Actina™ Pellet Softening Process

To soften hard water, Veolia Water Technologies has developed Actina™, a pellet softening process tailored to municipal drinking water softening. By reducing calcium hardness, Actina™ allows municipalities and industries to enhance the asset management of their distribution network while preventing negative impacts on the end users. This solution also allows a significant reduction of impacts on downstream on-site or centralized wastewater, groundwater, and well water treatment.

Operating principle

The Actina™ process is based on the pellet softening principle, which consists in modifying the calcium-carbon equilibrium in the water to be treated. Soda or lime injection is used, causing limestone crystallization on the sand. 

Actina™ is composed of a vertical reactor in which a bed of sand is maintained in fluidization, thanks to the pumping of water to be softened. This very fine sand is used as a crystallization seed for the pellet softening reaction, that is to say, the calcium carbonate’s precipitation on the surface of grains of sand. The highly basic pH that enables crystallization is obtained by alkaline (soda or lime) addition to the reactor base.

The calcium carbonate thereby removed presents as beads, a few millimeters in diameter that are easily storable, transportable and recoverable. The use of a fluidized bed allows Actina™ to run with high rising rates, around 32 to 90 gpm/sf and results in a smaller footprint.


  • Veolia’s more than 35 years of expertise in pellet softening;
  • Compactness, simplicity and reliability of operation;
  • Robustness and additional barriers against iron, manganese and metals;
  • No limit on calcium hardness removal 
  • >media regeneration not required;
  • Energy savings
  • >unlike an electric carbonate removal system;
  • No associated sludge treatment needed
  • No brine to dispose of