Boiling water is often used for purification, with many assuming it removes various impurities. A common question concerns its effectiveness against fluoride, a mineral found in public water supplies. This article clarifies what happens to fluoride when water is boiled and outlines effective methods for its reduction. Understanding these processes helps in making informed decisions about water quality.
Boiling Water and Fluoride Concentration
Boiling water does not remove fluoride; instead, it increases its concentration. When water boils, pure water (H2O) evaporates as steam, leaving behind dissolved solids and minerals, including fluoride, in the remaining liquid. This process is similar to boiling salt water, where the water evaporates but the salt remains, resulting in a more concentrated solution.
The chemical compounds that make up fluoride are stable and do not break down or evaporate at boiling temperatures. Consequently, individuals who boil water in an attempt to reduce fluoride levels are inadvertently increasing its concentration. While boiling effectively kills bacteria and reduces chlorine, it is not a suitable method for fluoride removal.
Practical Methods for Fluoride Reduction
Since boiling water is ineffective for fluoride removal, other proven methods exist to reduce its presence in drinking water.
Reverse Osmosis (RO) Systems
RO systems are highly effective for removing a broad range of contaminants, including fluoride. They operate by forcing water through a semi-permeable membrane that has extremely small pores, blocking the passage of fluoride ions and other impurities while allowing purified water to pass through. RO systems can reduce fluoride levels by a significant amount, often removing over 90% of the fluoride present in tap water.
Distillation
Distillation is another highly effective method for fluoride removal. In this method, water is heated to its boiling point, turning it into steam, which leaves behind dissolved solids like fluoride in the boiling chamber. The steam is then collected and condensed back into pure liquid water, resulting in water that is virtually free of fluoride and many other contaminants.
Activated Alumina Filters
These filters contain a granular form of aluminum oxide designed to adsorb fluoride ions from water. Unlike standard activated carbon filters, which are generally not effective at removing fluoride due to the small size of fluoride molecules and their inability to easily adhere to activated carbon, activated alumina is specifically engineered for this purpose. While activated alumina filters can be effective, their efficiency can be influenced by water pH, and they often require frequent replacement to maintain optimal fluoride reduction.