Ashok J Gadgil

6419821, Jul 16, 2002

Feb 25, 2000

09/513799

Ashok J. Gadgil - El Cerrito CA
Anushka Drescher - Berkeley CA

WaterHealth International, Inc. - El Cerrito CA

C02F 132

210 86, 210748, 210109, 210138, 210143, 2101981, 210202, 210203, 2102571, 210261, 210262, 210209, 210256, 250430, 250434, 250438, 4221863

A low cost system for providing drinking water includes a feed water container with a simple ceramic filter covering an outlet of the feed water container. The preferred filter is generally cylindrically shaped with a bore extending partially therethrough, in a configuration commonly referred to as a âceramic candleâ filter in developing countries. Under force of gravity, feed water filters through the ceramic to a storage container below. The filtered water is irradiated with ultraviolet (UV) energy either as it flows or after collection in the storage container. In one embodiment, filtered water is temporarily collected in an intermediate holding tank, where it can be irradiated constantly on in batches and periodically released to the lower container. Filtration through ceramic provides clear water with a low UV extinction coefficient for more efficient UV disinfection. Additionally, gravity fed filtration through ceramic provides a slow rate of water flow and a consequently high UV dose for a given UV intensity.

6464884, Oct 15, 2002

Aug 25, 2000

09/648320

Ashok J. Gadgil - El Cerrito CA

The Regents of the University of California - Oakland CA

C02F 132

210748, 210787, 210806, 210807, 210241, 210258, 210259, 210295, 210314, 2103231, 210324, 2104161, 210473, 422 24, 4221863

A portable water treatment unit is provided for purifying contaminated water, especially in the aftermath of a natural disaster that compromises a regions water supply. The treatment unit is configured to treat water drawn into the unit. The treatment unit comprises an inlet connected to a pump. The pump outlet is connected to a solid separator for removing larger particles such as sand and silt. A series of filters is connected to the pump outlet, the filters being arranged from coarsest to finest. The filters remove smaller particles from the water. The water from the filters eventually flows into an ultraviolet light disinfection unit configured to purify water by emitting ultraviolet light thereon. An outlet of the UV light disinfection unit is configured to expel purified water for drinking and other uses. Pressure gages are provided for monitoring the pressure drops across the filters.

6602425, Aug 5, 2003

Apr 5, 2002

10/118072

Ashok J. Gadgil - El Cerrito CA
Anushka Drescher - Berkeley CA

Water Health International, Inc. - El Cerrito CA

C02F 132

210744, 210748, 250434, 250430, 250438, 422 24

A low cost system for providing drinking water includes a feed water container with a simple ceramic filter covering an outlet of the feed water container. The preferred filter is generally cylindrically shaped with a bore extending partially therethrough, in a configuration commonly referred to as a âceramic candleâ filter in developing countries. Under force of gravity, feed water filters through the ceramic to a storage container below. The filtered water is irradiated with ultraviolet (UV) energy either as it flows or after collection in the storage container. In one embodiment, filtered water is temporarily collected in an intermediate holding tank, where it can be irradiated constantly on in batches and periodically released to the lower container. Filtration through ceramic provides clear water with a low UV extinction coefficient for more efficient UV disinfection. Additionally, gravity fed filtration through ceramic provides a slow rate of water flow and a consequently high UV dose for a given UV intensity.

6803587, Oct 12, 2004

Jan 10, 2002

10/043647

Ashok Gadgil - El Cerrito CA
Eduardas Kazakevicius - Vilnius, LT
Anushka Drescher - Berkeley CA

Waterhealth International, Inc. - Napa CA

A61L 110

250434, 250432 R

A device that permits the in-home UV treatment of drinking water such as tap water is disclosed. The device employs a bare low-energy UV lamp suspended below a reflector and above a free surface of water flowing within the device. The water is supplied from a tap or other store of drinking water and proceeds through the device by the force of gravity. The device itself is not pressurized. The flow of water within the device is exposed to UV radiation from the UV lamp and is disinfected as a result. In the illustrated embodiment, the device is of a small size to permit its use, for example, directly at a tap for drinking water within the home. The flow rate of the device is commensurate with the normal flow rate of tap water, preferably less than about 8 liters per minute. The lamp power for safely disinfecting the water can be less than 20 watts, and in the illustrated embodiment the lamp is a low-pressure Hg lamp.

6974958, Dec 13, 2005

Oct 12, 2004

10/982857

Ashok Gadgil - El Cerrito CA, US
Eduardas Kazakevicius - Vilnius, LT
Anushka Drescher - Berkeley CA, US

WaterHealth International, Inc. - Napa CA

A61L001/10

250434, 250432 R

A device that permits the in-home UV treatment of drinking water such as tap water is disclosed. The device employs a bare low-energy UV lamp suspended below a reflector and above a free surface of water flowing within the device. The water is supplied from a tap or other store of drinking water and proceeds through the device by the force of gravity. The device itself is not pressurized. The flow of water within the device is exposed to UV radiation from the UV lamp and is disinfected as a result. In the illustrated embodiment, the device is of a small size to permit its use, for example, directly at a tap for drinking water within the home. The flow rate of the device is commensurate with the normal flow rate of tap water, preferably less than about 8 liters per minute. The lamp power for safely disinfecting the water can be less than 20 watts, and in the illustrated embodiment the lamp is a low-pressure Hg lamp.

7217933, May 15, 2007

Dec 12, 2005

11/302417

Ashok Gadgil - El Cerrito CA, US
Eduardas Kazakevicius - Vilnius, LT
Anushka Drescher - Berkeley CA, US

WaterHealth International, Inc. - Lake Forest CA

A61L 1/10

250423R, 250434, 250428, 250435

A device that permits the in-home UV treatment of drinking water such as tap water is disclosed. The device employs a bare low-energy UV lamp suspended below a reflector and above a free surface of water flowing within the device. The water is supplied from a tap or other store of drinking water and proceeds through the device by the force of gravity. The device itself is not pressurized. The flow of water within the device is exposed to UV radiation from the UV lamp and is disinfected as a result. In the illustrated embodiment, the device is of a small size to permit its use, for example, directly at a tap for drinking water within the home. The flow rate of the device is commensurate with the normal flow rate of tap water, preferably less than about 8 liters per minute. The lamp power for safely disinfecting the water can be less than 20 watts, and in the illustrated embodiment the lamp is a low-pressure Hg lamp.

D590202, Apr 14, 2009

May 2, 2008

29/317650

Ashok J. Gadgil - El Cerrito CA, US
Ken P. Chow - Moraga CA, US
Howdy Goudey - El Cerrito CA, US

The Regents of the University of California - Oakland CA

0702

D 7339

7544636, Jun 9, 2009

Feb 24, 2005

11/065867

Ashok Gadgil - El Cerrito CA, US

The Regents of the University of California - Oakland CA

B01J 20/02
C01B 31/08
A62D 3/00
B32B 5/16

502406, 502423, 588256, 428403

A method for low-cost arsenic removal from drinking water using chemically prepared bottom ash pre-treated with ferrous sulfate and then sodium hydroxide. Deposits on the surface of particles of bottom ash form of activated iron adsorbent with a high affinity for arsenic. In laboratory tests, a miniscule 5 grams of pre-treated bottom ash was sufficient to remove the arsenic from 2 liters of 2400 ppb (parts per billion) arsenic-laden water to a level below 50 ppb (the present United States Environmental Protection Agency limit). By increasing the amount of pre-treated bottom ash, even lower levels of post-treatment arsenic are expected. It is further expected that this invention supplies a very low-cost solution to arsenic poisoning for large population segments.