Raw water: Refers to untreated water. In a broad sense, the water before entering the water treatment process is also referred to as the raw water of the water treatment process. For example, the water sent from the water source to the clarification tank for treatment is called raw water.

Softened water: refers to water that removes or reduces the hardness of water (mainly calcium and magnesium ions) to a certain extent. During the softening process of water, only the hardness decreases, while the total salt content remains unchanged.

Demineralized water: refers to water in which salts (mainly strong electrolytes soluble in water) are removed or reduced to a certain extent. Its conductivity is generally 1.0-10.0 μ S/cm, resistivity (25 ℃) 0.1-100000 Ω. cm, salt content 1.5mg/L.

Pure water: refers to the strong and weak electrolytes (such as SiO2, C02, etc.) in water. Remove or reduce water to a certain extent. Its conductivity is generally 1.0-0.1 μ S/cm, resistivity 1.0-100000 Ω. cm. The salt content is less than 1mg/l.

Ultra pure water: refers to water in which the conductive medium is almost completely removed, while non dissociating gases, colloids, and organic substances (including bacteria) are also removed to a very low level. Its conductivity is generally between 0.1-0.055 μ S/cm, resistivity (25 ℃) ＞ 10 × 1000000 Ω. cm, with a salt content of<0.1mg/l. The ideal pure water (theoretically) has a conductivity of 0.05 μ S/cm, resistivity (25 ℃) is 18.3 × one million μ S/cm.

1. Demineralized water refers to the finished water obtained by using various water treatment processes to remove suspended solids, colloids, inorganic cations, anions, and other impurities in the water. Demineralized water does not necessarily mean that all salts in the water are completely removed. Due to technical reasons and considerations of water production costs, depending on different uses, it is allowed to contain trace impurities in the desalinated water. The less impurities in the desalinated water, the higher the purity of the water.

2. The hardness of water is mainly composed of cations: calcium (Ca2+) and magnesium (Mg2+) ions. When the raw water containing hardness passes through the resin layer of the exchanger, the calcium and magnesium ions in the water are adsorbed by the resin, while releasing sodium ions. In this way, the water flowing out of the exchanger is softened water without hardness ions. When the resin adsorbs calcium and magnesium ions to a certain saturation, the hardness of the water increases. At this time, the water softener will automatically regenerate the failed resin according to the predetermined program, Use a high concentration of sodium chloride solution (saline water) to pass through the resin and restore the failed resin to a sodium type resin.

Desalted water

Overview:

Demineralized water refers to the finished water obtained by using various water treatment processes to remove suspended solids, colloids, inorganic cations, anions, and other impurities in the water. Demineralized water does not necessarily mean that all salts in the water are completely removed. Due to technical reasons and considerations of water production costs, depending on different uses, it is allowed to contain trace impurities in the desalinated water. The less impurities in the desalinated water, the higher the purity of the water. In production practice, people start from the concept of desalinated water and use different terms to distinguish the purity of desalinated water. For example, in boiler feed water treatment, water with a conductivity less than 3uS/cm (25 ℃) is usually referred to as distilled water, water with a conductivity less than 5us/cm (25 ℃) and a SiO2 content less than 100ug/L is referred to as primary desalinated water, water with a conductivity less than 0.2us/cm (25 ℃) and a SiO2 content less than 20ug/L is referred to as secondary desalinated water, water with a conductivity less than 0.2us/cm (25 ℃), Cu, Fe, Na content less than 3ug/L, and SiO2 content less than 3ug/L is referred to as high-purity water or ultrapure water.

Salt content in water is the reason why water conducts electricity. The higher the salt content of water, the smaller the resistance, and the stronger the conductivity. In other words, the strength of water's conductivity is an inevitable reflection of the high or low salt content of water. The conductivity of water is easily measured using a conductivity meter. The conductivity of water can be used to measure its purity. Because water temperature has a significant impact on conductivity, generally for every 1 ℃ increase in water temperature, the conductivity increases by about 2%. Therefore, the conductivity should indicate the water temperature. The conductivity of various ions varies, so water with the same conductivity may also have different types and contents of impurities. The conductivity generated by H and OH - only ionized by water at 25 ℃ is 0.555us/cm, which is the theoretical limit for the purity of desalinated water. Conductivity and resistivity are reciprocal to each other, i.e. conductivity=1/resistivity, for example, 0.2us/cm=5M Ω. cm.

The above definitions and water quality standards for desalinated water have not yet been fully unified, especially the differences between different industries.

Research on heart disease and cancer has shown that healthy water is water with a certain hardness and TDS content. Demineralized water, as a type of artificially softened or purified water, does not contain calcium or magnesium, and has low total dissolved solids. Drinking it is not conducive to health.

However, many people still drink it for their own reasons. Usually, they think this way: I know I should drink water, but the water is contaminated with various chemicals such as chlorine and toxic metals, which is not safe at all. Therefore, I bought a distiller or reverse osmosis device, which can remove all substances from the water, making it suitable for drinking. Do these words sound familiar?

When we think this way, we only see a part of something, not the whole. We only emphasized the harmful components in water, but did not understand the beneficial components. In order to drink healthy water, we must look at the problem from two aspects: we need to significantly reduce or eliminate harmful substances, but still need to retain beneficial minerals in the water. In most cases, appropriate filtration systems or bottled mineral water can meet the requirements - desalination water cannot!

Proponents of drinking desalinated water claim that inorganic minerals (such as calcium, magnesium, selenium, etc.) in water cannot be metabolized and therefore do not cause health problems, but this is incorrect.

In fact, minerals in water are more easily and better absorbed by the human body than those in food! Dr. John Sorenson, an authority on mineral metabolism theory (Western medicine chemist), said, "Minerals in drinking water can be well absorbed. He found that the ratio of major metal elements to non major elements involved in metabolism is greatly influenced by the quantity of major elements in water. If the required major elements are met, there is little or no absorption of non major elements, and non major elements will be excreted.

For example, if the content of calcium and magnesium in water is high but the lead content is low, the human body will choose the main elements (calcium and magnesium) and excrete the non main elements (lead); But if the content of calcium and magnesium is also low, cells may choose non major element lead, leading to dysfunction of protein or enzyme function. If this happens, the protein or enzyme may become toxic.

Distillers and reverse osmosis devices can produce softened, mineral free desalinated water, and the effect of any harmful substance in this soft water will be amplified. A small amount of harmful substance in desalinated water will have more harmful and negative effects on our health than the same amount of harmful substance in hard water. So, for completely different reasons, drinking contaminated water and desalinated water can cause harm to our health.

Working principle of softened water:

The hardness of water is mainly composed of cations: calcium (Ca2+) and magnesium (Mg2+) ions. When the raw water containing hardness passes through the resin layer of the exchanger, the calcium and magnesium ions in the water are adsorbed by the resin, while releasing sodium ions. In this way, the water flowing out of the exchanger is softened water without hardness ions. When the resin adsorbs calcium and magnesium ions to a certain saturation, the hardness of the water increases. At this time, the water softener will automatically regenerate the failed resin according to the predetermined program, Using a high concentration of sodium chloride solution (saline water) to pass through the resin, restore the failed resin to a sodium type tree Sodium type resin.

Features:

Soft water reduces or avoids the formation of scale, making it suitable for washing and bathing. In addition, it also avoids energy waste caused by scale in water pipes and reduces the efficiency of water equipment.

The main characteristics of soft water:

(1) Prevent household appliances such as water pipes, water heaters, coffee machines, humidifiers, steam electric irons, bathtubs, shower heads, and water closets from accumulating scale, often clogging, and low thermal efficiency.

(2) Hairdressing, dandruff removal and itching relieving, gentle and natural hairstyle. Skincare, bathing, and skin softening and smoothness, significantly reducing body dandruff. Makeup, the skin does not feel tight, making it easy to apply and remove makeup

(3) Making coffee and brewing tea leaves has a unique taste and a pure taste. Cultivate flowers to extend the flowering period, with spotless green leaves and bright flowers. Fish farming to prevent various fish diseases.

(4) The shelf life of tofu is extended, and soybean milk is more fragrant. The bean sprouts do not need auxin and grow strong. Wash vegetables, remove pesticide ingredients, and extend the freshness period of vegetables. Cook rice, shorten the time, make the rice grains soft and smooth, and the pasta is not easy to swell. Cook to maintain the natural taste and nutritional composition of vegetables.

(5) Effectively inhibit fungi, promote wound healing, and reduce the incidence of constipation, gastrointestinal and stone related diseases.

(6) Laundry, prevent static electricity, discoloration, and deformation, clean tableware, remove water stains, and improve the glossiness of utensils. Clean the kitchen and bathroom, effectively remove dirt and odors.

(7) Save expenses, reduce water equipment and pipeline maintenance costs by more than 60%, reduce hot water fuel costs by more than 30%, and reduce detergent purchase costs by more than 50%.

The applicable fields of softened water ：include bathrooms, kitchens, laundry, heating, boilers, central air conditioning equipment water supply, beauty and health care, and other fields.

(Source: New Horizon of Water Treatment)