New technology from Aerzen will treat water for 340,000 Swedes at Himmerfjärdsverket treatment plant

18/03/2021

AERZEN will deliver vital water treatment technology to upgrade one of the largest wastewater treatment plants in Sweden, at Himmerfjärdsverket, south of Stockholm. The turnkey contract will be managed by Veidekke, on behalf of Syvab, at a budgeted cost of SEK 1.3 billion. “This marks a milestone in the use of this type of technology in Sweden for both Aerzen and Swedish wastewater treatment. All credit goes to Veidekke and Syvab, for investing in energy efficiency and sustainability,” says Leif Persson, customer manager at Aerzen.

Himmerfjärdsverket is located in Grödinge, about 40 km south of Stockholm; it is operated by Syvab and is the fifth-largest wastewater treatment plant in Sweden. It was built in 1974 and has not undergone any major renovation since then. A growing population (just over 340,000 people are connected to the plant today) together with rising environmental requirements have led to the need for extensive renovation and expansion. The work is expected to be completed in stages between 2023 and 2026.

“Renovation and expansion of Himmerfjärdsverket has finally reached the production phase. Design and planning of the blower systems and the bottom aeration system was an important element in meeting performance requirements and the strict environmental requirements. We are satisfied and confident about the solution that Aerzen has presented and the solution that will now be installed in the basins,” says Jenny Johansson, works manager at Veidekke.

New technology will reduce energy costs

Water purification in treatment plants involves several stages, from coarse screening to remove litter, to filtration at particle level. By far the most energy-consuming and costly part of the process is the biological treatment stage, which often accounts for up to 80 percent of operating costs and the largest share of energy consumption by far. Large amounts of air are pumped into huge water-filled treatment basins where oxygen activate the bacteria, which then purify the wastewater.

Aerzen’s contribution to the renovation of the Himmerfjärdsverket treatment plant is to supply and commission the technology that provides aeration of the treatment basins. Powerful blowers deliver the required volume of air – many hundreds of cubic metres per minute – which is distributed by ingeniously designed panels at the bottom of the basins. The panels use a technology that disperses the air in a unique way as tiny bubbles, to ensure uniform oxygenation of the basins. This leads to a highly efficient oxygen transfer process using technology that is successfully applied around the world and which only Aerzen offers in Sweden and Norway.

Flexible system handles irregular loads

One common problem for treatment plants lies in handling variations between periods of high and low load. The load is generally high in the evenings, mornings and at weekends, which requires high capacity. But at night and during the day, the demand is usually low, so it is necessary to avoid unnecessary processing and energy-intensive operations. The combination of energy-efficient blowers and aeration panels provides the best ability to adapt to the current load.

“If you can cut energy consumption it offers large potential savings. To do this, it is necessary to have a clear and up-to-date picture of how the plant is operating, so that the most energy-hungry processes can be identified. If this information is missing, it makes it harder to know which measures will be effective,” says Leif Persson, customer manager at Aerzen.

Strict demands were placed on sustainable energy consumption during the procurement process, and Aerzen’s solution showed the best results. To achieve this, Aerzen has developed methods that both monitor and control flow rates, pressures and energy consumption.

“Thanks to the large savings that can be made using our methods, we are seeing growing interest in the marketplace. We hope that this will lead more municipalities and consultants to realise the potential savings that are available with modern technology, and that we can continue to contribute to many more efficient, high-performance plants in the future,” says Leif Persson.

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