The wastewater treatment plant of the “Vorderes Renchtal” wastewater association treats wastewater from nine municipalities, including the “Grimmelshausen City” of Renchen, as well as Oberkirch and Achern. The wastewater flows through the local sewer network and two main collectors to the mechanical-biological treatment plant. “Essentially, we are a completely normal municipal wastewater treatment plant, like many others – but with one special feature,” explains plant operations manager Christian Spinner. “The Renchtal region is a traditional distillery area. 80 % of Germany’s kirschwasser comes directly from this region.” This means that, particularly in the winter months – the peak production period for local spirits – large quantities of spent mash from distilleries end up at the Renchen treatment plant. This poses an ongoing challenge for all sections of the facility, which has a capacity of 32,000 population equivalents (PE).
Due to the specific wastewater composition, the Renchen plant also operates two massive digesters, each with a capacity of 1,500 cubic meters, which co-digest the distillery residues. With these two digesters, the plant covers 90 % of its own energy demand – producing around 800,000 kWh of electricity per year.

Seamless installation with a flexible reuse factor

However, the plant could soon become entirely energy self-sufficient. In 2024, the entire aeration system of the three biological treatment lines at the “Vorderes Renchtal” wastewater treatment plant was converted from (Messner) plate diffusers to the significantly more energy-efficient AEROSTRIP aerator modules Type G – each consisting of four Type Q2.0 strip diffusers. “We started retrofitting the first aeration line in mid-2023,” Spinner explains. “By October, we had completed the third line – each conversion took three to four days. The installation of the 109 new AEROSTRIP modules went smoothly, and we were able to maintain normal operation throughout.” Existing floor fixtures and piping were reused by AQUACONSULT technicians, highlighting the flexible installation options of AEROSTRIPs.

Strip Diffusers Achieve Up to 30 % reduction in power consumption

The efficient performance of the strip diffusers became evident from day one: “Our blowers were not originally designed for the extremely efficient oxygen transfer that AEROSTRIPs can achieve,” says Spinner. “After quickly adjusting to this, the plant now runs in an extremely energy-saving mode – especially at night – and we are already seeing a reduction in power consumption of around 30 %.” Additionally, the AEROSTRIPs offered cost advantages, as they were significantly more affordable than the previously used solution.
In the future, the Renchen wastewater treatment plant will also benefit from the flexible replacement options of AEROSTRIPs: “Each strip aerator can be individually replaced if needed, which is a major improvement in handling compared to our previous system,” notes Spinner. The operations manager also emphasizes the overall package offered by AQUACONSULT’s AEROSTRIP strip diffusers: “From our initial contact with AQUACONSULT’s specialists to installation and operational efficiency, I can only recommend this product.”

Innovative Technology – A Global Success Story

AQUACONSULT Anlagenbau’s innovative diffusers ensure optimal flexibility and adaptability for various operating conditions in many types of wastewater treatment plants, leading to significant energy savings. “Thanks to continuous research and development, as well as regularly conducted performance tests, our AEROSTRIP diffusers are now considered among the most efficient fine-bubble deep diffusers available,” emphasizes Rüdiger Vrabac, branch manager at AQUACONSULT Anlagenbau Germany, based in Rinnthal, Rhineland-Palatinate.
The AEROSTRIPs, produced in Traiskirchen, Lower Austria, are now used in over 2,500 industrial and municipal wastewater treatment plants worldwide. AQUACONSULT Anlagenbau currently boasts several prestigious references in Germany, such as the “Alte Emscher” treatment plant in Duisburg, one of the largest wastewater treatment plants in Germany, and the Zweibrücken treatment plant in Rhineland-Palatinate, which serves as a model for cost-effective plant operation. Moreover, AEROSTRIPs are also utilized in Copenhagen’s three wastewater treatment plants (Lynetten, Damhusåen, and Avedore) as well as in the “Western Treatment Plant” in Melbourne, Australia. The decision by plant operators to install AQUACONSULT’s strip diffusers consistently results in impressive energy and CO2 savings.