METHOD AND APPARATUS FOR TREATING CONTAMINATED

MATERIAL

BACKGROUND OF THE INVENTION

1. Field of Invention

This invention relates to treating contaminated material and more particularly to methods and apparatus for decontaminating contaminated material through exposure to an electrical arc.

2. Description of Related Art

Air quality is an important consideration in most industrialized countries, since poor air quality has been shown to have deleterious effects on the health, comfort, and wellbeing of the population. Air quality is adversely affected by a number of factors, among which exhaust emissions from industry and transportation are some of the most severe pollutants. More recently, concern has been expressed over causes of airborne diseases, such as for example, avian influenza, swine-type influenzas, and Severe Acute Respiratory Syndrome (SARS).

Hospitals and airports are particularly vulnerable to airborne diseases due to the large number of potentially infected people passing through these facilities on a daily basis. Further, in the present political environment, concern has been expressed over bio-terrorism and there has been increasing effort to plan for such attacks by providing air-treatment systems for large buildings that would be effective in countering such an attack. Most micro-organisms that cause disease or produce toxins may be used as biological weapons, and these include viruses, bacteria, fungal spores, and toxins.

The eradication of contaminated material from air may be undertaken at source by subjecting emissions to treatment processes prior to venting to the atmosphere. Alternatively or additionally, dwellings and buildings may subject

heating and ventilation air to one or more processes in order to deliver clean, pathogen free air to occupants of the building. The vast majority of airborne pathogens are uniquely adapted for spreading in indoor environments since the absence of direct sunlight and other natural oxidants, along with controlled temperature and humidity for the comfort of occupants, serves to protect pathogens during their exposed and vulnerable period when they are transmitted from one person to the next.

There remains a need for improved methods and apparatus for treating contaminated material.

SUMMARY OF THE INVENTION

In accordance with one aspect of the invention there is provided a method for treating contaminated material. The method involves establishing an arc between first and second electrodes mounted in spaced apart relation in a treatment chamber by raising an electric potential between the first and second electrodes and sustaining the arc between the first and second electrodes. The method further involves causing the contaminated material to follow a helical path from the first electrode to the second electrode such that the contaminated material is exposed to the arc for a sufficient time to permit a desired quantity of contaminants in the contaminated material to become decontaminated by the exposure.

The method may involve forming a first low pressure region by causing the contaminated material to follow the helical path at a sufficiently high flow rate, the first low pressure region extending at least partway between the first and second electrodes such that the arc follows a path generally coincident with the first low pressure region.

Establishing the arc may involve forming the first low pressure region before raising the electric potential, thereby facilitating the establishing of the arc through the first low pressure region.

Sustaining the arc may involve controlling at least one of the electric potential and the flow rate such that the arc generally extends along the first low pressure region from the first electrode to a location partway between the first and second electrodes.

Causing the contaminated material to follow the helical path may involve causing first and second flow components in the contaminated material, the first flow component being generally parallel to a longitudinal axis passing through the first and second electrodes, the second flow component being angularly directed about the longitudinal axis.

Causing the first and second flow components may involve drawing the contaminated material through the treatment chamber.

Drawing the contaminated material through the treatment chamber may involve drawing the contaminated material into the treatment chamber over a plurality of vanes, each of the vanes being disposed angularly to the longitudinal axis.

Drawing the contaminated material through the treatment chamber may involve causing an impeller to rotate such that the contaminated material is drawn through the treatment chamber.

The method may involve causing a direction of rotation of the impeller to generally match a flow direction of the second flow component.

Causing the second flow component may involve receiving the contaminated material and causing the contaminated material to follow an inwardly spiraling flow path about the longitudinal axis.

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Causing the contaminated material to follow the inwardly spiraling flow path may involve causing the contaminated material to follow a generally logarithmically spiraling flow path about the longitudinal axis.

Causing the contaminated material to follow the inwardly spiraling flow path may involve drawing the contaminated material into the treatment chamber over a plurality of vanes, each of the vanes being disposed angularly to the longitudinal axis.

Causing the contaminated material to follow the inwardly spiraling flow path may involve causing the contaminated material to form a plurality of spiraling paths about the longitudinal axis, the plurality of spiraling paths causing a plurality of concentric alternating high and low pressure regions extending into the treatment chamber, each successive region surrounding a preceding region and being coaxially aligned with the longitudinal axis, the plurality of regions comprising at least a first low pressure region extending into the treatment chamber along the longitudinal axis and a first high pressure region surrounding the first low pressure region.

Establishing the arc may involve raising the electric potential to a first level and sustaining the arc may involve lowering the electric potential to a second level.

The first and second electrodes may be spaced apart by about 4 meters and lowering the electric potential to the second level may involve lowering the electric potential to between 2,400 and 3,300 kilovolts.

Lowering the electric potential to the second level may involve lowering the electric potential to a level such that the arc includes a current of between 0.7 and 1.2 milliamps.

The method may involve neutralizing charge imparted to the contaminated material by the exposure to the arc.

Neutralizing charge may involve causing the contaminated material to flow through a grid, the grid being held at a reference potential.

The method may involve introducing an oxidation agent into the treatment chamber at a position proximate the first electrode, the oxidation agent being operable to facilitate at least some decontamination of the contaminated material.

The method may involve controlling the introduction of the oxidation agent in response to a concentration of at least one constituent of the contaminated material, such that a desired quantity of the at least one constituent is decontaminated by the exposure to the arc.

The oxidation agent may include oxygen, and the arc may cause a portion of the oxygen to be converted into ozone, and the method may further involve controlling the introduction of the oxygen in response to a concentration of ozone proximate the second electrode, such that the concentration of ozone in decontaminated material exhausted from the treatment chamber meets a criterion.

The method may involve controlling at least one of the electric potential and a flow rate of the contaminated material in response to a concentration of at least one constituent of the contaminated material such that a desired quantity of the at least one constituent is decontaminated by the exposure to the arc.

The method may involve controlling at least one of the electric potential and a flow rate of the contaminated material in response to a temperature of the

contaminated material such that a desired quantity of the contaminated material becomes decontaminated by the exposure to the arc.

The method may involve receiving the decontaminated material at a water generation system for producing clean water by dehumidifying the decontaminated material.

In accordance with another aspect of the invention there is provided an apparatus for treating contaminated material. The apparatus includes a treatment chamber having an inlet for receiving the contaminated material and an outlet for discharging treated material. First and second electrodes are mounted in spaced apart relation in the treatment chamber such that an arc can be established and maintained between the electrodes when an electric potential between the electrodes is raised, the first electrode being generally proximate the inlet and the second electrode being generally proximate the outlet. The apparatus also includes a flow controller, operably configured to cause contaminated material received at the inlet to follow a generally helical path in the treatment chamber between the first electrode and the second electrode before being discharged through the outlet, such that the contaminated material is exposed to the arc for a sufficient time to permit a desired quantity of contaminants in the contaminated material to become decontaminated by the exposure, before being discharged as treated material from the outlet.

The flow controller may be operably configured to permit a flow rate that is sufficiently high to form a first low pressure region extending at least partway between the first and second electrodes such that the arc follows a path generally coincident with the first low pressure region.

The apparatus may include a potential generator operably configured to establish the arc after the first low pressure region has been formed.

The apparatus may include a controller operably configured to control at least one of the electric potential and the flow rate such that the arc generally extends along the first low pressure region from the first electrode to a location partway between the first and second electrodes.

The apparatus may include a flow generator, the flow generator being operably configured to cause a first flow component in the contaminated material, the first flow component being generally parallel to a longitudinal axis passing through the first and second electrodes.

The flow controller may be operably configured to cause a second flow component in the contaminated material, the second flow component being directed angularly about the longitudinal axis.

The flow controller may include a plurality of vanes, each of the vanes being disposed angularly to the longitudinal axis and operable to cause the second flow component in the contaminated material.

Each of the vanes may include a concave curved surface oriented towards the longitudinal axis, the vanes being operable to cause the contaminated material received at the inlet to follow an inwardly spiraling flow path about the longitudinal axis.

The concave curved surface may generally conform in shape to a portion of a logarithmic spiral, the curved surfaces being operable to cause the contaminated material to follow a generally logarithmically spiraling flow path about the longitudinal axis.

The flow controller may include an inlet chamber generally surrounding the longitudinal axis, the inlet being disposed at an outer periphery of the inlet chamber and in communication with the inlet chamber, and wherein the vanes

are disposed in the inlet chamber in spaced apart relation about the longitudinal axis, the inlet and the vanes being oriented to cause the contaminated material entering the inlet to form a plurality of spiraling paths about the longitudinal axis, the plurality of spiraling paths being operable to cause a plurality of concentric alternating high and low pressure regions extending into the treatment chamber, each successive region surrounding a preceding region and being coaxially aligned with the longitudinal axis, the plurality of regions comprising at least a first low pressure region extending into the treatment chamber along the longitudinal axis and a first high pressure region surrounding the first low pressure region.

The treatment chamber may include an opening for receiving the contaminated material, the opening being in communication with the flow controller, the inlet and the opening being spaced apart in relation to the longitudinal axis and wherein each of the vanes comprises a contaminated material receiving area and a contaminated material release area, the receiving area being longitudinally aligned with the inlet and the release area being in proximity to the opening.

The flow generator may include an impeller, the impeller being configured to rotate in a direction that enhances the second flow component.

The flow controller may include a plurality of vanes, each of the vanes having an axis disposed generally tangential to the longitudinal axis.

The apparatus may include a flow generator, the flow generator being operable to draw the contaminated material through the treatment chamber.

The flow generator may include a rotating impeller, the rotating impeller being configured to rotate in a direction that matches a flow direction of the second flow component.

The potential generator may be operably configured to raise the electric potential to a first level to establish the arc and to lower the electric potential to a second level to sustain the arc.

The first and second electrodes may be spaced apart by about 4 meters and the second level of the electric potential may include an electric potential between 2,400 and 3,300 kilovolts.

The apparatus may include a controller, the controller being operably configured to cause the potential generator to lower the electric potential to a second level such that the arc is sustained at a current of between 0.7 and 1.2 milliamps.

A charge may be imparted to the contaminated material by the exposure to the arc and the second electrode may include a neutralizer positioned in the helical path such that the contaminated material flows therethrough, the neutralizer being held at a reference potential and being operable to generally neutralize the charge on the contaminated material.

The neutralizer may include a conducting grid.

The apparatus may include a nozzle positioned proximate the first electrode, the nozzle being operable to introduce an oxidation agent into the treatment chamber, the oxidation agent being operable to facilitate at least some decontaminating of the contaminated material.

The apparatus may include a controller operably configured to control the introduction of the oxidation agent in response to a signal representing a concentration of at least one constituent of the contaminated material, such that a desired quantity of the at least one constituent is decontaminated by the exposure to the arc.

The oxidation agent may include oxygen, and the arc may cause a portion of the oxygen to be converted into ozone, and the apparatus may further include a controller operably configured to control the introduction of the oxygen in response to a signal representing a concentration of ozone proximate the second electrode, such that the concentration of ozone in decontaminated material exhausted from the treatment chamber meets a criterion.

The apparatus may include a concentration sensor positioned proximate the first electrode, the concentration sensor being operable to produce the signal representing the concentration of the at least one constituent of the contaminated material.

The apparatus may include a controller operably configured to control at least one of the electric potential and a flow rate of the contaminated material in response to a signal representing a concentration of at least one constituent of the contaminated material, such that a desired quantity of the at least one constituent is decontaminated by the exposure to the arc.

The apparatus may include a concentration sensor positioned proximate the second electrode, the concentration sensor being operable to produce the signal representing the concentration of the at least one constituent of the contaminated material.

The apparatus may include a controller operably configured to control at least one of the electric potential and a flow rate of the contaminated material in response to a temperature of the contaminated material such that a desired quantity of the contaminated material becomes decontaminated by the exposure to the arc.

In accordance with another aspect of the invention there is provided an apparatus for treating contaminated material. The apparatus includes a

treatment chamber having an inlet for receiving the contaminated material and an outlet for discharging treated material. First and second electrodes are mounted in spaced apart relation in the treatment chamber such that an arc can be established and maintained between the electrodes when an electric potential between the electrodes is raised. The first electrode is generally proximate the inlet and the second electrode is generally proximate the outlet. The apparatus also includes provisions for causing contaminated material received at the inlet to follow a generally helical path in the treatment chamber between the first electrode and the second electrode before being discharged through the outlet, such that the contaminated material is exposed to the arc for a sufficient time to permit a desired quantity of contaminants in the contaminated material to become decontaminated by the exposure before being discharged as treated material from the outlet.

The provisions for causing the contaminated material to follow the helical path may be operably configured to permit a flow rate that is sufficiently high to form a first low pressure region extending at least partway between the first and second electrodes such that the arc follows a path generally coincident with the first low pressure region.

The apparatus may include provisions for generating the electric potential, and the means for generating the electric potential may be configured to establish the arc after the first low pressure region has been formed.

The apparatus may include provisions for controlling at least one of the electric potential and the flow rate such that the arc generally extends along the first low pressure region from the first electrode to a location partway between the first and second electrodes.

The provisions for causing the contaminated material to follow the helical path may include provisions for causing first and second flow components in the

contaminated material, the first flow component being generally parallel to a longitudinal axis passing through the first and second electrodes, the second flow component being angularly directed about the longitudinal axis.

The provisions for causing the second flow component may include provisions for causing the contaminated material received at the inlet to follow an inwardly spiraling flow path about the longitudinal axis.

The provisions for causing the contaminated material to follow the inwardly spiraling flow path may include provisions for causing the contaminated material to follow a logarithmically spiraling flow path about the longitudinal axis.

The provisions for causing the contaminated material to follow the inwardly spiraling flow path may include a plurality of vanes, each of the vanes being disposed angularly to the longitudinal axis.

The vanes may include a concave surface, the concave surface being generally oriented towards the longitudinal axis, the vanes being operably configured to cause a first low pressure region extending into the treatment chamber and coaxially aligned with the longitudinal axis and a plurality of concentric alternating high and low pressure regions extending into the treatment chamber, each successive region surrounding a preceding region and being coaxially aligned with the longitudinal axis, the plurality of regions comprising at least a first low pressure region extending into the treatment chamber along the longitudinal axis and a first high pressure region surrounding the first low pressure region.

The provisions for causing the first flow component may include provisions for drawing the contaminated material through the treatment chamber.

The provisions for causing the second flow component may include a plurality of vanes, each of the vanes being disposed angularly to the longitudinal axis.

The provisions for drawing the contaminated material through the treatment chamber may include a flow generator having an inlet in communication with the outlet of the treatment chamber, such that the flow generator is operable to draw fluid from the treatment chamber through the outlet.

The flow generator may include an impeller, the impeller being configured to rotate in a direction that enhances the second flow component.

The apparatus may include provisions for generating the electric potential, and the provisions for generating the electric potential may include provisions for raising the electric potential to a first level to establish the arc and provisions for lowering the electric potential to a second level to sustain the arc.

The first and second electrodes may be spaced apart by about 4 meters and the provisions for lowering the electric potential to the second level may include provisions for lowering the electric potential to between 2,400 and 3,300 kilovolts.

The provisions for lowering the electric potential to the second level may be operably configured to lower the electric potential to a level such that the arc includes a current of between 0.7 and 1.2 milliamps.

The apparatus may include provisions for neutralizing charge imparted to the contaminated material by the exposure to the arc.

The apparatus may include provisions for introducing an oxidation agent into the treatment chamber, the provisions being positioned proximate the first electrode, the oxidation agent being operable to facilitate decontaminating of the contaminated material.

The apparatus may include provisions for controlling the introduction of the oxidation agent in response to a concentration of at least one constituent of the contaminated material, such that a desired quantity of the at least one constituent is decontaminated by the exposure to the arc.

The oxidation agent may include oxygen, and the arc may cause a portion of the oxygen to be converted into ozone, and the provisions for introducing may include provisions for controlling the introduction of the oxygen in response to a concentration of ozone proximate the second electrode, such that the concentration of ozone in decontaminated material exhausted from the treatment chamber meets a criterion.

The apparatus may include provisions for controlling at least one of the electric potential and a flow rate of the contaminated material in response to a concentration of at least one constituent of the contaminated material such that a desired quantity of the at least one constituent is decontaminated by the exposure to the arc.

The apparatus may include provisions for controlling at least one of the electric potential and a flow rate of the contaminated material in response to a temperature of the contaminated material such that a desired quantity of the contaminated material becomes decontaminated by the exposure to the arc.

In accordance with another aspect of the invention there is provided a system for producing clean water by dehumidifying a stream of gaseous decontaminated material, the system includes the apparatus above and further includes a water generation apparatus having an inlet for receiving the decontaminated material, the water generation apparatus being operable to dehumidifying the decontaminated material.

Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

In drawings which illustrate embodiments of the invention,

Figure 1 is a schematic diagram of a system for treating contaminated material according to a first embodiment of the invention;

Figure 2 is a perspective view of an embodiment of an apparatus for facilitating treating contaminated material for use in the system of Figure 1 ;

Figure 3 is a cross sectional view of a flow controller having a variable vane angle for use in the apparatus of Figure 2, taken along line 3-3, wherein the vane angle is of a first value;

Figure 4 is a further cross sectional view of the flow controller of Figure 3 wherein the vane angle is of a second value;

Figure 5 is a schematic diagram of an exemplary implementation of a system for treating contaminated material employing the apparatus of Figure 2;

Figure 6 is a schematic diagram of a circuit for implementing a potential generator for use in the system shown in Figure 5;

Figure 7 is a block diagram of a processor circuit for implementing a controller for the system shown in Figure 5;

Figure 8 is a flowchart of codes for directing the processor circuit of Figure 7 to implement one embodiment of the controller for the system shown in Figure 5;

Figure 9 is a detailed cross sectional view of a portion of an arc generated in the system shown in Figure 5;

Figure 10 is a flowchart of codes executed by the processor circuit of Figure 6 to implement another embodiment of the controller for the system shown in Figure 5;

Figure 11 is a perspective view of an embodiment of an electrode used in the apparatus shown in Figure 2;

Figure 12 is a perspective view of an alternate embodiment of a flow controller for use in the apparatus shown in Figure 2;

Figure 13 is a cross-sectional view of the flow controller shown in Figure 12, taken along the line 13-13 in Figure 12; and

Figure 14 is a cross-sectional view of the flow controller shown in Figure 12, taken along the line 14-14 in Figure 12; and

Figure 15 is a schematic view of a system for producing water according to a further embodiment of the invention.

DETAILED DESCRIPTION

Referring to Figure 1 , a system for treating contaminated material according to a first embodiment of the invention is shown generally at 10. The system includes a treatment apparatus 100 for treating the contaminated material and a flow generator 152 in communication with the treatment apparatus. The treatment apparatus 100 includes a treatment chamber 102 and a flow controller 110. The treatment chamber 102 includes first and second electrodes 104 and 106 between which an arc 105 is established. A potential generator 108 is connected to the electrodes 104 and 106 to establish the arc 105.

The flow controller 110 is operable to control the flow of contaminated material into the treatment chamber 102 so it can be exposed to the arc 105. The flow generator 152 is operable to draw the contaminated material into the treatment chamber 102 and to discharge material treated by the arc 105.

A controller 168 is in communication with the flow controller 110, the flow generator 152 and the potential generator 108, to cause the flow controller and flow generator to create a helical flow of material within the treatment chamber 102 while at the same time establishing the length of the arc 105 in a helical path between the electrodes 104 and 106. Because the arc follows a helical path, the arc is longer than a point-to-point distance between the first and second electrodes 104 and 106, and since the flow controller 110 and flow generator 152 cause the contaminated material to flow in a helical path, the contaminated material is exposed to the arc 105 for a longer period of time than it would be if the flow between the electrodes and the arc between the electrodes were linear. This increase in path length of the flow of the contaminated material and the length of the arc 105 increases the exposure time of the contaminated material to the arc sufficiently to permit contaminants in the contaminated material to become neutralized by exposure to the arc 105 before being discharged by the flow generator 152 as treated material.

The contaminated material may be entrained or otherwise included in an air stream fed into the treatment chamber 102 and may, for example, include microorganisms, allergens, mould, fungi, dust, pollen, or any other contaminants that may cause discomfort or disease to people, pets or livestock exposed to the air stream. Alternatively the contaminated material may be entrained or otherwise included in an emission stream from an industrial or other process, and the contaminants may include, for example, particulate, offensive and/ or noxious odours, volatile organic compounds (VOCs), and/or other contaminants.

Referring to Figure 2, the treatment apparatus 100 for facilitating decontamination of contaminated materials in accordance with one embodiment of the invention is shown generally at 100.

The apparatus 100 includes the treatment chamber 102, and the flow controller 110. The apparatus 100 also includes an inlet 112 for receiving the contaminated material and an outlet 114 for discharging treated material. The apparatus 100 also includes the first and second electrodes 104 and 106, which are mounted in spaced apart relation in the treatment chamber 102 such that the arc 105 can be established and maintained between the electrodes when an electric potential between the electrodes is raised. In one embodiment the treatment chamber 102 has a diameter of approximately 20 cm and a distance between the first electrode 104 and the second electrode 106 of approximately 4 m.

Flow Controller

Still referring to Figure 2, the flow controller 110 is operably configured to cause contaminated material received at the inlet 112 to follow a generally helical path in the treatment chamber 102 between the first electrode 104 and the second electrode 106 before being discharged through the outlet 114, such that the contaminated material is exposed to the arc 105 for a sufficient time to permit a desired quantity of contaminants in the contaminated material to become

decontaminated by the exposure, before being discharged as treated material from the outlet 114.

Contaminated material may be drawn into the inlet 112, through the treatment chamber 102 and through the outlet 114 by a flow generator such as the flow generator 152 shown in Figure 1. Alternatively, a blower (not shown) may be located upstream of the inlet 112 and the contaminated materials may be forced into the inlet 112, through the treatment chamber 102 and through the outlet 114.

In one embodiment, the flow controller 110 includes an inlet chamber 208 in communication with the inlet 112. The inlet chamber 208 is defined between an end wall 225, a wall 220 separating the flow controller 110 from the treatment chamber 102, and a wall 212 joining the end wall 225 to the wall 220. The wall 220 includes an opening 218 which is in communication with the treatment chamber 102.

A plurality of generally planar vanes 116 are located in the inlet chamber 208. The vanes 116 are disposed angularly to a longitudinal axis 118 of the treatment chamber 102. A rotatable outer ring 200 and an inner race 202 support the plurality of vanes 116. The outer ring 200 includes a plurality of openings 213, and the inner race 202 includes a plurality of openings 215.

The flow controller 110 is shown in cross-section in Figure 3. The outer ring 200 includes a plurality of hinges 204 for pivotally connecting the vanes 116 to the outer ring. The race 202 includes a plurality of slots 206, each slot for receiving a respective one of the plurality of vanes 116. In this embodiment a link 209 couples an actuator 207 to the outer ring 200, such that translation of the link 209 causes the ring 200 to rotate about the longitudinal axis 118 of the treatment chamber. Rotation of the ring 200 causes the vanes 116 to slide in the slots 206 while pivoting about the hinges 204, thus changing an angle "a"

between the vanes and respective lines drawn radialy intersecting a connection point between the vane and the race 202.

For example, referring to Figure 4, rotation of the outer ring 200 by the actuator 207 in a direction indicated by the arrow 201 , causes the vanes 116 to assume a second value of the angle a', which is greater than the value of the angle a shown in Figure 3. The actuator 207 facilitates varying of the angular disposition of the vanes 116 relative to the longitudinal axis 118, in response to a flow control signal (F1) received at an input 216 thereof.

An exemplary implementation of a system for treating contaminated material employing the apparatus shown in Figure 2 is shown generally at 150 in Figure 5. The apparatus 100 is shown and is as described above with reference to Figure 2.

Flow Generator

Referring to Figure 5, the flow generator 152 is mounted on the treatment chamber 102 and has an inlet 154 in communication with the outlet 114 of the treatment chamber 102 and also has an exhaust 156. The flow generator 152 further includes a motor 160 and an impeller 158, which are coupled by a shaft 162, to provide rotational drive to the impeller. The motor 160 has an input 161 for receiving a second flow control signal for controlling a rotational speed thereof. In operation, the impeller 158 draws decontaminated material into the inlet 154 from the treatment chamber 102 through the outlet 114, and discharges the decontaminated material through the exhaust 156.

Potential Generator

The system 150 also includes the potential generator 108 connected by wires to the electrodes 104 and 106. The potential generator 108 is operable to raise an electric potential between the first and second electrodes 104 and 106 to generate the arc 105. The potential generator 108 has an input 184 for

receiving a potential control signal, and generates and controls the electric potential between the electrodes 104 and 106 in response to the control signal received at the input 184.

Referring to Figure 6, in one embodiment the potential generator 108 may be implemented using a Tesla coil potential generator as shown. In this embodiment, the potential generator 108 includes a tank circuit 402, a rotary spark gap 404, and a high voltage transformer 406. The tank circuit 402 includes a tank capacitor 410 and primary coil 412, which are connected in parallel with the spark gap 404, and are supplied with energy from the high voltage transformer 406.

The rotary spark gap 404 includes a first point 426, a second point 428, and a rotary switching element 430. The rotary switching element 430 includes a pair of electrodes 432 and 434, which are connected to each other and located diametrically opposed on the rotary switching element. The rotary switching element 430 is driven by an induction motor (not shown) at a shaft speed of about 60rpm. The first point 426 and the second point 428 are positioned such that when the electrodes 432 and 434 are adjacent the first and second points respectively, there is a small gap of a few thousandths of an inch between each of the points and the electrodes 432 and 434.

The high voltage transformer 406 is connected to a mains supply via an autotransformer 408. The autotransformer 408 includes a coil 414, which is wound on a core 416, and an adjustable tap point 418, which may be set to provide a desired voltage at the tap point for supplying the high voltage transformer 406. In this embodiment the mains supply voltage is 240V AC, the mains supply frequency is 60Hz and the voltage at the tap point is varied between 105V and 220V AC. In other embodiments the mains supply voltage, frequency and the voltage at the tap point may vary depending on local energy supply characteristics.

The potential generator 108 also includes a secondary coil 420 which is air coupled to the primary coil 412. One end of the secondary coil 420 is connected to a reference potential terminal 422 and the other end is connected to a high voltage terminal 424.

The operation of the potential generator 108 is described with reference to Figure 6, in which the electrodes 432 and 434 of the rotary switching element 430 are initially located away from the first and second points 428 and 426 (i.e. the rotary spark gap 404 is open as shown in Figure 6.) In this embodiment, the tap point 418 of the autotransformer 408 is adjusted to provide a voltage V ₁ of approximately 21 ,000V AC. The voltage Vi has a sinusoidal waveform with a frequency matched to the mains supply frequency, in this case 60Hz. While the rotary spark gap 404 is open, the voltage V ₁ charges the tank capacitor 410.

The rotary switching element 430 is driven at a rotational velocity of 60 revolutions per second and is synchronized to the waveform of the voltage V ₁ , such that whenever V ₁ is at a peak positive or a peak negative voltage, the rotary spark gap is closed (i.e. the electrodes 432 and 434 of the rotary switching element 430 are aligned with the first and second points 428 and 426). Consequently, the rotary spark gap 404 closes each time the voltage V ₁ reaches a peak and discharges the tank capacitor 410, causing the tank circuit 402 resonate at a natural frequency determined by the capacitance of the tank capacitor 410 and the inductance of the primary coil 412. In this embodiment the resonant frequency is approximately 61 ,440 Hz but in general the resonant frequency depends on the inductance of the coils 412 and 420 and may be in the range of 30 kHz to 500 kHz.

The close proximity of the primary coil 412 and the secondary coil 420 causes magnetic coupling between the coils and the resonant current flowing in the primary coil causes a current to be induced in the secondary coil. The secondary coil 420 is constructed such that the natural frequency due to the

inductance of the coil and the self capacitance of the coil closely matches the natural frequency of the primary tank circuit 402 (i.e. 61 ,440 Hz). Advantageously, the rotary spark gap 404 may be configured such that once a significant portion of energy in the primary tank circuit 402 has been transferred to the secondary coil 420, the rotary spark gap opens and the next charging cycle of the tank capacitor 410 commences. In this embodiment, the energy coupled into the secondary coil 420 increases the electric potential at the high voltage terminal 424 to approximately 3,000,000 V AC (at a frequency of 61 ,440 Hz). Advantageously, the autotransformer 418 allows the potential generator to be set to a first level to establish the arc 105, and then lowered to a second level to sustain the arc.

Sensors

Referring back to Figure 5, the system 150 may optionally include a first concentration sensor 164, positioned in proximity to the first electrode 104, to produce a first concentration signal representing a concentration of a constituent of the contaminated material entering the treatment chamber 102.

The system 150 may also optionally include a second concentration sensor 166 which may be positioned in proximity to the second electrode 106. The second concentration sensor 166 may be used to produce a second concentration signal representing a concentration of at least one constituent of the decontaminated material discharged from the treatment chamber 102 through the outlet 114.

The system 150 may also optionally include an oxidation agent reservoir 176, a control valve 174, and a nozzle 172. The nozzle 172 may be positioned in proximity to the first electrode 104 in communication with the treatment chamber 102. The oxidation agent reservoir 176 is in communication with the nozzle 172 via the control valve 174. The control valve 174 has an input 177 for receiving a control valve signal for controlling introduction of an oxidation agent from the

reservoir 176 into the treatment chamber 102, to enhance the efficacy of the treatment.

The system 150 may further include a temperature sensor 165, positioned in proximity to the first electrode 104. The temperature sensor 165 may be used to produce a temperature signal representing a temperature of the contaminated material entering the treatment chamber 102.

System Controller

Still referring to Figure 5, the system 150 also includes the controller 168. The controller 168 has an input 169 for receiving the first concentration signal, an input 170 for receiving the second concentration signal, and an input 171 for receiving the temperature signal. The controller 168 also has an output 178 for producing the control valve signal to control introduction of the oxidation agent through the nozzle 172, and an output 180 for producing the potential control signal. The controller 168 also has an output 183 for producing the first flow control signal, and an output 182 for producing the second flow control signal. The output 182 is in communication with the input 161 of the motor 160 for controlling the rotational speed of the impeller 158. The output 183 is in communication with the input 216 of the actuator 207 (shown in Figure 3) for controlling the flow controller 110, as described in greater detail later.

Referring to Figure 7, in one embodiment the controller 168 (shown in Figure 5) may be implemented using the processor circuit shown generally at 250. The processor circuit 250 includes a microprocessor 252, random access memory (RAM) 254, program memory (ROM) 256, an input/output interface (I/O) 258, and a media interface 260, all in communication with the microprocessor 252. The RAM 254 and the ROM 256 may, of course, be integrated within the microprocessor 252. The I/O 258 includes the inputs 169 and 170 for receiving the first and second concentration signals, and the input 171 for receiving the temperature signal. The I/O 258 includes the outputs 178, 180, 182, and 183 for

producing the oxidization agent control signal, the potential control signal, and the first and second flow control signals respectively.

The media interface 260 facilitates loading program codes into the ROM 256 or the RAM 254 from a computer readable medium for directing the processor circuit 250 to carry out functions according to a method associated with one aspect of the invention. The computer readable medium may include a CD ROM 262, which is encoded with the program codes. Alternatively the computer readable medium may include a wired or wireless internet connection 264, and the codes may be encoded in a computer readable signal which is received by the processor circuit 250 through a network connection, for example.

Operation

The operation of the system 150 is described with reference to Figures 3 - 5, 8 and 9. Referring to Figure 8, a flowchart depicting blocks of code for causing the processor circuit 250 to implement the controller 168 is shown generally at 300. The blocks of code generally cause the controller 168 to interact with various components of the system to effect a process for treating contaminated material, in accordance with one aspect of the invention. The blocks generally represent codes that may be read from the computer readable medium 262 or 264 and stored in the RAM 254 or the ROM 256 for directing the microprocessor 252 to control the system 150 shown in Figure 5. The actual code to implement each block may be written in any suitable programming language such as C, C++, and/or assembly code, for example.

In this embodiment, the process begins with a first block of codes 302, which directs the microprocessor 252 to cause the I/O 258 to produce the second flow control signal, causing the motor 160 of the flow generator 152 to be activated at an initial rotational speed. Block 304 then directs the microprocessor 252 to cause the I/O 258 to produce the first flow control signal which causes the angle of the vanes 116 to be adjusted to an initial orientation. Then block 306 directs

the microprocessor 252 to set the potential generator 108 to a first level to strike the arc 105 and then block 308 directs the processor to set the potential generator to a second potential level to sustain the arc. Block 310 then directs the processor to admit contaminated material into the inlet 112. This last activity may be automatically performed by the processor or may be manually controlled by opening a valve or chute of a system from which contaminated material is obtained.

Generating Flow components

When the flow generator 152 is activated at block 302, it causes a first flow component in the contaminated material. The first flow component is generally aligned with the longitudinal axis 118 and directed from the first electrode 104 to the second electrode 106. Referring to Figure 3, the first flow component draws contaminated material 210 into the inlet chamber 208, through the inlet 112. The contaminated material 210 is prevented from directly entering the treatment chamber 102 by the wall 220 (shown in Figure 2), and is channelled through the openings 213, over the vanes 116, and through the openings 215 in the race 202. The vanes 116 cause a second flow component in the contaminated material which is angularly directed about the longitudinal axis 118 in a direction indicated by the arrow 226. The contaminated material 210 is then channelled through the opening 218 (shown in Figure 2) and into the treatment chamber 102.

A magnitude of the second flow component may be varied by changing the angular disposition of the vanes 116. For example the magnitude of the second flow component will be greater for the value of the vane angle a shown in Figure 4, than for the vane angle a shown in Figure 3.

Referring back to Figure 8, block 304 directs the processor to set the vane angle to a suitable value such that the combined first and second flow components will establish a helical flow of fluid in the treatment chamber that will ultimately cause

the arc and contaminated material to follow a helical path 190 (shown in Figure 5) through the treatment chamber 102.

Rotation of the impeller 158 generates a low magnitude angularly directed flow component in the treatment chamber 102. Advantageously, in one embodiment the flow generator 152 may be configured such that a direction of rotation of the impeller 158 matches a flow direction of the second flow component, such that the low magnitude flow component enhances the second flow component.

In one embodiment where the treatment chamber 102 has a diameter of approximately 20 cm and a distance between the first electrode 104 and the second electrode 106 of approximately 4 m, contaminated material is drawn through the treatment chamber at a flow rate of approximately 34 cubic meters per minute.

Causing first low pressure region

Referring to Figure 5, at high flow rates the fluid flow is forced outwardly towards the wall 192 of the treatment chamber 102 by the helical motion along the path 190 due to inertia of the contaminated materials. This causes contaminated material near the wall 192 to have a pressure that is slightly higher than atmospheric pressure. Similarly the contaminated material near the longitudinal axis 118 has a pressure that is slightly lower than atmospheric pressure, thus forming a first low pressure region between the first and second electrodes 104 and 106.

Establishing & sustaining arc

Referring back to Figure 8, block 306 directs the microprocessor 252 to cause the I/O 258 to produce a potential control signal which causes the potential generator 108 to raise the electric potential between the first and second electrodes 104 and 106 to a first level sufficient to establish the arc 105 between the electrodes. Advantageously, the first low pressure region facilitates

establishment of the arc 105, since fluid at lower pressures is more easily ionized by the electric potential than fluid at higher pressures. The first low pressure region thus operates to guide and confine the arc 105 between the first and second electrodes 104 and 106.

In one embodiment where the treatment chamber 102 has a diameter of approximately 20 cm and a distance between the first electrode 104 and the second electrode 106 of approximately 4 m, an appropriate electric potential for operation in this embodiment may include an electric potential of between 2,400 and 3,300 kilovolts at a frequency of 61440 Hz.

A portion of the arc 105 is shown in greater detail in Figure 9. The first low pressure region is shown in broken lines at 196, and follows a generally helical form. The arc 105 generally follows the helical first low pressure region 196 and further includes outwardly reaching arc portions 350, which extend radially in all directions from the arc 105 towards the wall 192 of the treatment chamber 102. Advantageously, the helical path of the arc 105 increases a path length of the arc between the first and second electrodes 104 and 106, thus increasing the arc exposure time of the contaminated material drawn through the treatment chamber 102. The outwardly reaching arc portions 350 occur due to a portion of an electrical current associated with the arc 105, coupling into stray capacitances between the first electrode 104 and the contaminated material in the treatment chamber 102. Advantageously the outwardly reaching arc portions 350 also increase exposure of the contaminated material to the arc 105.

Referring back to Figure 8, Block 308 then directs the microprocessor 252 to cause the I/O 258 to produce a potential control signal which causes the potential generator 108 to lower the electric potential to a second level sufficient to sustain the arc 105. In one embodiment, the second level of the electric potential is selected such that the arc 105 generally extends along the first low

pressure region 196 from the first electrode 104 to a location 352, which is just short of the second electrode 106 (as best shown in Figure 9). In this embodiment the electric current associated with the arc 105 is substantially coupled into stray capacitances, and negligible current flows through the second electrode 106. Advantageously, in this embodiment the electric current in the arc 105 is minimised, while still maintaining exposure between the arc and the contaminated material throughout a substantial portion of the treatment chamber 102. Higher electric currents will generally result in excess thermal heating of the contaminated material, thus unnecessarily increasing a power consumption of the system 150. Furthermore, higher electric potential levels required to sustain higher currents may result in outwardly reaching arc portions 350 arcing over to the wall 192 of the treatment chamber 102, which may result in a shortening of the arc 105, thus causing a corresponding reduction in exposure time of the contaminated material. Once a basic helical fluid flow and helically shaped arc are established in the treatment chamber the action shown at 310 in Figure 8 can be taken, to permit contaminated material to be admitted into the inlet 112 and follow the helical path while being exposed to the arc for treatment.

Controlling operation based on sensor input

Referring to Figure 5, the first concentration sensor 164 may be configured to produce a first concentration signal which is representative of one or more of a variety of contaminants such as, for example, carbon monoxide, nitrogen oxides (NOx), sulphur oxides (SOx) etc. in the contaminated material. By measuring the concentration of certain target contaminants proximate the first electrode 104, the system 150 may be configured such that the target contaminants are effectively treated. For example, the potential level, the rotational speed of the motor 160, and/or the angular disposition of the vanes 116 (as shown in Figures 3 and 4), may be varied in response to the first concentration signal to change operating conditions of the system 150, thus increasing or reducing decontamination of the contaminated material.

An amount of oxidizing agent introduced from the reservoir 176 may also be varied in response to the first concentration signal by varying the control valve signal to the control valve 174. For example, an amount of oxygen introduced via the nozzle 172 may be increased in response to an increasing concentration of carbon monoxide in the contaminated material. Oxygen is effective in converting carbon monoxide into carbon dioxide, which is a less deleterious emission.

The second concentration sensor 166 may be configured to produce a second concentration signal which is representative of one or more of a variety of constituents in the decontaminated material stream proximate the second electrode 106. Such constituents may include, but are not limited to ozone, carbon monoxide, and carbon dioxide. For example, where the second concentration signal is representative of a concentration of carbon monoxide, a concentration above a certain level may indicate that an insufficient amount of oxygen is being introduced from the oxidation agent reservoir 176, in which case the amount of oxygen introduced into the treatment chamber 102 may be increased by causing the processor 252 to vary the control valve signal provided to the control valve 174.

In one embodiment the temperature signal from the temperature sensor 165 is also used as an input to the controller 168 to control the system 150. For example, the electric potential level and/or the magnitude of the first and second flow components may be varied in response to changes in the temperature of the contaminated material. Changing the electric potential level and/or the angular disposition of the vanes 116 changes the shape and extent of the arc 105 and outwardly reaching portions 350, thus altering the exposure of the arc to the contaminated material. Reducing the contaminated material flow rate extends an exposure time, but may also change the shape and extent of the arc.

The further operation of the system 150 is described with reference to Figure 10, in which a flowchart depicting blocks of code for causing the processor circuit 250 to implement the further functions of the controller 168 is shown at 320. A first block of codes 322 directs the microprocessor 252 to receive the first concentration signal, the second concentration signal, and the temperature signal.

Block 324 directs the microprocessor 252 to calculate new control values for the electric potential control signal, the flow control signals, and the oxidation agent control signal. The calculation may be based on formulae or tables, which are derived from theoretical considerations or empirically determined for a particular configuration of the system 150.

Block 326 directs the microprocessor 252 to regulate the flow signals by producing first and second flow control signals at the outputs 182 and 183 respectively, in accordance with the calculated new control values, thus changing the rotational speed of the impeller 158 and/or the angular disposition of the vanes 116 of the flow controller 110.

Block 328 directs the microprocessor 252 to regulate the electric potential by producing a potential control signal at the output 180, in accordance with the calculated new control values.

Block 330 directs the microprocessor 252 to regulate the amount of oxidation agent introduced via the nozzle 172, by producing a control valve signal at the output 178, in accordance with the calculated new control values.

The microprocessor 252 is then directed back to block 322, for a further iteration of the process 320. Advantageously, by continually repeating the process 320, the system 150 may be continuously configured to account for changes in the composition of the contaminated material and other environmental effects.

Treatment effects

Referring to Figures 5 and 9, the arc 105 treats contaminated material through rapid transfer of electrons to the contaminants in the material exposed to the arc. The helical path 190, which is followed by the contaminated material, and the outwardly reaching arc portions 350 cause exposure to the arc 105 to be prolonged. Advantageously the arc 105 also generates ozone and ultraviolet light (UV). The treating provided by the arc 105 may occur due to a plurality of effects including but not limited to ionization, ozonation, ultraviolet light exposure, and ultrasonic sound exposure.

The treatment of contaminated material through ionization by transfer of electrons has the potential to reduce the concentration of micro-organisms and other contaminants. Contaminated material having small molecules may be ionized by exposure to the arc 105, rendering the molecules benign and causing the small molecules to agglomerate, thus forming larger molecules. Large benign molecules may be more easily removed by subsequent processes. For example, very small dust particles may carry micro-organisms and agglomeration of these dust particles facilitates their removal in a subsequent filtration process.

Contaminated material may be oxidized by oxidation agents such as oxygen and ozone. Ozone is a very effective oxidizing agent and may participate in redox reactions with contaminated material to effectively neutralize their deleterious effects. Ozonization is believed to be effective in treating organic compounds such as viral nucleic acids and bacteria.

Under exposure to the arc 105, oxygen will be continuously converted into ozone. Additionally, should there be insufficient oxygen entrained in the contaminated material, additional oxygen may be introduced into the treatment chamber 102 through the nozzle 172. However, ozone is a highly corrosive, poisonous substance and a common pollutant, and therefore excessive ozone

generation is undesirable. In one embodiment the second concentration signal is representative of a concentration of ozone in the decontaminated material, and the oxidation agent control valve 174 is controlled to introduce an amount of oxygen, such that the concentration of ozone in the decontaminated material meets an accepted criterion for ozone emissions. Advantageously, by controlling the amount of introduced oxygen, ozone generation may be tailored to the contaminated material such that sufficient, but not excess ozone is generated for oxidizing contaminants to decontaminate the contaminated material.

As mentioned above, the arc 105 also generates UV light, which possesses an amount and wavelength of energy just sufficient to break many organic molecular bonds. Micro-organisms are uniquely vulnerable to the effects of UV light due to resonance of their molecular structures under exposure to UV light wavelengths.

Advantageously, the arc 105 may also generate ultrasonic sound, which is capable of atomizing water droplets, and may also atomize bacteria, viruses, and other organisms, which contain, or are contained in water.

Second Electrode

Referring to Figure 11 , an alternative embodiment of the second electrode 106 is shown generally at 157. In this embodiment, the second electrode 106 includes a charge neutralizing grid 380 positioned near the outlet 114 of the treatment chamber 102. The grid 380 acts as the second electrode and is connected to a terminal 382. The terminal is held at a reference potential, which in this embodiment is a ground potential. Exposure to the arc 105 may result in decontaminated material having a substantial charge when reaching the outlet 114 of the treatment chamber 102. The charge may interfere with the effective operation of further processing steps such as filtration by electrostatic

precipitation. The grid 380 functions to neutralize the charge on the decontaminated material, prior to being discharged through the outlet 114.

Flow controller

An alternative embodiment of the flow controller is shown generally at 500 in Figure 12. The flow controller 500 is in communication with the opening 218 of the treatment chamber 102 and replaces the flow controller 110 shown in Figure 2.

The flow controller 500 includes an inlet 502 and an inlet chamber 504, the inlet chamber being in communication with the inlet for receiving contaminated material. The flow controller 500 includes a plurality of vanes 506, each vane having a concave surface 508 oriented towards a longitudinal axis 510 of the treatment chamber 102. Each vane 506 also includes a contaminated material receiving area 512 and a contaminated material release area 514, the release area being proximate the opening 218 of the treatment chamber 102.

In general the vanes 506 receive contaminated material from the inlet chamber 504 at the receiving area 512, and guide the contaminated material to the release area 514 such that the contaminated material generally follows an inwardly spiraling path between the inlet 502 and opening 218.

The flow controller 500 is shown in cross sectional detail in Figure 13. Referring to Figure 13, the receiving area 512 is generally longitudinally aligned with the inlet 502 (along the longitudinal axis 510) and the release area 514 is in proximity to the opening 218 of the treatment chamber 102. The flow controller 500 further includes a deflector 540 and a guide 542, the deflector and guide having generally complementary frusto-conical shapes. The deflector 540 and the guide 542 operate to longitudinally constrain the contaminated material while flowing over the vanes 506.

Referring back to Figure 12, in one embodiment, the concave surfaces 508 of the vanes 506 generally conform in shape to a first portion of a logarithmic spiral. The inlet chamber 504 also includes a wall 516 that may generally conform in shape to a second portion of a logarithmic spiral, the first and second portions of the logarithmic spiral generally being complementary and operable to cause the contaminated material to flow in a generally logarithmically spiraling path from the inlet 502 to the opening 218.

In one embodiment, the flow controller 500 shown in Figure 12 is used in place of the flow controller 110 in the treatment apparatus 100 shown in Figure 1 and Figure 2. The operation of the flow controller 500 is described in reference to Figures 13 - 14 and Figure 5. Referring to Figure 12, when the flow generator 152 (shown in Figure 5) is activated, thus causing the first flow component to be generated along the longitudinal axis, contaminated material is drawn into the inlet chamber 504 of the flow controller 500 through the inlet 502. The wall 516 of the flow controller 500 causes the contaminated materials to generally follow a spiral path from the inlet 502 to the receiving area 512 of each of the vanes 506.

Referring to Figure 14, a first portion of the contaminated material, drawn from the inlet 502 generally along the path 560 is received at the receiving area 561 of the vane 562, and a second portion of the contaminated material drawn along the path 564, is received at the receiving area 567 of the vane 568. In this embodiment the paths 562 and 564, and other spiral paths generally converge to form a first high pressure region 570.

Similarly a third portion of the contaminated material drawn from the inlet 502 generally along the path 572, is received at the receiving area 573 of the vane 574 and a fourth portion of the contaminated material drawn along the path 576 is received at the receiving area 577 of the vane 578. The paths 572 and 576,

and other spiral paths, generally converge to form a second high pressure region 580.

The first high pressure region 570 and second high pressure region 580 are generally coaxially aligned with the axis 510 and a first low pressure region 582 is formed inside the first high pressure region 570. Similarly, a second low pressure region 584 is formed between the first and second high pressure regions 570 and 580.

Referring back to Figure 13, the first flow component along the longitudinal axis 510 causes the first low pressure region 582 to extend into the treatment chamber 102. The first low pressure region 582 is further supported along the longitudinal axis 510 by outward inertia of the contaminated material due to the helical motion 544 as described above. In this embodiment, the inwardly spiraling flow through the flow controller 500 generates an intensified first low pressure region 582, thus further facilitating establishing of the arc 105.

The alternating high and low pressure regions 570, 584 and 580 also extend into the treatment chamber 102, aligned generally coaxially along the longitudinal axis 510. In general, it is desirable that the arc 105 reach from the first electrode 104 almost to the second electrode (not shown in Figure 13) and that the arc not terminate to the wall 192 of the treatment chamber 102, as this would shorten the arc and reduce the exposure of the contaminated material thereto. Advantageously, in this embodiment, the alternating high and low pressure regions 582, 570, 584 and 580 operate to further confine the outwardly reaching arc portions 350, thus preventing the arc 105 from arcing over to the wall 192 of the treatment chamber 102.

In an alternative embodiment, the first and second flow components may be generated by forcing contaminated material through the inlet 502, over the vanes 506 and through the treatment chamber 102.

While, two high pressure regions 582 and 584 have been shown in Figure 13 and Figure 14, in general the vanes 506 may be shaped and aligned to generate a plurality of alternating low and high pressure regions for confining the arc 105.

Water Generation system

Referring to Figure 15, the system 150 shown in Figure 2, is exemplified for use in a water generation system shown generally at 390. The water generation system 390 includes a unit 394, which is operable to produce water by dehumidifying the air stream. An example of a suitable unit 394 is the Vapaire unit distributed in the United States by Vapaire, of Salt Lake City, Utah. The unit 394 may include several filtration and treatment stages, some of which may be rendered redundant by the use of the system 150, in which case the unit may be adapted or configured to alter or eliminate certain process steps.

The system 150 is configured to receive the air stream at the inlet 112. The air stream received at the inlet 112 may be subjected to one or more optional preceding filtration processes shown at 392, which may include, for example High-Efficiency Particulate Air (HEPA) filtration. In this case an air stream 393 is received and subjected to the process 392, prior to being channelled to the inlet 112. A decontaminated air stream is discharged through the exhaust 156 which feeds the water generation system 394.

Advantageously, contaminated material is removed from the air stream prior to dehumidifying, since the removal of some contaminants from water may be more difficult than removing the same contaminants from the air stream from which the water is produced.

Suitable dimensions for the treatment chamber 102 of the system 150, for the application in the system 390 may include a treatment chamber diameter of approximately 10 cm, a distance between the first electrode and the second electrode of approximately 0.6 m. A suitable flow rate would be approximately 3

cubic meters per minute. An appropriate electric potential for operation in this embodiment may be between 240 and 330 kilovolts at a frequency of 290 kHz, for example.

While specific embodiments of the invention have been described and illustrated, such embodiments should be considered illustrative of the invention only and not as limiting the invention as construed in accordance with the accompanying claims.