Hard water is water that has high mineral content, typically containing high levels of calcium and magnesium ions. The main cause of hard water is the natural process of water passing through rocks and soil, dissolving minerals along the way. The presen

What is Hard Water?

Concept

Although water is typically clear, odorless, colorless, and tasteless, it still contains various minerals and chemicals.

Beneficial minerals in water can contribute to the health of consumers, but if the concentration of certain minerals exceeds a certain level, it will result in hard water.

Composition of Hard Water

Hard water is water that contains a high concentration of dissolved minerals in the form of ions, increasing the water's hardness. The most common are metal cations, such as Calcium (Ca 2+) and Magnesium (Mg 2+), present in 1 liter of water. The levels of these substances are beyond the permissible range, exceeding the standard for safe water sources.

For example, if the total concentration of Ca 2+ and Mg 2+ exceeds 300 mg/liter of water, it is considered hard water. Additionally, other types of cations such as iron, aluminum, manganese can also be found in certain water sources.

Due to the high calcium content in water, it is also known as limestone water. This type of water has negative effects on human life and leads to many negative consequences for users and the environment.

Causes of Hard Water

Water is a very good solvent, capable of absorbing and dissolving impurities easily. The formation of hardness in water can be attributed to the following reasons:

Originating from the Source

Water starts flowing from the source, passing through various environments such as soil and rocks. During this journey, water carries along various minerals and dissolves a small amount, while the rest remains unchanged.

Each time it passes through a rock formation, water will continue to accumulate and dissolve these minerals, notably Ca2+ and Mg2+. Eventually, the concentration of these minerals will gradually become sufficient to impart a high degree of hardness to the water, creating harmful hard water sources.

In Underground Water Channels

Secondly, water in underground channels passes through various layers of minerals such as rock layers, limestone layers, and sediments, each layer carrying a certain amount of heavy metal ions, accumulating to the final layer with a high concentration of mineral ions exceeding the threshold, resulting in hard water. Water in ponds, lakes, rivers, and streams also becomes harder due to this phenomenon.

However, in many provinces and cities, the issue of hard water has not been thoroughly addressed during water treatment, directly impacting the health and daily activities of individuals.

Effects of Hard Water

This type of water has extremely serious effects on human health, daily life, and various industries. Specific effects of hard water include:

On Human Health

• Regular use for bathing or personal hygiene can lead to dry skin and hair.
• When this water enters the body along with bicarbonate salts, it forms calcium carbonate precipitate Ca(HCO3)2 that cannot pass through the intestines and arteries, remaining in the body. Over time, this salt buildup can lead to the formation of stones or, more severely, become an obstruction causing blockages in arteries, reducing blood flow to nourish the body.
• When used for cooking, making tea, coffee, etc., it alters the taste of food and beverages. Additionally, when herbs are brewed with highly hard water, it can alter the composition of the herbs, causing harm to users.

On Daily Living Environment

Impact on Objects

• Items in the kitchen used for cooking, such as kettles, water heaters, etc., are prone to scaling at the bottom or becoming objects, reducing the lifespan of the products.
• Formation of yellow stains, rust, blockages in pipelines, faucets, or water tanks.
• Calcium carbonate salts from limestone-contaminated water undergo chemical reactions to form deposits at the bottom of water heaters, reducing the heat conduction and transfer capabilities of the equipment, leading to excessive energy consumption compared to normal, resulting in wastage.

Impact on Clothing

Reduces the foaming ability of soap, limiting the cleaning function due to the formation of insoluble calcium salts. Clothes washed with hard water for a long time will become dull and the fabric will deteriorate quickly.

On Industrial Production Processes

• When the water hardness exceeds the permissible limit, some industries cannot use hard water for operations, processing, requiring companies to soften the water before use.
• If hard water is continuously used in production lines, it damages equipment, machinery, affecting daily work output and causing significant losses to businesses. Particularly for equipment such as boilers, refrigeration equipment, or heating and cooking devices, prolonged use of hard water can create high pressure, leading to fire hazards.

Types of Hard Water

Temporary Hard Water

Temporary hard water is caused by the components of salts such as Ca(CO3)2, Mg(HCO3)2 (these salts carry calcium Ca 2+, magnesium Mg 2+ cations, and HCO3 - anions).

Typically, in daily life, if temporary water is boiled (exists at high temperatures), it will undergo thermal decomposition to form insoluble substances in water, reducing hardness due to bicarbonate salts.

Permanent Hard Water

Permanent hard water differs in that it does not reduce hardness at high temperatures because the hardness of this water is caused by salts like MgSO4, MgCl, CaCl2, CaSO4. These types of salts do not undergo thermal decomposition or form precipitates when boiled, requiring the use of specific water softening agents.

Total Hard Water

Total hard water is a combination of the two types mentioned above, meaning this water contains all the salts from both types: Ca(HCO3)2, Mg(HCO3)2, CaSO4, CaCl2, MgSO4, MgCl2. The method of softening total hard water involves a combination of both softening methods from the two types of water, meaning using both boiling and chemical methods to reduce the water hardness.

Reputable Hard Water Treatment Services in Hanoi

At Toan A JSC - a provider of high-quality ion exchange resins, advanced chemicals, or cutting-edge filtration materials that support well in the process of treating hard water, ensuring the safety and purity of the finished water according to usage needs. The products sold at Toan A have clear origins, carrying top-quality reputable brands in the market at competitive prices.

You can confidently use the products here, place orders through the website, or contact the Hotline 0913.543.469 for quick advice and support from experienced specialists to understand this type of water and find suitable softening methods.