CZ20001887A3 - Process for treating waste water and apparatus for making the same - Google Patents

Abstract

A method for separating contaminants from a water source containing the same contaminants is that it uses very strong oxidant dissolved in the aqueous system. The gas dissolves in a reservoir in an aqueous solution where within the reservoir pressure can be regulated. This allows maximum contact of the dissolved oxidizing gas with the contaminated substance. Output from the container is adapted to allow it after oxidation hydraulic cavitation. The net effect of cavitation is induction foam formation, which converts the flakes from the aqueous phase to the special phase. In this way, an efficient transfer process is performed mass with dissolved oxidizing gas. Furthermore, you can the method of separation improved by electrocoagulation, use electrode chambers disposed in a reservoir containing oxidizing agent. Introducing electrodes and inserting a current source the electrodes are contaminated in aqueous solution or otherwise degraded, complementing the oxidation caused gaseous oxidant. The device is adapted to the above these effects.

Description

Technical field

The present invention relates to a method and apparatus for treating wastewater. In particular, the present invention relates to the separation of contaminants from an aqueous solution using mass transfer and electrocoagulation technology.

Background

The problem of separating and removing contaminants from aqueous systems has been a complication that has been lamented in the art for many decades. The industry thus developed in proportion to other industrial processes and to the increase in pollution as industry progressed. Originally, water treatment was simply a matter of adding suitable substances to cause precipitation of certain substances, filtration, ion exchange and other processes. With the steady increase in stringent water purity requirements, electrochemistry has become popular. The use of suitably spaced electrodes in the chamber and the introduction of electrical current have been found to be useful for treated contaminant-containing solutions. In some cases, other process units have been combined with this treatment process to obtain inert compounds.

One of the references that was chosen to describe the prior art is U.S. Patent No. 1,095,893 issued to Landrett on May 5, 1914. This patent relates to electrochemical water treatment and describes chambers suitable for water treatment. As disclosed in this patent, copper, aluminum, brass, or other alloys are suitable as chamber electrode materials. The patent further teaches that settling tanks may be suitable for improving flocculation. Section 2 of the patent shows that a series of electrodes is arranged so that water flows upward through the device and is forced to "rotate" so that the substances to be added, or substances found therein, are thoroughly mixed and all liquid particles are come into contact with the electrodes ... ”. As also indicated in the text of Section 2, the electrodes are horizontally spaced plates, and these plates may be provided with apertures that may be axially aligned with plates of another row of other plates having at the ends of the shoulder. Section 3 states: “To ensure proper passage or circulation of fluid between plates 14 and its movement through the device, the plates are alternately provided with holes marked 14A, while the intermediate plates have cut corners with notches or shoulders as in 14B as shown in Figures 8 and 9. In this way, the liquid to be treated deviates from its flow direction and causes contact with the entire surface of the corresponding plates, thereby providing the desired electrical treatment.

Although this description is good for briefing on the electrochemical treatment of water, there is no indication of the addition of an oxidizing agent such as ozone. The teaching in this patent is limited to electrochemistry; the description lacks any detail regarding dissolved air flotation, fluid hydrodynamics, cavitation, flocculation or any other principles of fluid dynamics that would extend the usefulness of the electrochemical chamber disclosed in this patent.

U.S. Patent No. 1,146,942, issued to Landrett on July 20, 1915, discloses a modification whose variant was disclosed in a previous patent. This reference clearly states that the electrodes have different polarities and that a suitable pole switch, an example of which is shown in Figure 26, can be used to turn current into one set of electrodes that act as cathodes for some time while another set The plates act as anodes during this time. This reference shifted the field by introducing reverse polarity with a change in the polarity of the individual chambers in the unit. This reference, like the foregoing, lacks the introduction of countercurrent oxidation with dissolved gas. Furthermore, it is not believed that the device is particularly suitable for handling a wide range of different types of contaminants (organic substances, inorganic substances, combinations thereof, etc.).

Another reference to Landrett, namely US Patent No. 1,131,067, issued March 9, 1915, discloses the reintroduction of a treated liquid for further processing into the apparatus. There is also a discussion concerning

an oxidative action or flocculation treatment by either metal electrodes or a simple chemical reaction or other electrical stimulated reaction; or any other modification. In Section 2, beginning with line 25 et seq., Discusses recirculation of the substance for further treatment in the plant.

Preis, et al., U.S. Patent No. 3,728,245, issued April 17, 1973, discloses a sewage treatment apparatus having a series of electrolytic plates for electrocoagulation. The patentee discusses the need to maintain circuit pressure so that both chlorine and ozone are kept in solution in order to enhance the bactericidal effect. This reference improved the method developed by Landrett, et al., By introducing an oxidant to enhance electrocoagulation. The reference, while providing further guidance on this method, lacks any discussion of cavitation or flocculation by pressure drop in the stream of exiting treated aqueous material.

Another generally relevant reference is U.S. Patent No. 913,827 to Korten on March 2, 1909, U.S. Patent No. 3,523,891 to Mehl on August 11, 1970, U.S. Patent No. 5,928,493; 5,705,050; 5,746,904 and 5,549,812, 3,846,300, 5,587,057 and 5,611,907.

It has been found that electrolytic processes are generally suitable, although the design of the chambers was such that the electrodes were often clogged with sludge and therefore the current conditions in the chamber changed. Moreover, many of the plates in the present arrangements were large and they did not allow any improvement to increase the surface area in order to adequately increase the intensity of the reaction with the contaminants in question in water. However, this leads to a reduction in the degree of interaction due to sludge formation and to higher operating costs of the chambers in relation to the current requirements.

It has also been proposed to use dissolved air flotation systems. One such arrangement was made by Precision Environmental Systems Company. This company produces devices suitable for flocculation and coagulation in the same unit. This unit is perfectly suited for the purposes for which it was designed, but the machine has an extremely large footprint and different chemical processes in progress in the same unit.

One moderately successful and suitable arrangement that has been developed in this field for the treatment of water is probably the use of dissolved gases for oxidation. What is commonly known in the art are typical oxidation chambers open to the atmosphere where the gas dissolved in the solution is allowed to evolve from the solution. In this arrangement, the zigzag passage of water through the device must be ensured so that the bubbles remain in solution as long as possible. The surface of the bubbles is where the oxidant reacts with the contaminants. Once the gaseous substance has reached the surface, the contaminant flocculates and can be separated. This is commonly known as aeration, and various devices have been proposed in this field to keep the bubbles in solution to improve the degree of interaction of the bubble surface with the substance to be oxidized or otherwise decontaminated.

It would be advisable to use, where possible, a process with gaseous oxidant introduced into a container or other chamber or enclosure under sufficient pressure to keep the gas in solution. This makes it possible to form the smallest possible bubbles in the solution to oxidize the contaminants present in the solution. In particular, it is advisable to be a system capable of keeping dissolved oxidizing gas in solution in order to produce the smallest bubbles and thus the highest possible degree of surface area for reaction with the contaminants to be separated and further to allow for bubble size control.

The present invention is directed to providing a mass transfer mechanism and advanced oxidation technology to separate contaminants from an aqueous solution, where the oxidant is kept in solution for as long as required, and to allow pressure reduction and the oxidant to leave the solution . _t

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an improved method for separating contaminants from aqueous solutions. A counter-current mass transfer mechanism is used.

Another object of the present invention is to provide a continuous process for separating contaminants from an aqueous solution consisting of the following steps:

providing an aqueous solution containing contaminants;

providing a closed container having an inlet and an outlet, of which the inlet is higher than the outlet;

introducing the aqueous solution into the reservoir;

entraining the oxidant into an aqueous solution;

maintaining a pressure higher than atmospheric in the reservoir to minimize the size of the oxidant bubbles and thereby maximize the surface area of the oxidant bubbles with the contaminants contained in the aqueous solution;

oxidation of contaminants; and selectively inducing pressure failures outside the reservoir to cause flocculation of contaminants to the phase separated from the aqueous solution.

As to the oxidant, the oxidant to which the ^one given for use in the present invention prefer the ozone, but it should be appreciated that it is possible to use any other suitable oxidant, among others, chlorine, bromine, hydrogen peroxide and suitable nitro compounds.

It has been found that efficient oxidation of contaminants can be achieved by providing an effective invert or reverse aeration system. The container may be an insulated chamber, a closed-end tube, or alternatively it may be a ground formation for the subsurface treatment of contaminants contained in an aqueous solution. In current methodology, input is higher than output. In this method, the gaseous oxidant supplied is entrained downstream of the solution and will therefore be countercurrent to the treated solution. By keeping the reservoir chamber pressure above atmospheric pressure, the oxidant gas is kept in solution in very fine bubbles. This produces significant results because smaller bubbles have a considerably increased surface area for contact with the contaminant to oxidize it. This is achieved by regulating the pressure in the container and the outlet pressure. In this way the pressure is effectively adjustable and can be changed by the user according to his requirements. This is in a significant contrast to the previous state when open vessels were operated and thus the pressure could be equilibrated to barometric pressure and the gas was simply spiraled or otherwise winding. The concept of the prior art method was a winding path in an attempt to keep the bubbles in solution and thus at least partially in contact with the substance to be treated. The technology of the previous method was an efficient aeration technology where the gas was forced to pass through the solution for oxidation.

The difference in the current application can be described as considerable progress in the art. It has been found that by maintaining the pressure in a closed chamber, the gaseous oxidant can be kept in solution for the time required by the user; this contrasts with previously proposed technologies. The present case makes it possible to control the size of the oxidant bubbles in the chamber and facilitates countercurrent contact of the oxidant bubbles with the aqueous solution and further allows the user to cause pressure drop in various ways, for example by hydraulic cavitation, to induce flocculation. Regulation at this level has never been proposed before; previous methods have effectively utilized a "random" aeration process over a controlled process, which also results in the formation of rich floccules and a clear aqueous solution.

In reviewing the development of the present invention, the present invention integrates a variety of technologies including dissolved air flotation, hydraulic cavitation, fluid dynamics, mass transfer, and electrocoagulation. This concept is designed to jointly ensure an efficient process for separating contaminants, regardless of the contaminant. This is the role of the procedure, which was not feasible in previous techniques; Existing methods in most cases propose methods that are sensitive to the substances present in the treated system.

By controlling the pressure at the inlet of the substance into the reservoir and the outlet, it is possible to return the maximum amount of gaseous oxidant to the solution, thereby ensuring the smallest bubbles with the highest possible density and the highest retention time in the solution. These advantages, together with the principles of electrocoagulation, contribute to the success of the present disclosure.

In order to increase mass transfer in the above process, it has been found that the combination of such technology together with electrocoagulation provides excellent

results and greatly reduces the limitations and problems associated with it. Regarding another object of one of the solutions of the present invention, the control performed with the gaseous oxidation system can be associated with the advantages of electrocoagulation. As a further object of one embodiment of the present invention, there is provided a continuous process for separating contaminants from an aqueous solution comprising the steps of: providing an aqueous solution containing contaminants;

providing a closed container having an inlet and an outlet, an inlet higher than an outlet; placing the electrode chamber in a reservoir to insert an electric field onto the aqueous solution;

introducing the aqueous solution into the reservoir;

entraining the oxidant into an aqueous solution;

maintaining the pressure in the reservoir higher than barometric to minimize the size of the oxidant bubbles and thereby maximize the surface area of the oxidant bubbles with the contaminant in the aqueous solution;

oxidation of contaminants and oxidant and flocculation of contaminants by exposure to an electric field; and selectively inducing pressure drops outside the container to flocculate the remaining oxidized contaminants from the solution to a particular phase.

Another object of the invention is to provide a method of separating contaminants from an aqueous solution consisting of the steps of:

providing an aqueous solution containing contaminants;

b. oxidizing the aqueous solution with an adjustable pressure greater than barometric to maintain the oxidant in solution;

c. exposing the aqueous solution to electrocoagulation of contaminants in the electrode chamber;

d. selectively inducing pressure failures to flocculate the coagulated and oxidized contaminants from solution to a separate phase.

Of particular note is that the aqueous solution may contain both organic and inorganic waste materials or a combination of both.

Yet another object of the present invention is to provide a device for separating contaminants from an aqueous solution consisting of: an aqueous source containing a contaminant;

a sealable pressurized container having an inlet and an outlet, wherein the inlet is higher than the outlet and wherein the inlet is connected to a water source;

means for introducing the oxidant into the pressurized container;

electrode chambers situated in a reservoir for electrocoagulation of the substances in the water source;

means for supplying current to the electrode chamber; and means for selectively inducing hydrodynamic cavitation in the treated solution to flocculate the oxidized contaminants from the solution to a separate phase.

The present invention will be explained in more detail in the accompanying drawings showing a preferred solution.

Overview of pictures

Picture invention. 1 Yippee schematic by illustration one solution according to submitted Picture invention. 2 Yippee schematic by illustration second solution according to submitted Picture invention. 3 Yippee schematic by illustration third solution according to submitted Picture invention. 4 Yippee schematic by illustration fourth solution according to submitted Picture invention. 5 Yippee schematic by illustration fifth solution according to submitted

Figures 6A and 6B are schematic illustrations of the backwash circuit used in the present invention.

Figures 7A and 7B are schematic representations of alternatives of Figures 6A and 6B.

Figures 8A and 8B are schematic representations of alternatives of Figures 6A and 6B and Figures 7A and 7B.

Figure 9 is a longitudinal cross-section of one solution of the chamber of the present invention.

Figure 10 is a cross-sectional view of the alternative of Figure 9.

Figure 11 is a front view of a plate used in the present invention.

Figure 12 is a cross-sectional view taken along line 12-12 of Figure 11.

Figure 13 is a schematic representation of a circuit used in the present invention.

Figure 14 is a schematic representation of the switching circuitry used in the present invention.

Figure 15 is a schematic representation of a microprocessor circuit utilized in the present invention.

Figure 16 is another schematic representation of a switching circuit utilized in the present invention.

Figure 17 is a schematic representation of another solution according to the present invention.

Figure 18 is a cross-section of Figure 17.

Figure 19 is a schematic representation of a plasma chamber utilized in the present invention.

Figure 20 is a schematic illustration of another solution according to the present invention.

Figure 21 is a schematic illustration of yet another solution according to the present invention, and

999 ·· · 9 · 9 ·

Figure 22 is a schematic illustration of yet another solution according to the present invention.

Similar numerals in the figures indicate similar elements.

Examples

When used here, the abbreviation BOD (Czech abbreviation BOD) means biological oxygen demand; when COD is used here, it means chemical oxygen demand; and when abbreviated as TOD is used herein, it means total oxygen consumption. When percentages are given as percentages (%), reference is made to percentages by weight. %, unless otherwise indicated. The w / v symbol (w / v) indicates mass in volume. The symbol 03 indicates ozone gas. All other symbols referred to herein have the usual meaning. As used herein, the abbreviations TSS refer to total suspended matter. As used herein, the abbreviations TDS refer to total solutes.

Referring now to the figures, Figure 1 shows an overall schematic view of the equipment used to operate this methodology. In the example, the water source contaminated with organic contaminants, inorganic contaminants, or a combination thereof is represented by 10. The pump 12 can provide the pumping of fluid from the source 10 to the reservoir 14. Between the source 10 and the reservoir 14 is a diffuser 16 whose source is indicated by 18. If the oxidizing agent is in the gaseous state, it may be ozone, bromine, chlorine, nitro compounds. When the oxidizing agent is selected from liquids, hydrogen peroxide and other related oxidants may be suitable. If the selected agent is not in the gaseous state, it can be converted into it, for example, from the liquid state by any suitable means known to those skilled in the art. The oxidant is introduced from the source 18 into the container 14 via a diffuser 16.

The reservoir 14 shown in the figure consists of a pressurizable tank constructed of a material capable of withstanding the pressure of at least several atmospheres. The reservoir 14 has an inlet 20 connected to the liquid via a diffuser 16 and an outlet 22. The inlet 20 is situated higher than the outlet 22. The diffuser 16 delivers the oxidant to the water source by entrainment. As the entrained oxidant and the aqueous solution enter the container 14, its contents are pressurized.

In this technology, it is important that pressure is maintained in the container 14. This will facilitate the dissolution of ozone gas in the solution and promote the formation of small bubbles (not shown). The flow from the inlet 20 leads to the outlet 22 co-current. In this way, the oxidant bubbles are countercurrent with the aqueous solution. This flow diagram is very effective when the solution is dense with small bubbles. Small bubbles, as surely experts know, create a huge surface area over larger bubbles. In addition, if pressure is maintained, the smaller bubbles in solution have a longer lifespan and thus greater oxidative effects. The countercurrent flow mechanism in the cartridge 14 is better represented by arrows 24 and 26.

After a sufficient period of residence in the container 14, the oxidized substance exiting through the outlet 22 to induce hydrodynamic cavitation is subjected to a pressure drop. By this mechanism, when the pressure is released, the gaseous oxidant is released from the solution and the flocculated substance is effectively washed away so that the flocculated phase is separated from the aqueous phase. Pressure loss can be affected by a throttle valve, variable plate or other pressure relief mechanism, generally designated 28. Once the separate phases have been formed and the contaminants are separated from the aqueous solution, the individual phases can be subjected to further operations. In the case of the aqueous phase, the water may undergo further purification, including, for example, special distillation technologies and ion exchange. With respect to the flocculated mass, it can be treated by special technologies to regenerate any valuable substances that may be present in the flocculated mass. The above operations are not shown in the drawing.

Figure 2 shows a modification of the device of Figure 1. In this solution, the device is provided with an instrumented sensor numbered 30 to provide supersaturation of the aqueous solution before the aqueous solution exits outlet 22 and controlling the amount of oxidant supplied by diffuser 16. This is accomplished by float a valve 32 that floats on the surface of the liquid in the reservoir 14 and is electrically connected to the sensor 34. The sensor, in turn, is in electrical or mechanical communication with the valve 36. The valve 36 is directly

connected to the oxidant supply 18 and thus if the float 32 at the liquid level in the reservoir 14 registers a sufficient drop, the sensor 34 signals to the valve 36 that the diffuser 16 interrupts the oxidant supply to the system and particularly to the inlet 20. This arrangement can alternatively be replaced by a simple degassing tube (not shown).

Figure 3 shows an alternative to those discussed in Figures 1 and 2. In this solution, the container 14 is an underground body that is a source of contamination with the aqueous phase 10. This solution indicates that this technology is immediately applicable to off-road use. This may be relevant where deposition of hydrocarbons or other petroleum or organic compounds is present in the ground. If the ground formation consists of substances which would not withstand a pressure higher than atmospheric, the formation may be pretreated with a substance which would create an impermeable cover of the interior, cure its surface or separate it to withstand the pressure treatment. Suitable technologies, compounds or further processing are known to those skilled in the art.

In this process, the oxidant can be introduced mostly in the same manner as described above. The oxidant can be introduced into the formation 14 through the inlet of the formation 20. As mentioned above, the formation 14 contains an aqueous mixture of organic, inorganic and other substances and thus the pressurized introduction of the oxidant into the formation will result in oxidation of contaminants by the same mechanism (countercurrent). 1 and 2. The oxidized substance may be transported from the outlet 22 in the formation 14 by a pump 38 to a throttle valve 28 to release the pressure and thereby flocculate the oxidized compounds. Once flocculated contaminants are effectively separated from the aqueous phase and can pass through the next processing unit as described above.

To increase the efficiency of the system discussed in Figures 1 to 3, the aqueous solution may be subjected to electrocoagulation. Various solutions will now be specified.

Figure 4 shows further modifications of the apparatus. In this solution, the waste water is pumped from the tank 40 by a pump 12 through a diffuser 16 co-current with the pump 12. The ozone produced by the ozone source 18 is entrained into the waste water by a diffuser. The waste water then passes through the electroflocculation chamber 42 located in the reservoir 14. The cartridge 14 and the chamber 42 The waste water is vortexed through a strong electric field created by the electronic circuit of the chamber 44, then the waste water passes from the reservoir 14 through a flow throttle valve, an example of which is a metal orifice 28 and then back to the tank 40.

In the waste water line between pump 12 and diffuser 16 is a chamber shut-off valve 46. Between the pump and chamber shut-off valve 46 is connected a tank drain line 48 with a drain shut-off valve 50. The shut-off valve for chamber 46 is open during wastewater treatment and wishes to drain the waste water from the tank 40 after processing, it is closed. Conversely, during waste water treatment, the drain valve 50 is closed, and opens to discharge the treated waste water.

The gas valve 52 is equipped to control the flow of ozone into the waste water. The gas valve 52 may optionally be electrically controlled for some solutions of the inventive apparatus, as described in more detail below.

The sheet metal shutter 28 may consist of a stainless steel disk or other wastewater-resistant dissolution material disposed in the connection line of the chamber 42 and the tank 40 and have at least one sharp edge outlet (not shown). In the apparatus of this example described in more detail herein below, one outlet in the metal orifice 28 is used that is approximately 10% greater than the passage through the diffuser 16 so that during operation the wastewater pressure in chamber 42 is reasonably lower than the outlet pressure proper operation of the diffuser 16 within the designed operating range of the diffuser parameters.

It will be appreciated that a higher pressure in the chamber 42 may be advantageous for some wastewater compositions, but if this higher pressure is used, then the pump 12 must be selected so as to provide a pressure drop across the diffuser 16 to entrain the ozone into the waste. water in an amount necessary for a given composition of the treated water. Reducing the area of the aperture or apertures in the sheet metal diaphragm 28 to increase the pressure in the chamber 42 is not recommended, since into the stream in the diffuser 16 the

99

9 9 •

9 9 99 99 99 99

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9 9 9 9 9 • 9 9 9 9 9

99 99 cannot absorb enough ozone because the pressure drop across the diffuser is reduced. It is also not recommended that the area of the aperture or apertures in the sheet metal shutter 28 is too large, even if sufficient pressure is maintained in the chamber 42, as this would result in a too high pressure drop across the diffuser 16 and waste water. it would deplete too much ozone, which would lead to an increase in gas in chamber 42 and ozone losses, as well as poorly efficient operation of chamber 42.

Figure 5 shows another variant of the device. In this solution, a plurality of chambers 42, 42 'and 42 "are shown with different electrode arrangements. The electrodes in chamber 42 are numbered 54 and are connected to rods 56 and 58, which rods are in turn connected to a direct current supply 60 with a control circuit. More details about chamber 42 will be provided elsewhere. In this arrangement, the outlet 22 of the chamber 42 becomes the inlet 20 of the chamber 42 'and so on relative to the chamber 42'. The oxidant 18 may be added as desired, and further, a separator 61 may be easily introduced into the circuit to separate the liquid from the solid to isolate the flocculated and aqueous phases before passing through to the next chamber.

With respect to the electrode geometry, the chamber 42 has a coaxial configuration with a parallel plate system with gaps in the vertical sense. The chamber 42 'has a longitudinal arrangement of the electrodes, while the chamber 42' has a plurality of free beads / grains / beads.

Although Figure 5 shows three different electrode geometries, this is only an example. The chambers 42 may have the same geometric configuration or any other combination and number.

Figures 6A and 6B show arrangements for backwash chambers when arranged in a row. In Figure 6A, chamber 42 utilizes oxidant entrainment and the aqueous solution enters through inlet 20 in the direction of flow indicated by arrow 62 and is discharged through outlet 22 to inlet to backwash chamber 43 through inlet 20. A suitable valve 64 is situated between outlet 22 and inlet 20. in the chamber 43 is indicated by an arrow 66. The substance in the chamber 43 is transported to the outlet 22 and optionally to an outlet 22 and optionally to an outlet. A flow control throttle valve 28 is provided between the outlet 22 and the throttle valve 28.

Figure 6B shows the reverse procedure with respect to Figure 6A; here the chamber 42 acts as a backwash chamber and the chamber 43 as a working chamber. The flow in the chambers is also reversed as indicated. In operation, the treated substance from chamber 43 is transferred to the inlet 20 of chamber 42. A valve 64 may be used to restrict or prevent flow. The treated substance leaves outlet 22 and throttle 28. Valve 70 is located between throttle 28 and outlet 22.

The chambers 42 and 43 may alternatively operate to provide backwash and thus alternate between the flow of Figures 6A and 6B. In doing so, references to the outlets and inlets of the chambers are changed in the description; not for design differences, but rather for operational differences.

The cycling of Figures 6A and 6B will vary over time depending on requirements; the short cycle can be from 30 seconds to about 10 minutes and the longer cycle can be from one hour to eight or more hours. Any number of chambers can be at any time in the operating mode or backwash mode.

FIGS. 7A and 7B show a similar arrangement to FIGS. 6A and 6B with provision for trapping sludge from the aqueous solution. As shown, the sludge traps designated by the numeral 72 are generally close to each inlet and outlet of the corresponding chamber. The traps may contain any suitable substance capable of trapping and releasing sludge, such as fine pore filters, liners, ceramic spheres or other porous media, but allowing fluid to pass through. This task is useful for keeping each chamber clean and therefore optimum performance.

Figures 8A and 8B illustrate a solution where a backwash circuit can be used to fluidize a deposited bead cartridge designated by the numeral 72. The beads 72 are of an electrically conductive material (detailed below) and are partially consumed in the chamber 42 and 43. Along with weight loss, stratification occurs; a backwash of the liquid layer depicted, and further preferably provides self-cleaning of the bead charge.

Figures 9 and 10 show two possibilities of internal configuration of chamber 42. Figure 9 shows one solution in which an electrical circuit 74 (not shown in Figure 9) for driving chamber 42 is not enclosed in chamber 42; Figure 10 shows a portion of the bottom of the chamber configuration 42 that is formed at the bottom of a cavity 76 in which the circuit of the electronic excitation of the chamber 74 is enclosed within a working well 76. The solution of Figures 9 and 10 has a gas evacuation tube 30). controlling the waste water level within the chamber 42. The waste water level within the chamber 42 can optionally be controlled by a system with a float valve sensor 30 shown in Figure 2.

As shown in Figure 9, the electroflocculation chamber 42 generally consists of a cylindrical longitudinal sleeve comprised of a plurality of portions 80 of generally circular radial cross section, which may consist of suitable non-conductive materials such as a PVC tube or extruded plastic or fiberglass.

The cover 80 has a cavity 82 in which a set of parallel plates with gaps 84 is mounted; 16 shows such plates 84. The cavity 82 is sealed except for the inlet 20 into which the waste water flows from the diffuser 46, the outlet 22 from which the waste water flows to the metal orifice 28 and the gas outlet pipes 30 have been mentioned above.

The plates 84 may be made of a suitable metal, such as aluminum. An example of one such plate is shown in Figures 11 and 12. The plate 84 has three through-hole bores 86 located off-axis whose centers are located on a circle at equal angular distances of 88,90,92. The flow holes 86 have sharp edges 94. The plate 84 also has a central hole 96 and three rod holes 98, each centered on a circle 88, 90, 92 so that the centers of the rod holes 98 are situated at the same distances as the hole centers. 86 in the middle of their distance. The plate 84 has circular symmetry; the holes for the bars 98 alternate on the circle with the flow holes 86.

• 4 * ·

44

As shown in Figure 9, the plates 84 are mounted on a rod 100 of a chemically inert and solid material such as nylon, with a rod at each end having threads to attach the nuts 102 to the rod. A set of 15 identical annular washers is mounted on the rod 100. 104 alternating with the plates 84 so as to define an appropriate distance between the plates 84. The array of plates 84, washers 104, and rod 100 are held together by fastening nuts 102 contracting end plates 84. As previously mentioned, it is desirable that wastewater pass the chamber 42 in a zigzag way to improve flocculation. It is also desirable to provide a strong electric field near the apertures 86 and 98 through which the waste water is forced to flow. To create a zigzag wastewater flow path, the plates 84 are phase shifted along the bar 100 so that the centers of the flow holes 86 of each plate 84 are aligned to the holes of the bars 98 of the adjacent plate 84 from both sides (in longitudinal direction). The sharp edges 94 of the openings 86 furthermore cause a swirl of the wastewater stream and locally concentrate the electric field.

To connect the plates 84 to the excitation circuit of chamber 74 and to maintain the plates 84 in the desired configuration described above, two metal bars 106 and 108 are inserted through radially opposed flow holes and rods 86 and 98 and welded to the edges of the rod holes 98 in Thus, the rods 106 and 108 extend parallel to the rod 100 in a plane passing through the center of the plate 84. Each rod 106 and 108 alternately passes freely through the center of the orifice 86 of one plate and passes through and is welded to the bar hole 98 of the other plate. 84. The resulting structure divides the plates alternately into two groups, each group being welded and hence electrically connected to a particular single rod 106 or 108. The rods 106 and 108 are connected to each other.

to the excitation circuit of chamber 74 by conductors 110 and 112 and are powered by the method described below.

Electric current is applied to the plates 84 by two rods 106 and 108. The plates 84 may be made of aluminum, but may also be made of iron and other materials that allow the metal to dissolve in solution. For some composition

It is advantageous to use multiple chambers 42 in series having plates of different materials for each chamber 42, so that a different electrochemical effect is produced. Plate materials are best searched empirically to suit specifically contamination. For example, copper, carbon or titanium are used for some contaminants.

It has been found that configurations of plates 84 in which wastewater is forced to swirl in plates 84 (causing partial flow restraints), together with the controllable oxidant discussed in Figures 1 to 3, result in improved electrocoagulation effect compared to the simple prior art. designed rectangular plates submerged in the flow chamber or with concentric tube arrangements in the through-chamber construction, where the waste water flows in both previous constructions parallel to the plates.

The electronic driver circuit 74 generally rectifies and controls the current from an external source line (not shown), with pulse width modulation, and inserts it over the conductors 110 and 112 onto the plates 84 such that the alternating plates have a voltage potential sufficient to establish a relatively strong electric field. by varying the pulse width of the current pulses applied to the plates 84, the total current (and hence the power of chamber 42) can be controlled. The pulse frequency is in the range of about 1 Hz to about 1000 Hz and the total current density is in the range of about 0.1 A.in-1 to 10 A.in-1, which generally satisfies most requirements. Since the current depends on the conductivity of the waste water and the conductivity changes during operation of the device, the excitation electronic circuit 74 uses the conductivity measurement between the plates 84 between pulses to determine the optimum pulse width for the next pulse. The chamber drive circuit 74 also periodically changes the pulse polarity to prevent agglomerations on the plates.

The chamber electronic drive circuit 74 may include a chamber wake-up generator, a power switch, an analog to digital converter, a timer, a signal multiplier, and other circuit elements to optimize chamber operation. Such electronics can be introduced into separate devices such as diodes or transistors, but are preferably logic devices capable of modifying the electronic equivalent of a mathematical expression as shown in Figures 13 and 14. * «• · ··· 9 9 · · · ·

9 9 · 9 • 9 · 99

99

9 9 9

9 9 9

9 · 9 9

9 9 9

99 of chamber 74 may be represented by a microprocessor 114 programmable by an external computer device such as a laptop or other serial data transmission systems as shown in Figures 15 and 16.

Figures 13, 15, 16 and 14 show detailed circuit diagrams (in the case of Figures 13 and 14) or functional block diagrams (in the case of Figures 15 and 16) of suitable solutions for the excitation circuits of chamber 74.

The preferred circuit solution 74 comprises a single-pole power supply consisting of a bridge rectifier (not shown) that provides a rectified DC output to chamber 42. The reverse polarity reversal circuit is equipped to periodically change the polarity of the current passing through the chamber 42. The polarity may be changed. by placing the chamber 42 in the flow diagram of the "H" switch shown in Figure 14 (generally indicated by 116 in Figure 13) or as shown in Figure 16, where the microprocessor control system used in Figure 15 is used. be semiconductor switching elements such as silicon rectifiers, insulated reverse bipolar transistors or other devices capable of switching large currents, examples of which would be outside the wide frequency range. The frequency of polarity reversal is best determined empirically and is believed to depend on the nature and amount of pollutants to be removed from the wastewater.

For periodic polarity reversal, the current supplying the pulse width modulated chamber 42 is that portion of the electronic circuit 74 shown in Figures 13 or 15. The pulse width is determined from the wastewater conductivity and the selected pulse width determines the time averaged current passage through the chamber 42. in the range of a few nanoseconds to a few seconds, thus allowing wastewater with a wide conductivity range to be treated with only one chamber arrangement and with a stable feed. In the example described below, the range of waste water quality ranges from almost fresh water having a conductivity of 50 (ohm ^-1 , typical of lake drinking water) to concentrated seawater having a conductivity in excess of 100 Mohm ^-1 . measures conductivity, the device can treat wastewater with rapidly fluctuating conductivity, eg waste water from a fish processing plant that changes the conductivity from fresh water conductivity to salt water conductivity. Such a measurement is used to limit the power input to the chamber to maximize the electrocoagulation phenomenon.These conductivity values can be obtained by an external conductivity sensor (not shown) bordering the electronic circuit 74 or by using a time multiplex on the internal electrodes (bars 106 & 108) of the chamber 42 can be performed The current in the chamber is measured by a conventional transformer current measuring device, shown in figure 15 by the number 118, the input of which is fed to the microprocessor 114 to control the energy consumption of the chamber; this same data can also be used to calculate the conductivity of wastewater.

Figures 15 and 16 generally illustrate the use of microprocessor 114 for PWM control. The corresponding numerals 120, 122 and 124 in Figure 15 indicate the data lines for the temperature, conductivity, and turbidity sensors to the microprocessor 114. Figure 16 illustrates a separate component solution of the portion of Figure 15 limited by the dashed line. Block 126 in Figure 15 shows the function that is performed by the four separate devices 128, 130, 132 and 134 shown in Figure 16. Similarly, the streaming data designated by the numeral 136 in Figure 15 represents the four signal lines 138, 140, 142 and 144 as is shown in Figure 16. Figure 146 shows a data line providing current to the microprocessor 114 from a conventional transformer current meter 118 through an operational amplifier 146. The numeral 148 indicates the flow of communication data from an external computer such as a laptop or other serial data transfer system. to program the microprocessor 114.

As previously mentioned, the diffuser 16 and the sheet metal orifice 28 are selected such that the chamber 42 operates under pressure and provides gas dissolution in the chamber 42. The gas produced in the chamber 42 by electrolysis during the electrocoagulation process will remain in solution until a pressure loss occurs by reducing it. The ozone entrained into the wastewater through the diffuser 16 will be dissolved in the wastewater in the chamber 42 as long as the wastewater remains at a higher pressure than the barometric pressure. Ozone is known as a strong oxidant and as a coagulant (alternatively hydrogen peroxide, chlorine, bromine, nitro compounds or other suitable oxidants may be used).

The mechanical arrangement of the chamber 42 solving the best characteristics of providing a concentrated electric field through which the wastewater passes and acting under pressure in a swirling environment can be replaced by another arrangement. As noted, in the spiral arrangement 150 of Figure 17, for example, wastewater is subjected to centrifugal acceleration which causes solids to separate as a concentrated electric field is applied between the top plate 152 and the bottom plate 154 (Figure 18) to limit water flow. between the vertical walls 156 of the spiral arrangement. As water flows from the inlet 158 'at the outer ends to the center of the spiral arrangement 150, two separate outlets are formed; one outlet flows as a solid sludge and the other as a treated liquid. The two effluent streams as soon as they reach the center are separated by the baffle 160, thereby separating the treated water stream into a treated water stream into outlet 162 and solid sludge into outlet 164.

Further contributing to the overall electrochemical reaction in chamber 42 may optionally be provided by the discharge of high voltage pulsed plasma interposed between the plates 84 of chamber 42 by the circuit shown in dashed line in Figure 19. energy in the gaps between the submerged electrodes. The plates 84 of chamber 42 are time-lapse controlled by the drive circuit of chamber 74. In this method, normal excitation of plates 84 for a short predetermined period of time during which a plasma discharge is triggered between plates 84 is stopped. After termination of the plasma discharge, normal excitation occurs. The resulting highly ionized and pressurized plasma transfers energy to the wastewater stream by dissociation, excitation and ionization. Plasma discharge generates high pressure shock waves (> 14000 atm). There will be intense cavitation and the associated chemical changes, and further suspended and dissolved from the water. solids. The plasma discharge also acts on the plates by their cleaning effect and helps to keep the surface electron-free.

Figure 19 illustrates how a plasma discharge was successfully formed in a test chamber 166 with one pair of plates 168 during a brief interruption under normal plate excitation 168. The plasma discharge is generated by a high capacity capacitor 170 charged from a suitable current supply 172 connected via an inductor 174 to chamber 166. the capacitor 170 is not sufficient to cause a plasma discharge between the plates 168 of the chamber 166. The discharge is initiated by a feedback coil comprising the pulse generator 176 and the boost transformer 178. The pulse generator 176 is controlled by a signal line 180 controlled by the drive driver circuit 74. 178, a high voltage pulse trigger pulse that is interposed between the plates 168 and generates a spark discharge between the plates 168. The spark causes the chamber 166 to ionize. Once this path has been established, the charge in capacitor 170 is already able to flow through the ionized path. The inductor 174 prevents the spark current from passing through the capacitor 170 into the ground.

In a typical multi-plate operation chamber 42, a spark between any adjacent plate pair 84 is expected to produce a plasma discharge sufficient to clean all plates 84, thereby allowing high voltage pulses to be applied to all plate pairs 84 by time-lapping the same connection lines 110 and 112. used to supply normal excitation of the plates 84, despite a certain probability that the spark will jump between only one adjacent pair of plates 84 by some particular discharge. Therefore, the circuit shown in dashed line in Figure 19 can be used for a multi-plate chamber 42. However, a time-lapse circuit (not shown) must be used to isolate the shock effect of the spark discharge from the excitation voltage.

Alternatively, a separate spark gap (not shown) may also be used near the plates 84. A special spark gap must be located near the inlet 20 where there may be some gas (mostly ozone) to facilitate the formation of the spark.

Further contributing to the overall electrochemical reaction in chamber 42 may optionally be a magnetic field coil 182 wound around the chamber 42, as shown in Figure 20. The field of the coil 182 repeatedly pulses and produces a magnetic field. In a device according to the example of the following type in the Example, a magnetic field intensity of up to 10,000 Gauss was achieved using 180 volts pulses. As a result of this treatment, a reduction of up to 20% in the time or number of chamber passes required to remove impurities from the waste water was observed.

Before illustrating the effects of the present invention, reference will be made to Figures 21 and 22 showing other alternative chambers 42.

In Figure 21, parts have been removed for clarity and the rod 100 (of Figure 9) is rotatably mounted in chamber 42 and rotates with it a motor 182. The motor 182 can be started by circuit 74 or other suitable power source (not shown). The individual plates 84 are mounted on the bar 100 and can rotate in the housing 80 in situ. Rotation of the plates 84 helps to maintain their cleanliness and hence the operation of the entire chamber. To further improve the oxidative flocculation process, the rod may have a helical profile 184 so as to be able to transport liquid in the chamber 42 and thereby assist the countercurrent action of the dissolved gas in the aqueous solution. This concept has been discussed with respect to Figures 1 to 3.

Figure 22 shows a similar view of chamber 42, but using beads 72 instead of plates 84. The beads 72 are of a material similar to that used for the plates 84. The beads 72 may have dimensions from 50 mesh to 1.5 "but this will depend to the specific requirements of chamber 42. The current supplied from lead 60 (not shown) is connected to rods 56 and 58 that are in contact with electrically conductive beads 72. Helical rod measures 184 serve to circulate or wash beads 72 in chamber 42 and preferably is that the beads are effectively cleaned from the deposit by this process, thus retaining a fresh reaction surface for proper process flow. This fluidization also ensures more uniform bead wear and thus avoids disproportionation in the weight of the beads to each other. The accompanying advantage is the possibility of regulating the process.

In a beaded or granular version of the device, the beads have been found to bring a relatively large surface area to the passing water volume proportional to the water supply procedure.

low conductivity. When using beads, essentially only low current is required to operate the chamber to achieve the same effect as using large plate type electrodes.

Having thus described the invention, we will turn to the examples.

Examples

An example of a test apparatus was constructed according to the invention as described above and has these characteristics.

For the chamber 42 of the example shown in Figures 9-12, a pump 12 capable of pumping turbid water or contaminated effluent at a rate of 6 gallons per minute at a nominal pressure of 60 psi was selected, diffuser 16 was a Mazzie injector type 684, gas valve 52 was a needle the valve and ozone source 18 have been selected to provide approximately 4 grams of ozone per hour. The waste water pressure in chamber 42 was selected at approximately half the pump pressure, in this case 30 psi, for the pump outlet pressure of 60 psi. In the construction of such chambers 18, there is generally sufficient pressure drop across the diffuser 16 at half the pressure of the pump. Higher pressure can be used in the chamber to improve process efficiency, but at a higher cost because of the need for a larger pump and power input to operate the pump.

In the following description, the exact dimensions of the corresponding chamber 42 with which the test results have been obtained are given, but it should be understood that the chamber 42 can be made on a different scale, in the designer's opinion.

The diameter of the housing 80 is not critical. A 3 inch inner diameter was used to illustrate the following discussion.

The plates 84 were made of 6061-T6 aluminum of 0.125 "thickness, 2.990" diameter. The holes 86 had a diameter of 1,000 "and their centers positioned 0.875" from the center of the plate on circle 88, 90, 92. The hole 96 had a diameter of 0.380 "and the three holes for bars 98 a diameter of 0.265", each with a center distance of 0.875 " ", On a separate circle in the middle of the arcs 88, 90, 92.

• ·

The plates 84 were mounted on a 6,500 "3/8" length nylon rod 100 threaded at each end for the nylon nut 102. The plates 84 were equally spaced longitudinally from each other by a set of fifteen 0.500 "diameter Teflon washers 104 each having a central hole diameter 0.375 "and thickness 0.250".

The metal bars 106 and 108 were selected with a diameter of 1/4 "and a length of 14,250" and spaced by 1,750 "from each other.

The excitation circuit of chamber 50 has drawn current from a 220 V ~, 60 Hz three-phase line. The potential between successive plates 84 was chosen with respect to the conductivity of the waste water. For highly conductive effluents, a typical voltage of up to 30 volts in a chamber with a flow of 20 amps, say for wastewater from a fish processing plant, was typical. This entails a chamber power input of about 600 W, resulting in a suitable power consumption value for water with a lower conductivity in a 3 inch diameter chamber. The plates are powered by pulses at a frequency of 600 Hz, with a pulse width varying from 6.5 microseconds to 2 seconds to achieve a time current average of 20 to 25 amperes. Higher currents would be possible and desirable (albeit at higher cost) for larger chambers, but to avoid overheating of the small chambers, the current must be limited. For contamination with substances removed by the test, it was found appropriate to alternate the polarity of the inserted pulses within the range of 30 seconds to 2 minutes.

If a discharge plasma was used, it was found that for an average saline wastewater, a discharge voltage of about 4000 V and subsequent discharges at 5 second intervals were sufficient. The test results of the waste water treatment example with the apparatus described above are given below. “BOD” means BOD for five days (BODs).

Example 1

A spill point sample was taken from a large fish processing plant in Killybegs, Ireland. At the time of sampling, the plant was processed by horse mackerel and herines. The sample was taken behind the screen and before being discharged into the municipal waste system.

• 9 •

Approximately 6 liters of discharged water sample were treated in the test unit. A raw and treated sample of the discharged water was sampled and analyzed. The analytical results are shown in Table 1.

Table 1

Case of treatment of fish processing waste

Raw waste behind screen (sample 1) Treated waste (sample 2) PH 6.7 7.3 BOD ₅ (mg.r) 1160 50 * BOD (mg.I ' ¹ ) 2080 70 Suspended substances (mg.l · ¹ ) 580 23

* calculated from the ratio of BOD and COD or treated sample 4.

During the process, the waste flocculated well, most of the flocculated material washed up to the surface of the liquid. BOD waste was reduced by approximately 95% (significant reduction) with a similar reduction in COD and suspended solids levels. The pH of the sample rose slightly to 7.3, but this is not due to the discharge. In this test, the sample passed through chamber 42 three times.

Example 2

A sample of the waste was taken behind the screen from the second fish processing plant in Killybegs, Ireland. The results of the test treatment are shown in Table 2.

Table 2 • 9 • 9 • 9 • 9 9 9

Case of treatment of fish processing waste

Raw waste behind screen (sample 3) Treated waste (sample 4) PH 6.6 7.3 BOD ₅ (mg.I- ¹ ) 2580 104 BOD (mg.I ' ¹ ) 6400 152 Suspended substances (mg.r ¹ ) 1560 30

BOD, COD and suspended matter were reduced by up to 95%. The pH of the sample rose to 7.7 after adjustment. In this test, the sample passed through chamber 42 three times.

Example 3

A sample was taken from the third fish processing plant in Killybegs, Ireland behind the screen. The plant processed mackerel and large amounts of oil (up to 20%) were expected in the waste. The plant management stated that in their opinion this activity represents the worst possible conditions for waste quality. The results of the samples are shown in Table 3.

Table 3

Sample of mackerel waste processing

Raw waste behind screen (sample 3) Treated waste (sample 4) PH 6.4 6.85 BOD ₅ (mg.r ¹ ) 7400 24 BOD (mg.r ¹ ) 28800 320 Suspended substances (mg.r ') 5460 78

The results show that BOD, COD and suspended matter values were reduced by more than 95%. In this test, the sample passed through the chamber 18 six times.

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9 9 ·

99

It has been found that the plates 84 of the device according to the invention have eroded slowly compared to the plates used in the prior art electroflocation chambers. It can be assumed that this is due to the combination of countercurrent gas dissolution and the reduced surface area of the plates 84 as opposed to the original plates and the sharp edges of the apertures 86 and 98 in the plates 84 and the sharp edges of the aperture. using plasma discharges are believed to be the result of cavitation. Cavitation breaks up solids, but once this breaks up, fragments begin to recombine, resulting in cleaner water than before cavitation. Cavitation caused by either the sharp edges of the openings 86 and 98 in the plates 84 and the opening in the metal plate 28 or the additional use of a plasma discharge is not necessary for the operation of the chamber 42. The back pressure into chamber 42 is necessary so that the metal orifice 28 can be replaced by a throttle valve of appropriate size.

In summary, the use of an oxidant in a closed chamber or backpressure container will improve the ability of the small oxidant bubbles in the system to react. This self-operating arrangement is extremely effective for separating contaminants in aqueous systems. If the process is extended to the above-mentioned electrochemical process, there will be an enhanced effect providing a highly efficient separation system that can be incorporated into other processes as an operating unit.

Although the above solutions have been described above, the invention is not limited thereto and those skilled in the art may make many modifications to the parts of the present invention as long as they do not depart from the spirit, nature and scope of the claims described herein.

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Claims (47)

Patent claims A continuous process for separating contaminants from an aqueous solution, characterized in that it comprises the steps of: providing an aqueous solution containing contaminants; providing a closed container having an inlet and an outlet, of which the inlet is higher than the outlet; introducing the aqueous solution into the reservoir; entraining the oxidant into an aqueous solution; maintaining a pressure higher than atmospheric in the reservoir to minimize the size of the oxidant bubbles and thereby maximizing the surface area of the oxidant bubbles with the contaminants contained in the aqueous solution; oxidation of contaminants; and selectively inducing pressure failures outside the container to cause flocculation of contaminants to the phase separated from the aqueous solution. 2. The method of claim 1, further comprising the step of adjusting said pressure above atmospheric relative to said pressure outside said container. 3. The method of claim 1 wherein the entrained oxidant and said aqueous solution flow countercurrent in said container. 4. The method of claim 1, further comprising the step of releasing excess pressure in said container to release undissolved gaseous oxidant. 5. The method of claim 1, wherein the time the said aqueous solution and the oxidant remain in said container. Method according to claim 1, characterized in that the pressure failures are caused by passing the oxidized aqueous solution through a metal orifice plate. 7. The method of claim 6, wherein hydroxy radicals are formed through the passage of said metal orifice plate in said solution. • i · * · 4 ♦ ♦ ♦ * • 44 • 4 99 • 9 9 4 4 4 · 44 44 The method of claim 1, wherein the flocculated phase is recovered from the aqueous solution. 9. The method of claim 1 wherein an electrode chamber is inserted into said reservoir to electrocoagulate said contaminants in said aqueous solution. 10. The method of claim 9, wherein a plurality of spaced apart electrodes contacting said solution are inserted into said reservoir. 11. The method of claim 9 wherein an electrical current is introduced into said granular electrically conductive material in said container to effect electrocoagulation in said electrode chamber. 12. The method of claim 9, wherein vortex flow is induced in said electrode chamber. 13. The method of claim 1 further comprising the step of pretreating said aqueous solution prior to treatment in said container. 14. The method of claim 13 wherein said pretreatment step comprises removing suspended matter from said solution. 15. A continuous process for separating contaminants from an aqueous solution comprising the steps of: providing an aqueous solution containing contaminants; providing a closed container having an inlet and an outlet, said inlet higher than said outlet; placing an electrode chamber in said reservoir to insert an electric field on said aqueous solution, introducing said aqueous solution into said reservoir; entraining an oxidant into said aqueous solution; maintaining the pressure in said reservoir higher than barometric to minimize the bubble size of said oxidant and thereby maximizing the surface area of the oxidant bubbles with said contaminants in said aqueous solution; oxidizing said contaminants and exposing said oxidant and flocculated said contaminants to said electric field; and selectively causing pressure drops outside said container to flocculate the remaining oxidized contaminants from said aqueous solution to a separate phase. 16. The method of claim 15 further comprising the step of pretreating said aqueous stream to remove insoluble matter from said aqueous solution. 17. The method of claim 15, wherein a countercurrent flow is produced between the entrained oxidant and said aqueous solution. 18. The method of claim 15, wherein vortexing in said container is induced to facilitate contact between said electrode chamber, said oxidant, and said aqueous solution. 19. The method of claim 15, further comprising the step of rotating said electrode chamber within said reservoir. 20. The method of claim 15, wherein a plurality of spaced apart electrodes are placed in said electrode chamber, each of said electrodes being insulated from the adjacent electrode. 21. The method of claim 15, wherein a plurality of spaced apart electrodes are placed in said electrode chamber to improve contact of said electrodes with said oxidant and said aqueous solution. 22. A method for separating contaminants from an aqueous solution, comprising the steps of: providing an aqueous solution containing contaminants; b. oxidizing said aqueous solution with an oxidant under controllable pressure higher than barometric to maintain said oxidant in solution; c. exposing said aqueous solution to electrocoagulation of contaminants in the electrode chamber; and You ♦ ·· ♦ · * · d. selectively inducing pressure failures to flocculate the coagulated and oxidized contaminants from said solution to a separate phase. 23. The method of claim 22 wherein in step c there is a plurality of electrode chambers wherein the treated water from one electrode chamber of said electrode chambers is water for an adjacent electrode chamber. 24. The method of claim 22, wherein at least one of the plurality of spaced-apart plate electrodes in the electrode chamber is formed by granular electrodes or a combination thereof with the plate electrodes. 25. The method of claim 1, further comprising the step of providing a plurality of containers arranged such that the outlet of one container of said containers is connected by a flow valve to an inlet of an adjacent container of said containers, and wherein the connection of said flow valves is adjustable for return. flushing of connected tanks. 26. The method of claim 15 further comprising the step of providing a plurality of containers arranged such that the outlet of one container of said containers is connected by a flow valve to an inlet of an adjacent container of said containers, and wherein the connection of said flow valves is adjustable for. backwashing of connected tanks. 27. The method of claim 22 further comprising the step of providing a plurality of containers arranged such that the outlet of one container of said containers is connected by a flow valve to an inlet of an adjacent container of said containers, and wherein the connection of said flow valves is adjustable for. backwashing of attached containers. 28. Apparatus for separating contaminants from an aqueous solution, comprising: an aqueous source containing contaminants; a closed pressurized container having an inlet and an outlet, said inlet being higher than said outlet and wherein said inlet is connected to said water source; means for introducing an oxidant into said pressurized container; s an electrode chamber situated in said reservoir for electrocoagulation of substances in said water source; means for supplying current to said electrode chamber; and means for selectively inducing hydrodynamic cavitation of the treated solution to flocculate the oxidized contaminants from said aqueous solution to a separate phase. 29. The apparatus of claim 28, wherein said container comprises at least one pressurized tank. 30. The apparatus of claim 28, wherein said reservoir resides in an underground formation. 31. The apparatus of claim 28 wherein said electrode chamber comprises a plurality of spaced apart electrodes. 32. The apparatus of claim 31, wherein said plurality of spaced apart electrodes are aligned. 33. The apparatus of claim 31, wherein said electrodes consist of individual plates of electrically conductive material. 34. The apparatus of claim 33, wherein said plates are rigid. 35. The apparatus of claim 33, wherein said individual plates have a permeable housing in which a granulated electrically conductive material is located or enclosed. 36. The apparatus of claim 31, wherein said electrode chamber has separate beads or granules of electrically conductive material between said spaced apart electrodes in said reservoir. 37. The apparatus of claim 33, wherein said plates have means for causing a swirling flow of said aqueous solution in said container. 38. The apparatus of claim 36, wherein said container has means for imparting movement to said beads or granules in said chamber. // / 0 / 'row 999 9 ♦ · 4 · 9 · 9 9 9 9 9 9 9 9 9 9 9 9 39. The apparatus of claim 28, wherein said device comprises a plurality of cartridges, each cartridge comprising an electrode chamber having said electrodes, and further wherein each cartridge has at least one of a plurality of solid plate electrodes, permeable electrodes comprising beads or electrically conductive granules. material, beads or granules between said electrodes in said reservoir or a combination thereof. 40. The apparatus of claim 28, wherein said container has an overpressure relief device for releasing excess pressure from said container. 41. The apparatus of claim 28 wherein said device comprises a liquid sensor operating at the level of an aqueous solution in said container and said means for introducing an oxidant into said container to release the oxidant into said container. 42. The apparatus of claim 28, wherein said means for selectively inducing hydrodynamic cavitation comprises a variable orifice valve for varying the outlet pressure at said outlet of said container. 43. The apparatus of claim 34, wherein said plates have apertures in a particular configuration. 44. The apparatus of claim 43, wherein said apertures cause a vortex flow of said aqueous solution. 45. The apparatus of claim 44, wherein said apertures are profiled to locate the concentration of electric field formed on said apertures. 46. The apparatus of claim 28, wherein said apparatus has a plurality of pressurized tanks with variable function, wherein the outlet of one tank of said tanks is connected to an inlet of an adjacent tank of said tanks. 47. The apparatus of claim 46, wherein said interconnected tanks have an interposed valve device therebetween for selecting operation to backfill the contents of the container.