1 METHOD FOR THE ELECTROCHEMICAL DISINFECTION OF WATER DESCRIPTION TECHNICAL FIELD OF THE INVENTION 5 The invention relates to a method for electrochemically disinfecting water, without the addition of any chemical product, by passing this water through at least one electrolytic cell contained in a casing provided with means for conveying and removing the water and by exploiting the direct virucide, bactericide and bacteriostatic effect linked to the oxidation actions in the anode 10 and the reduction action in the cathode, as well as the supplementary indirect bactericide effect and the residual bacteriostatic effect linked to the action of the oxidants generated by the electrolysis of water. DESCRIPTION OF THE TECHNICAL BACKGROUND 15 The patent EP1597202 by the same applicant describes a method: - which consists of making the water to be continuously treated pass through an electroperoxidation module using catalytic electrodes so it undergoes an electrochemical treatment; - using, on the one hand, the direct effect linked to the oxidation actions 20 in the anode and the reduction action in the cathode on the solved organic materials (virucide, bactericide and bacteriostatic effects) and on the other hand, the indirect effect linked to the action of the oxidants generated by the water electrolysis (supplementary bactericide effect and residual bacteriostatic effect); 25 -which enables, by prolonged contact with the electrochemically generated oxidants, an additional reduction of bacteria and water protection during the transportation and storage thereof to the point of use, the action being prolonged at the outlet of the electrolyzer (residual disinfection capacity). The oxidants generated from the dissolved oxygen (cathodic reduction) 30 and water (anodic oxidation), posses an appreciable residual effect and induce oxidation products at harmless rates, contrary to the most used oxidants, such as chlorine. The device for implementing said method includes an anode and a cathode, both plate-shaped and parallel to one another, the opposing catalytic 35 faces of which are symmetrical and have identical surface areas in order to 2 enable the inversion of polarity in optimum conditions (the current density being identical on both electrodes) with the effect of preventing premature degradation relative to each other due to the decarbonation, which is not identical, and side reactions, which are more Important on the smaller electrode (higher current 5 density). The operating conditions applied to said device were as follows: - implementation of a continuous laminar flow regime between the two opposing electrodes in order to limit turbulence that promote the adhesion of lime deposits (encrusting) on or between the electrodes, which have the effect 10 of producing premature aging thereof, - feeding the opposing anodes and cathodes, by means of a direct and/or pulsed electric current, in order to compensate for variations in the current density from one end to the other of each electrode. During qualification tests under real conditions, it was found that certain 15 bacteria were less or even hardly affected by the passage between the electrodes. Among these the Pseudomonas aeruginosa and Clostridium perfringens bacteria are worth mentioning. The performance of the bacterial treatment has therefore proved to be 20 inefficient in laminar regime mainly for the aforementioned bacteria. In fact, in laminar regime, the sheet of water that passes right through the cell from one end to the other, equidistant from the anode and the cathode, undergoes only the effect linked to the current passing between the electrodes (via electron transfer between anions and/or cations and electrodes). 25 SUMMARY OF THE INVENTION It is with the aim of increasing the efficiency of the bactericidal treatment mainly for Pseudomonas aeruginosa and Clostridium perfringens bacteria that the applicant has developed the claimed method, which also uses an 30 electrochemical cell including an anode and cathode, both plate-shaped, parallel to one another, the opposing catalytic faces of which have identical surface areas and form a symmetrical inter-electrodes space with no preferential path or short circuit. Using the result of his research as starting point and based on the fact 35 that the potential of hydrogen (pH), reflecting the acidity of the water, is very low 3 (lower than 1) in the vicinity of the anode (where the oxygenation takes place) and on the contrary very high (higher than 14) in the vicinity of the cathode (where the reduction takes place), the applicant has implemented a specific turbulent hydraulic regime between the opposing electrodes in order to: 5 - apply, alternatively and successively, on the microorganisms existing in the water, along their entire passage within the cell, strong pH variations with the aim of deactivating them; - place, alternatively and successively, said microorganisms in very close contact with the radicals 02 and OH formed on the surface of the electrodes 10 with the aim of improving direct and indirect effects. In addition, the electric field between the electrodes being of the order of ten volts, at the level of bacterial membranes is sufficient to induce a "dielectric breakdown". The operation of the cell in such turbulent regime, constitutes a real 15 advancement in the performance of the system, thus allowing for tests on more evolved organisms such as protozoa (for example, amoeba), fungi and yeasts. In order to optimize the treatment performance, namely the disinfection treatment, the applicant has found that the introduction, in the downstream flow, of metal parts, namely made of copper, in contact with water, had the effect of 20 accelerating, by the formation of powerful radical compounds with a short life span, decomposition rates of oxidizing compounds generated by the water system (formation of powerful radical compounds with a short life span). As for the scaling of the electrodes and the water circuit, it has been limited by controlling the scaling capacity of the water upstream from the cell 25 using at least one of the following technologies: - the selective retention of calcium and magnesium cations on the cation exchange resin; - the sequestration of calcium ions by contact with polyphosphates in the form of crystals or in liquid form; 30 - the inhibition of the encrusting capacity of limestone (calcium carbonate) by the action of a magnetic, inductive or equivalent scale inhibitor. PRESENTATION OF THE FIGURES The characteristics and advantages of the invention will appear more 35 clearly on reading the following detailed description of at least a preferred 4 embodiment thereof, given by way of non-limiting example and the accompanying drawing (Fig. 1), which is a schematic outline showing the path of microorganisms between the electrodes and the chemical reactions in the vicinity thereof. 5 DETAILED DESCRIPTION OF THE INVENTION The invention relates to a method for the electrochemical disinfection of water by passing said water through at least one electrolytic cell contained in a casing provided with means for conveying and removing said water and by 10 exploiting the direct virucide, bactericide and bacteriostatic effect linked to the oxidation actions in the anode and the reduction action in the cathode, as well as the supplementary indirect bactericide effect and the residual bacteriostatic effect linked to the action of the oxidants generated by the electrolysis of water. The method according to the invention is substantially characterized in 15 that it consists: a) of using an electrolytic cell that includes one anode and one cathode, both plate-shaped and parallel to one another, the opposing catalytic faces of which have identical surface areas and form a symmetrical inter-electrode space with no preferential path or short circuit; 20 b) of creating, between said plates, by means of a device located upstream or downstream thereof, along the entire length of the passage of the water to be treated, a turbulent regime that has the effect of alternately and successively casting, the microorganisms contained in the dissolved substances against the anode and against the cathode so that they experience 25 the deactivating effect caused by the strong variations in pH that are present between the electrodes, as well as the additional bactericidal effect upon contact with the 02 and OH radicals formed on the surface of the electrodes. Figure 1 exhibits: - the anode A (pH < 1) and the cathode C (pH > 14) 30 - the path followed by the microorganisms M between said two electrodes; - the chemical reaction at the anode: 2 H 2 0 = 4 H* + 3e + 02 - the chemical reaction at the cathode: 2 H 2 0 = 2 OH- + H 2 The method according to the invention, further consists, in order to 35 optimize the treatment's performance, particularly regarding disinfection, of 5 placing, in the downstream flow, metal parts, namely made of copper, in contact with the water, so as to accelerate, by the formation of powerful radical compounds with a short life span, the decomposition rates of oxidizing compounds generated by the water system. 5 In addition, it further consists, in order to inhibit the scaling of the electrodes and the water circuit, of applying, upstream thereof, a technology chosen from among: - the selective retention of calcium and magnesium cations on the cation exchange resin; 10 - the sequestration of calcium ions by contact with polyphosphates in the form of crystals or in the liquid form; - the inhibition of the encrusting capacity of calcium carbonate by the action of a magnetic or inductive scale inhibitor. In addition, it further consists, in order to clean the electrodes, of applying 15 thereto: - either an ultrasonic field; - or a high-frequency field that generates resonance phenomena. The device for implementing said method includes flow disturbers such as for example: 20 - at the inlet of the cells, a turbulence generator provided with a series of deflectors mounted in opposite directions and supported by a cylindrical ring, which fits over the inlet nozzle of the electrolytic cell; - on the leading edges of the plates, in order to increase the turbulence regime between the plates, U-shaped interlocking profiles. 25 The role of a disinfection system is to maintain sufficient concentrations of oxidizing disinfectants in the water flowing through the internal distribution network so that the bacteria, which are suspended in the water (coming from the existing city's cold water system, backwaters or biofilms), are destroyed or deactivated before they reach the drawing points. The assurance of using a 30 quality water, consistent with its use implies therefore checking on site and over time, for the presence of a sufficient concentration at the water drawing points, the target values measured as chlorine equivalent being comprised between 0.5 and 1 mg/I. The implemented electrolysis principle enables producing oxidizing 35 disinfectants based on the oxygen contained in the water.
6 An internal study has shown that the persistence of the oxidants generated by the method according to the invention tended to a logarithmic evolution of the persistence as a function of the initial concentration of oxidizing agents. For example, the life span is approximately 24 hours for an initial 5 concentration of 0.5 mg/I and increases to 30 hours for 1 mg/I. It is 15 days for 2.5 mg/I and more than one month (31 days) for 10 mg/I. The electrolytic cell is generally associated with a flow meter (of the paddle type, with pulse generator, or other) and an electronic panel, which manages the control of the electric current sent to the cell as a function of the 10 flow volume passing by and the settings adopted by the operator. According to two operating variants of the invention, several cells may be hydraulically mounted: - either in series to cumulate the disinfectant effects thereof; - or in parallel to cumulate the flow rates thereof. 15 The cells may be, in both cases, enclosed in a common casing provided with conveying and removing means that are also common to said cells assembly. The cells may be hydraulically mounted in series or in parallel, but not necessarily electrically, each cell can be fed separately. 20 According to various operating variants of the invention, an electrochemical treatment module may be: a) submerged in a treatment or sedimentation tank; b) placed on the loop of a treatment or sedimentation tank; c) coupled with a filtering system, especially of the granular type, or with 25 membranes, and/or to other electro-chemical treatment module. The cell or cells may be supplied with direct and/or pulsed current. The electrode polarity reversal is programmed according to a well determined percentage of the elevation of the voltage as a function of the characteristics of the water to be treated and/or according to a well-determined 30 timing depending on the water quality. The space between the two electrodes is generally comprised between 2 and 6 mm depending on the conductivity of the water used. The electrodes have thickness generally comprised between 1 mm and several millimeters. 35 The electrochemical treatment modules may include, 2, 4, 6 or more 7 electrodes. The direct and/or pulsed electric current that is used has a value generally comprised between 1 and 10 A per dm 2 . The optimal water pressure in the cell is 3 bar. 5 When the cells are mounted forming a loop on a vat, they produce a volume of water at a higher concentration of total oxidants, for example to protect the treated water against any recontamination caused by germs and/or organic matter in the storage and distribution system and that up to the points of use. This water can then be injected into the water to be treated, as in this 10 application only the indirect effect is used. This implementation can be used to disinfect equipment for example surgical instruments, by immersion in the vat described above. The system can also be used as tertiary wastewater treatment or as a main or secondary treatment of water intended for recreational or therapeutic 15 uses (thermal waters, thalassotherapy...). For the applications mentioned above, as well as for water disinfection, cooling towers or other air treatment system, the implementation may be different in the case where the sets of electrodes are bare (not contained in a cell). 20 The liquid mass can then be brought into contact with the oxidants generated by convective motions (convection phenomenon). This type of implementation can be adopted for example, in buffer tanks and water cisterns. Several sets of electrodes can be implemented in the same vat. The electrode sets may also be implemented integrated inside or outside 25 the pipes and submerged in the water to be treated (for example for pools in the water recycling system). The water treated with the device, regardless of the implementation type, can eventually be used for medical applications (therapies). When this technique is combined with a granular filtration system, a 30 technical synergy occurs since microfiltration stops completely parasites and bacteria, but not viruses while the device contributes to the destruction of virus. In addition, the device brings about a residual disinfection capacity to the water that neither microfiltration nor ultra-violet irradiation can supply. Finally, the device contributes to the degradation of dissolved organic 35 matter, while the microfiltration only stops the suspended matter (particles 8 larger than 0.1 microns, or 0.01 microns in the case of ultrafiltration). Of course, the skilled person will be capable of performing the invention as described and depicted by applying and adapting known means without being it necessary to describe or represent them. 5 The skilled person may also envisage other variants without departing from the scope of the invention as determined by the terms of the claims.