What is an UV water sterilizer?
The UV water Sterilizer is a water filtration device that uses an ultraviolet light bulb to kill microscopic organisms that are free floating in the water. Parasites, viruses, algae and bacteria (good and bad) are the type of things that are "killed" after passing through the ultraviolet sterilizing unit. UV sterilizer devices can be used on swimming pools, in liquid factories (think beer) and in the home aquarium using an aquarium UV sterilizer. Some large water purification centers employ some sort of UV sterilization on the outgoing water. These sterilizer units are also sometimes used in outdoor ponds to help control algae growth and they seem to do a decent job.
When using a UV Sterilizer in a home aquarium, the UV unit should be placed last in the filtration line. You want to first filter the aquarium water through your mechanical filter and then run the water through the UV device before returning the water to your fish tank. By first removing the solids in the aquarium water with your mechanical filter (canister filter, etc), you are helping your UV unit to attain maximum operational efficiency.
How does an UV water sterilizer work?
The ultraviolet ray is a kind of invisible light wave to the naked eye. It exists on the outside of the purple ray on the spectra thus it is called the ultraviolet ray. The ultraviolet ray is subdivided in wave band A (UVA), wave band B (UVB), wave band C (UVC). The wave length of UVC is between 100nm to 280nm - and the most effective germicidal wave band is 253.7nm.
1. Principles: If you expose the water to UVC spectrum at the wave peak of 254nm for a period of time the nucleic acid, deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) of microorganisms will absorb UV rays and be damaged by the rays - thus they perish - so the water is sterilized. UV rays have a certain effect on protein and other life forms too.
2. Sterilization range: UV water sterilizer can effectively kill the algae, fungi, bacteria, rickettsia and virus to purify the water.
3. Merits of the sterilizer: UV sterilizer is a completely physical way to sterilize water. It is easy to use, cost effcetive , broad spectrum, does not require any chemicals, generates no secondary pollution, does not create corrosion, leaves no residue and is easy to maintain.
4. Application range: UV water sterilizer can be mounted as a pre or rear sterilization equipment with domestic or industry water purification equipment. It can be applied to various kinds of water purification.
5. For it to work effectively the water must be free of aprticles larger than 5 micron.
Application
1. Food processing industry, including juices, milk, drinks, beer, practical oil and canned food.
2. Electronic industry.
3. Hospitals, various laboratory and high levels of pathogenic body water disinfection.
4. Households building, residential, office buildings, hotels, restaurants, water factories.
5. Purification and disinfection of shellfish, fish cleaning and disinfection
6. camp, field water supply system
7. Urban wastewater disinfection.
8. Swimming pool, other recreational water disinfection
9. Thermal power, nuclear power plant industrial, central air conditioning system cooling water.
10. Biological, chemical and pharmaceutical, cosmetics for the production of cooling water.
11. Sea water, fresh water breeding, aquaculture water
12. Agricultural water disinfection
UV specification
Product application
Ultraviolet light treatment is a widely recognized and proven method of disinfection of water and has several advantage over other disinfection methods such as chlorination, ozonation, etc. UV light does not add anything to the water, such as, undesirable color, odor, taste, or flavor, nor does it generate harmful byproducts. It adds only energy in the UV radiation. Also, UV disinfection requires only a fraction of the contact times required by other disinfection methods. It is fast, efficient, effective, economical and environmentally-friendly.
Principle of Operation
UV water disinfection system design has been carefully conceived to provide adequate germicidal dosage throughout the disinfection chamber. The dosage, as it applies to UV disinfection, is a function of time and the intensity of UV radiation to which the water is exposed. Exposure time is related to the flow rate, the higher the flow rate, the lower the exposure time or the lower the flow rate, the higher the exposure time. The UV intensity is the amount of energy, per unit time, emitted by germicidal lamp. The Dosage is the product of UV intensity and the exposure time.
Limitation of Use
The UV water disinfection system NOT intended for the treatment of water that has an obvious contamination or intentional source, such as raw sewage, nor is the unit intended to convert wastewater to microbiologically safe drinking water.
Water Quality (in)
Water quality plays a major role in the transmission of germicidal UV rays. It is recommended that the water does not exceed following maximum concentration levels
Maximum Concentration Levels (Very Important)
Iron≤ 0.3ppm(0.3mg/L)
Hardness≤ 7gpg(120mg/L)
Turbidity≤ 1NTU
Manganese≤ 0.05ppm(0.05mg/L)
Tannins≤ 0.1ppm(0.3mg/L)
UV Transmittance≥ 750‰
Effectively treating water with higher concentration levels than listed above can be accomplished, but may require added measures to improve water quality to treatable levels. If, for any reason, it is believed the UV transmission is not satisfactory, contact the factory.
UV wavelength (nm)
DOSAGE is the product of intensity & time
Dosage=intensity*time=micro watt/cm2*time=microwatt-seconds per square centimeter
(μ W-s/cm2)
Note: 1000μ W-s/cm2=1mj/cm2(milli-joule/cm2)
As a general guideline, the following are some typical UV transmission rates (UVT)
City water supplies850-980‰
De-ionized or Reverse Osmosis water950-980‰
Surface waters(lakes, rivers, etc)700-900‰
Ground water(wells)900-950‰
Other liquids10-990‰
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