MXPA01005705A

MXPA01005705A - Electrolytic apparatus, methods for purification of aqueous solutions and synthesis of chemicals.

Info

Publication number: MXPA01005705A
Application number: MXPA01005705A
Authority: MX
Inventors: Guillermo Daniel Zappi
Original assignee: Zappi Water Purification Syste
Priority date: 1998-12-07
Filing date: 1999-12-06
Publication date: 2003-07-14
Also published as: WO2000034184A1; NZ512645A; CZ20012002A3; NO20012804D0; PL348151A1; AU3112000A; IL143529A0; AP2001002197A0; IS5954A; AU767548B2; CN1329576A; JP2002531704A; EP1150921A1; OA11806A; CA2355346A1; CA2355346C; SK7672001A3; ID30239A; TW490444B; NO20012804L

Abstract

An apparatus for electrolysis, method for eletropurification and method for the electrosynthesis of chemical products, where the electropurification of contaminated aqueous media, such as napa water and water served from industrial factories such as paper mills, food processing plants and textile factories , is easily purified, bleached and sterilized by the improvement of a more economical open configuration electrolysis cell design, with electrodes comprising a plurality of conductive porous elements in electrical contact with respect to each other. The cells can be divided or not, and connected in a monopolar or bipolar configuration. When they are connected with a very narrow capillary electrode space, the operation is more economical, particularly when the treated solutions have a relatively low relative conductivity. The novel cell design is also useful in the electrosynthesis of chemical products, organic or inorganic, such as hypochlorite bleach and other oxygen species.

Description

APPARATUS FOR, ELECTROLYSIS, METHOD FOR ELECTROPURIFICATION AND METHOD FOR THE ELECTROSINTESIS OF CHEMICAL PRODUCTS FIELD OF THE INVENTION The present invention relates to an apparatus for electrolysis, method for electropurification, and method for the electrosynthesis of chemical products, and generally refers to the purification of aqueous solutions and the preparation of useful chemical products, and more specifically, to electrochemical methods and more efficient, economical and safe electrolytic devices for the electropurification of drinking water, industrial waste water and contaminated underground water, as well as electrochemical synthesis (electrosynthesis) of useful products, for example, organic and inorganic chemicals.

BACKGROUND OF THE INVENTION Sewage or wastewater can be a valuable source in cities and towns where the population is constantly growing and water supplies are limited. In addition to facilitating the effort of the limited supply of fresh water, the use of sewage can improve the quality of streams and lakes by reducing the discharges of effluents they receive. The sewage can be taken and reused for the irrigation of fields and crops, in the recharge of water tables, or recreational purposes. The provision of adequate water for drinking is essential for life. The quality of natural water availability varies from location to location, and it is often necessary to remove microorganisms such as bacteria, fungi, spores and other organisms such as Crypto Sporidium, salts, heavy metal ions, organisms and the combination of such contaminants. Many years ago, numerous primary, secondary and tertiary processes were used for the decontamination of industrial wastewater, the purification of napa water and the treatment of the municipal water supply, converting them into healthier drinking waters. These processes mainly include the combination of mechanical and biological processes, such as spraying, sedimentation, mud digestion, activated sludge filtration, biological oxidation, nitrification and so on. Chemical and physical processes have also been widely used, such as flocculation and coagulation with chemical additives, precipitation, filtration, chlorine treatments, ozone, Fenton reagent, reverse osmosis, sterilization through ultraviolet rays, to name a few. Numerous electrochemical technologies have also been proposed for the decontamination of industrial wastewater and groundwater, including the treatment of municipal water supply for human consumption. As the population grows, the role of electrochemistry in the treatment of water and effluents, until now has been relatively small compared to some of the mechanical, biological and chemical processes mentioned previously. In some instances, alternative technologies were found more economical in terms of initial capital cost and energy consumption. Very often, previous electrochemical methods had no competitive cost in the initial capital cost and operating costs with more traditional methods such as chlorination, ozonation, coagulation and the like. The previous electrochemical processes required the introduction of supporting electrolytes as conductivity modifiers which increased the costs of the operation, and could create later problems with the disposal of their products. Electrochemical processes in some instances have been ineffective in the treatment of solutions, through the reduction of pollutant concentrations to levels permitted under government laws. Until now, such electrochemical processes have generally lacked sufficient credibility to consistently perform substantially complete mineralization of organic contaminants., as well as the ability to remove enough color from industrial sewage in accordance with government laws. Nonetheless, to the deficiencies previously associated with. the technologies. In previous electrochemical processes, electrochemistry is still seen as an important technology in the decontamination of aqueous solutions. Consequently, there is a need for a more efficient and safer configuration of electrochemical cells and the process for a more economical treatment of large volumes of industrial sewage, effluent streams and polluted water bodies, including the decontamination of municipal water supplies making them potable for human consumption, such configurations of electrochemical cells can also be used in the electrosynthesis of chemical products.

SUMMARY OF THE INVENTION The present invention relates to improved means for the electrophoresis of aqueous solutions, particularly effluent streams comprising polluted or contaminated sewage with a wide spectrum of chemical and biological contaminants, including components of such representative groups as organic components. and some inorganic chemical components. Inorganic contaminants include ammonia, hydrazine, sulfides, sulfites, nitrates, nitrites, phosphates, metal ions, etc. Included as organic contaminants are the organometallic components; textile mill dyes, carbohydrates, fats and plant protein substances food processing, effluent streams, such as black liquor from pulp and paper mills containing lignins and other body colors, general types of pollutants water, including pathogenic microorganisms, for example, bacteria, fungi, mold, spores, cysts, protozoa and other infection agents such as viruses, oxygen demand wastes, etc. While it is impractical to specifically identify by name all possible contaminants which can be successfully treated in accordance with the intended methods, it will be understood for the language apparent in the claims, namely "aqueous contaminated electrolyte solution", or the variations thereof. , it is intended to cover all susceptible contaminants whether organic, inorganic, metallic or biological ions. The methods of electrophoresis and apparatuses for practicing this invention are particularly noteworthy in their ability to virtually and effectively purify any aqueous solution comprising one or more organic, inorganic contaminants, including dangerous and biological metal ions present in varying concentrations. from at least 1 ppm to a maximum of 300,000 ppm. In most cases, only electricity is required to make the desired chemical change in the composition of the pollutants. The tap water conductivity is sufficient for the operation of the improved cell design. Accordingly, it is not required, nor necessarily desirable, to incorporate additives in the contaminated aqueous solutions to modify the conductivity of the solution to be treated in order to perform the desired decomposition of the contaminant.

Advantageously, in most cases, the solid byproducts are not produced in the electropurification reactions, creating a costly waste problem. The improved electrochemical process of the invention is capable of performing color removal completely or virtually; the complete mineralization of the organic pollutant and the total destruction of the biological contaminants even in the presence of mixed contaminants, and at a cost which is competitive with traditional non-electromechanical methods, such as chlorination, ozonization and coagulation, in this way fulfills or exceeds government laws. Accordingly, it is a principal object of the invention to provide an electrolysis cell which comprises at least one anode and at least one cathode as electrodes positioned in an electrolyzed zone. The electrodes are preferably spaced close enough not only to provide an interelectrode space capable of minimizing cell voltage and IR loss, but also to conduct conductivity without the need for extra supporting electrolytes or current carriers. Means are provided for directly feeding the electrolyte solutions to the electrodes for distribution through the interelectrode space. Means are provided for regulating the residence time of the electrolyte solution in the electrolyzed zone. When the electrolysis cell is used in electropurification, the electrolyte will remain in the electrolyzed zone for a sufficient period of time for the modification of the contaminants to occur, and the ether electrochemically by direct means and / or by chemical modification of contaminants for the less hazardous substances during residence in the cell. Additional means are provided to collect the treated electrolyte solution descending from the electrolyzed zone. It should be noted that the electrolysis cell according to the invention has an open configuration. According to the electrochemical cell of this invention, subsequent means are provided for a practical and efficient operation, directly feeding the contaminated electrolyte aqueous solution to the cell by means of pumping or gravity, pre-treatment means for aqueous solutions electrolytes contaminated , for example, means for aeration,. pH adjustment, heating, filtering of large particles; as well as means for post-treatment, for example, pH and cooling adjustments or chlorination to provide residual death for potable water applications. In addition, the invention contemplates online monitoring with sensors and microprocessors for a computer-assisted automatic process control, such as a pH sensor, visible and UV light, sensors for biological contaminants, temperature, etc. It is still an object of the present invention to provide a system for purifying aqueous solutions; which comprises: an electrolysis cell comprising at least one anode and at least one cathode as electrodes positioned in an electrolyzed zone. The electrodes are spaced sufficiently close to each other to provide an interelectrode space capable of minimizing cell voltage and IR loss. It also includes a conduit means for directly feeding a contaminated aqueous electrolyte solution to the electrodes in the electrolyzed zone. The electrolysis cell is characterized by an open configuration. A control valve means for regulating the flow of contaminated electrolyte aqueous solution to the electrodes, directly through conduit means. Means are included for pumping the contaminated aqueous electrolyte solution through the conduit means, and then, rectifying means are included to provide a supply of DC power to the electrolysis cell. The purification system may also include censor means and computer means for receiving the input from the censor means and providing an output signal to control at least one operating condition of the system selected from the group, consisting of a current density, a average flow of the contaminated aqueous solution to the electrolysis cell, temperature and pH of the contaminated aqueous electrolyte solution. The optional components include exhaust means to further handle the gaseous byproducts produced electrochemically; means for pre-treating the contaminated aqueous electrolyte solution selected from the group consisting of filtration, pH adjustment, and temperature adjustment. As has been discussed previously, the electrochemical cells of this invention are especially novel in their open configuration. As apparent from the specification and claims, the term 'open configuration' or variations thereof are defined as designs of electrochemical cells adapted to control the loss or discharge of the treated or decontaminated aqueous electrolyte solution and the gaseous or volatile by-products. The above definition also attempts to describe the elimination or exclusion of conventional closed electrochemical cells and designs of cells of the type using conventional indirect means to feed electrolyte to the electrodes.The closed flow type electrochemical cells, for example, are generally manufactured from a plurality of machining and injection of molded cell frames, which are typically joined under pressure in a hermetically sealed stack with gaskets or O-rings to prevent leakage or leakage of the electrolyte from said cell.This type of sealed electrochemical cell is typically found in cel of the type of closed disc and frame. The adjustment and sealing tolerances for the cell components are very high in order to seal the cell and prevent leakage of the electrolyte and gases into the atmosphere. Consequently, the initial capital costs of such electrochemical cells, the costs of renewal, including repair costs for breakage of cell frames and joints from which the disarming of the closed-disc and frame-type cells is very high. Because the configuration of the electrochemical cells of this invention are open, and not sealed, they allow the control of the loss of the aqueous solution electrolyte and gaseous byproducts. The designs of sealed cells, including gaskets, O-ring and other sealing devices are eliminated. In contrast, the parts of the cell component are held together close to various mechanical means when they are used, including, for example, staples, screws, adjustments, ropes or adjustment means which interact by means of stapling, etc. As a result, with the novel concept of the open cell of this invention, the initial costs of the cell, maintenance and renovation costs are minimized. In the open cell configuration of this invention, the electrolyte is fed directly to the electrodes in the electrolyzed zone from a feeder which can be positioned centrally relative to the charge of the electrodes, for example, where the contaminated solution involves with the electrodes through the fluid through very narrow spaces of the interelectrode or spaces between the electrodes. During this period the contaminants in the aqueous solution are either directly converted into electrodes to less hazardous substances, and / or through autogenous generation of oxidizing or reducing chemicals, such as color, bleach, for example, hypochlorite, hydrogen, oxygen, or species of reactive oxygen, such as ozone, peroxide, for example hydrogen peroxide, radical hydroxides, etc., chemically modifying less toxic substances, such as carbon dioxide, sulfate, hydrogen, oxygen and nitrogen. In some instances, depending on the composition of the contaminants in the solution to be treated, it may be desirable to add certain salts such as chloride salt, iron salts or other catalytic salts, in a low concentration to the solution before or during the treatment in the cell. For example, this can be used to generate some active chloride to provide a residual level of sterilant in the treated water, or to produce ferrous iron to promote the formation of Fenton reagent with the addition or electrogenerated hydrogen peroxide. Also, oxygen or air can be introduced into the stream that feeds to improve the generation of peroxide.

Because the electrolyte is fed directly to the electrode stack usually under positive pressure, gases such as hydrogen and oxygen generated during electrolysis are less likely to accumulate on the electrode surface through the formation of insulating plates or pockets of bubbles. The blindness of the electrodes produces great internal resistance to the flow of electricity resulting in a high voltage cell and higher power consumption. However, with the direct flow of the electrolyte to the cell, the dynamic flow of the solution in the spaces of the interelectrodes, according to this invention, minimizes the gas cover, and in this way, minimizes the voltages of the cell. The aqueous solution that enters the cell by means of pumping or feeding by means of gravity, falls in cascade form on and through the available spaces of interelectrodes, and when leaving the electrolyzed zone of the cell through gravitational forces, it descends into a reserve for post-treatment or discharge, for example, such as within a natural waterway. Any undissolved gas generated by electrolysis, in contrast, is vented upward from the cell into the atmosphere or can be guided into a smoke collector or bell, if necessary, for collection or further processing. Whereas direct feeding of the open configuration of the electrochemical cell, as described herein, preferably provides for the elimination of the housing of conventional cells or tanks, as will be described in more detail below, the expression "open configuration" as it appears In the specification and claims, in addition to the continuing definition, it is also intended to include designed electrochemical cells in which the direct electrode supply is disposed in the interior region of an open tank or open housing cell. A representative example of an open tank electrochemical cell is disclosed by Patent No. 4,179,347 (Krausse et al) used in a continuous system for disinfecting wastewater streams. The cell tanks have an open top, a bottom wall, side walls and spaced electrodes positioned inside the tank. Instead of feeding the contaminated aqueous solution directly to the electrodes positioned inside the tank the electrolyte, according to Krausse, is initially fed to the first end where the interior deflector generates currents in the waste water causing upward and through circulation and between the parallel electrodes. Consequently, instead of sending the electrolyte directly to the electrode stack where it is forced under pressure, through the interelect spaces between adjacent anodes and cathodes according to the present invention, the electrolyte in the open tank cell of Krausse indirectly engages with the electrodes through a flow effect by virtue of positioning the electrode in a lower region of the tank where the aqueous solution resides. This effect of passive flow is insufficient to realize the conditions of transport of the thickness necessary for the efficient destruction of particularly the contaminants, when they occur in low concentrations. Consequently, the gaseous by-products of the electrolysis reactions can and generally give results in the development of a blanket of gas bubbles on the surface of electrodes, this generates a high voltage in the cells and a higher power consumption due to the internal resistances elevated. Accordingly, for purposes of this invention, the term "open configuration" appears in the specifications and claims and is also intended to include an electrochemical cell type tank, wherein the electrode cell is positioned inside a tank / housing open and includes means for directly feeding the aqueous solution fed to the electrodes. With direct feeding, the 'housing does not serve as a reservoir for the contaminated aqueous solution, which could otherwise passively involve the electrodes indirectly by means of a fluid effect. For the purposes of this invention, it is understood that the expression "open configuration" is also intended to allow positioning of the safest device adjacent to electrochemical cells and purification systems, such as splash guards, shields and cages installed. to minimize the potential for accidents in operators. However, the confinement of the electrolysis cells or an entire water purification system of this invention within a small room, for example, is also intended to be within the meaning of "open configuration" as it appears in the specification and the claims. Another type of electrochemical cell design is disclosed by Beck in U.S. Patent No. 4,047,047. The Beck cell design comprises a bipolar stack of circular electrode plates separated by spacers to provide inter-electrode spaces ranging from 0.05 to 2 mm. The electrolyte liquid is fed directly to the electrode disks through a pipe into a central opening in the electrode stack and then out to run out of the stack. However, the electrode stack is located in a closed housing assembly with a cover layer to avoid loss of reactive gases, vapors or reactive products. In this way, the closed configuration of the Beck cell does not meet the criteria of a cell of an open configuration according to the present invention. While the "open configuration" of the improvement has been mentioned, the highly economical electrochemical cell designs of this invention are based on the elimination of traditional closed cell designs, including a plate and frame type cell and tank type cells conventional As well as a cell design of the partially traditional open tank type, where discontinuously or continuously, it is understood, the expression "open configuration", as it appears in the specifications and claims, also contemplates the electrochemical cells, which can be modified with | several inserts, barriers, partitions, deflectors, and the like, in some instances positioned adjacent to the electrode cells, or their peripheral edges. Such modifications can have the effect of altering the circulation and direction of the electrolyte, and increasing the residence / retention time, and in this way, affecting the residence time and the average discharge of the electrolyte from the cells. However, such a modified electrochemical cell which is partially open, falls within the intended meaning of "open configuration" when the electrode itself remains substantially accessible. Electrochemical cell designs representatively modified with electrodes, which remain substantially accessible that are included within the definition for "open configuration" as it appears in the claims includes the modification, of the so-called Swiss cell design where, for For example, the closed tubular containment of the electrodes, which are superimposed in one with respect to the other and concentrically wound, is removed, thus forming a "Swiss roll cell" of the open type. It is still an object of the present invention to provide a more efficient electrochemical cell design which can be used in the effective treatment of a wide spectrum of chemical and biological contaminants in aqueous media, but also in the evaluation of concentration (less than few ppm to several thousand ppm) which are economically competitive in capital costs and energy consumption for a more conventional water purification system. The electromechanical system and the method of the invention, have such significant economic improvements to be easily adaptable to treatment through continuous processes, large volumes of industrial sewage from factories, such as chemical plants, textile plants, paper mills, food processing plants, etc. The cells Low voltage and high current densities are achieved with the open, highly economical configuration, especially when configured as a monopolar electrochemical cell equipped with electrodes that have a narrow capillary interelectrode space. Generally, the width of the space between the electrodes is sufficiently narrow to conduct the conductivity without an extra supply of electrolytes or current carriers added to the contaminated aqueous solutions, in this way the need to add electrolytes or carriers to the contaminated electrolyte solution, as a current carrier or carriers, can be avoided. It is further an object of the present invention to provide for improvement, a more economical and safe continuous, semi-continuous or discontinuous method for the electropurification of aqueous solutions contaminated by the steps of: providing an electrolysis cell comprising at least one anode and minus one cathode as electrodes positioned in an electrolyzed zone. The electrodes are spaced close enough, one with respect to the other to provide an interelectrode space capable of minimizing cell voltage and IR loss. Means are provided for directly feeding the contaminated aqueous solution to the electrodes in the area, electrolyzed, means are provided to regulate the residence time of the electrolyte solutions in the electrolyzed zone during electrolysis for the modification of the contaminants. The electrolysis cell is characterized by an open configuration as previously described. The direct feeding into the electrolysis zone of the electrolysis cell of a contaminated aqueous electrolyte solution, and the imposition of the voltage across the electrodes of the electrolysis to modify, and preferably destroy the contaminants in the aqueous electrolyte solution. It is understood that generally the process can include the step of recovering a purified electrolyte solution from the electrolysis cell. However, the invention contemplates the direct distribution of purified aqueous solution to a slope, for example, or optionally to other post-treatment stations. As previously mentioned, the methods are performed in an electrolysis cell of open configuration, which may be a monopolar or bipolar configuration. Due to the open configuration, as defined herein, the electrochemical cells of this invention can be easily configured for a design. monopolar This is a special advantage since high current densities may be desirable in electrolyzing the contaminated aqueous solution which has relatively low conductivity while also keeping the cell voltage low. Also, the improvement in electrochemical cell of this invention can have a bipolar configuration, especially for large installations to minimize the costs of rectification and the conductive bar. Typically, in the monopolar open cell design, the electrical connections are made for each electrode. Where in a bipolar configuration the electrical connections are made at the ends of the electrodes. However, several applications require the increase of the electrode surface area, especially in the enlargement from a laboratory scale of the electrochemical cells to a pilot scale, and finally, for the open cell commercial size. It will be advantageous if in the sizing of cells one could perform an efficient cell design to perform the process of this invention, and minimize capital and operating costs even more. It is then still another object of the present invention to provide a more economical, alternative embodiment of the open electrolysis cell concept of this invention, wherein the faces of the multiple pore electrode are positioned adjacent to each other, and arranged either in a vertical plane or superimposed horizontally, relatively to one another in the form of a stack. The porous electrodes, generally meshes or grids, are in electrical contact with each other. With each electrode stack it required an individual feeder electrode to introduce a voltage.

However, by arranging the electrodes in these representative formats, the effective electrode surface area is also significantly increased by increasing the number of external electrical contacts otherwise required to the power source. By accommodating the electrode connections, the costs are minimized, while also making capital savings in the purchase of the electrodes. Another benefit includes improving the efficiency of the operation with the configuration of the open cell, reducing energy consumption and lowering costs, as a result of lower voltages, in the cells. Accordingly, the invention contemplates the embodiment of open cell configuration wherein the electrolysis cells comprise at least one anode and at least one cathode with electrodes positioned in one. electrolyzed zone. At least one of the electrodes comprises a plurality of conductive porous elements positioned adjacent one to the other and in electrical contact. Means are provided for directly feeding an aqueous electrolyte solution to the electrodes in the electrified zones, and for regulating the residence time of the electrolyte solution in the electrolyzed zone. As an alternative, the electrode consists of a plurality of conductive porous elements whmay be in combination with a solid non-porous conductive electrode element. Also included is a method for the electropurification of aqueous solutions contaminated by the steps of: providing an electrolysis cell of open configuration with at least one anode and at least one cathode as electrons positioned in the electrolyzed zone. At least one of the electrodes comprises a plurality of conductive porous elements, such as, for example, grids or meshes, positioned adjacent to each other in an electrical contact with respect to each other. Means are provided to directly feed a contaminated electrolyte solution to the electrodes in the electrolyzed zone. Means are also provided to regulate the time of. residence of the aqueous electrolyte solution in the electrolyzed zone for the modification of contaminants in that place. A contaminated aqueous electrolyte solution is introduced into the electrolysis cell of (i), and a voltage applied across the electrodes of the electrolysis cell to modify the contaminants in the electrolyte in the aqueous electrolyte solution. The improved electropurification method of the invention also contemplates the treatment of aqueous solutions contaminated with metal ions. Generally, these are toxic substances derived from effluents from plating baths, metal stripping bath, biocidal formulations, and paints, and can be isolated by a complex agent, a reducing agent or an acting agent on surfaces. The electropuri fi cation methods of the invention destroy the complex agent, the surface active agent or the reducing agent to release the dangerous metal for other treatments in the electrolysis cell, or alternatively, transfer it to a metal recovery cell for plating metals. from the solution. While the electrolysis cells disclosed above have as a main activity the electropurification of contaminated solutions, the open cell configuration of this invention can be easily used in other useful applications. Representative examples include the electrochemical synthesis of organic and inorganic components, such as iodate and periodic salts, chlorine dioxide, persulfate salts, and reducers through the Kolbe method of electrolysis of carboxylic acids, or by the electrohydrodimerization of activated fine ole , the electrolysis of water to form hydrogen and oxygen, etc. It is then also a main object of the present invention to provide an electro synthesis process in the production of useful products, by the steps of: (i) providing an electrolysis cell with an open configuration in which the cell is equipped with at least one anode and at least one cathode as electrons positioned in an electrolyzed zone. At least one of the electrodes comprises a plurality of porous conductive elements, for example, mesh or grid, positioned adjacent one to the other in electrical contact. Means are provided to directly feed an electrolyte solution to the electrodes in the electrolyzed zone. In addition, means are included to regulate the residence time of the electrolyte solution in the electrolyzed zone. The introduction into the electrolysis cell of (i) an electrolyte comprising a solution of an electroactive substrate, such as an inorganic salt, for example, an aqueous solution of an alkali metal chloride when the bleaching is carried out, an iodized salt when the paryodate is made, an aqueous solution of an acid, etc., and the imposition of a voltage through the electrodes of the electrolysis cell to electrolyze the electrolyte solution to make a useful chemical. This embodiment of the invention includes methods for the synthesis of a useful product wherein the electrolysis cell is equipped with a porous diaphragm or selective waterproof membrane.

BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of the invention and its characterizing features, references will now be made to the accompanying drawings, wherein: Figure 1 is a side elevational view illustrating a first embodiment of a direct feeder, an open configuration, a cell leakage controlled electrochemistry of the invention wherein the electrodes are positioned above a water collecting container in a horizontal orientation; Figure 2 is a side elevational view of the electrochemical cells of Figure 1 except that the electrodes are in a vertical orientation. Figure 3 is a side elevational view illustrating a second embodiment of a direct feed, an open configuration, a controlled leakage electrochemical cell of the invention wherein the electrodes are positioned within an open cell housing; Figure A is an exploded view of the electrode cell stack of Figure 1; Figure 5 is a side elevation view of an electrode stack of the invention connected to a monopolar configuration; Figure 6 is a side elevation view of an electrode stack of the invention connected to a bipolar configuration; Figure 7 is an elevated view of an electrode stack divided by a separator; Figure 8 is a side elevation view of an open electrochemical cell, with stacks of porous electrodes connected in a monopolar configuration, Figure 9 is a side elevational view of an open electrochemical cell, with stacks of porous electrodes connected in a configuration bi-polar, and Figure 10 illustrates the results of the electropurification of an aqueous solution of a decontaminated phenol according to the methods of the invention, as performed in example I.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring first to Figure 1, an electrochemical cell 10 is illustrated, for purification of contaminated aqueous solutions, as previously described, represented by contaminated water 12, which passes through an access 22. Contaminated water 12 is treated in the electrolysed zone 14 of cell 10, which is illustrated in a fully open configuration allowing gaseous byproducts of the electrolysis reaction, such as oxygen and hydrogen 16, to be released to the atmosphere. It may be desirable, in. some examples, the storage of certain potentially dangerous gases generated during the electrolysis reaction to avoid discharge into the atmosphere, chlorine, for example, can be generated in the. anode during the electrolysis of an aqueous effluent stream containing brine or seawater. Such gases can be recovered, for example, by means of a bell device energized by a vacuum cleaner of conventional design (not shown), positioned adjacent to the electrochemical cell 10. The electrolyzed zone 14 includes an electrode stack 17 shown in an orientation horizontal in Figure 1 and 4, and comprises at least one cathode 18 and at least one anode 20. The anodes 20, for example, can also serve as end plates 21 to accommodate an arrangement of electrodes, spacers, and spacers, when they are used in an assembled electrode cell 17. The non-conductive electrode spacers positioned between the electrodes provide the desired interelectrode space or a spacing between the adjacent anodes and cathodes. While Figure 1 and 4 of the drawings can be shown with only a central cathode with anodes on opposite sides of the cathode, for example, it is understood that the electrode stack can be formed from several alternating anodes, spacers , cathodes, etc., with means of screws 25 passing through the stack and end plate to maintain the components in a stable structure arrangement. The extreme plates, the electrodes and the spacers may have a generally rectangular geometry, however, any number of alternative geometric shapes and sizes are within the scope of the invention, including a square, round or circular configuration, to name just a few. The contaminated electrolyte aqueous solutions are fed directly to the electrodes in the electrolyzed zone 14 through the supply line 22. The supply line 22 is shown positioned centrally and relatively to the anode / end plate 21. The electrodes, which can be solid and flat, are preferably of the mesh and grid type. This allows the aqueous electrolyte solution to enter the electrode stack to directly engage with the electrodes, and thus flow radially across the face of the surface of the individual electrodes within the cell, to its peripheral edges. In addition, the incoming solution usually flows axially, or usually to the longitudinal axis of the electrode plane, so that the contaminated aqueous solution simultaneously falls in cascade on and through the electrode stack in a spring-like effect to maximize contact with the surface of electrodes during the process. The purified water 24, free or possibly free of contaminants leaving the electrolyzed zone 14, can be accumulated in an open tank 26, or channeled in a discharge line (not shown) to empty it in a natural spring, etc. It is understood that direct feeding of the contaminated aqueous solution to the electrolyzed zone does not necessarily have to be positioned centrally and relatively to the electrode path, as illustrated in figures 4. Alternative routes of direct feeding, they include the inversion of the feeding point, so that the contaminated aqueous solution is fed from the base of the electrode stack, or at an oblique or obtuse angle to the flat surface of the electrodes. In addition, the entry point of the direct feed can also be axial with the axis of the flat surface of the electrodes, where the contaminated solution is derived to the peripheral edge of a stack of electrodes. A convenient means for regulating the residence time of the contaminated aqueous solution in the electrolyzed zone 14, and for controlling the leakage of the purified and decontaminated water 24 in that way, can be through the valve 28 and / or pump pumping means. conventional design (not illustrated). The flow velocity of contaminated water directly entering the electrode stack and leaving the stack as decontaminated water, can be regulated through automatic or manual flow control valves 28 of standard design. The flow rate (liters / minute) is adjusted to provide sufficient effective destruction of contaminants for the time of the treated solution leaving the electrolyzed zone. A person of medium skill in the art, having the benefit of this disclosure, will also be able to recognize the realization of the electomechanical cells of this invention, which can be optimized by alternating the increment of the passage of the solution in the electrolyzed zone. The installation of baffles, for example, can increase the residence time of the solution in the electrolyzed zone. Alternative means include enlarging the surface area of the electrodes to reduce the residence time in the electrolysis zone. In practice, the electrochemists understood in the art will also be able to recognize the realization of the cell, which can be. increased with a high current density. Since the geometry of the cell, and the ability to conventionally use the monopolar and bipolar configurations, virtually any electrode material can be used, including metals in the form of a flat plate, grid, foam or other materials, such as graphite, glassy carbon, crosslinked glassy carbon and carbon particles. This also includes combinations of electrode materials, such as bilayer elements comprising two metal stages separated by appropriate insulation or conductive materials, and the like. 'Representative examples of useful anodes may include those generally known as anodes, of noble metal, dimensionally stable anodes, carbon, glassy carbon and graphite-containing anodes, diamond-mixed anodes, substoichiometric titanium oxide-containing anodes and anodes which They contain major oxides. More specifically, representative examples include noble-metal arides based on titanium-plated titanium; the anodes available under the DSA-O2 brand and other anodes, such as the anodes of the high surface area type such as felts, foams, meshes, and the like available from The Electrosynthesis CO. INC. -Lancas / ter-New York. Another anode of another material, comprises ruthenium oxide or titanium, platinium / iridiuiti, in titanium and iridium oxide in titanium, silver oxide in silver metals, tin oxide in titanium, oxide 3 nickel in nickel, or oxides of substioquiométrico titanium, and particularly those called magneli titanium oxides that have a formula TiOx where x varies from 1,67 to about 1,9. A preferred substioquiometric titanium oxide species is TÍOO7. The magneli phase titanium oxide and manufacturing methods are described in US Pat. No. 4,422,917 to Hayfield, which is incorporated by reference. They are also commercially available under the Evonex brand. Where the electrocatalytic metal oxide, such as Pb02, Ru02, and R02, S02, Ag20, Ti407 and others are used as anodes, mixing such oxides with various cations and anions, have been used to increase the behavior of electrocatalytic oxidation , the stability, or the conductivity of the decontamination reactions of this invention. The selection of the appropriate anode materials is made by considering such factors as cost, stability of the anode material in the solutions to be treated and their electrocatalytic properties to realize high efficiencies.

Suitable materials for the cathode that includes metals, such as lead, silver, steel, nickel, copper, platinum, zinc, tin, etc., as well as carbon, graphite, evonex and various alloys, etc. The diffusion of gas from the electrodes are also useful in the methods of this invention. In this regard they can be used as cathodes in converting oxygen or air into useful quantities of peroxide, minimizing the evolution of hydrogen and / or to lower cell voltages. The electrode material, either the anode or the cathode, can be covered with an electrocatalyst, either from the high or low surface area. Electrodes of high or higher surface area, eg, expanded metal meshes, graphite or metal beads, carbon filters, or crosslinked glassy carbon, are especially useful in performing high efficiencies for the destruction of toxic or hazardous substances when they occur in a low concentration in aqueous electrolyte. The specific anode and cathode materials are selected based on cost, stability and electrocatalytic properties. For example, people moderately understood in the field of electrochemistry, can recognize. Which electrode material to select when it is desired to convert chloride into chlorine, water into ozone, radical hydroxides or other species of reactive oxygen, oxygen or air into hydrogen peroxide or radical hydroxides, through a Fenton reagent generated electrochemically using for example , a metal anode containing slowly dissolving iron,. a catalytic reduction of nitrate to nitrogen or of organohalogen components to halide ions and less toxic organic media. The special importance in the selection of electrocatalytic anode and cathode materials occurs when the aqueous solution treatment comprises complex mixtures of contaminants in which the electrode materials can be selected for the paired destruction of the contaminants. For example, an aqueous stream contaminated with organisms, microorganisms, and nitrate contaminants, can be treated, simultaneously in the same electrochemical cell using a method of destruction paired with a reactive oxygen species generating an anode, such as platinum or niobium or evonex for the destruction of microorganisms and the oxidation of organics. In addition, the same cell may also be equipped with lead. or another electrocatalytic cathode material designated for the destruction of nitrate. As previously mentioned, non-conductive electrode spacers 23 provide the desired interelectrode space or space between adjacent anodes and cathodes. The thickness of the spacers 23, which are non-conductive, insulating pore meshes made of a polymeric material, such as polyphelines, such as polypropylene and polyethylene, determine the width of the interelectrode space. Alternatively, it is permissible to use ionic polymer spacers which can, in effect, increase the ionic conductivity of the cells, to reduce the cell voltage and operating costs. Ion exchange resins of suitable dimensions, such as the cation and the anion in which the resin beads are exchanged, remain immobile within the space between the electrodes. For more applications, the interelectrode space varies from a space close to zero, to avoid shortening the electrode to 2 millimeters. More specifically, this very small capillary size space is preferably less than 1 rain, varying from 0.1 to greater than 1 mm. The space of the interelectrode that is too small makes it possible to pass through a non-conductive relative medium. For example, in water contaminated with organic components. Furthermore, with the present invention it is now possible to destroy contaminants in the solution, without the addition of any inorganic salt stream carrier to increase the ionic conductivity in the aqueous medium. further, the very narrow interelectrode space provides the important advantage of reducing the cell voltage which is transferred to a reduction of energy consumption and a reduction of operating costs. However, the open configuration electrochemical cell and the very narrow interelectrode space of this invention provide a very low initial cost of capital, as well as lower operating costs. This achievement is especially important in large volume applications, such as in the purification of drinking water, and water served in accordance with. the required processes. Figure 2 depicts a further embodiment of the electrochemical cell of this invention wherein the electrolyzed zone 30 is also in an open configuration. The electrolyte 32 is fed directly to the electrode stack 34 which is in a vertical orientation. As a result, the treated aqueous solution 36 is shown coming out mainly from the upper and lower peripheral edges of the electrode stack 34. This can be altered, further, depending on the use of baffles, for example, in the control of residence time for the solution to be treated. The purified solution is coupled in a vessel or container 38 below the electrolyzed zone 30. Figure 3 still represents a third embodiment of the invention wherein the electrolyzed zone 40 comprises an electrode stack 42, described above, positioned therein of an open housing tank 44. The housing 44 is open at the top, allowing gaseous by-products of the electrolysis reaction, for example hydrogen and oxygen, for example, to be easily discharged into the atmosphere or stored through the help of an appropriate device, such as a bell. { not illustrated). The contaminated aqueous electrolyte solution 46 is fed directly to the electrode stack 42 positioned in the open housing 44, distinctly from other tank cells where the electrodes receive the solution indirectly as a result of the immersion in the derived solution towards the tank. The purified water 48 cascading as a result of the gravitational forces is stored in the base of the interior of the housing 44, and is subsequently removed. As an important advantage of the open-configuration electrochemical cell of this invention, it resides in the possibility of being easily adaptable to either a monopolar or a bipolar configuration. Concerning this, figure 5 illustrates an electrochemical cell of monopolar open configuration. In the monopolar cell of FIG. 5, the anodes 52, 54 and 56 each require an electrical connector as a power supply, in this case through the conductive base 58, as a common external supply line. Similarly, cathodes 60 and 62 each require an electrical connection, shown through a common busbar 64. It is also characteristic of the design of the monopolar cell, that both faces of each electrode are active with the same polarity. Since water purification for a municipality, in general, is a high volume application, reduced cell voltages are essential in order to minimize energy consumption. The open configuration monopolar cell design of the present invention, in combination with a very narrow interelectrode space, offers not only the benefit of a low initial capital cost, but also a very low operating cost, due to the low internal resistance, low cell voltages and high current densities. This combination is especially desired when it comes to contaminated aqueous media, of relatively low conductivity, without the addition of inorganic salts as carriers of currents according to certain embodiments of this invention, for example, aqueous solutions contaminated with non-polar organic solvents. The controlled leakage electrochemical cell, monopolar and open configuration with very small interelectrode space of this invention, are particularly unique in comparison to the Beck cells of American Patent No. 4,048,047. The closed configuration of Beck's electrochemical cells makes it very difficult and expensive to make a monopolar connection with high density currents associated with external electrical contacts for each electrode.

In contrast, with the open configuration of the electrochemical cell of this invention, the electrical conditions to individual electrodes are facilitated, irrespective of whether the cell is of a monopolar or bipolar design. In addition, Beck's closed bipolar electrochemical cell configuration may not be economical and competitive with respect to cost with the improved electrochemical cell of the present invention, or with other non-electrochemical technologies used in high volumes of water purification process. As previously indicated, the open-loop controlled electrochemical leakage cell of this invention, which has a very narrow capillary interelectrode space, is also easily adaptable to the bipolar configuration. Figure 6 illustrates a bipolar cell of open configuration 70, according to the present invention, which requires only two external electrical contacts 72 and 74 through two end electrodes or end plates 76 and 78. Each inner electrode 80, 82 and 84 of the bipolar cell has a different polarity on opposite sides. While the bipolar cell can be economical in the effective utilization of the same current in each cell of the electrode stack, an important aspect of the invention relates to the treatment of solutions by means of the passage of a current through means relatively not conductors, using a very narrow interelectrode space. That is, the contaminated aqueous solution may have a relatively low conductivity, about the equivalent for the tap water. In order to efficiently treat such a solution it will be desirable to operate at a high current density. The monopolar cell configuration of the invention allows operation at desirably low cell voltages and high current density. While not specifically illustrated, it is understood that standard power supplies are used in the electrolysis cells of the invention, including an alternating current power supply, direct current power supply, pulsed power supply, and battery power supply. The invention further contemplates electrochemical cells of open configuration with distribution means for contaminated aqueous electrolyte solutions, such as the length of a pipe 81 with multiple openings or pores, or a feeder tube extending from the entering of the feed of the aqueous electrolyte. contaminated through the submerged electrode battery in the electrolyzed zone. This can realize a uniform flow of solution to the electrode elements. These porous tubes of metal or plastic material are especially useful for batteries that contain many electrode elements of sufficient porosity, diameter and length. which are applicable to the monopolar and bipolar and for example, to the Swiss winding cells of, open configuration. For deeper cell stacks with electrode elements, each larger surface area can be provided with more than one porous feeder tube, joined together with a manifold tube with the feed inlet conduit. The controlled leakage electrochemical cell of the bipolar type of open configuration of the present invention can be used effectively in the purification of aqueous solutions having higher ionic conductivities than those previously described, allowing economical operation at a low current density. In each example, the open configuration of the electrochemical cell of this invention facilitates the electrical connection, whether the design of the cell is a monopolar or bipolar cell.

Large volume applications such as water purification that require a low cost of operation and capital are highly desirable, in order to be economically attractive, these inventors found that capital costs are widely, reduced by means of the elimination of the need for precision machining components, boards, expensive membranes and cell separators. The low operating costs can be achieved through lower cell voltages starting from the narrowest spaces of interelectrodes and a lower IR, from the elimination of separators and cell membranes, for example, undivided electrochemical cells. The small interelectrode space, however, also makes possible the operation of the cells of this invention in an organic medium, for example, containing a low concentration of supporting electrolytes, with a variety of electrodes, insulating material, etc. Many such applications may be readily adaptable to an open cell configuration of this invention, but with the use of a cell splitter that forms an analyte and catholyte compartment, such as membranes or cell separators. Examples of processes useful for the electrochemical cell of this invention may include intermediate reactants in the electrochemical synthesis wherein the objective of the membrane or separator will be to prevent the reduction of an anodically produced species at the cathode, and / or the oxidation of cathodically produced species at the anode. Figure 7 is a representative example of an open electrochemical configuration 90 having an anode / plate end. 92/94 with a central cathode 96 and cathode exchange membranes 98 and 100 positioned between the electrodes .. Membranes 98 and 100 prevent mixing of the anolyte and the catholyte in the cell, while allowing the solution to flow through of the apertures 102 in the center of the membrane. Those embodiments of the electrochemical cells using a diaphragm or separator are preferably equipped with ion exchange membranes, although separators of the porous diaphragm type can be used. A wide range of inert materials are commercially available based on thin microporous sheets of polyethylene, polypropylene, polyvinylidene difluoride, polyvinylidene chloride, ethylene polytetrafloride (PTFE), asbestos-polymer mixtures, etc., are useful as porous diaphragms or separators.

Useful types of cationic and anionic permoselective membranes are commercially available from any supplier or manufacturer, including such companies as RAI Research Corp., Hauppage, NY, under the Raipore brand eg DuPont, Tokuyama Soda, Asahi Glass, and others. Generally, these membranes, which are fluorinated, are most preferred because of their stability above all. A membrane of exchange class of permoselective ions especially used are those membranes of perfluorosulfonic acid, such as those available in, for example, DuPont under the trademark Nafion®. The present invention also contemplates membranes and electrodes made in solid polymer electrolyte compounds. That is, at least one of the electrodes, either the anode or the cathode or both. Which are attached to the ion exchange membrane forming an integral component. While the previously described embodiments of the invention mention the electrode stacks, for example, 17 and 34 of FIGS. 1 and 2, respectively, such stacks of electrodes are comprised of individual anode and cathode elements, spaced apart one from the other. another by a narrow interelectrode space. Figure 4 illustrates the electrode stacks in an exploded view comprising a cathode 18 consisting of a single flat screen element having its own external electrical contact 4 19. The non-conducting porous spacers 23 on each side of the cathode 18 provide the spaces for desired electrodelectrodes separating the cathode element from the ends of the adjacent anode 20. While FIG. 4 illustrates an electrode stack with an individual cathode screen positioned between the ends of the anodes 20, it is understood that a greater commercial capacity and a semi-commercial pilot scale cell of this invention will usually have a stack of cells comprising a multiplicity of alternating anodes and cathodes, each having an external electrical contact in a monopolar configuration. However, these scaled versions of the electrolysis cells of this invention, which require an area increase in the electrode surface, can perform this result more economically by stacking a plurality of individual porous electrode elements as illustrated in Fig. 8 and 9. The multiple electrode elements consisting of porous conductive elements, for example, the grids or meshes, are positioned adjacent to one electrical contact with respect to another in either a monopolar open cell configuration (Fig. 8). ) and bipolar (figure 9). Both the anodes and the cathodes of the open cell embodiments can. have a design of multiple electrode elements. That is, an anode stack consisting of multiple electrode elements that are held together in an electrical contact, and may be positioned adjacent to the cathode, which consists of a single electrode element and vice versa. This is best visualized in Figure 8, which consists of a monopolar open cell 104 maintained between end plates 105 with multiple porous anode elements 106 positioned between a simple element cathode 108, illustrated as a porous cathode, but may also be a plate electrode, non-porous. The anodes 106 are separated from the cathodes 108 by means of porous non-conductive spacers 107. Advantageously, the anode stack 106 only needs a single feeder electrode 110 to transfer a voltage, on either side of the other electrode element of the same stack in contact with the same. By stacking the electrode elements in this manner, the effective electrode surface can be significantly increased without increasing the number of external electrical contacts 112 to the power source 113, which is otherwise required. This not only minimizes the costs of external electrical connectors and capital costs for the electrodes, if not also improves the efficiency of the operation results in the reduction of the voltages in the cells and the reduction of energy consumption to reduce operating costs. The conductive porous elements of the electrodes can be made of metal or carbon, for example, they can be in the form of a perforated metal plate, a welded wire blanket, a woven wire blanket, an expanded metal, carbon felts, woven carbon blankets, cross-linked vitreous carbon, including metal foams, such as nickel foam having a sponge-like characteristic. Representative examples of commercially available perforated metal plates are. Low carbon and microlave steel sheets of 316 stainless steel sheet type with an orifice pattern which are uniform and precise in size.

The welded wire blanket of 304 stainless steel cloth type and stainless steel woven wire grating. The wire cloth is a welded or woven material made of metallic wire, and is available in a variety of screening sizes. The type of 304 stainless steel is also available. The expanded metal consists of plates which have been torn and stretched. The plates / sheets are very light, although they are strong due to the pattern of diamonds in their openings. These are commonly manufactured from carbon metal and 304 stainless steel. The invention contemplates a combination of different porous materials for, for example, the use as electrode elements, in a single cell to perform a combination of oxidation / reduction effect. The pore density of the conductive porous elements of the electrodes can vary from 1 to 500 crosslinks / linear inch. Conductive porous elements can also have an open area ranging from about 10% to about 69%. Some elements, such as foams, can have porosities ranging from 1 to 1000 pores / linear inch and a density that ranges from 51 to 85%. The electrode elements can easily be stacked in a closed or soldered electrical contact, and to the 1-electrode electrode, as appropriate, to ensure electrical connectivity through all the components of the cell. Fig. 9 also shows an open electrolysis cell design 114 similar to Fig. 8, but in a bipolar configuration showing all intermediate electrode stacks 116 consisting of a plurality of porous electrode elements. The individual elements of each electrode stack are in electrical contact with other components of the same cell. The energy is guided to the cell through the end plate anodes 118. The cells 116 are spaced apart from one another by means of porous spacers 120. The optimum number of electrode elements, which can be used with or without the feeder electrode, it is a function of a variable number, including the thickness of each porous electrode element, the conductivity of the solution to be treated and, above all, the optimal design of the cell. The number of electrode elements, in addition to the feeder electrode (FIG. 8), can vary from 1 to 100, and more specifically, from 1 to 10 electrode elements. The feeder electrode can. be of the same construction material as the individual electrode elements, or it may be different, making the feeder stable under electrolysis conditions, and being electrically conductive. In the purification of solutions, the invention is provided for the treatment of a low conductivity medium. However, it may be necessary to add several low concentrations of inerts, soluble salts, such as alkali metal salts, for example sodium or potassium sulfate, chlorine, phosphate, to name a few. Quaternary stable ammonium salts can also be used. As previously mentioned, ion exchange resin beads of appropriate size can be inserted into the spaces between the electrodes to increase the conductivity. This also provides reductions in cell voltage and total operating cost. Contaminated solutions entering the cell can vary in temperature from almost a freezing temperature to a boiling temperature, and more specifically from 40 ° to 90 ° C. Higher temperatures can be beneficial in reducing cell voltages and increasing the rate of contaminant extrusion. Such high temperatures can be carried out, if necessary, by preheating the incoming solution, heating the electrodes, or through IR heating in the cell, especially when the conductive solutions are low, as for example in the purification of drinking water. By means of proper adjustment of the cell voltage - and the residence time within the cell, beneficial temperatures in the upper ranges are possible. As a preferred embodiment of the invention, in the form of an undivided cell, for the purification of contaminated aqueous solutions, a variety of useful species of anodes and cathodes can be generated during electrolysis, which become integral in the chemical destruction of pollutants and in the purification of aqueous solutions. These include such species as oxygen, radical hydroxide, and other reactive oxygen species. The less preferred species, however useful in the process that includes the generation of chlorine or hypochlorite (bleach), through the electrolysis of brine or seawater. While it is not desired to maintain a specific mechanism of action for the success of processes in the decontamination, decolorization and sterilization of solutions contaminated with toxic organisms and microorganisms, several processes, including those previously mentioned, can occur simultaneously. These include, but are not limited to the direct oxidation of contaminants at the anode; the destruction of pollutants by direct reduction in the cathode, the oxygenation of the feed source by microbubbles of oxygen produced at the anode, the degassing of volatiles in the feed stream by oxygen and the microbubble hydrogen; the IR heating in the cell, the aeration of the water current that exists in the open cell, etc. A wide range of components, microorganisms and other dangerous substances, such as metal ions that have been previously described and successfully destroyed and removed in the open cell configuration of the invention, using the process as described herein. Representative examples include aliphatic alcohols, phenols, nitrates or halogenated aromatic components, etc. Color reduction or complete color removal can also be performed, throughout the disinfection, including the destruction of viruses. There are several types of metal salts in aqueous solutions, including toxic metals in ionic form in the effluents of veneer baths, metal tear baths, biocidal formulations, paints, etc., which are difficult to remove or recover by medium of ion exchange or by conventional chemical or electrochemical means. Such metals include precious metals, such as platinum, metal and gold, as well as precious metals, such as copper, nickel, cobalt and tin, to name a few. On the other hand, the governmental laws are being strictly increased, so that the levels of metals in which they can be discharged in the effluents of water are maximum. These solutions of solubilized metals are often difficult to treat due to their other components which may be present, complex agents, surfactants, reducing agents and other types of similar materials. Accordingly, the present invention also contemplates the electropurification of aqueous solutions contaminated with dangerous metal ions by means of the treatment of the open electrolysis cell, described above, using the previously discussed methods. This includes the decontamination of solutions through the reduction of metal in the cathodes of the open cells, as well as the treatment of metal ions from the effluents of platinum baths, metal tear baths, biocidal formulations, paints, and other contaminated industrial aqueous solutions, where the metals are sequestered by various complex agents, surfactants or reducing agents. The components of solutions, include complex agents that are initially destroyed electrochemically, greatly facilitating the recovery, removal of metals from the solutions. Representative complex agents may include cyanides, ferrocyanides, tisulfates, imides, hydrocarbonyl acids, such as tartaric, citrus and milk acids, etc. This method of the effective release of the ionized metal by means of the reduction in the cell or for the removal / recovery. Alternatively, the partially treated aqueous solution can be subsequently treated outside the open cell using such methods as ion exchange, base precipitation, by means of electrolysis in the recovery of electrochemical cell metal, such as a Renocell manufactured by Renovare International. This prior method allows the metal to be rolled at a cathode of high surface area. The specific examples below demonstrate various embodiments of the invention, however, it is understood that these are for illustrative purposes only and it is not the purpose to be totally definitive as a condition and scope.

EXAMPLE I A monopolar electrochemical cell having an open configuration was disposed with an electrode stack comprising an end plate of 316 stainless steel each with a diameter of 12.065 cm and a thickness of 0.95 cm. The end plates were connected as cathodes. A central cathode was also assembled within the stack and consists of a 316 stainless steel mesh with 7.8 x 7.8 openings / linear centimeter, 0.046 cm wire diameter, 0.081 cm wide opening and 41% open area. The anode consisting of two platinum-plated niobium electrodes manufactured by Blake Vincent Metals Corp. of Rhode Island. The anodes that were plated on both sides of the niobium substrate, have a thickness of 636 micrometers, which were expanded in a screen with a thickness of about 0.51 cm with 0.159 cm diamond-shaped interstices. The spacers positioned between the adjacent electrodes were made of polypropylene screening with 8.27 x 8.27 openings / linear centimeter, 0.0398 cm threaded diameter, 0.048 cm opening and 46% open area that was supplied by McMaster -Carr of Cleveland, Ohio. The space between the electrodes was approximately 0.04 cm, determined by the thickness of the polypropylene weft. A schematic cell of the electrochemical cell corresponds to Figure 1 of the drawings, except for a bell which was omitted. The recirculation of aqueous solutions between the glass coupling tank and the cell was effected by means of a March AC-3C-MD centrifugal pump with an average flow rate of about 1 liter / minute. A Sorensen DCR 60-45B power supply was used to generate the necessary voltage drop across the cells.

A test solution was prepared containing 1 gr. of phenol and 1 liter of tap water. The solution was re-circulated through the cell while the constant current of 25 amps was supplied. The solution was initially turned into a red color after about 2 to 3 minutes in the treatment process, possibly indicating the presence of quinone type intermediates. The initial cell voltage of 35 V quickly drops to 8/9 V, and the temperature of the solution stabilized at about 56-58 ° C. The tests taken were periodically analyzed for the total organic carbon (TOC). The results, which are shown in Figure 10, apparently suggest that the decrease in Tdc is from the phenol and probably being the complete oxidation to the carbon dioxide, which is then eliminated in the form of gas from the solution.

EXAMPLE II In order to demonstrate the reduction of color in a textile effluent, 1 liter of solution was prepared with tap water containing 0.1 gr. of textile dyeing brand Remazol Black B (Hoeschst Celanese), 0, 1 g of surfactant Tergitol 15-S-5 (Union Carbide) and 1 g of NaCl. The composition of the test solution was similar to those typical effluents produced in the textile dyeing process where even with low concentrations of Black Remazol, it imparts a very strong coloring to the solution. Black Remazol is a textile ink that is particularly difficult to treat. However, other methods used to treat Black Remazol ink, such as ozonation with hypochlorite whiteners have failed to proceed satisfactorily in color reduction. The aforementioned solution containing the Black Remazol ink was electrolyzed in the disposition of the monopolar cell of the aforementioned example 1, and at a constant current of 25 amps. The cell voltage was around 25 V and the temperature of the solution reached 52 ° C. The initial color of the solution was a dark blue. After 10 minutes of electrolysis, the color of the solution turned pink, and after 30 minutes the solution was virtually colorless.

EXAMPLE III Another experiment was conducted in order to demonstrate the decontamination of the water of nappas. Humic acids are typical contaminants of the waters of napas, produced by the decomposition of vegetable matter. Water containing humic acids is strongly colored even at low concentrations, and color removal can be difficult. A dark brown solution was prepared in tap water containing 30 ppm sodium salt of humic acid (Aldrich), without the addition of any additive to increase the electrical conductivity of the solution. The solution was re-circulated through a monopolar electrochemical cell similar to that used in Example 1, but equipped with only one anode and two cathodes. A constant current of 10 amps was supplied for 2.5 hours. The cell voltage was 24-25 V and the temperature reached 58 ° C. At the end of the experiment the solution was completely clear, demonstrating the effective destruction of humic acid.

EXAMPLE IV Another experiment was conducted to demonstrate the effectiveness of the electrolysis cells and the method of this invention in the sterilization and reduction of the chemical oxygen demand in effluents from the food processing plants. 250 ml of wastewater from a Mexican malt manufacturing company was treated using a monopolar open electrochemical cell similar to that used in Example 1, except that the total anode area was 6 cm2. The objectives were to reduce, the COD, the total or partial reduction of color, and the elimination of microorganisms and odors. A current of 1 amp was supplied for 150 minutes; The initial voltage of the cell was 22 V, down to 17.5 V, and the temperature of the solution reached 44 ° C. The results were shown in the following table: EXAMPLE V Another experiment was conducted to demonstrate the effectiveness of the electrolysis cells and the methods of this invention in the removal of color in a one-step configuration. A dark purple solution containing methyl violet ink in tap water at a concentration of 15 ppm was circulated through a monopolar open electrochemical cell similar to that used in Example I, in a single-pass mode, to a Flow rate of 250 ml / minute. The objective was to make the total color reduction. A 25 amp current was supplied; the cell voltage was 25 V and the temperature of the solution reached 65 ° C. After the simple passage through the cell a clear solution was obtained.

EXAMPLE VI An experiment can be conducted to demonstrate the usefulness of the configuration of the open electrochemical cell in the electrosynthesis of chemicals, in this instance sodium hypochlorite. The electrochemical cell of Example I is modified by the replacement of the anodes with anodes containing catalytic chloride, such as the DSA® anodes manufactured by Eltech Systems. A brine solution containing 10 g of sodium chloride per liter is introduced into the electrolyzed zone where chloride is generated at the anode and sodium hydroxide is produced at the cathode. Chloride and caustic soda are allowed to react in the cell to produce a dilute aqueous solution of sodium hypochlorite bleach.

EXAMPLE VII To demonstrate an open cell configuration using electrodes comprising a plurality of conductive porous elements positioned adjacent and electrically in contact with each other, an experiment is performed using a monopolar cell configuration illustrated in Figure 8. The cell is equipped with an anode of woven weft Pt / Nb having ten filaments per linear inch. Two of the Pt / Nb screens are in electrical contact and stacked, and on top of a third Pt / Nb screen, as a feeder electrode, which becomes connected to the positive terminal of the DC power supply. The cathode element is a simple nickel screen connected to the negative terminal of the DC power supply. The electrolyte to be treated consists of 5 g of sodium chloride added to the liter of electroless plated nickel aqueous effluent at 60 ° C, containing 60 g of nickel salt, 25 g of sodium hypophosphite, and a COD of 20,000 ppm. The electrolysis is conducted at 55 mA / cm2, even a cell voltage of 5.5 V until the COD of the effluent drops to around 10% of its initial value. The effluent is thus treated in an electrochemical cell containing a carbon cathode of high surface area to laminate the largest amount of nickel remaining in the solution. This demonstrates the destruction of the complex agents in the effluents of the electrolysis platinum bath and that releases the metal ions to recover the plating media. While the invention has been described in conjunction with various embodiments, these have been illustrative only. Consequently, various alternatives, modifications and variations will be apparent to persons skilled in the art in view of the detailed description mentioned above and it is then the intention to cover all alternatives and variations that may fall within the scope and scope of the claims.

Claims

1. An apparatus for electrolysis characterized in that said apparatus comprises at least one anode and at least one cathode as electrodes positioned in an electrolyzed zone; said electrodes are spaced apart from one another, the electrodes include conduit means for introducing therein an electrolyte for electrolysis, said electrolysis apparatus has an open configuration, and excludes a cell housing for retaining an electrolyte solution in said electrolyzed zone.

2. An apparatus for electrolysis according to claim 1, characterized in that said open configuration comprises a leakage control of electrolyte solution and gaseous byproducts.

3. An apparatus for electrolysis according to claim 1, characterized in that it comprises an electropurification cell for treating contaminated aqueous solutions.

4. An apparatus for electrolysis according to claim 1, characterized in that said electrolysis cell is an electrosynthesis cell for the production of organic or inorganic chemicals.

5. An apparatus for electrolysis according to claim 1,. characterized in that said electrodes are connected in a monopolar or bipolar configuration.

6. An apparatus for electrolysis according to claim 5, characterized in that at least one of said electrodes comprises. a plurality of conductive porous elements positioned adjacently and electrically in contact with each other.

7. An apparatus for electrolysis according to claim 6, characterized in that said porous conductive element of said electrodes are made of metal or carbon.

8. An apparatus for electrolysis according to claim 6, characterized in that said porous conductive elements of the electrodes comprise a material independently selected from a group consisting of a perforated metal, a woven wire cloth, a welded wire cloth, expanded metal, an carbon felt, a woven carbon cloth, a metal foam and reticulated vitreous carbon.

9. An apparatus for electrolysis according to claim 6, characterized in that said electrodes comprising a plurality of conductive porous elements have a feeder electrode and from 1 to 100 additional conductive porous elements in an electrical connection with said feeder electrode.

10. An apparatus for electrolysis according to claim 1, characterized in that it has means for regulating the residence time of the electrolyte.

11. An apparatus for electrolysis according to claim 10, characterized in that it comprises means for the uniform distribution of the electrolyte solution on said electrodes.

12. An apparatus for electrolysis according to the rei indication 1, characterized in that said anodes are electrocatalytic for the production of reactive oxygen species.

13. An apparatus for electrolysis according to claim 12, characterized in that said electrocatalytic anodes are of a material of construction selected from a group consisting of a noble metal, tin oxide, lead oxide, substiochiometric titanium oxide and impure diamond.

14. An apparatus for electrolysis according to claim 1, characterized in that said cathodes are electrocatalytic for the destruction of nitrate.

15. An apparatus for electrolysis according to claim 1, characterized in that said cathodes are a gas diffusion suitable for the reduction of oxygen to water or peroxide.

16. An apparatus for electrolysis according to claim 1, characterized in that said cell is an undivided electrochemical cell.

17. An apparatus for electrolysis according to claim 1, characterized in that it comprises the presence of a cell splitter between said anode and cathode to form an anolyte and catholyte compartment.

18. An apparatus for electrolysis according to claim 1, characterized in that it comprises at least one sensor selected from a group consisting of pH, UV light, visible light conductivity, hydrogen and chlorine.

19. An apparatus for electrolysis according to claim 1, characterized in that it comprises at least one energy supply selected from a group consisting of a direct current power supply, alternating current power supply, power supply, punctured and power supply Of battery.

20. An apparatus for electrolysis according to claim 1, characterized in that it comprises sensor means and computer means for receiving an input signal from said sensor means and providing an output signal for controlling at least one operating condition in said selected electrolysis cell. of a group consisting of a density, current, an average flow of the electrolyte solution of said electrolysis cell, the temperature and the pH of the electrolyte.

21. A method for electropurifying contaminated aqueous solution for use with the electrolysis apparatus of claim 1, characterized in that it comprises the steps of: providing an electrolysis cell comprising at least one anode and at least one cathode as positioned electrodes in an electrolyzed zone, said electrodes are spaced apart from each other, the electrodes include conduit means for introducing there an electrolyte for electrolysis, said electrolysis apparatus has an open configuration, and excludes a cell housing for retaining an electrolyte solution in said electrolyzed zone; the introduction into the electrolysis cell of a contaminated aqueous electrolyte solution and the introduction of a voltage through said electrolysis cell to electrolyze the contaminated aqueous solution and modify the contaminants.

22. The electrophoresis method of claim 21, characterized in that said open configuration of said electrolysis cell comprises a leaking controller of electrolyte solution and gaseous by-products.

23. The electropurification method of claim 21, characterized in that it comprises the electrodes of said electrolysis cell connected in a monopolar or bipolar configuration.

24. The electropurification method of claim 23, characterized in that it comprises at least one of the electrodes of said electrolysis cell comprises a plurality of porous conductive elements positioned adjacently and in electrical contact with respect to each other.

25. The method of electrophoresis of claim 21, characterized in that said aqueous electrolyte solution comprises contaminants selected from a group consisting of organic components, inorganic components, microorganisms, viruses, metal ions and the mixture thereof.

26. The electropurification method of claim 21, characterized in that said aqueous electrolyte solution comprises microorganisms selected from the group consisting of bacteria, spores, cysts, protozoa, fungi and mixtures thereof.

27. The electropurification method of claim 21, characterized in that the aqueous electrolyte solution introduced into the electrolysis cell comprises a dye or other color that produces contaminants, and the modified aqueous electrolyte solution recovered from said electrolysis cell which is substantially colorless .

28. The electropurification method of claim 21, characterized in that it comprises the electrolysis being conducted with the introduction of a current carrier to the aqueous electrolyte solution in an amount sufficient to improve the destruction of the contaminants.

29. The electropurification method of claim 28, characterized in that the current carrier is an alkaline substance or an acidic substance selected from a group consisting of acid and acid salts.

30. The electropurification method of claim 21, characterized in that it comprises the step of adding sufficient salt to the contaminated aqueous electrolyte solution to provide an active halogen residue in the purified solution.

31. The electropurification method of claim 21, characterized in that it comprises the aqueous electrolyte solution introduced into the electrolysis cell being contaminated with metal ions.

32. The electropuri fication method of claim 31, characterized in that it comprises said metal ions which are toxic metals coming from platinum bath effluents, metal tear baths, biocide iormulations, and paints, said metals are sequestered by a complex agent, surfactant or reducing agent.

33. The electropurification method of claim 32, characterized in that it comprises said complex agent, surfactant or reducing agent being modified in the electrolysis cell to release the metal ions to further treat in said electrolysis cell or to transfer the metal recovery cell .

34. A method for the electrosynthesis of chemical products characterized in that it comprises the steps of: the provision of the electrolysis cell comprising at least one anode and at least one cathode as electrodes positioned in an electrolyzed zone, said electrodes are spaced apart from each other , the electrodes include conduit means for introducing there an electrolyte for electrolysis, said electrolysis apparatus has an open configuration, and excludes a cell housing for retaining an electrolyte solution in said electrolysed zone; the introduction into the electrolysis cell of a contaminated aqueous electrolyte solution and the introduction of a voltage through said electrolysis cell to electrolyze the electrolyte to form a useful product.

35. A method of electrosynthesis according to claim 34, characterized in that it comprises said electrodes connected in a polar or bipolar configuration.

36. A method of the electrosynthesis of chemicals according to claim 35, characterized in that at least one of said electrodes comprises a plurality of porous conductive elements positioned adjacently and in electrical contact with respect to each other.

37. A method for the electrosynthesis of chemicals according to claim 36, characterized in that it comprises said conductive porous elements of said electrodes made of metal or carbon.

38. A method for the electrosynthesis of chemicals according to claim 34, characterized in that said electrolyte comprises an aqueous solution of salt or an acid.

39. A method for the electrosynthesis of chemicals according to claim 34, characterized in that it comprises the useful product which is an inorganic or organic component.

40. A method for the electrosynthesis of chemicals according to claim 34, characterized in that it comprises the electrolysis cell (i) having a porous diaphragm or a permoselective membrane.