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    Pellet softening

A very effective technology for the removal of hardness from water is pellet softening.

The technology is exceptionally suited for large-scale and centralized water treatment. Pellet softening is therefore frequently applied for the production of drinking water.

The name pellet softening originates in the waste product formed: small, rock-hard marble balls that are called pellets. Pellet softening is distinguished by the following advantages:

  • ompact installation, small footprint
  • Robust and reliable process
  • Simple and flexible operation
  • Low total cost of ownership (TCO)
  • Production of easily transportable and reusable waste product
  • Pellets produced can be delivered to the cement or metal industries, or in the livestock feed industry.


The heart of the pellet softening installation is the reactor. The pellet reactor is a reactor filled with fine-grain sand. Supply water and chemicals (caustic soda, lime wash or sodium carbonate) are injected into the bottom of the reactor and mixed intensively.

The chemicals increase the pH of the water so that calcium carbonate, lime, leaves the solution and crystallizes on the fine sand in the form of rock-hard balls, the pellets.

The pellets formed are fluidized by the upward force of the water. The pellets gradually grow. This makes them heavier, and the surface of the whole pellet bed becomes smaller. Large pellets also fluidize less well than small ones. In most applications, the pellets grow to about 1 mm. Through periodic removal of the large pellets and input of new fine sand, the composition of the pellet bed can be controlled.

Experience RWB

RWB has a great deal of experience with the realization of pellet softening installations. Pellet softening requires very specific knowledge and practical experience in order to be able to translate the theory into a problem-free, working solution. We not only have the know-why, but especially also the know-how that is needed in house.

RWB has experience with building from an existing design, but also on the basis of a completely new design. We have the ability to do pilot testing when it comes to specific applications.

Realized projects

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