Drinking Water Purification Using UV Lamps Becoming Even More Important
2 April 2007, News release from Heraeus Noblelight GmbH
· International Symposium at Heraeus in Hanau, Germany
· UV radiation destroys germs and pathogens in drinking water without the need for chemicals
Drinking water treatment with UV radiation was the theme of an international symposium of the materials network, Materials Valley e.V., which took place at the end of February at the Hanau headquarters of Heraeus, the precious metals- and technology group. The workshop was carried out as a joint venture involving the specialist light source manufacturer Heraeus Noblelight, the equipment and plant builders ITT Wedeco AG from Germany and the Canadian company Trojan Technologies. More than 70 engineers and technicians from Europe, North America and Asia attended and were able to gain an insight into the state of the technology through a wide range of presentations from both R&D and industry itself.
Alongside conventional techniques for disinfecting drinking water, notably the use of chemicals such as chlorine and ozone and the use of filtration systems, ultraviolet light is assuming increasing importance as an environmentally friendly alternative. Drinking water is a valuable and scarce resource, accounting for only 2.5% of the world's total water, with the remainder being salt water. Clean drinking water is even more rare. Untreated water containing germs is increasingly a health risk. Two million people die every year as a result of drinking untreated drinking water, resulting in infections and intestinal sicknesses. Worldwide drinking water consumption is now six times what it was in 1900, while the population over this time has only trebled. Impressive numbers, which do much to explain what has become one of the most important problems of our times. Will there be enough clean drinking water for us in the future and how can this be managed technically?
UV Lamps: more efficient and longer-lasting
The treatment of drinking water with UV radiation is a very effective physical process, used to disinfect water and to break down pollutants. The very high energy radiation (at wavelengths from 200 to 300 nanometres) destroys the genetic material and inactivates the individual cells of the pathogens in the water such as bacteria, micro-organisms, fungi or parasites and breaks down any chemicals harmful to health. Even chlorine-resistant parasites such as cryptosporidia are inactivated with UV light. An important benefit lies in the fact that this treatment technique does not use chemicals.
The first patented UV purification was carried out in France in 1910 using quartz glass lamps - a development going back to Richard Kuech, who was director of R&D at Heraeus. Today, the challenges for UV lamps are those of achieving significant increase in lamp efficiency and operating life.
To meet these challenges, Heraeus Noblelight has developed new UV lamps (high power amalgam lamps) which offer up to 16,000 operating hours at virtually constant UV output power, yielding significantly more power than conventional lamps after 8000 hours. Thanks to this higher power and long operating life, systems builders now need specify fewer lamps when designing disinfection plants. This naturally gives rise to the potential for significant savings in numbers of lamps, system components, energy consumption and maintenance costs.
"In Germany and its neighbours Austria and Switzerland, the use of UV lamps is a guarantee of the high drinking water quality which we take for granted. There will be a need for a single European standard in UV treatment to cater for the increasing European demand," explained Dr. Sven Schalk from Heraeus Noblelight.
UV technology is also becoming of increasing interest to system builders who operate worldwide. ITT Wedeco AG, of Herford / Germany, can already point to 50,000 installations worldwide, from small domestic units to large commercial plants, handling 90,000 cubic meters per hour, reported Peter Kruger from ITT Wedeco.
The increase in environmental pollution caused by medications and drugs in ground water was the theme of the presentation by Marc-Olivier Buffle of Trojan Technologies, Canada. In order to destroy very complex pharmaceuticals such as antibiotics and steroids, it makes good sense to use a combination of UV radiation and a strong oxidant such as hydrogen peroxide. This technique has already been used successfully in Holland's largest drinking water reservoir at Isselmeer. However in Germany, to date, this technique can only be used for wastewater treatment.
For further information please email Heraeus Noblelight GmbH