Environment, health and safety

Which is a typical treatment method for wastewater containing hydrofluoric acid?

  1. ADischarge it directly into a river
  2. BHeat it to evaporate only the water
  3. CAdd calcium compounds to precipitate it as calcium fluoride and remove it
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Answer: C. Add calcium compounds to precipitate it as calcium fluoride and remove it

Calcium compounds such as slaked lime are added to fluoride-containing wastewater to precipitate poorly soluble calcium fluoride (CaF2), which is removed. Treated wastewater is discharged only after confirming that it meets legal and local discharge standards.

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