New solar sewage sludge drying plant in Kodersdorf successfully in operation since April 2025

Kodersdorf in Saxony lies on the River Weißer Schöps and is nestled in a picturesque landscape between the Königshain Mountains and the Upper Lusatian Lakeland, in the immediate vicinity of Görlitz. The sewage treatment plant is located in the industrial estate; its capacity was expanded from 4,500 p.e. to 7,500 p.e. in 2023. The plant operates using aerobic sludge stabilisation.

As part of the capacity expansion, a new pre-treatment system was installed, comprising a HUBER Complete Plant ROTAMAT® Ro5 100 and a HUBER Rotary Drum Fine Screen ROTAMAT® Ro2 1000/3. A second sludge storage tank and a HUBER Screw Press Q-PRESS® 440.2 for stationary sludge dewatering were also installed, creating the conditions for modern sewage sludge drying. Subsequently, the plant was equipped with a solar sludge drying system as a sustainable and future-proof solution. Since its successful commissioning in April 2025, the system has been in continuous operation throughout the first drying season, proving itself to be reliable and stable while delivering consistently excellent results.

Premiere of the HUBER Sludge Turner SOLSTICE® FloorRunner

The municipality of Kodersdorf installed this new, fully automated plant design, enabling unmanned, autonomous operation. While the plant does require monitoring, adjustment and maintenance, the drying process itself runs entirely without staff.

The entire process, from low-viscosity sludge to finished dry granulate, is automated. This significantly reduces the workload for operating staff and makes the Kodersdorf sewage treatment plant particularly future-proof, especially in view of the growing shortage of skilled workers.

Details of the process

A HUBER Screw Press Q-PRESS® 440.2 dewaters around 150 tonnes of dry matter annually to approximately 20–23% dry residue. The approximately 730 tonnes of dewatered sewage sludge are then conveyed by a HUBER Screw Conveyor Ro8 TSF to the solar sewage sludge dryer.

There, the HUBER Sludge Turner SOLSTICE® FloorRunner takes over; Kodersdorf was the first site to use this newly developed model. The machine spreads the sludge across a 660 m² drying area. The drying hall is a 68 m long, 12 m wide greenhouse structure equipped with controlled fans.

Through the combination of

• gentle sludge turnover by the FloorRunner
• air turbulence from the fans
• accumulated heat in the greenhouse
• and direct sunlight

the sludge achieves an annual average dry residue of over 80%. Approximately 550 tonnes of water evaporate in the process each year. This leaves around 180 tonnes of dry granulate with a density of approximately 0.8 kg/l.

A HUBER Screw Conveyor Ro8 TSD and a bucket elevator are used for automated sludge discharge. The dry granulate is then distributed into two containers by the elevator. Consistent use of HUBER machinery ensures a perfectly coordinated system.

A particular technical advantage is that the FloorRunner can transport sludge in a targeted manner, thus enabling the feed and discharge points to be arranged compactly on the same gable side. This allowed the greenhouse structure to be built right up to the property boundary in a space-saving manner, without the need to construct a rear access road.

Proven technology and successful real-world operation

The FloorRunner was extensively tested in a prototype plant at HUBER SE’s headquarters prior to its first delivery. All findings from these tests were incorporated into the system design for implementation in Kodersdorf. Representatives from the engineering firm IBOS and the Weißer Schöps/Neiße Administrative Association had the opportunity to observe the system’s functionality and efficiency first-hand in advance.

Since commissioning in April 2025, the plant has consistently produced outstanding results in real-world operation. The first full drying season was completed without any significant incidents. The plant is performing exactly as planned, confirming the confidence placed in HUBER’s mature, highly automated technology.

Sludge turner now available worldwide

Following the successful tests and impressive performance in Kodersdorf, HUBER SE is now offering the HUBER Sludge Turner SOLSTICE® FloorRunner worldwide. The solar sewage sludge drying plant in Kodersdorf serves as an important reference installation. The consistently high quality of HUBER products, combined with their high operational reliability and autonomous plant operation, is sure to continue impressing customers around the world.