Water output index and water quality standard of pure water equipment
China's water resources are relatively abundant, and the amount of water output is relatively large. The drinking water requirements are very strict. The water output indicators and water quality standards of pure water equipment are also restricted accordingly. Those that fail to meet the requirements will be dealt with according to law.
Water hardness standard
Untreated water contains more metal ions and impurities. The concentration of these metal ions in water is usually referred to as the hardness of the water. The metal ions contained in water are mainly calcium ions and magnesium ions. In the process of water heating, evaporation and concentration will form white scale. There are carbonate ions (Co32-), bicarbonate ions (HCO3-), sulfate ions (SO42-), chloride ions (Cl-), and other negative ions in the raw water. These negative ions will interact with the positive ions calcium, magnesium ions The reaction produces harmful substances such as nitrate.
Water resistance value <br /> Water has a certain conductivity. The resistance value of water is inversely proportional to the conductivity. The higher the resistance value is, the worse the conductivity is. The resistance value of water is strongly related to the salt, ion concentration, and ion movement contained in the water. In treated water, ultrapure water has the largest resistance, which contains very few ions, followed by purified water. Mineral water is rich in mineral elements, so it has the best conductivity.
Electrical conductivity of water <br /> The electrical conductivity of water is calculated using the formula: S = 1 / R, S = (1 / ρ) • (F / L), and 1 / ρ is called electrical conductivity. Water contains a certain amount of salt. When the electricity is applied, the charged ions will move, negative ions will move to the anode, and cations will move to the cathode. This will form the conductivity of water. Electrical conductivity is the strength of the electrical conductivity of water. Conductivity reflects the salt content of a tax.
The unit of hardness is usually mmol / L or mg / L. The equivalent concentration N commonly used in the past has been discontinued. When converted, 1N = 0.5mol / L
Since hardness is not formed by a single metal ion or salt, in order to have a uniform comparison standard, it is necessary to convert it to another salt. It is usually expressed by the mass concentration of Ca0 or CaCO3. When the hardness is 0.5 mmol / L, it is equal to 28 mg / L of CaO, or equal to 50 mg / L of CaCO3. In addition, some countries use German and French degrees to indicate hardness. 1 German degree equals 10mg / L CaO, 1 French degree equals 10mg / L CaCO3. 0.5mmol / L is equivalent to 208 German degrees and 5.0 French degrees.
PH value of water <br /> The pH value of water is the negative logarithm of hydrogen ion concentration in water, expressed as: pH = -lg [H +] pH value is sometimes called hydrogen ion index. From the concentration of hydrogen ions in the water, it can be known whether the aqueous solution is alkaline, neutral or acidic. Because the value of hydrogen ion concentration is often very small, it is very inconvenient to apply, so the concept of pH is used as an indicator of acidity and alkalinity of the aqueous solution. In addition, the negative logarithmic value of the hydrogen ion concentration can just show the number and size of the change range of acidity and alkalinity, which is very convenient to apply. And thus get:
(1) Neutral aqueous solution, pH = -lg ［H +］ =-lg10-7 = 7
(2) Acidic aqueous solution, pH <7, the smaller the pH value, the stronger the acidity. (3) Basic aqueous solution, pH> 7, the greater the pH value, the stronger the acidity. Water quality is further classified in detail, and you can get:
(1) Strong acidic aqueous solution, pH <5.0
(2) Strong acidic aqueous solution, pH = 5.0-6.4
(3) neutral aqueous solution, pH = 6.5-8.0
(4) Weak alkaline aqueous solution, pH = 8.1-10.1
(5) Strong alkaline aqueous solution, pH> 10.0
Suspended matter in water
The suspended matter in the water is particles with a particle diameter of about 10-4 mm or more, which is visible to the naked eye. These particles are mainly composed of sediment, clay, protozoa, algae, bacteria, viruses, and high molecular organic matter, etc., which are often suspended in the water stream, resulting in water turbidity. These particles are unstable and can be removed by precipitation and filtration. When the water is standing, heavy particles (mainly inorganic substances such as sand and clay) will sink. Light particles (mainly organic compounds such as plants and animals and their remains) will float on the water surface and can be removed by filtration or other separation methods. Suspended matter is the main source of turbidity, color and odor. Their content in water is also unstable and often varies with seasons and regions.
Pure water equipment effluent indicators and water quality standards are provided by Henan Zhonglan Water Treatment Engineering Co., Ltd.