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Water utilities circular: the reuse of softening pellets as seeding material in drinking water process

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Water utilities circular: the reuse of softening pellets as seeding material in drinking water process

Watercycle reference

In this improved softening process, the normally used sand is replaced by a calcite seeding material. The residual from this new process becomes then an almost pure calcite, which is centrally processed in ‘The Calcite Factory’ into new seeding material (so 100% circular) and raw material(s) for other economic sectors.

In traditional softening processes in the drinking water industry, calcite crystalizes on a nuclei of sand, resulting in a residual which consists of a sand core (3%) and a calcite mantle (97%). A residual difficult to recycle/reuse because of these two components.

In this showcase, the sand nuclei in this softening process is replaced by a calcite particle, resulting in almost 100% pure calcite as a residual. In a specially for this case developed factory (‘The Calcite Factory’) this residual is dried, sterilized, ground and sieved into various products. Maybe the most important product being 100% circular calcite seeding material.

This new chain has led to:

  • Cost savings of the softening process, because this circular product has proven to be more efficient in the softening process;
  • A next step in the ambition of the water utilities to become more circular in their use of materials;
  • Much higher sales values and therefore revenues for the –now- sand free softening pellets;
  • Proof that looking at a production process from a circular point of view leads to new, feasible and solid value chains.

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