Raw water refers to untreated water. Generally speaking, 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 in which the hardness (mainly calcium and magnesium ions) is removed or reduced to a certain extent. During the softening process of water, only the hardness decreases while the total salt content remains unchanged
Desalinated water refers to water in which salts (mainly strong electrolytes dissolved in water) are removed or reduced to a certain extent. Its conductivity is generally 1.0-10.0 μ s/cm, resistivity (25 ℃) 0.1-1000000 Ω. cm, and salt content is 1.5mg/L.
Pure water refers to strong and weak electrolytes (such as SiO2, CO2, etc.) in water. Remove or reduce water to a certain extent. Its conductivity is generally 1.0-0.1 μ s/cm, and its resistivity is 1.0-1000000 Ω· cm. Salt content<1mg/L.
Ultra pure water refers to water in which the conductive medium is almost completely removed, while gases, colloids, and organic substances (including bacteria) that do not dissociate are also removed to a very low degree. Its conductivity is generally 0.1-0.055 μ s/cm, resistivity (25 ℃)>10 × 1000000 Ω. cm, and salt content<0.1mg/L. The ideal pure water has a theoretical conductivity of 0.05 μ s/cm and a resistivity of 18.3 × 1000000 μ s/cm at 25 ℃.
Desalinated water refers to the finished water obtained by using various water treatment processes to remove suspended solids, colloids, inorganic cations, anions, and other water impurities. Desalinated water does not mean that all salts in the water have been completely removed. Due to technical reasons and considerations of water production costs, desalinated water is allowed to contain trace impurities according to different uses. The less impurities in desalinated water, the higher the water purity.
The hardness of water is mainly composed of cations such as calcium (Ca2+) and magnesium (Mg2+) ions. When raw water containing hardness passes through the resin layer of the exchanger, calcium and magnesium ions in the water are adsorbed by the resin, while sodium ions are released. The water flowing out of the exchanger is softened water with hardness ions removed. When the resin adsorbs calcium and magnesium ions to a certain saturation, the hardness of the effluent increases. At this time, the water softener will automatically regenerate the failed resin according to the predetermined program, using a higher concentration of sodium chloride solution (salt water) to pass through the resin and restore the failed resin to a sodium type resin.
Desalted water refers to the finished water obtained by using various water treatment processes to remove suspended solids, colloids, inorganic cations, anions, and other water impurities. Desalinated water does not mean that all salts in the water have been completely removed. Due to technical reasons and considerations of water production costs, desalinated water is allowed to contain trace impurities according to different uses. The less impurities in desalinated water, the higher the water purity. In production practice, people use different names to distinguish the purity of desalinated water based on the concept of desalinated water. For example, in boiler feedwater treatment, water with conductivity less than 3uS/cm (25 ℃) is usually referred to as distilled water, water with conductivity less than 5us/cm (25 ℃) and SiO2 content less than 100ug/L is referred to as primary desalinated water, water with conductivity less than 0.2us/cm (25 ℃) and SiO2 content less than 20ug/L is referred to as secondary desalinated water, and water with 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 for water conductivity. The higher the salt content of water, the lower its resistance, and the stronger its conductivity. In other words, the strength of water's conductivity is an inevitable reflection of its salt content. The conductivity of water can be 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, conductivity increases by about 2%. Therefore, conductivity should indicate water temperature. The conductivity of various ions varies, so water with the same conductivity may have different types and contents of impurities. The conductivity generated solely by the ionization of H and OH - in water at 25 ℃ is 0.555 us/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 definition and water quality standards for desalinated water are not yet fully unified, especially with significant differences between different industries. For example, some industries refer to water with conductivity less than O.lF6/cm (25 ℃), pH value of 6.8-7.0, and removal of other impurities and bacteria as high-purity water. In there. In some industries, desalinated water is also known as pure water, desalinated water, saltwater free water, and purified water.
Desalinated water contains little or no minerals, which can be achieved through distillation, reverse osmosis, ion exchange, or a combination of these methods.
Research on heart disease and cancer shows that healthy water is water with a certain hardness and TDS content. Demineralized water, as an artificially softened or purified water, does not contain calcium or magnesium and has a low total dissolved solids. Drinking it is not conducive to health. However, many people still drink it for their own reasons, usually thinking: I know I should drink water, but water is contaminated with various chemicals such as chlorine and toxic metals, which is not safe at all. So 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 like this, 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 retain beneficial minerals in the water. In most cases, appropriate filtration systems or bottled mineral water can meet the requirements - but desalinated water cannot! People who support drinking desalinated water claim that inorganic minerals (such as calcium, magnesium, selenium, etc.) in the water cannot be metabolized and therefore do not cause health problems, but this is incorrect. In fact, minerals in water are easier and better absorbed by the human body than those in food! Dr. John Sorenson, an authority in mineral metabolism theory and a 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 amount of major elements in water; If the required primary elements are satisfied, there will be little or no absorption of non primary elements, and non primary elements will be excreted. For example, if the content of calcium and magnesium in water is high and the content of lead is low, the human body will choose the main elements (calcium and magnesium) and excrete the non main elements (lead); But if the calcium and magnesium content is also low, cells may choose non essential element lead, leading to dysfunction of proteins or enzymes. If this happens, proteins or enzymes may become toxic. Distillers and reverse osmosis devices can produce softened, mineral free desalinated water. Any harmful substances in this softened water will be amplified, and a small amount of harmful substances in desalinated water will have more harmful and negative effects on our health than the same amount of harmful substances 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 such as calcium (Ca2+) and magnesium (Mg2+) ions. When raw water containing hardness passes through the resin layer of the exchanger, calcium and magnesium ions in the water are adsorbed by the resin, while sodium ions are released. The water flowing out of the exchanger is softened water with hardness ions removed. When the resin adsorbs calcium and magnesium ions to a certain saturation, the hardness of the effluent increases. At this time, the water softener will automatically regenerate the failed resin according to the predetermined program, using a higher concentration of sodium chloride solution (salt water) to pass through the resin and restore the failed resin to a sodium type resin. Soft water reduces or avoids the formation of scale, making it suitable for washing and bathing. In addition, it also avoids energy waste and reduced efficiency of water equipment caused by scale in water pipes. The main characteristics of soft water include: 1) preventing water pipes, water heaters, coffee machines, humidifiers, steam irons, bathtubs, shower heads, flush toilets and other household appliances from accumulating scale, frequently clogging, and low thermal efficiency. 2) Hairdressing, dandruff removal and itching relief, gentle hair, natural hairstyle. Skincare, bathing, soft and smooth skin, significantly reducing body dandruff. Makeup, the skin does not feel tight, making it easy to apply makeup and remove makeup. 3) Brewing coffee and brewing tea leaves has a unique taste and pure flavor. Nurture flowers, extend flowering period, leave no spots on green leaves, and have vibrant 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 components, and extend the shelf life of vegetables. Cooking rice shortens the time, the rice grains are soft and smooth, and the noodles are not easily swollen. Cooking to maintain the natural taste and nutritional content of vegetables. 5) Effectively inhibit fungi, promote wound healing, reduce the incidence of constipation, gastrointestinal and stone related diseases. 6) Laundry, prevent static electricity, discoloration, and deformation, clean tableware, clean without water stains, and improve the glossiness of utensils. Clean the kitchen and bathroom, effectively remove dirt and odors. 7) Save expenses by reducing water equipment and pipeline maintenance costs by over 60%, hot water fuel costs by over 30%, and detergent purchase costs by over 50%. The applicable fields of softened water include bathrooms, kitchens, laundry, heating, boilers, central air conditioning equipment water supply, beauty and health care, and many other fields.
