Common water treatment methods

1.Sediment filtration method

The purpose of the sediment filtration method is to remove the suspended particulate matter or colloidal material from the raw water. These particulate matter, if not removed, will cause damage or blockage to other sophisticated filtration membrane. Commonly used in the initial treatment of water purification.

2.Hard water softening method

Hard water softening need to use ion exchange method, its purpose is to use cation exchange resin to exchange sodium ions to hard water calcium, magnesium ions, to reduce the concentration of calcium and magnesium ions within the raw water.

3.Activated carbon method

Activated carbon is made of wood, residual wood chips, fruit kernels, coconut shells, coal or petroleum residue and other substances in the high temperature dry distillation carbonization, made of hot air or water vapor to activate. Its main function is to remove chlorine and chloramines and other dissolved organic substances with molecular weights of 60 to 300 daltons.

4.Deionization method

The purpose of the deionization method is to remove inorganic ions dissolved in water, and hard water softening method, is also the use of ion exchange resin principle. These two types of resins are cation exchange resin and anion exchange resin. Cation exchange resin uses hydrogen ions to exchange cations; while anion exchange resin uses hydroxide ions to exchange anions, hydrogen ions and hydroxide ions combine with each other to form neutral water.

5.Reverse osmosis method

Reverse osmosis can effectively remove inorganic substances dissolved in water, organic matter, bacteria, thermogenic and other particles, etc., is the most important part of water treatment. The so-called "osmosis" refers to the use of semi-permeable membrane separating two different concentrations of the solution, the lower concentration of water molecules will be through the semi-permeable membrane to reach the higher concentration of the other side, until the concentration of both sides equal. Before reaching equilibrium, such as in the higher concentration of the side of the gradual application of pressure, when the applied pressure is greater than the osmotic pressure, then the movement of water molecules will travel in the opposite direction, that is, from the high concentration of the side of the flow to the low concentration of the side, this phenomenon is called "reverse osmosis".

6.More than filtration method

Over filtration method is similar to reverse osmosis method, also using semi-permeable membrane, but it can not remove ions, because the pore size of the membrane is larger, about 10 ~ 200 A. Can only remove bacteria, viruses, thermogenic and particulate matter, etc., the water-soluble ions can not be filtered. The main function of the overfiltration method is to act as a pretreatment for the reverse osmosis method to prevent bacterial contamination of the membrane. It can also be used in the final step of water treatment to prevent bacterial contamination of upstream water in the pipeline.

7.Distillation method

Distillation is an ancient but also effective water treatment method, it can remove any non-volatile impurities, but can not exclude volatile contaminants, it requires a large water storage tank to store, the storage tank and delivery pipe is an important cause of pollution.

8.UVC disinfection method

UV disinfection method is one of the methods often used. UV disinfection does not produce any secondary pollutants, belongs to the latest generation of international disinfection technology, it has high efficiency, broad-spectrum, low cost, long life, large water volume, no pollution and other disinfection means can not be compared to the advantages. Its disinfection mechanism is to destroy the genetic material of bacterial nucleic acid life, so that it can not reproduce, where the most important reaction is the pyrimidine salt group within the nucleic acid molecule into a double (dimer). Generally is the use of low-pressure mercury discharge lamps (germicidal lamps) artificial 253.7 nm wavelength of ultraviolet energy. The principle of UVC germicidal lamps and fluorescent lamps are the same, but the interior of the lamp is not coated with fluorescent material, the material of the lamp is made of quartz glass with a high penetration rate of UVC. General UVC devices have irradiation type, immersion type and flow type.

9.Biochemical method

Biochemical water treatment method uses a variety of bacteria and microorganisms that exist in nature to decompose organic matter in wastewater into harmless substances, so that wastewater can be purified. Biochemical water treatment method can be divided into activated sludge method, biofilm method, biological oxidation tower, land treatment system, anaerobic biological water treatment method. Flow of biochemical water treatment method: Raw water → grate → conditioning tank → contact oxidation tank → sedimentation land → filtration → disinfection → effluent.