Research Project Information

Research Project Summary Information

Electrically-for Wastewater & Drinking Water(ST8774-1)

Crystal IS, Incorporated


The efficiency of ultraviolet (UV) light for disinfection depends strongly on wavelength and peaks at 265 nanometers. Essentially all current UV disinfection light sources are based on mercury arc lamps. Electrically-efficient, mercury-free, highly reliable UV light emitting diodes (LEDs) with narrow emission output in the preferred 265-280 nm wavelength range would provide key benefits over mercury lamp approaches to UV water purification for both wastewater and drinking water applications. The optimal LED substrate for achieving this relatively short wavelength (below 340 nm) is aluminum nitride (AlN), which only recently became available. At 2% efficiency, UV LEDs could be used for smaller flow systems such as point-of-entry and point-of-use systems. When the efficiency increases to 5%, UV LEDs can be used for neighborhood and remote systems. At 10% efficiency, municipal drinking water facilities would benefit from the use of LEDs; and at 20% efficiency, municipal wastewater systems would benefit.

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Project Description

A next generation UV LED source was designed, fabricated, and packaged based on the results of previous work. The source was tested for disinfection effectiveness at the laboratory benchtop scale.


Compared to the incumbent mercury lamp UV disinfection technology, UV LEDs are expected to have a lifetime up to 10 times longer, similar initial cost, and two times the electrical efficiency. In New York State alone, UV LED-based water purification systems would eliminate three kilograms of mercury use per year and reduce energy costs by $2 million. Additional benefits include lower system maintenance costs and position of New York as the center of a new revolution in safer, lower cost, more environmentally friendly wastewater and drinking water treatment technology.

Project Results

Crystal IS has made significant progress in the development of UV LEDs fabricated on advanced AlN substrates, and have demonstrated UV LEDs operating below 300 nanometers with a wall plug efficiency of ~ 0.06%. Strategic partners were identified and project results conveyed to these potential partners. Nevertheless, to displace the incumbent technology, UV LEDs require further development to improve device efficiency.


Crystal IS, Incorporated
70 Cohoes Ave
Green Island, NY 12183

Principle Investigator

Leo Schowalter

Universities Involved


Project Type:

Product Development

Technologies Types:

Waste Management and Pollution Prevention
Water/Wastewater treatment systems

NYSERDA Contact Information

Kathleen O'Connor


R&D - Environment & Energy Res

Contract Details

Start Date: 1/11/2010
Project Status: Active
Contract Number: ST8774-1

Last Updated: 1/10/2011