The largest ever DVGW*-certified medium pressure UV disinfection system in Germany has been installed at the Essen-Horst drinking water treatment plant in the heart of the Ruhr region. Supplied by Netherlands-based Berson UV-techniek, the closed vessel UV system comprises four InLine 15000 DW-DVGW disinfection chambers and associated control and monitoring equipment.
Each of the four UV chambers disinfects up to 1,060 m3/hour (SAC value** of 6.5/metre) of ground water adjacent to the Ruhr River. Providing a log-3 microbial reduction, the Berson UV system is installed following chlorine dioxide treatment and provides an enhanced level of disinfection during flooding situations.
“One of the main reasons for installing UV was to provide extra disinfection capacity in the event of the Ruhr flooding over onto the drinking water catchment area,” commented Mr Langenberg, Head of Procurement at Wassergewinnung Essen GmbH. “Although it is a rare occurrence, we need to be sure that if flooding does occur, we have systems in place to ensure the quality of our drinking water.”
“We looked at a number of UV options, including low pressure UV systems,” continued Mr Langenberg. “However, due to the space requirements and long term operational costs, low pressure UV was ruled out. We chose Berson’s closed vessel medium pressure technology as it not only offered a technologically advanced, DVGW-approved disinfection solution with a small footprint, but will also prove to be the most economical in the long term. The very short lead-time for delivery was also a decisive factor.”
The Essen-Horst water treatment plant supplies drinking water to over 475,000 people in a very large urban area including the cities of Gelsenkirchen and Herne and parts of Bochum, Hattingen, Spröckhovel and Velbert-Langenberg.
The InLine 15000 DW-DVGW chambers feature Berson’s innovative MultiWave medium pressure UV lamps, which are orientated perpendicular to the water flow to achieve optimum UV exposure. Unlike conventional UV lamps, MultiWave lamps produce a broad spectrum of wavelengths which act on the whole microorganism, rather than its DNA alone. This provides permanent deactivation by ensuring photoreactivation and dark repair of the microorganisms’ DNA cannot occur.
Integral sensors monitor UV light intensity in each treatment chamber, while a custom-built control panel provides communication between the UV chambers and the control room. Also incorporated in each UV unit is an automatic DVGW-approved wiping mechanism which cleans the quartz sleeves surrounding the lamps and keeps them free of any deposits. A major benefit of automated wiping means no chemicals are required for cleaning, especially important for drinking water.
“Berson is one of the few suppliers in Germany capable of providing a complete range of DVGW-approved UV disinfection systems with capacities between 10 – 2,200 m3/hour,” commented the company’s European sales manager, Rob Frakking. “Since introducing our DVGW-certified systems in Germany a few years ago we have been working non-stop to keep up with demand from German waterworks,” he added.
* DVGW (German Technical and Scientific Association for Gas and Water) is the body responsible for industry self-regulation in the German water and gas and water supply industry and its technical rules are the basis for safety and reliability.
** SAC (Spectral Absorption Coefficient) is the measured value of the UV absorption of water. It is a total parameter for the measurement of the organic substances or load.