Download a PDF version

About Ultraviolet Sciences, Inc.

Ultraviolet Sciences, Inc. (UVSI), headquartered in San Diego, California, designs and manufactures UV water treatment systems for disinfection, TOC reduction, and chlorine reduction purposes. UVSI water treatment products are designed for industrial and commercial applications; pharmaceutical, microelectronics, beverage, pools/spas, hospitality, water reclamation, and small municipal drinking water delivery systems (<10 MGD).

UVSI developed a highly reflective UV treatment chamber (US Patent 7,511,281) that maximizes the use of the ultraviolet (UV) light emitted by conventional mercury amalgam lamps. The 99.8% reflective surface keeps the UV light inside the treatment chamber, reducing the amount of light energy necessary to achieve a proper UV dose. This reflective surface encapsulates the entire flow channel ensuring an even UV dose exists throughout the treatment chamber. No complicated internal baffling and mixing systems are necessary. This efficiency gain is unique to the UVSI product line, resulting in smaller UV systems with fewer UV lamps to achieve a given UV dose. As a result UVSI water treatment systems are more compact in design and require significantly less power to operate, saving the end user up to 90% in operating costs.

The UVSI product line of treatment chambers was launched commercially in March 2009 after nearly two years of demanding field trials with early adopters. UVSI products are currently being used in the microelectronics, pharmaceutical, beverage, and water reclamation applications.

Randy Cooper

Dr. Randy Cooper is President and CTO of Ultraviolet Sciences, Inc. Dr. Cooper's engineering and developmental experience with water purification began as VP of Engineering and R&D at PurePulse Technologies. Dr. Cooper founded Ultraviolet Sciences, Inc. (UVSI) in 2002 with the charter to deliver efficient, simple, low-cost new products to the water purification market. The first of these innovative new products, the UVS series, are the most energy efficient and compact UV water treatment chambers on the market.

Dr. Cooper continues to lead UVSI programs to develop and apply new technological advances for cleaning water, with the goal of providing even more economical and widely applied solutions to difficult water purification problems. This work currently includes the development and commercialization of a new high-intensity, mercury free UV light source. This light source will be a new generation of UV lightpowered purification equipment with the potential to replace many existing chemical-driven systems.

Ultraviolet Light for Disinfection

Ultraviolet light is an excellent choice for water disinfection. It is chemical free and produces no harmful by-products. The application of UV to disinfect water has been an accepted practice since the mid-20th century. It has been used primarily in medical sanitation and sterile work facilities. Increasingly it is used to sterilize drinking and beverage water, to purify water for microelectronics, and to disinfect wastewater. Ultraviolet light is electromagnetic radiation with wavelengths shorter than visible light shown in the chart. UV is separated into various ranges, with short range UV (UVC) considered "germicidal UV." At the 254 nm wavelength UV is mutagenic to bacteria, viruses and other microorganisms. UV will break the molecular bonds within the microorganisms DNA, producing thymine dimmers, thereby destroying them, rendering them harmless, or prohibiting growth and reproduction. The effectiveness of germicidal UV depends on a number of factors: the length of time a micro-organism is exposed to UV, power of the UV source at the 254 nm wavelength, the presence of particles that can protect the microorganisms from UV, and the microorganisms ability to withstand UV. Different species of microorganisms require varying level of UV exposure to render them harmless, but nearly all species can be reduced by 99.99% (4-log) with only a 30 mJ/cm2 dose of UV.

Using UV for TOC Reduction Total oxidizable carbons (TOC) are increasingly finding their way into all our water supplies. Many TOC's are carcinogens, such as dioxins, and others, like MTBE and endocrine disruptors, pose other serious health risks. Removing or reducing TOC's in water is becoming increasingly necessary to ensure public health and safety. UV radiation below 200 nm wavelengths can destroy TOC's in water through three different mechanisms. The primary mechanism for TOC destruction is direct photolysis of the water molecules. This creates hydroxyl radicals (chemical formula: OH-). The chemical equation is: H2O + UV (185 nm) H+ + OHHydroxyl radicals are one of the most chemically reactive agents known. These radicals attack and oxidize the organic chemicals, breaking them down into ionized organic species (which can be removed by deionization) and eventually to CO2 and water, following the general formula: CxHyOz + OH- CO2 + H2O A secondary mechanism by which UV radiation can destroy TOC's is by direct photolysis of the TOC molecule. The UV photons break the chemical bonds within the TOC molecule, transforming it to two or more smaller organic molecules. This process works only for organic chemicals which absorb light at the wavelengths produced by the UV source. The third mechanism is the conversion of dissolved oxygen into first hydrogen peroxide, and then hydroxyl radicals, by the 185 nm UV. The TOC destruction mechanism by hydroxyl ions is the same as above. The presence of dissolved oxygen in the water is not guaranteed, and in some applications is actively prevented, but this process will occur if dissolved oxygen is present.

Using UV for Chlorine Reduction Using UV for de-chlorination eliminates the problems of traditional methods. There is no saturation point, no overdose consideration, and no production of harmful or problematic by-products when using UV. Also, UV does not affect odor, taste, or color or the pH of the water. In fact, the UV de-chlorination method enhances the end product quality and its process stability.

An important point for consideration is that the UV dose for de-chlorination is significantly higher than used for typical disinfection, anywhere from 10 to 20 times more. This higher dosage produces an extremely high level of microbial disinfection in the water. As an added benefit, this dose will also reduce organic carbons such as Humic acid and pesticides and trace pharmaceuticals. None of these advantages exist using the traditional chlorine reduction methods.

Why UVSI Reflector Technology Works

Typical UV water treatment systems suffer from inefficiency. Whether a low pressure or medium pressure system, most of the UV light energy emitted is absorbed by the treatment chamber walls and is transformed into heat. Over 80% of the UV photons are wasted this way, meaning less than 20% are doing the work of disinfection. This is a tremendous loss of disinfection power. So reflecting the photons back into the water channel brings huge efficiency gains, resulting in direct performance, size and cost benefits.

UVSI determined that three fundamental design conditions must be met to benefit from any reflective technology:

1. The material must be reflective across the UV spectrum from 180 nm to 300 nm.

2. The reflectivity of the material must be greater than 99% over this spectrum.

3. The water chamber must be enclosed to the maximum extent possible with the reflective material.

No UV design has satisfied all three conditions, until now. After two years of R & D, UVSI engineered a new UV treatment chamber that meets all the conditions. The UVSI treatment chamber has a reflectivity factor greater than 99%. This patented design "traps" the UV photons in the treatment chamber. They have no place to go other than into a microbe.

Ray trace modeling (figures below) shows the behavior of just 10 photons launched into the chamber. There are hundreds of reflections per photon, creating a very uniform dose throughout the chamber, and numerous opportunities to engage a microbe. With billions of photons active in this chamber, the gain in performance becomes geometric.

The amount of chamber coverage with the reflective material is fundamental in gaining performance. The chart below illustrates that the chamber reflectivity must be greater than 98% to achieve meaningful performance gains. UVSI products have a 20X gain in performance over competing systems, making UVSI products the most efficient, the most compact, and the most economical UV systems available today.