Pulsed electric field for drinking water disinfection

Patent metadata

Field	Value
Publication number	US-2016280569-A1
Application number	US-201314442588-A
Country	US
Kind code	A1
Filing date	Nov 21, 2013
Priority date	Nov 21, 2012
Publication date	Sep 29, 2016
Grant date	—

Abstract

The present disclosure relates to a micro-mini pulsed electric field (PEF) device for point-of-use disinfection of drinking water. The pulsed electric field device comprises micro-engineered electrodes and a low-voltage pulsed electric field generator circuit. A pulsed electric field is generated across a micro-gap between the electrodes to achieve disinfection of drinking water.

First claim

What is claimed is:

1 . A device for point-of-use disinfection of water, said device comprising:
a plurality of micro-engineered electrodes having a micro-gap between the micro-engineered electrodes; a control system; and a low-voltage pulsed electric field generator circuit responsive to the control system, to generate a pulsed electric field strength across the micro-gap of the micro-engineered electrodes, thereby providing said pulsed electric field strength at a level effective to increase cell permeability and/or cause an irreversible damage to cells of microorganisms present in the water.

2 . The device of claim 1 further comprising a power converter.

3 . The device of claim 1 , wherein the low-voltage pulsed electric field generator circuit provides an output pulse frequency in the range of about 1 Hertz (Hz) to about 100 Hz.

4 . The device of claim 1 , wherein the low-voltage pulsed electric field generator circuit provides a pulse width in the range of about 20 nanoseconds to about 100 milliseconds.

5 . The device of claim 1 , wherein the micro-gap has a micro-gap dimension from about 10 μm up to about 300 μm.

6 . The device of claim 1 , wherein the micro-gap has a micro-gap dimension of 100 μm.

7 . The device of claim 1 , wherein the low-voltage pulsed electric field generator circuit provides a voltage of about 5 V up to about 30 V across the micro-gap.

8 . The device of claim 1 , wherein the low-voltage pulsed electric field generator circuit generates a pulsed electric field strength of at least 0.5 kV/cm.

9 . The device of claim 1 , wherein the low-voltage pulsed electric field generator circuit generates an electric field having a pulsed waveform selected from the group of square, sinusoidal, trapezoidal and triangular.

10 . The device of claim 1 , wherein the device is a stand-alone unit or a tap-mounted unit.

11 . The device of claim 1 , wherein the micro-gap is achieved by a method selected from the group consisting of a physical barrier between the micro-engineered electrodes, a non-electrical conducting protective layer on the micro-engineered electrodes, and microfabrication technology to position the micro-engineered electrodes on a solid substrate.

12 . The device of claim 1 , wherein the micro-engineered electrodes are installed so as to generate an electric field in a direction which is perpendicular or parallel to a water flow.

13 . The device of claim 1 , wherein the micro-engineered electrodes are made of a conducting material or a carbon-based material.

14 . The device of claim 1 , wherein the micro-engineered electrodes are coated with a conducting material or a carbon-based material.

15 . The device of claim 1 , wherein the micro-engineered electrodes are selected from the group consisting of micro-engineered porous electrodes, micro-engineered multi-rod electrodes, micro-engineered coated-electrodes and micro-engineered printed electrodes.

16 . The device of claim 15 wherein the micro-engineered electrodes are micro-engineered porous electrodes.

17 . The device of claim 15 wherein the micro-engineered electrodes are micro-engineered multi-rod electrodes.

18 . The device of claim 15 , wherein the micro-engineered electrodes are micro-engineered coated electrodes.

19 . The device of claim 15 , wherein the micro-engineered electrodes are micro-engineered printed electrodes.

20 . A method for point-of-use disinfection of water comprising:
providing a plurality of micro-engineered electrodes having a micro-gap between the micro-engineered electrodes; generating a pulsed electric field strength, across the micro-gap of the micro-engineered electrodes to provide said pulsed electric field strength at a level effective to increase cell permeability and/or achieve an irreversible breakdown of cells of microorganisms present in the water.

21 . The method of claim 20 comprising providing a voltage of about 5 V up to about 30 V across the micro-gap.

22 . The method of claim 20 comprising providing a pulsed electric field strength of at least 0.5 kV/cm.

Assignees

• Univ Hong Kong Science & Tech

Inventors

• Yeung King Lun
• Kwan Joseph Kai Cho
• Kwan Siu Ming
• Lam Ka Wo

Classifications

• C02F2201/46175

  Electrical pulses · CPC title

• C02F2303/04

  Disinfection · CPC title

• C02F2201/46125

  Electrical variables · CPC title

• C02F2307/12

  as part of household appliances such as dishwashers, laundry washing machines or vacuum cleaners · CPC title

• C02F2307/10

  as part of a potable water dispenser, e.g. for use in homes or offices · CPC title