limiting the invention, it can be stated that the usually used concentrations and the oxidant application ranges are those indicated in Table 1:

Table 1: Oxidant Application

<td> OXIDANT</td><td> USUAL CONCENTRATION *</td><td> MIN-MAX RANGÉ</td>

<td> Ózoné</td><td> 0.05 ppm</td><td> 0.01 - 0.58 ppm</td>

<td> Hydrogen peroxide</td><td> 0.04 ppm</td><td> 0.01 - 0.46 ppm</td>

<td> Sodium hypochlorite</td><td> 0.16 ppm</td><td> 0.04 - 1.50 ppm</td>

<td> Persulfate</td><td> 0.28 ppm</td><td> 0.07 - 3.30 ppm</td>

<td> Bromines</td><td> 0.22 ppm</td><td> 0.05 - 1.80 ppm</td>

<td colspan="3"> *Total amount added to reach and maintain the minimál 600 mV ORP fór 4 hours, divided by the totál volume ofthe water body.</td>

[0066] Step (e) includes adding a flocculating agent and cleaning the bottom of the structure of step (a) with a suction device in order to remove precipitated impurities from the bottom of the laké, together with the flocculant agents. [0067] Cleaning is performed in such a way that every sector of the laké is cleaned in time intervals no greater than 7 days, preferably every 4 days. With this step, together with the use of skimmers, traditional filtering processes used in swimming pools are replaced.

[0068] Among flocculants that can be added in this step (e), a cationic polymer is preferred, e.g. HICAT-1 ™, which is a biodegradable cationic polyelectrolyte with 25% solids, produced by Buckman Laboratories in the United States (it is accepted by the National Health Service of Chile and recommended to be used in swimming pools at concentrations 100 times higher) in concentrations between 0.02 and 1 ppm with maximai frequencies of 6 days, preferably 0.05 ppm every 24 hours; or addition of Crystal Clear™, which is a biodegradable cationic polyelectrolyte produced by AP Aquarium Products in the United States (it is used in aquariums in concentrations 100 times higher) in concentrations of 0.16 ppm every 24 hours.

[0069] Additionally, in another preferred aspect this step includes adding algaecides such as quaternary ammoniums (e.g. polyquats) and/or copper compounds (e.g. CuSO₄ 5 H₂O or copper chelates), keeping copper levels between 1 ppb and 1.5 ppm, depending on temperature and sunlight; 0.3 to 1.5 ppm of copper fór temperature ranges between 10°C and 30°C.

[0070] It is important to keep in mind that the objective ofthe suction device is nőt only the cleaning ofthe bottom in

EP 1 925 593 Β1 the described process, as is the case of vacuum devices of traditional pools, bút that said suction device replaces completely the traditional filtering system of swimming pools together with the use of flocculants. Furthermore, the fact that the process contemplates the displacement and removal of superficial water with impurities toward the structure slots complements the action of the suction device.

[0071] In other words, the suction device nőt only removes matéria! naturallydepositedon the bottom (leaves, branches, earth, etc.) bút alsó all the suspended particles that are eliminated by filtration in the case of swimming pools and that are converted intő floccules (large particles) and are suctioned by the device in this invention, thus decreasing their removal costs in two orders of magnitude.

[0072] In step (f) it is necessary to control the levels of injection of fresh water to ensure the correct displacement and removal of superficial water with impurities and oils through the skimmers of the structure provided in step (a) of the process ofthe invention.

[0073] As hereinabove mentioned, to carry out the process to implement and maintain large bodies of water larger than 15,000 m³ according to the present invention, it is necessary to provide a structure like that shown as an example in Figure 10.

[0074] A structure or pond suitable fór the process of the present invention includes bottoms and walls built with low permeability materials such as clay and bentonite, coated by a non-porous matériái, such as a polyvinyl chloride membráné, lineal low density polyethylene or high density polyethylene capable of being cleaned, with a depth of at least 0,5 meters, a system fór removing impurities and superficial oils by means of skimmers, a feeding pipe system that allows water replacement by entrance of fresh water and a feed water intake system.

[0075] In a preferred aspect, said fed water is maríné water, well water or spring water; in the case of maríné water the intake system can be through headers or wells positioned at a depth of more than 6 meters.

[0076] The structure has skimmers to remove surface oils and particles, since otherwise they accumulate and deter water quality, even after performing all the Chemical treatment steps, since these do nőt remove floating greases or solids. The process of movement of superficial water toward the skimmers caused by fresh water entry together with the flocculant-suction device system replaces the traditional filtering system of swimming pools.

[0077] The structure may have fresh waterfeeding pipes that allow causing the surface water movement that eliminates floating impurities and oils through the skimmers. These pipes contribute alsó the fresh water necessary to refresh water at the described rates, since otherwise oxidation sub-products accumulate, which render Chemical treatments inefficient and deter water quality.

[0078] The structure may have a pipe network with injectors that allow an efficient application of the products and water homogenization. In swimming pools this is irrelevant, bút in large volume water bodies the existence of isolated stagnant zones creates contamination centers that make disinfection treatments inefficient, thus deterring water quality. [0079] The plastic liner may have special non-porous characteristics. In swimming pools this may be irrelevant, bút in large volume water bodies cleaning would be unfeasible causing adherent linings and a dark layer.

[0080] The bottoms and walls may be built with low-permeability materials such as clay and bentonite, lined with a non-porous matéria! such as polyvinyl chloride membráné, etc. This is the economic way of constructing these large water bodies.

[0081] Water intake may be done in such a way as to avoid micro-mollusks, since besides blocking recycle pipes, said micro-mollusks adhere to surfaces generating a dark color.

[0082] Water intake may avoid water with metals such as iron and manganese, since this pond does nőt have traditional filtration and the flocculation treatment and suction device are inefficient at removing inorganic impurities, including metallic contaminants.

[0083] The crystalline structures or ponds may have water intakes that allow using low cost water since, in contrast to swimming pools that recycle water through their filters, in this case the water from the skimmers and the suction cárt or device is disposed of.

[0084] The structure provided in step (a) fór the process of the invention may additionally have:

1) light blue, white or light yellow bottom (liner) color, fór the water to take the color of tropical seas. This is obvious in the case of swimming pools, bút large ponds use dark plastics due to their durability and lower cost; that is the reason why there are no large water bodies with the described colors. Fór instance, if the plastic would be black (usual in ponds), the desired color would nőt be obtained even if the water had high quality and transparency.

2) a depth over 0.5 meters, preferably between 2 and 5 meters; Depth is important to achieve the desired color similar to tropical seas, since if it is too shallow the water does nőt reach turquoise shades of color and resembles a light-colored water body. Moreover, due to the high water transparency of these ponds, if depth is too low UV light penetration deters the liner rapidly.

3) a recycling system by means of pipes with injectors that allow maintaining water homogeneity and avoiding

ΕΡ 1 925 593 Β1 stagnating zones. This system can be avoided in windy zones.

4) the structure may be constructed in such a way that it avoids dragging organic matter such as leaves and soil by effect of wind, watering, etc.

5) Optionally, it can be made of cement with coatings such as painting, poliurethanes or fiberglass.

[0085] Therefore, in said structure it is alsó possible to generate a step consisting ofthe displacementof surface water containing impurities and oils by means of a current generated by fresh water injection through the pipe systems, thus removing said impurities and oils through said skimmers.

[0086] In the following, an optional suction device ofthe present invention is described in detail:

The suction device to carry out the cleaning ofthe structure bottoms, which is performed in step (e) ofthe process ofthe invention, may comprise: a supporting plate, a resin collar reinforced with fiberglass, puliing handles, a resin cover, a lateral membráné flap, a steel frame, high density polyurethane rollers, auto-lubricated plastic wheels, an opening in a PVC pipe to suction the bottom, a brush line comprising plastic-based brushes with synthetic bristles and a steel platen with perforations or slots to fasten the brushes in a continuous line, supporting platesforthe axles ofthe wheels and the rollers, and a suction PVC line with openings (see description of figures fór more details).

[0087] The suction device operates by suctioning dirt through connecting hoses by means of a pumping system, said device being pulled by a system that includes a propelling device to move the suction device, such as a boát, fór instance, a draining chamber, plastic buoys fór aiding a hőse to float, a platform fór the steersman and the boat’s deck operator in case a boát is used as propelling device, a puliing tubular labeled galvanized-steel connecting rod astern, a connection hőse between the boát and the cárt, a connection piece between the connecting hőse and the suction hőse that connects the pump placed at the structure edge. In any case, the propelling device of the suction device can alsó be formed by a remote mechanical traction system arranged out of the structure or any other propelling device useful to move the suction device.

[0088] The suction device is mainly formed by a structuring frame [10], a covering carcass [6] with coupling means to be coupled to the pumping system, rolling means fór continuous displacement over the surface to be cleaned and cleaning means consisting of a suction line and a brush line [16] to remove the matéria! to be cleaned by means of suction from the pumping system through the suction device.

[0089] The covering carcass eomprises a laminar resin body that covers the structuring frame [10] and the rolling and suction means. From the top section of the covering carcass supporting plates emerge fór the puliing tensors from the boát, which are internally joined to the structuring frame; at its top section, said carcass alsó has suction PVC tubes that form coupling means to the pumping system and are attached by their base section to a carcass collar formed in molded resin fiberwith glass fiber reinforcements fór supporting and seaiing said suction tubes; whereasfrom said carcass collar a resin mantle and a lateral membráné flap project to form the carcass body. Alsó its top section has handles fór puliing, handling and raising the device.

[0090] The structuring frame is a steel frame to which an aligned series of steel plates fór supporting the rolling means, which comprise the axles of high density polyurethane rollers and plastic auto-lubricated wheels, is supportively joined, and a perforated or slotted steel platen is likewise attached to support by means of bolts a continuous line of brushes having a plastic base and synthetic polyethylene bristles, or the like, which help in the task of removing the matéria! to be suctioned. To the rear section, the abovementioned supporting plates ofthe puliing tensors are joined.

[0091] The cleaning means comprise a suction line formed by vertical PVC tubes, corresponding to suction tubes emerging upwardly from the covering carcass, to which T-shaped PVC tubes are attached at their bottom part, which are coupled in turn to horizontal tubes that have suction openings in their bottom part through which the removed matéria! enters to be suctioned and taken out ofthe pond.

[0092] It is important to keep in mind that the objective ofthe suction device (suction cárt) is nőt only the cleaning of the bottom in the described process, as is the case of vacuum devices of swimming pools, bút that said suction device replaces completelythetraditional filtering system of swimming pools together with the useofflocculants and theskimmer system.

APPLICATION EXAMPLE [0093] A structure similar to an artificial lagoon was built in the Central Chilean shore, having a length of 1 kilométer, an area of 80,000 m² and a volume of 250,000 m³ (3320’59.91S; 7139’10.10W). The bottom was built using clay and bentonite, and it was lined with lineal low density polyethylene (LLDPE) and high density polyethylene (HDPE) plastic with white and yellow color. The walls were built in cement and clay and lined with LLDPE and HDPE membranes.

ΕΡ 1 925 593 Β1 [0094] Minimál and maximai depths were 1.2 and 3.5 meters, being 2.8 meters the average depth.

[0095] A pipe system of 100 to 250 mm diameter was installed all around the lagoon borders to facilitate recycling. The system has homogeneously distributed injectors every 10 meters around the entire lagoon that are placed in the bottom to inject the products and maintain water homogeneity. Systems fór the removal of impurities and superficial oils by skimmers were installed.

[0096] Water intake fór this structure was achieved through headers. Inlet water had 0.08 ppm írón and 0.15 ppm manganese, and a turbidity of 1.4 NTU. The water had a pH of 7.93 and natural bromine concentrations of 48 ppm, and consequently no addition of bromine salts was required. The water was impounded through headers at a depth of 8 m at sea shore. The intake was performed at this depth to avoid incrusting micro-mollusks. The presence of micro-mollusks in sea water causes problems by growing, development and adhesion to piping walls and lagoon structures. Other possible way to avoid incrusting micro-mollusks is the use of water pre-filtering.

[0097] ORP value was maintained over 600 millivolts (mV) during 4 hours in 24-hour cycles. This was achieved by applying oxidants, such as e.g. özöne, hydrogen peroxide, potassium persulfate, electrochlorination orsodium hypochlorite. All the former were tested with good results.

[0098] In an average September day with an air temperature between 10 and 16°C and a water temperature of 17°C, 0.11 ppm of sodium hypochlorite produced by electrochlorination were applied, which was sufficient to maintain ORP over 600 mV fór more than 4 hours. This system is advantageous when working with salt water, because the electrolytic process transforms chloride in sea water in hypochlorite, with no need to add additional Chemicals.

[0099] The established regulations fór swimming pools in other countries indicate higher ORP values (between 650 and 750 mV) permanently, bút this is nőt economically viable in large volumes of water and in this invention it has been demonstrated that keeping ORP over 600 mV during 4 hours in 24-hour cycles is enough to decrease the growth of microalgae and microorganisms in large water bodies, thus generating low-contamination conditions apt fór swimming. [0100] The bacteria Escherichia coli, a bacterial pathogen marker, dies after 100 seconds when exposed to a ORP of 600 mV, and consequently the 4-hour treatments have a high disinfectant power.

[0101] The water body volume of this example equals the volume of 6,000 familiar 8-meters-long swimming pools and is constructed in such a way that it does nőt récéivé visible contamination from the surroundings (leaves, soil, watercourses), and consequently contamination received from the environment is very low in relatíve terms when compared with a swimming pool. Proportionally, humán contamination is alsó insignificantgiven the highdilution power (fór example, 4 swimmers in a familiar pool equal 24,000 swimmers in the lagoon).

[0102] Additionally, theflocculation and bottom cleaning with the suction cárt, and the removal ofgrease and superficial impurities by means ofthe skimmers allows keeping low organic matter levels, which decreases the use of oxidants. [0103] Algaecide action was achieved by keeping an average copper level in the water of around 0.3 ppm, and the application was made by using coppersalts (coppersulfate pentahydrate) in closed sacs, which is applied in the chambers through which recycling system water passes, in such a way that the salts dissolve slowly, and alsó by an copper electrode ionization process in which an electric current is applied to said electrodes and copper ions are released intő the médium in a controlled way. Measured copper levels varied between 0.1 ppm at a temperature of 10°C and 1.5 ppm at 30°C (2 ppm are acceptable in potable water, see Table 4).

[0104] A cationic flocculating polymer was added. The flocculant used was HICAT-1™ in daily applications of 0.04 ppm through the recycling system.

[0105] With the aid ofthe suction cárt or device, the plastic ofthe bottom ofthe lagoon was cleaned subsequently to decantation. The device has a system of suction chambers, thus removing all the precipitated impurities together with the polymer, which allows the bottom ofthe lagoon (membráné) to be seen. The device that cleaned the plastic membráné was pulled by a boát and did nőt leave any residual layer, because it was a fine cleaning and nőt a dredging. This cleaning and suction method was permanent and the bottom ofthe lagoon was cleaned daily, in such a way that the suction system passes by every membráné sector every four days.

[0106] The water was maintained in movement by means of a recycling system thatoperated 8 hours per day in lowwind seasons, thus keeping water homogeneity. Injectors distributed around the structure throw the water up to a long distance and are placed every 10 meters. It should be mentioned that the water contained by the structure alsó shows an important circulation as an effect of the wind and it should be possible to decrease the artificial recirculation requirements by a suitable design ofthe structure, thus sparing energy.

[0107] This recycling system was used to apply Chemicals. The water of the structure was completely renewed in a period between 30 and 150 days. The aim ofthe renewal was to avoid water ageing, which is the formation of secondary compounds derived from oxidation reactions. The renewal was performed by taking new water through the feeding pipes, independently from the recycling pipes that end at the injectors.

[0108] A superficial water outiét flow was kept by means of the skimmers that remove oils and superficial impurities. [0109] The amount of added Chemicals depends mainly on the temperature and is orders of magnitude lower than those required in swimming pools.

[0110] The totál comparative maintenance cost per cubic meter was approximately 3% ofthe usual cost in swimming

ΕΡ 1 925 593 Β1 pools.

[0111] In this application example, the physicochemical conditions ofwaterwere determined to comply nőt only with regulations fór recreational waters with direct contact (see Table 2), which are those applied in this case, bút alsó with regulations fór potablewater (see Table 4), with the exception of characteristics inherentto sea water, and with regulations fór swimming pools (see Table 3), with the exception of chlorine permanent residual levels, which do nőt apply because of the applied technology..

Table 2: Comparison ofthe water treated with the process ofthe invention and the regulation fór recreational waters with direct contact (NCh 1333 *)

<td> PARAMETERS</td><td> MEASURED VALUE IN THE LAGOON</td><td> NCh1333</td>

<td> pH</td><td> 7.96</td><td> 6.5 to 8.3 except if natural water conditions show different values, bút in no case lower than 5.0 or higher than 9.0</td>

<td> Temperature, °C, maximai</td><td> 17.7</td><td> 30</td>

<td> Clarity, minimál *</td><td> 35 meters</td><td> Visualization of Secchi discs at a depth of 1.20 meters</td>

<td> Visible floating solids and unnatural foams</td><td> Absent</td><td> Absent</td>

<td> Floating oils and greases, mg/l, maximai *</td><td> &lt;5</td><td> 5</td>

<td> Emulsified oils and greases, mg/l, maximai *</td><td> &lt;5</td><td> 10</td>

<td rowspan="2"> Color, Pc-Co Scale unit, maximai *</td><td> 10</td><td> 100</td>

<td> Absent</td><td> Absence of artificial colors</td>

<td> Turbidity, Silica units, maximai *</td><td> 0.55</td><td> 50</td>

<td> Fecal coliforms /100 ml, maximai *</td><td> &lt;2.0</td><td> 1,000</td>

<td> Substances that cause inconvenient smell or taste</td><td> Absent</td><td> Absent</td>

<td colspan="3"> * Official Chilean regulations were used (Chile was the country ofthe application example), Chilean rule NCh 1333</td>

Table 3: Comparison of the water treated with the process of the invention and the regulation fór swimming pools (NCh 209 *)

<td> PARAMETERS</td><td> MEASURED VALUE IN THE LAGOON</td><td> NCh 209</td>

<td> pH</td><td> 7.96</td><td> 7.2-8.2</td>

<td> Free residual chlorine</td><td> +</td><td> 0.5 -1.5 (ppm)</td>

<td> Copper (algaecides) mg/l</td><td> 0.38</td><td> 1.5 maximai</td>

<td> Bromine (disinfectant) mg/l</td><td> +</td><td> 1-3</td>

<td> Foam, grease and suspended particles</td><td> Absent</td><td> Absent</td>

<td> Colonies of aerobic bacteria / ml</td><td> 2</td><td> &lt; 200</td>

<td> Fecal coliforms</td><td> Absent</td><td> Absent</td>

<td> Totál coliforms colonies /100 ml</td><td> &lt; 2</td><td> &lt; 20</td>

<td> Algáé, lárváé or other living organisms</td><td> Absent</td><td> Absent</td>

EP 1 925 593 Β1 (continued)

<td> PARAMETERS</td><td> MEASURED VALUE IN THE LAGOON</td><td> NCh 209</td>

<td> Clarity</td><td> 35 meters</td><td> 1.4 meters</td>

<td colspan="3"> * Official Chilean regulations were used (Chile was the country ofthe application example), Chilean rule NCh 209 + Do nőt apply because ofthe applied technology</td>

Table 4: Comparison ofthe water treated with the process ofthe invention and the regulation fór potable water (NCh 409 *)

<td> PARAMETERS</td><td> UNIT</td><td> ASSAY METHOD</td><td> MEASURED VALUE IN THE LAGOON</td><td> Official 2005 NCh 409</td>

<td> pH</td><td> -</td><td> (I)</td><td> 7.96</td><td> 6.5&lt;pH&lt;8.5</td>

<td> Turbidity</td><td> NTU</td><td> (I)</td><td> 0.55</td><td> 2.0</td>

<td> True color at pH = 7.71</td><td> Pt-Co</td><td> (I)</td><td> 10</td><td> 20</td>

<td> Smell</td><td> -</td><td> (I)</td><td> Odorless</td><td> Odorless</td>

<td> Taste</td><td> -</td><td> (I)</td><td> +</td><td> Tasteless</td>

<td> Ammónia</td><td> mg/l NH₃</td><td> (I)</td><td> 0.12</td><td> 1.5</td>

<td> Totál arsenic</td><td> mg/l As</td><td> (I)</td><td> &lt;0.005</td><td> 0.010)</td>

<td> Cadmium</td><td> mg/l Cd</td><td> (I)</td><td> &lt;0.002</td><td> 0.01</td>

<td> Zinc</td><td> mg/l Zn</td><td> (I)</td><td> &lt;0.05</td><td> 3.0</td>

<td> Totál cyanide</td><td> mg/l CN</td><td> (I)</td><td> &lt;0.05</td><td> 0.05</td>

<td> Chlorides</td><td> mg/l Cl</td><td> (I)</td><td> 18,914</td><td> 400 (2)</td>

<td colspan="5"> MICROBIOLOGICAL ANALYSIS</td>

<td colspan="5"></td>

<td> PARAMETERS</td><td> EXPRESSED AS</td><td> ASSAY METHOD</td><td> MEASURED VALUE IN THE</td><td> Official 2005 NCh 409</td>

<td></td><td></td><td></td><td> POND</td><td></td>

<td> Totál coliforms</td><td> MPN/100 ml</td><td> (V)</td><td> &lt;2.0</td><td> &lt;2.0</td>

<td> Escherichia coli</td><td> MPN/100 ml</td><td> (V)-D</td><td> ABSENT</td><td> ABSENT</td>

<td colspan="5"> n.d. Indicates nőt detected * Official Chilean regulations were used (Chile was the country ofthe application example), Chilean rule NCh 409 + Inherent values of sea water.</td>

[0112] In this example, it has been demonstrated that it is possible to maintain a water body or volume similar to a large-volume (250,000 m³) artificial sea water pond with a water quality similar to conventional swimming pools and tropical seas, both in its aesthetic characteristics as in its physicochemical and bacteriological properties. The achieved characteristics have nőt been found in any existing artificial lagoon in the world up to date (see Google Earth) and this can be demonstrated by satellite comparison ofthe transparency and color ofthe lagoon to be protected (3320’59.91S ; 7139’10.10W) with the tens of thousands existing in the world, such as golf court and public park lagoons, dams fór recreational use, lagoons of reál estate and tourist projects, and even dams over 15,000 m³ builtwith swimming purposes (e.g. Piscina do Ramos in Brazil, Darwin Swimming Pool in Australia, Orthlieb Swimming Pool in Casablanca, Morocco). [0113] We have nőt found any artificial water body in the world with a volume higher than 15,000 m³ having crystalline water with this quality, exceptforthe structure similarto an artificial lagoon that we wantto protect, which has 250,000 m3. [0114] Ina Google Earth™ fórum (Internet software fór satellite photography ofthe world) people has been searching fór two years fór the biggest swimming pool in the world that can be seen from the air. The conclusion, when reviewing

ΕΡ 1 925 593 Β1 their results, is that the lagoon of the application example is by far the biggest crystalline water body found.

[0115] The biggest known swimming pool in the world that uses traditional filtering and recycling systems is Sunlite Pool of Coney Island, United States, having 11,350 cubic meters of water. In the remaining tens ofthousands of large artificial water bodies existing in the world, the water is nőt filtered or it is only partiaiiy filtered. As previously mentioned, the characteristics of the water of these bodies are very different from swimming pools or tropical seas and their uses are limited.

[0116] Filtering large water volumes is technically complex and highly costly, and consequently this is a barrierforthe scaling-up of crystalline water bodies. The process of the present invention removes suspended solids (turbidity) that flocculate together with the polymer in an efficient and economic way, thus replacing filtering.

[0117] In addition to the high costs, the traditional filtering system does notsolve the cleaning ofthe bottom ofthe lagoon. [0118] The technology described in the present invention, allows breaking the barrier that hinders the construction of crystalline lagoons with unlimited extensions and volumes, thus opening a new field of tourist applications.

[0119] The main advantage ofthe implemented process is evidenced by comparing the regulations fór recreational waters and the results obtained in the artificial lagoon ofthe example. Additionally, the level of transparency obtained in the water is highly important, being the clarity equal or higher than 35 meters, which is a result nőt found in any water body larger than 15,000 m³ nor in the majority of swimming pools; in fact, the swimming pool regulation demand only 1,4 meters of clarity (see Table 3).

[0120] Other advantages of the disclosed process of the present invention are:

• Low maintenance costs.

• Established regulations fór recreational waters with direct contact are widely fulfilled (see Table 2) and comparable parameters ofthe swimming pool and potable water regulations are alsó fulfilled (see Tables 3 and 4).

• The water in the lagoon is always absolutely transparent, with no turbidity, with the characteristic turquoise color of swimming pools or tropical seas and with a clean bottom, which are optimál visual characteristics fór the acceptation of the user public.

• Use of oxidant, algaecide and disinfectant concentrations up to 100 times lower that those recommended to be applied in conventional swimming pools; this advantage favors the users and is more environmentally-friendly.

• As these water bodies are disconnected from the sea or near natural lakes, they are nőt affected by temperature variations produced by oceanographic currents, ice thawing, etc. bút only by environmental variables (temperature, solar radiation, wind). In practical terms, in the lagoon ofthe application example in summer, temperatures of more that 10°C higher than those ofthe sea are obtained.

• Flocculation and bottom cleaning by suction together with skimmers replace the filter system of conventional swimming pools, thus generating high transparency conditions at a very low cost. The removal of sediments prevents said sediments to consume oxidants and generate anoxic zones, and they allow the bottom membráné to give an attractive tonality to the lagoon’s water.

• Water bodies can be built with no size limit having optimál aesthetical, physicochemical and sanitary conditions, which generates large tourist attraction poles.

[0121] In order to make more evident the surprising effect of the process disclosed in the present invention, Table 5 is shown, which illustrate the costs fór both cleaning methods in the water body ofthe application example (250,000 m³).

EP 1 925 593 Β1

Table 5: Comparison ofthe traditional filtering method* and the suction device

<td></td><td> Specifications</td><td> Volume circulated through pumps</td><td> Installatio n costs</td><td> Monthly operation costs</td>

<td> Traditional filter</td><td> • 120 15 HPThree-phase Aral-C 3000 pumps (Astral code 01206) • 60 Praga 3000 filters (Astral code 15781) • 714,000 kilograms of sand (Astral code 905000) • 60 batteries of 250 mm valves (Astral code 19133) • Installation labor • Shed of 2,500 m² • Totál monthly energy required, 24 hours*30 drays*1343.28 kW/hour (967,164.18 kW/hour) • Operators • Maintenance</td><td> 2,893 Its/sec</td><td> US$ 2,686,648+</td><td> US$ 119,246</td>

<td> Suction device</td><td> • Windglider boát • Protected outboard 9.5 HP motor • Suction device • Suction pump 7.5 HP • Hoses, accessories • Fuel • Flocculant • Operator • Maintenance</td><td> 10 Its/sec</td><td> US$25,166</td><td> US$ 2,242</td>

<td colspan="5"> Considering T=2 (minimál rate fór swimming pool filtration) according to regulation NCh 209 + Does nőt consider the cost of the land fór the 2,500 m² shed.</td>

[0122] It is important to keep in mind that to obtain the desired final result of color, transparency and cleanness characteristics similar to swimming pools or tropical seas at low cost, it is preferred to have a water containing structure that have the required elements fór water treatment and features that allow obtaining the desired results. The isolated application of the physicochemical process fór water treatment would nőt be possible nor would it produce the desired results.