1, what is pure water treatment?
Pure water refers to the pure water in general city water as the water, through the multi-layer filtration, microbiological and other harmful substances can be removed, but also to remove the fluoride, potassium, calcium, magnesium and other minerals required by the human body.
With the rapid development of modern technology and modern industry, and the relative lag of environmental governance, China's water pollution situation is grim. Due to industrial waste water, living wastewater uncontrolled emissions and agricultural pollution, the current surface water not only contains mud, animal and plant rotten things. There are a lot of bleach, pesticides, heavy metals, calcareous, iron and so on harmful to human health substances, these pollutants in the human body long-term accumulation of great harm to human health, can cause cancer, mutagenicity, Zheng's killer. The traditional tap water production process not only can not remove the organic compounds in it, if the water production in the chlorine, but will generate new and more organic organic pollution, resulting in tap water mutations than natural water is more intense , Then the water after the factory to go through a long water pipeline system, especially high-rise residential roof water tank, there is a more serious "secondary pollution." This type of water, of course, can not drink, even if the boil, can only be sterilized and can not remove harmful chemicals. Furthermore, drinking pure water, not only for the health of pesticides, but also benefit from health and longevity. Because the water is more pure, as the carrier's function more play, the ability to dissolve a variety of metabolites in the body the stronger, the more easily absorbed by the body, is conducive to thirst, relieve fatigue. Therefore, in order to maintain health, improve people's health level, the development of pure water business, the production of high-quality drinking water water treatment is the secondary water purification, the tap water chloride, bacteria and other harmful substances to further filter Bacteria, disinfection effect.
2, pure water treatment methods
1. Film microporous filtration (MF) pure water treatment
Film microporous filtration method includes three forms: deep filtration, screen filtration, surface filtration. Deep filtration is made of woven fibers or compressed material matrix, the use of inert adsorption or capture to retain the particles, such as the commonly used multi-media filter or sand filter; deep filtration is a more economical way to remove 98 % Of the suspended solids above, while protecting the downstream purification unit from being blocked, so it is usually used as a pretreatment.
Surface filtration is a multi-layer structure, when the solution through the filter, the membrane within the pores of large particles will be left, and mainly deposited on the membrane surface, such as the commonly used PP fiber filter. Surface filtration can remove more than 99.9% of the suspended solids, it can also be used as pretreatment or clarification.
The screen filter is basically a consistent structure, like a sieve in general, will be larger than the diameter of the particles, are left on the surface (the filter pore measurement is very accurate), such as ultra-pure water machine terminal use Screen filter microporous filtration is generally placed in the end point of use in the purification system to remove the final residual trace resin sheet, carbon chips, colloids and microbes.
2. Activated carbon adsorption of pure water treatment
Activated carbon adsorption is the use of activated carbon porous nature, so that one or more harmful substances in water is adsorbed on the solid surface and remove the method. Activated carbon adsorption for the removal of organic matter in water, colloid, microorganisms, chlorine, smell, etc. have a good effect. At the same time because the activated carbon has a certain reduction effect, so for the water oxidants also have a good removal.
As the adsorption capacity of activated carbon has a saturation value, when the saturated adsorption capacity, the activated carbon filter adsorption capacity will be greatly reduced, it is necessary to pay attention to analysis of the adsorption capacity of activated carbon, the timely replacement of activated carbon or through high-pressure steam for disinfection recovery. However, the organic matter adsorbed on the activated carbon surface may become a nutrient source or a breeding ground for bacterial propagation. Therefore, the propagation of microorganisms in the activated carbon filter is also worthy of attention. Regular disinfection is necessary to control bacterial reproduction. It is noteworthy that a small amount of very fine powdered activated carbon may enter the reverse osmosis system with the flow into the reverse osmosis system at the beginning of the initial use of the activated carbon (or the early operation of the activated carbon), resulting in fouling of the reverse osmosis membrane Increased pressure, decreased water production and increased system pressure drop, and this damage is difficult to use conventional cleaning methods to restore. So the activated carbon must be washed, remove the fine powder before the filter water can be sent to the follow-up RO system. The role of activated carbon is very large, but also pay attention to the use of disinfection and the new activated carbon must be rinsed.
3, reverse osmosis (RO) pure water treatment
Reverse osmosis means that the solvent in the concentrated solution flows to the dilute solution when a pressure greater than the osmotic pressure is applied to the concentrated solution side. The flow direction of the solvent is opposite to that of the original infiltration. This process is called reverse osmosis. The principle is used in the field of liquid separation for the purification, removal and treatment of liquid substances.
Reverse osmosis membrane works: the permeability of the material through the selective film called semipermeable membrane, generally only through the solvent and can not pass through the solute of the film called the ideal semipermeable membrane. When the same volume of dilute solution (e.g., fresh water) and a concentrated solution (e.g., brine) are placed on both sides of the semipermeable membrane, the solvent in the dilute solution will naturally flow through the semipermeable membrane and spontaneously flow to the concentrated solution side, This phenomenon is called infiltration. When the penetration reaches equilibrium, the liquid side of the concentrated solution side will be higher than the liquid level of the dilute solution to form a pressure difference, which is the osmotic pressure. Reverse osmosis is a reverse migration movement that is permeable. It is a separation method that separates the solute in the solvent from the solvent by means of the selective interception of the semipermeable membrane. It has been widely used in the purification of various solutions And concentrated, one of the most common application examples is in the water treatment process, with reverse osmosis technology in raw water in the inorganic ions, bacteria, viruses, organic matter and colloidal impurities to remove high-quality pure water.