What Are the Pros and Cons of Drinking Hard Water?

Hard water refers to water containing more soluble calcium and magnesium compounds. Hard water is not a direct health hazard, but it can cause a lot of troubles in life, such as scaling on water appliances, and reduced washing efficiency of soap and detergent.

When water condenses in the atmosphere, it reacts with carbon dioxide in the air to form what is called

Water is a good solvent and can effectively remove dirt and impurities. Pure water-colorless, odorless, and odorless. It is called a "universal solvent". When no specific solvent is mentioned, the solvent will default to water. When water and carbon dioxide are combined to form a trace amount of carbonic acid, the dissolution effect of water is better. When water flows over the land and

Hard water is not a direct health hazard. In fact, according to the National Research Council,

Grading

Generally speaking, "hard water" and "soft water" mainly refer to the content of calcium carbonate and magnesium carbonate, expressed as "mg of calcium carbonate / liter of water" or "ppm", which is called water hardness.

Water hardness is generally divided into 4 levels:

1. Soft water: 0-60ppm

2. Slightly hard water: 60-120ppm

3. Hard water: 120-180ppm

4. Extremely hard water: 181ppm or more

Hard water requirements

When the hardness of the water is too high, it is not delicious to drink, and it is easy to produce white precipitated scale in the water. If the scale is attached to a heating container or heater, it will extend the heating time and waste energy. When the hardness of the water is high, soap is not easy to foam, and more detergent is wasted. After the scale enters the body, it cannot be absorbed and is the enemy of health.

In this increasingly polluting industrial society, the problem of water is not just hardness or the amount of total dissolved solids. Pollutants in the water include bacteria, microorganisms, chlorine and organic substances. There are a variety of water filters on the market that can help us remove pollutants, but due to different methods of treating water quality, the ability to remove is also different.

Known methods for treating drinking water include:

Add an ammonia buffer solution with pH = 10.0 and a little chrome black T indicator to a water sample. The solution is red. With the EDTA standard solution titration, EDTA first coordinates with free Ca ²⁺ and then with Mg ²⁺ Coordination; at the point of measurement, EDTA captures Mg ²⁺ from MgIn-, so that the indicator is released, and the color of the solution changes from red to pure blue, which is the end point.

When there is very little Mg ^{2 + in the} water sample, because the color rendering sensitivity of CaIn ^-is much worse than that of MgIn-, the sharp end point is often not obtained. In order to improve the sensitivity of endpoint discoloration, an appropriate amount of Mg ²⁺ can be added to the EDTA standard solution (before EDTA calibration, so that it does not affect the quantitative relationship between the titration of EDTA and the measured ion), or in a buffer solution. A certain amount of Mg-EDTA salt.

The total hardness of the water can be calculated from the concentration of the EDTA standard solution cEDTA and the consumption volume V (ml). In CaO, the unit is mg / L.