Simply, "water treatment" is through physical, chemical, biological methods to remove some unwanted harmful substances for water production and life of process. It is suitable for a specific purpose of the water sedimentation, filtration, coagulation, flocculation, and corrosion, scale and other water quality conditioning process.
This article summarizes the common methods of sterilization for water treatment:
Sterilization mainly kills pathogens and viruses, which are harmful for human health, to ensure the health and safety of drinking water. China's drinking water health standards stipulate: total number of bacteria in 1 ml waters no more than 100, the total coli form in 1 liter water no more than 2.
In process of industrial water treatment, sterilization is to prevent bacteria, microorganisms on the ion exchange membrane, reverse osmosis membrane and other pollution measures, and some industrial water also has requirements for water sterilization, remove virus.
There are many ways to sterilize water, basically can be divided into two major categories of physics and chemistry. Physical aspects are heated to boiling, UV sterilization, ultrasonic sterilization and other methods; chemical chlorinated sterilization, ozone sterilization, sterilization of heavy metal ions and other methods.
The light begins from the blue-green spectrum
Wavelength of 390nm ~ 200nm with bactericidal sterilization ability, 254nm is the best. UV sterilization using light irradiation between this wavelength ranges, in order to achieve a physical method of sterilization.
UV mercury lamp has high and low pressure (according to the lamp when the mercury vapor pressure tube to distinguish) two, the lamp made of quartz glass. Ultraviolet mercury lamp emits a large amount of germicidal ultraviolet rays while igniting, and also emits a small amount of visible light.
Reliable Machine using UV sterilization for water, its character is: short contact time, strong bactericidal ability; simple equipment, easy operation and management, and can be automated; no side effects of water treatment, no risk of poisoning. It can be used in small-scale industrial water that does not allow increased chloride ion in the treated water. The disadvantage is: there is no residual chlorine bactericidal effect, and the current life of our lamp is shorter, more expensive and so on.
UV sterilization: mainly contains by the lamp, magnetic leakage transformer, reflector composition. Some notes in UV sterilization operation:
(1) UV sterilization unlike residual chlorine can maintain the role of sterilization of the water to strengthen management to prevent further pollution.
(2) When using UV lamp to sterilize, the lamp must be lit after the stabilization time of 5 to 15 minutes.
(3) Electrical measures should be taken to ensure that the lamp rated power and voltage stability, or lighting power is insufficient, will affect the sterilization effect.
(4) UV sterilization of the equipment and management are relatively simple, but the current lamp life is shorter, the price is more expensive, so the promotion and application is limited.
Chlorine has strong sterilization ability, abundant supply and cheap, simple equipment, after adding water to maintain a certain amount of residual concentration (often referred to as residual chlorine), to prevent re-contamination and breeding bacteria, while the residual concentration of convenient detection.
Based on above advantages, it is widely used in waterworks. However, chlorine is toxic and should be handled safely and carefully during transport and storage.
Ozone technology is both ancient and new technology, invented by German chemists in 1840, and used in the water treatment and sterilization industry in 1856. We Reliable Machine is still continuing to use this method.
Ozone sterilization is a bacteriolytic method, thorough sterilization, no residue, bactericidal broad-spectrum, can kill bacteria and spores, viruses, fungi, etc., and can undermine the botulinum toxin. In addition, ozone has a very strong killing effect on molds. Due to poor stability, ozone will soon be decomposed into oxygen or a single oxygen atom, and a single oxygen atom can combine into oxygen molecules, leaving no toxic residue, therefore, ozone is a non-polluting disinfectant. Ozone is a gas that can rapidly diffuses throughout the sterilizing space without dead spots.