Fluoride naturally enters groundwater from rocks. While low levels strengthen teeth, excess causes fluorosis, harming teeth and bones. Affected Indian regions include Rajasthan, Andhra Pradesh, and Karnataka. Safe limit is 1.5 mg/L. Removal methods include Activated Alumina, Reverse Osmosis, and the Nalgonda Technique, especially used in rural areas.
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Excess Fluoride in the Groundwater can harm people’s health if they drink water with high levels of it.
Fluoride is a natural mineral that exists in the Earth's crust. It often mixes with water when rain or rivers flow through rocks containing fluoride compounds. This process adds fluoride to groundwater, which is the water under the Earth's surface.
The national drinking water limit for fluoride is 1.50 mg/L.
The most affected groundwater fluoride endemic regions are the northwestern states of Rajasthan, Gujarat, Punjab, Haryana, and Delhi and southern states of Andhra Pradesh, Telangana, Karnataka, and Tamil Nadu.
Fluoride in groundwater can be both helpful and harmful, depending on its concentration.
Helpful Side: Small amounts of fluoride are good for teeth. They make enamel stronger and prevent cavities. Many countries even add fluoride to drinking water to improve dental health. For example, if you drink water with the right amount of fluoride, your teeth stay healthier.
Harmful Side: Too much fluoride is dangerous. High levels can cause a condition called fluorosis. In children, it leads to discolored or weak teeth. In severe cases, excessive fluoride harms bones, causing pain or stiffness. For example, in some parts of India and Africa, people suffer from bone problems because their groundwater has very high fluoride levels.
Activated Alumina: Scientists pass water through filters made of activated alumina, which traps fluoride. For example, a water treatment plant uses this method to purify drinking water before supplying it to homes.
Reverse Osmosis: This process forces water through a thin membrane that blocks fluoride and other impurities. Imagine squeezing juice through a fine strainer to remove seeds—this works similarly.
Nalgonda Technique: This method mixes water with chemicals like aluminum sulfate (alum), lime, and bleaching powder, to bind fluoride, which then settles at the bottom. Workers remove the clean water from the top. Villages without advanced technology often use this method.
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PRACTICE QUESTION Q. In the question given below, there are two statements marked as Assertion (A) and Reason (R). Mark your answer as per the codes provided: Assertion (A): Boiling fluoride-contaminated water before drinking does not effectively remove fluoride. Reason (R): Fluoride salts have high boiling points and are non-volatile. Which of the options given below is correct? A) Both A and R are true, and R is the correct explanation for A. B) Both A and R are true, but R is not the correct explanation for A. C) A is true, but R is false. D) A is false, but R is true. Answer: A Explanation: Assertion (A) is True: Boiling targets microorganisms and removes some volatile substances, but it doesn't eliminate dissolved minerals or salts like fluoride compounds. Reason (R) is True: The fluoride present in water is usually in the form of dissolved ionic salts (like sodium fluoride or calcium fluoride). These salts have high boiling points, much higher than water's, and they do not readily evaporate (they are non-volatile) when water boils. The reason boiling fails to remove fluoride is that the fluoride compounds are non-volatile. They don't turn into gas and escape with the water vapor; instead, they stay dissolved in the remaining liquid water. |
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