Defluoridation of Water

Water defluoridation is the process of removing fluoride from water in order to reduce its concentration to a safe level. Excess fluoride in drinking water can cause fluorosis, a disease of the teeth and bones.

There are several methods for defluoridating water:

1. Adsorption on activated carbon or aluminum oxide. These adsorbents absorb fluoride ions from water.

2. Reverse osmosis. Water is passed through a semi-permeable membrane, which retains fluoride ions.

3. Coagulation using aluminum or iron salts. The resulting flocs carry away fluoride.

4. Electrodialysis. Fluoride ions move from water to concentrate under the influence of an electric field.

5. Ion exchange. Fluoride ions are retained by the ion exchange resin, and hydroxide or chlorine ions pass into the water.

Defluoridation is necessary for regions with high fluoride content in groundwater. This process produces drinking water that is safe for human health.