Odour-Neutral Zone – thanks to H₂S control with Donau Bellair green

Corrosion and unpleasant odours that disturb residents: these are the consequences of hydrogen sulphide (H₂S) in pressure sewer systems. Many municipalities face this problem – including St. Peter ob Judenburg. However, the challenge can be overcome by treating wastewater with Donau Bellair green. The product demonstrably reduces H₂S concentrations and ensures odour-free, reliably operating pressure sewer systems.

When wastewater does not flow by itself

In the idyllic Styrian municipality of St. Peter ob Judenburg (approx. 1,500 population equivalents), the wastewater treatment plant was decommissioned several years ago. Since then, the wastewater volume of around 180 m³ per day has been conveyed via a pumping station, as discharge through a gravity sewer – where wastewater flows by gravity and natural slope – is not possible.

Instead, a 1,300-metre-long pressure pipeline is used. It transports the wastewater from the pumping station in St. Peter ob Judenburg to the pumping station in Rothenthurm and subsequently to the wastewater treatment plant in Judenburg.

Hydrogen sulphide causes odour nuisance

The challenge is that, due to delayed pumping intervals, the wastewater remains in the pressure pipeline for extended periods – ideal conditions for anaerobic processes and thus for the formation of hydrogen sulphide (H₂S).

As a result, significant odour nuisance occurred at the end of the line in Rothenthurm within the adjacent residential area. In addition, hydrogen sulphide attacks the manholes by dissolving lime from the concrete. Concrete corrosion and long-term structural damage to the shafts are the undesirable consequences.

The solution: dosing Donau Bellair green

To eliminate odours, hydrogen sulphide must be bound. For this purpose, a dosing system for Donau Bellair green was installed at the starting point – the pumping station in St. Peter ob Judenburg. No additional structural modifications were required.

The product from Donau Chemie Water Technology effectively reduces sewer odours and corrosion in wastewater systems, as it inhibits anaerobic processes and neutralises problematic substances. Proper dosing is key: for a wastewater volume of 180 m³, the required dosage is 9 litres of Donau Bellair green per day.

The result: since commissioning the dosing system, unpleasant odours have disappeared. In addition, at the Rothenthurm pumping station, which further conveys the wastewater to the Judenburg treatment plant, no additional wastewater treatment is required. The dosing at St. Peter ob Judenburg is sufficient for the entire transport route.

As hydrogen sulphide concentrations in the wastewater are significantly reduced, concrete corrosion no longer occurs. The shafts remain in good and safe condition, and ongoing repairs are no longer necessary.

Measurement results: with and without dosing of Bellair green

Donau Chemie Water Technology supported the process with a series of measurements. The data clearly confirm the effectiveness of the measure: without dosing of Donau Bellair green, H₂S concentrations in the pumping station were significantly higher. This resulted in strong odour formation and high environmental and residential impact.

Without Donau Bellair green: High H₂S levels measured over two days in January 2023.

Approximately two weeks later, after installation of the dosing system and addition of Donau Bellair green, a completely different picture emerged: H₂S levels were significantly reduced and measurements were stable. There was no odour nuisance, and operating conditions were safe.

With Donau Bellair green: Approximately two weeks later, H₂S levels were significantly lower.

The results clearly demonstrate the effectiveness of Donau Bellair green: without dosing, H₂S concentrations in the pumping station were significantly elevated, leading to strong odour nuisance and environmental impact. After installation of the dosing system and addition of Bellair green, H₂S levels were significantly reduced and stable. Odour problems no longer occurred, and operating conditions improved significantly.

Conclusion: H₂S control pays off – especially for small municipalities

St. Peter ob Judenburg is a clear example of how small municipalities in hilly regions can efficiently solve H₂S problems in pressure sewer systems. The chemical dosing of Donau Bellair green binds hydrogen sulphide directly in the pressure line, prevents odour nuisance immediately, and ensures safe pumping stations – without costly structural modifications or additional treatment at the wastewater plant.

More information: DC Water Tech – wastewater solutions