SYSTEM FOR WATER DISINFECTION USING ELECTROPORATION

Abstract

A system for water disinfection by means of electroporation, comprising a reactor (1) composed of a plurality of electrodes that form an electrolytic cell, where they act as a plurality of anodes (2) and cathodes (3); a circuit that allows the water to be confined within the electrolytic cell and to flow through it between the water inlet point into the cell (4) and the water outlet point (5); a pump (6) used to propel the water through the reactor; at least one direct current source (7), which is connected to the reactor (1); and at least one device for process control (PLC) (8). The system produces the irreversible electroporation of bacterial membrane by applying specific electric potentials that alter the transmembrane potential and cause the oxidation of the exposed chemical groups in membrane proteins.

Claims

1. A system for water disinfection by means of electroporation, comprising a reactor (1) composed of a plurality of electrodes that form an electrolytic cell, where they act as a plurality of anodes (2) and cathodes (3); a circuit for water flow, which allows water to flow between the inlet point into the cell (4) and the outlet point (5); a pump (6) used to propel the water through the circuit; a direct current source (7), which is connected to the reactor (1); and a device to control the process (8).

2. A system for water disinfection by means of electroporation according to claim 1, wherein the period of time for water flow between the anodes (2) and cathodes (3) inside the reactor (1), from the time the water enters the cell until it leaves, is equal or superior to 0.576 s.

3. A system for water disinfection by means of electroporation according to claim 1, wherein the current density applied to the anodes (2) ranges from 100 to 300 A/m.sup.2.

4. A system for water disinfection by means of electroporation according to claim 1, wherein the induced electric potential must be equal to or greater than 0.2 V.

5. A system for water disinfection by means of electroporation according to claim 1, wherein the electrodes used on the reactor (1) are made of titanium, ruthenium, iridium or other metals or metal alloys, or are electrodes made of any of these metals or metal alloys doped with metal oxides or a mixture of metal oxides.

6. A system for water disinfection by means of electroporation according to claim 1, wherein the electrodes are composed of ceramic materials and ceramic materials that are doped with metals such as titanium, ruthenium or iridium.

7. A system for water disinfection by means of electroporation according to claim 1, wherein the electrodes present a mixed metal/organic or organic/ceramic composition.

8. A system for water disinfection by means of electroporation in accordance to claim 1, including diamond electrodes and metal-doped diamond electrodes, which are doped with metals such as titanium, ruthenium or iridium.

9. A system for water disinfection by means of electroporation according to claim 1, wherein the cell consists of a sequence of alternate anodes (2) and cathodes (3).

10. A system for water disinfection by means of electroporation according to claim 1, wherein the cell is exclusively composed of activatable anodes (2) that operate as a cathode (3) when they are inactive or as an anode (2) when they are active.

11. A system for water disinfection by means of electroporation in accordance to claim 1, wherein the cell is made up of a system of bipolar plates that comprise a side acting as an anode (2) and another side acting as a cathode (3), both induced by the flow of current through them.

12. A system for water disinfection by means of electroporation according to claim 1, wherein the electric current is continuously or intermittently applied, using pulsed current, in accordance to current activation/deactivation sequences.

Description

DESCRIPTION OF THE DRAWINGS

[0024] With the aim of complementing the present description and contributing to a better understanding of the invention characteristics, according to a preferable example of the invention embodiment, a set of drawings is attached to this description as an integral part of it, including the following information by way of illustration and not limitation:

[0025] FIG. 1 is a schematic drawing of the system comprising the reactor, which is embedded in the water circuit and connected to the electric circuit.

[0026] FIG. 2 is a schematic view of each part of the reactor, including the water inlet and outlet, and the electrolytic cell with its electrodes.

[0027] FIG. 3 is an internal view of the cell where the electroporation process is accomplished.

DESCRIPTION OF A PREFERABLE EMBODIMENT OF THE INVENTION

[0028] The system of the present embodiment consists of a reactor (1) comprising a plurality of electrodes that form a filter press type electrolytic cell, where the desired number of anodes (2) and cathodes (3) are alternated, and the electrodes may be made of any material and produced by any manufacturing process, provided that they allow the required electric potentials to be achieved.

[0029] An electrolyte composed of water and the dissolved substances in it.

[0030] A circuit for water flow, which allows water to be confined to the electrolytic cell and to move through it, between the inlet point of water into the cell (4) and the outlet point (5), forcing the water to flow between anodes (2) and cathodes (3), and assuring this flow from the moment it enters the cell until it leaves. Thus a known transit time of water is assured between both electrodes, being this time equal to or greater than 0.576 s in order to achieve disinfection rate Log 3.

[0031] A system promoting water flow by means of an impulse pump (6) or the gravity effect.

[0032] At least one source of direct current (7) allowing to guarantee the desired current density in the anode(s); this density will depend on the existing anode type, water conductivity and cell geometry, together with the potential of the electrode to be used.

[0033] At least one device for process control (PLC) (8), which allows to opportunely apply the required voltage in order to obtain the specified work intensity, considering that water conductivity and, as a result, system conductivity may vary over time and a stable current density must be kept at the anode(s).

[0034] Infected water is pumped from a reservoir (9) using a pump (6) and propelled to the inlet (4) of the reactor (1), considering that the reactor (1), as explained above, consists of a plurality of anodes (2) and cathodes (3) forming an electrolytic cell; disinfected water leaves the reactor (1) through an outlet (5). The reactor (1) is connected to a circuit actuated by a direct current source (7) and controlled by a PLC system (8).

[0035] The current density applied to the anodes (2) ranges from 100 to 300 A/m.sup.2.

[0036] The induced electric potential must be equal or superior to 0.2 V. The electric field to which bacteria are subjected must have a maximum length of 3 mm. The electric field is applied for at least 0.576 s to achieve disinfection rate Log 3.

[0037] The use of fields with a lower potential, provided that they are greater than 0.1 V, may bring the same results by means of long duration pulses (100 ms) and long duration intervals (100 ms).

[0038] The electrodes used may be composed of any material and derive from any manufacturing procedure, provided that they allow the designated potentials to be applied. Examples of electrode types that may be used include, but are not limited to:

[0039] Electrodes made of titanium, ruthenium, iridium or other metals or metal alloys, or electrodes of any of these metals or metal alloys doped with metal oxides or a mixture of metal oxides (for instance, titanium, ruthenium, iridium, boron, caesium or other metals);

[0040] Electrodes made of ceramic materials and electrodes made of ceramic materials doped with any of the aforementioned metals;

[0041] Electrodes with mixed metal/organic or organic/ceramic composition;

[0042] Diamond electrodes and metal-doped diamond electrodes;

[0043] Any type of electrode that is capable of conducting electric current with the required densities and generating the desired electrode potentials.

[0044] The cell may be constituted by a sequence of alternate anodes (2) and cathodes (3); or only by activatable anodes (2), which act as a cathode (3) when they are inactive or as an anode (2) when they are active, in accordance with connections, wherein the system includes a polarity reversal allowing the alternating anode activation of the electrodes; or by a system composed of bipolar plates comprising a side acting as an anode (2) and another side acting as a cathode (3), both induced by the flow of current through them, whether or not this is combined with any of the aforementioned systems.

[0045] The electrolytic cell and its enclosure form a reactor (1) that may be:

[0046] A closed reactor when the water is fully confined inside it, with only an inlet point (4) and an outlet point (5) in the reactor, flowing the water through it by means of the pressure provided by a pump (6) or by the water circuit.

[0047] An open channel reactor (1) with a water inlet (4) and a water outlet (5) located at different heights, which may be a physically open system, wherein the water flow in the desired direction is achieved by means of the gravity effect on the water mass.

[0048] The electric current may be continuously or intermittently applied, using pulsed current, according to current activation/deactivation sequences.

[0049] Having sufficiently described the nature of the invention, as well as the form of practical embodiment, it should be placed on record that the previously indicated provisions represented in the attached drawings can have detail modifications as long as they do not alter the fundamental principles, which are included in the paragraphs above and summarised in the following claims.