Sludge Handling

High organic solids content in treatment plant processes

As wastewater treatment plants become larger and more sophisticated, so do the demands for handling large amounts of sludge, which is an expensive and complex operation. Pumps have got to handle high solids concentrations and are expected to provide continuous operation, high reliability and energy efficiency. Flygt has the proven experience and equipment to provide reliable and efficient solutions for handling sludge in the wastewater treatment process.

Secondary sludge pumping is part of the treatment plant process. It includes return activated sludge (RAS), which is continuously pumped back into the secondary biological treatment tank as part of the treatment process, and waste activated sludge (WAS), which is excess from settled sludge that is pumped to the sludge handling process.

Dewatering is typically the last step before disposal of sludge from secondary treatment and external sources. Sludge volume decreases by removing the water content in order to create a thicker and more manageable mass. Dewatering may also reduce handling costs and minimize leachates and odors at landfills.

After dewatering, the dry solids contents are significantly higher. This may cause high head loss in transporting the sludge for disposal or further treatment. Thickened sludge needs to be pumped downstream, directly to disposal or sludge storage. 

Understanding your challenges

  • Handling heavy concentrations of sludge is a complex process
  • Ability to handle heavy sludge with high concentration of solids (often up to 8-10 %)
  • Continuous duty operation
  • Maintaining a high pump efficiency


Sludge Pumping
Wastewater > Sludge Handling Sludge Pumping
Sludge Mixing
Wastewater > Sludge Handling Sludge Mixing
Sludge Areation
Wastewater > Sludge Handling Sludge Areation