| 摘要 |
To remove fluoride from raw water, whether the fluoride is in solution as an ion or in the form of a colloidally-dispersed salt, calcium ions are first introduced into the water. The resultant calcium fluoride is adsorbed on a floc during passage of electric current through the raw water. The floc may be formed from organic matter already present in the raw water or from diatomaceous earth floc in a separate operation, the diatomaceous earth floc then being added to the raw water. Adsorption on floc whether originating in organic matter or in diatomaceous earth is facilitated by the passage of electric current through the raw water and by the addition of a surfactant.
|
