World's largest WEDECO UV wastewater disinfection system starts operation
WEDECO AG Water Technology, the leading manufacturer of water disinfection systems based on ultraviolet (UV) light, reports that worlds largest wastewater disinfection system is now operational in Manukau (Auckland), New Zealand. Wedeco Chairman Mr. Werner Klink announced that the UV unit has been officially handed over to the owner, WaterCare Services Ltd. Mr. Klink explained that the upgrade of the 30-year-old sewage treatment plant, involving the integration of the latest UV disinfection technology, was carried out as part of a 244 million EURO modernization project, coordinated by Manukau Wastewater Services. The screening system has been revamped, nine new combined reactor-clalifiers tanks have been installed and a new tertiary wastewater treatment system is now in place, consisting of sand filtration reinforced by UV disinfection.
The purpose to this ambitious large-scale project is to protect the environment of the flora and fauna in the coastal waters of Manukau/Auckland and safeguard the health of bathers. According to the New Zealand authorities, the upgraded system will soon bring about a considerable improvement in water quality, so that the local population will soon be able to swim and gather shellfish again in an area that has been closed to the public for 40 years due to the extreme pollution caused by the discharge of wastewater from the city of Auckland.
The UV disinfection system consists of 12 open, 17m-long wastewater channels, which are integrated into a purpose-built structure. It took one year to build this complex. Each channel contains 3 banks of UV lamps. Nearly 8000 high-performance SPEKTROTHERM® UV lamps disinfect the wastewater, with tests showing a reduction in viral incidence by a factor of 104. The permissible bacterial concentration in the treated wastewater is a monthly average of no more than 80 faecal coliform units or 35 enterococci units per 100 ml. Microprocessor controllers automatically regulate the number of lamps switched on and the output of each individual lamp, depending on the rate of flow. This ensures that the system, which can disinfect a maximum of 57,600 cubic metres of wastewater per hour, always operates economically.
In Mr. Klink's view, the Manukau project represents a successful contribution by WEDECO AG to a trend-setting, ecologically relevant, large-scale project. Chemical-free disinfection is gaining in importance not only in New Zealand but also in many other parts of the world, where this environmentally friendly method is now regarded as state-of-the-art technology and is increasingly referred to in legislation governing wastewater treatment. The decision to entrust this major order to WEDECO came after extensive testing by WaterCare Services Ltd of a number of competing systems.
Source: WEDECO AG Water Technology