GasMix Cases & References

Cases & References for GasMix Solutions

Why Choose Landia GasMix? • 100% gas-tight system No loss of methane or CO2

• Easy service and routine maintenance Fewer man-hours required

• Improved health & safety No personnel working in the gas zone

• No gas leaks or temperature drop During maintenance

• Landia chopper pump technology

Effective solids reduction - prevents clogging

• Lower lifecycle assessment Reduced demands on tank construction

• Minimal space required for service

Compared to other digester mixers

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Tuas STW, SG

Client: PUB Singapore Consultant: Jacobs

Digesters: Digester diameter

25 m

Sludge level

32 m

Digester volume

10,088 m³

TS

5.4 %

No. of tanks

8

Image Credit: Jacobs And PUB, Singapore’s National Water Agency

Vimercate, IT Digesters: Digester diameter

18 m

Height

10 m

Digester volume

2,500 m³

TS

3-4 %

No. of tanks

1

Tank type

Steel

Taeyoung, KR Digesters: Digester diameter

14 m

Height

16.75 m

Digester volume

1,757 m³

TS

2-3 %

No. of tanks

1

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Increase digester efficiency.

Sparta WWTP LOCATION: United States

The City of Sparta operates a wastewater treatment plant serving around 10,000 residents and several industrial contributors.

To improve biogas production and reduce maintenance issues, the plant upgraded its digester mixing with the Landia GasMix system.

Poor mixing from the existing air-based system had led to debris buildup, reduced digester efficiency, and costly maintenance that required tank drainage. Landia GasMix was installed as an external mixing solution, using a chopper pump and venturi nozzles to deliver full-tank mixing with all mechanical components located outside the digesters.

The upgrade resulted in a 25 % increase in biogas production, more stable digester temperatures during winter, reduced downtime, and improved digestate quality for agricultural reuse.

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• Plant type: Municipal WWTP with industrial influent Digesters: Primary

1,264 m³

Secondary

693 m³

Key benefit

Full-tank mixing with no internal mechanical components

Results: • +25 % biogas yield through improved breakdown of volatile solids • Stable digester temperatures, even during cold Wisconsin winters • Lower maintenance and downtime, with all

Landia GasMix

mechanical components accessible outside the tanks • Improved digestate quality, reused locally as a nitrogen-rich fertilizer • Reduced energy costs, driven by higher and more consistent biogas production

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Better Mixing.

Higher Biogas Yield.

Nigg Wastewater Treatment Works LOCATION: Scotland

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Nigg Wastewater Treatment Works, operated

by Scottish Water, has become a leading site for biogas production from sewage sludge.

The new system provides reliable mixing of the two 4,000 m³ digesters while using significantly less energy than conventional mixing methods.

To improve efficiency and energy recovery, the facility upgraded its thermal hydrolysis process and installed a Landia digester mixing system.

Together with the process upgrade, the improved mixing has helped optimise sludge digestion and increase biogas production, turning the site into a strong producer of renewable energy.

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Digesters:

Landia GasMix

Digester diameter

17 m

Digester height

20 m

Volume

3,950 m³

Substrate

Sewage sludge

Tank type

Concrete

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Say goodbye to poor mixing.

Damhusaaen WWTP LOCATION: Denmark

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After the failure of a top-mounted mixer at the Damhusaaen wastewater treatment plant, BIOFOS – Copenhagen’s leading utility company – needed a reliable replacement for one of the plant’s digester tanks.

Instead, BIOFOS chose the Landia GasMix system, an externally mounted solution that recirculates biogas and sludge to ensure efficient mixing without internal mechanical components.

The existing mixer required extensive upgrading, which would have caused downtime and increased safety risks.

The system was installed on a full tank using the Hot Tap Drilling method, eliminating the need to empty the digester and minimizing operational disruption.

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Results: • Short installation time compared to alternative solutions • Full operation achieved after 14 days – compared to up to 4 months • Total installation costs significantly lower than a 1:1 replacement

• Screenings effectively reduced by the cutting system, improving downstream handling • Stable operation with 100 % uptime for nearly 3 years

• Plant type: Municipal WWTP Digesters: Digester diameter

16.8 m

Digester volume

7,600 m3

Substrate characteristics

sludge from WWTP

Average TS, input

4 % TS

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One Upgrade.

Big Results.

Gigablok WWTP LOCATION: Poland

To improve efficiency and reduce operating costs, the plant needed to replace its outdated digester mixing system, which had led to insufficient mixing and unstable process conditions.

Gigablok therefore upgraded to a Landia GasMix system, where all mechanical components are located outside the digestion chamber, eliminating the risk of internal mechanical failures. The installation was completed without emptying the chambers, minimizing both costs and operational downtime.

Results: • More stable fermentation process • Improved sludge decomposition • Reduced risk of process disruptions • Lower installation impact

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When mixing finally works.

Dabrowa Górnicza WWTP LOCATION: Poland

Digesters:

In February 2026, Landia successfully finalized a mixing system upgrade project at another wastewater treatment plant in Poland. The facility Dąbrowa Górnicza operates three anaerobic tanks, each 16.75 m height and 1,757 m³.

One of the digesters had begun showing signs of reduced process efficiency due to inadequate mixing. The existing mixing equipment had become outdated, resulting in poor circulation and process instability.

Landia GasMix

Digester diameter

14 m

Height

16.75 m

Digester volume

1,757 m³

TS

2-3 %

No. of tanks

1

To address this issue, the customer decided to install a Landia GasMix system in the affected tank. The system was commissioned and operational within a short timeframe.

Already within the first month of operation, the plant reported significantly improved mixing performance and overall process stability. The results have been sufficiently positive that the customer is now considering upgrading the mixing systems in the two remaining anaerobic tanks as well.

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Simplicity at Low Power Demand.

Kawana STW LOCATION: Australia

The digester is equipped with a single Landia GasMix mixer with an installed motor power of 18.5 kW. The system operates intermittently (on/off), providing reliable mixing and circulation of the digester contents.

Actual power consumption during operation is approximately 7-8 kWh.

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Kawana Sewage Treatment Works is a major wastewater treatment facility on the Sunshine Coast in Queensland, Australia, serving areas such as Maroochydore, Mooloolaba, and Kawana. It treats municipal wastewater before the treated water is released or reused.

Digesters Digester diameter

10.0 m

Digester height - total

11.5 m

Volume

800 m³

Substrate

Waste activated sludge

TS

3-4 %

Type of tank

Concrete

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Smarter Digester Mixing.

Radegast WWTP LOCATION: Germany

In cooperation with Landia, ReTech Resources Technology has installed an external sludge recirculation system in Germany.

By placing all mechanical components outside the digester, maintenance becomes safer and easier, while equipment is protected from corrosion and wear.

The system improves process stability and energy efficiency, supported by modern sensors for precise monitoring and control.

In addition, ReTech Resources Technology has developed a separator for hair, fibres and microplastics.

This patented unit is installed upstream of the digester, removing inorganic materials before the sludge enters the tank.

The result is better use of digester volume, fewer operational disturbances, and increased biogas production.

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Results: • Complete tank mixing without dead zones • Minimized foam formation and sediment build-up • Reduced internal power consumption • Robust and stable process performance

Landia GasMix

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