How a Municipal Wastewater Treatment Plant Survives a Rock Festival

When around 85,000 heavy metal fans flock to Schleswig-Holstein in August for the world-famous Wacken Open Air, not only do noise levels and visitor numbers rise – the demands on the regional wastewater infrastructure increase as well. To sustainably and compliantly manage these loads, the Hanerau-Hademarschen wastewater treatment plant is now also equipping its second aeration tank with AEROSTRIP® diffusers from AQUACONSULT Anlagenbau.

Operated by the Süderdithmarschen Water Association, the plant treats wastewater from the municipalities of Hanerau, Hademarschen and Thaden, serving a total of approximately 3,800 population equivalents. It has two aeration tanks, and the treated wastewater is subsequently discharged via the Viehbach and the Hanerau into the Kiel Canal. As early as 2013, 50 AEROSTRIP® Type Q units were installed in one tank – with measurable success: “We achieved enormous energy savings,” recalls Dennis Behrens, plant manager of the wastewater treatment facility. Following the retrofit, electricity consumption decreased by around 30 percent to approximately 85,000 kWh per year. At the same time, biological degradation improved significantly. “The sludge settles better, the turbid water can be removed easily, and the sludge volume has almost been halved,” says Behrens.

Second Line for Safety and Regulatory Compliance

The decision to now equip the second aeration tank with an additional 50 AEROSTRIP® diffusers is not only a consequence of the positive operating experience but also a regulatory requirement. “We operate a two-line plant, and both lines must be fully operational,” explains Behrens. “We need this redundancy, especially during maintenance or rehabilitation work.”

However, the plant is particularly challenged in summer: During the Wacken Open Air, enormous volumes of wastewater are generated daily from more than 1,300 mobile toilets, around 500 showers and the festival’s catering facilities. In total, approximately 2,000 m³ of highly loaded wastewater are delivered to the Hanerau-Hademarschen plant within a short period – several truckloads per day. “This is the biggest challenge for our plant,” says Behrens. “We buffer in advance, dose specifically, and for that we need both aeration tanks and, of course, reliable aeration.”

Efficient Aeration for Extreme Peak Loads

The AEROSTRIP® diffusers ensure consistently high oxygen transfer with low energy consumption and enable stable operation even under heavily fluctuating loads. “The strength of our diffusers becomes particularly evident in plants with varying loads,” emphasizes Rüdiger Vrabac, Branch Manager of AQUACONSULT Anlagenbau in Germany. “They offer high oxygen transfer efficiency, are durable and can be controlled very energy-efficiently.”

The project implementation is scheduled to be completed before August, in time for the next festival season. For this purpose, the existing steel tanks will be prepared and sandblasted, and the diffuser and other supports will be welded on accordingly. “After more than 20 years of very good experience, it was clear to us: if we upgrade, it will be with AEROSTRIP® again,” summarizes Behrens. With the follow-up order in Hanerau-Hademarschen, AQUACONSULT once again underlines that its innovative aeration technology from Lower Austria proves itself not only in large cities, but also under extraordinary operating conditions – from everyday municipal operations to heavy metal exceptional states.

Photos:

1. As early as 2013, 50 AEROSTRIP diffusers were installed in one aeration tank of the wastewater treatment plant. The achieved energy efficiency and performance values convinced the plant operators to also upgrade the second aeration tank. (© both AQUACONSULT)
2. The Hanerau-Hademarschen wastewater treatment plant is equipping itself with additional AEROSTRIP diffusers in order to manage the peak loads during the summer heavy metal festival in nearby Wacken. (© Süderdithmarschen Water Association)
3. “The strength of our AEROSTRIP diffusers becomes particularly evident in plants with varying loads.” Rüdiger Vrabac, Branch Manager of AQUACONSULT Anlagenbau in Germany (© AQUACONSULT)