02 Jul 2024
Analysis of commonly used professional names in chemical water treatment
Analysis of commonly used professional names in chemical water treatment
1. Surface water: refers to water that exists on the surface of the earth's crust and is exposed to the atmosphere. It is a general term for four types of water bodies: rivers, glaciers, lakes, and swamps. It is also called "land water".
2. Groundwater: refers to water stored in the stratum voids below the aeration zone (the aeration zone refers to the geological medium located below the earth's surface and above the water table), including rock pores, cracks, and caves. Groundwater exists in the cracks of the earth's crust rocks or soil voids.
3. Raw water: refers to water collected from nature, including but not limited to groundwater, reservoir water, and other water sources that can be seen in nature, without any artificial purification treatment.
4. PH: represents the value of the acidity and alkalinity of the solution, pH=-lg[H+], which is the negative value of the common logarithm of the concentration of hydrogen ions contained.
5. Total alkalinity: the total amount of substances in water that can neutralize strong acids. Such substances include strong bases, weak bases, and strong base and weak acid salts.
6. Phenolphthalein alkalinity; it is the alkalinity measured using phenolphthalein as an indicator (titration end point pH = 8.2 ~ 8.4).
7. Methyl orange alkalinity; it is the alkalinity measured using methyl orange as an indicator (titration end point pH = 3.1 ~ 4.4).
8. Total acidity; acidity refers to the total amount of substances in water that can neutralize strong bases, including inorganic acids, organic acids, strong acid and weak base salts, etc.
9. Total hardness; in general natural water, it is mainly Ca2+ and Mg2+, and the content of other ions is very small. The total content of Ca2+ and Mg2+ in water is usually called the total hardness of water.
10. Temporary hardness; the hardness formed by the presence of Ca(HCO3)2 and Mg(HCO3)2 in water can be removed by boiling. This hardness is called carbonate hardness, also known as temporary hardness.
11. Permanent hardness: The hardness formed by salt substances such as CaSO4 (CaCl2) and MgSO4 (MgCl2) in water cannot be removed even after boiling. This hardness is called non-carbonate hardness, also known as permanent hardness.
12. Dissolved matter: It exists in the form of simple molecules or ions in water (or other solvent) solutions. The particle size is usually only a few tenths to a few nanometers. It is invisible to the naked eye and there is no Tyndall phenomenon. It cannot be seen with an optical microscope.
13. Colloid: A particle group composed of several molecules or ions. The size is usually tens of nanometers to tens of microns. It is invisible to the naked eye, but the Tyndall phenomenon will occur. Small colloidal particles cannot be seen with an optical microscope, but large ones can be seen.
14. Suspended matter: It is a small particle visible to the naked eye formed by a large number of molecules or ions. The size is usually more than tens of microns. It can be clearly seen with an optical microscope. Suspended particles can settle after being left still for a long time.
15. Total salt content: The total amount of ions in water is called total salt content. It is obtained by adding up the amounts of all cations and anions obtained from the complete water quality analysis, and the unit is mg/L (also PPM in the past).