How to measure water hardness?

People often drink water and use water in their daily lives. Everyone knows that water is composed of hydrogen and oxygen, but there must be many people who don’t know the hardness of water. In fact, water hardness is an important indicator for evaluating water, because the water we drink usually contains many substances, such as some minerals. It is very important to choose water with moderate hardness to drink. So how do you detect the hardness of water in your daily life?

Methods for measuring water hardness:

You can add a large amount of ammonium carbonate and then weigh the mass of the precipitate.

The hardness of water refers to the content of salt substances dissolved in the water, that is, the content of calcium salt and magnesium salt. The total amount of calcium and magnesium ions is equivalent to 10 mg of calcium chloride, which is called 1 "degree". Usually based on hardness

Water is divided into hard water and soft water according to its size: below 8 degrees is soft water, 8 to 16 degrees is medium water, above 16 degrees is hard water, and above 30 degrees is extremely hard water.

Hardness is divided into temporary hardness and permanent hardness. The hardness formed by the presence of calcium bicarbonate and magnesium bicarbonate in the water can be removed after boiling. This hardness is called temporary hardness, also known as carbonate hardness. The hardness formed by the presence of salt substances such as calcium sulfate and magnesium sulfate in the water cannot be removed after boiling and is called permanent hardness. The above two types of hardness, temporary and permanent, are collectively called total hardness.

The country's "Sanitary Standards for Domestic Water" stipulates that the total hardness of water shall not exceed 25 degrees. If the hardness is too high, drinking it will have a certain impact on human health and daily life; if someone who does not drink hard water regularly occasionally drinks hard water, it will cause gastrointestinal dysfunction, the so-called "water and soil incompatibility". If you use hard water to cook fish or vegetables, their nutritional value will be destroyed or reduced because they are difficult to cook. Using hard water to brew tea will change the color, aroma and taste of the tea and reduce the pleasure of drinking it. Using hard water to make tofu will not only reduce the yield but also affect the nutritional content of the tofu. The hardness of water used for brewing wine must not exceed 4 degrees, otherwise the wine will be turbid and the taste will be affected.

China has a vast territory, and the hardness of water varies from place to place. But in general, the water hardness in plateau and mountainous areas is generally higher, the water hardness in plains and coastal areas is relatively low, and the hardness of groundwater is generally higher than that of surface water. Generally, the suitable hardness of drinking water is between 10 and 20 degrees.