Abstract
The simple and effective removal method of fluoride ions in wastewater has been investigated by using a powdery fine calcium oxide as the removal reagent for fluoride ions.
It was found that the treatment using the calcium oxide could reduce fluoride ions to a lower level below 8 mg · dm-3 than the use of industrial calcium hydroxide and that the treatment is made further efficient by multiple addition method of the calcium oxide, i.e., it was found that only 0.5 mass% calcium oxide in the wastewater containing large amount of fluoride ions (200 mg · dm-3) is fully enough to treat the wastewater.
The technology of treating wastewater containing fluoride ions by adding the calcium oxide seems to be simple and effective method overcoming the disadvantages of the conventional treatment method using calcium hydroxide and high aluminum salts.
