Ultraviolet System (UV): It works by exposing micro-organisms (such as cryptosporidium, giardia lamblia and more) to UV radiation, via a special UV light bulb, which disrupts their DNA and disables their ability to replicate.UV is Ultraviolet radiation, an energy band within the electromagnetic energy spectrum. It is a colorless, tasteless, odorless and chemical free way to ensure your water supply is safe and clear of germs and other microorganisms that can make you sick. UV does not affect sediment, particulates or other mineral contaminants which will require additional water treatment methods.

UV light, which continues to be a reliable means of disinfection, involves exposing contaminated water to radiation from UV light. The treatment works because UV light penetrates an organism’s cell walls and disrupts the cell’s genetic material and making reproduction impossible. A special lamp generates the radiation that creates UV light by striking an electric arc through low-pressure mercury vapor. This lamp emits a broad spectrum of radiation with intense peaks at UV wavelengths of 253.7 nanometers (nm) and a lesser peak at 184.9 nm. Research has shown that the optimum UV wavelength range to destroy bacteria is between 250 nm and 270 nm. At shorter wavelengths (e.g. 185 nm), UV light is powerful enough to produce ozone, hydroxyl, and other free radicals that destroy bacteria.

UV light, which continues to be a reliable means of disinfection, involves exposing contaminated water to radiation from UV light. The treatment works because UV light penetrates an organism’s cell walls and disrupts the cell’s genetic material and making reproduction impossible. A special lamp generates the radiation that creates UV light by striking an electric arc through low-pressure mercury vapor. This lamp emits a broad spectrum of radiation with intense peaks at UV wavelengths of 253.7 nanometres (nm) and a lesser peak at 184.9 nm. Research has shown that the optimum UV wavelength range to destroy bacteria is between 250 nm and 270 nm. At shorter wavelengths (e.g. 185 nm), UV light is powerful enough to produce ozone, hydroxyl, and other free radicals that destroy bacteria.

Typical UV light components include:

• A stable high-voltage source of electricity because low-line voltage would result in a lower UV dose
• A chamber made of stainless steel or any other material that is opaque and will not corrode
• UV lamps that are properly secured inside quartz sleeves, easing installation replacement, and maintenance
• Quartz sleeves with sufficiently high transmission rates to deliver the UV energy produced by UV lamps
• Mechanical wipers to maintain optimum transmission between scheduled cleaning and maintenance work
• Sensors to monitor the UV intensity passing through the water. These sensors need to be connected to alarm systems to alert the operator in case of low UV intensity. The operator must have easy access to these sensors for necessary installation, replacement, calibration, and maintenance
• Safety control to shut off UV lamps in case of low-flow levels and elevated lamp temperature
• Arc and lamp-out monitors to alert the operator of system failure
• Electronic ballasts

Advantages:

• UV is simple to install and requires little supervision
• minimum service time, low operation and maintenance costs
• absence of a chemical smell or taste in finished water are primary factors for selecting UV technology rather than traditional disinfection technologies.
• UV treatment breaks down or removes some organic contaminants.
• UV achieves 1-log reduction of Giardia lamblia at an intensity of 80-120 mWs/cm2, and 4-log reduction of viruses at an intensity of 90-140 mWs/cm2.
• UV as a highly effective tool for Cryptosporidium 
• UV light disinfection does not form any significant disinfection by products, nor does it cause any significant increase in assimilable organic carbon (AOC).
• UV effectiveness is relatively insensitive to temperature and pH differences.
• UV application does not convert nitrates to nitrites, or bromide to bromines or bromates.
• Has no known toxic or significant nontoxic by-products
• Has no danger of overdosing
• Has no volatile organic compound (VOC) emissions or toxic air emissions
• Requires very little contact time (seconds versus minutes for chemical disinfection)
• Does not require storage of hazardous material
• Requires minimal space for equipment and contact chamber
• Improves the taste of water because of some organic contaminants and nuisance micro-organisms are destroyed
• Does not affect minerals in water
• has little or no impact on the environment except for disposing of used lamps or obsolete equipment
• activity in drinking water—but coliforms are sensitive to UV light.
• An effective dose is measured as a product of the lamp’s intensity (the rate at which photons are delivered to the target), including radiation concentration, proper wavelength, exposure time, water quality, flow rate, and the microorganism’s type, and source, as well as its distance from the source light.
• UV units are currently used as stand-alone treatment systems or as part of a series of other drinking water treatment processes or multiple barrier system. A common treatment that uses UV light to remove and disinfect contaminants from groundwater sources involves a combined ozone or hydrogen-peroxide process along with UV application.
• The drinking water treatment industry provides UV equipment (mainly closed chamber units) for short-term uses.
• Monitoring and Operation Requirements:

Applications

• Residential
• Commercial
• Industrial Applications
• Sewage Treatment Plants.
• Effluent Treatment
• Swimming Pool Water disinfection
• Domestic Water Disinfection
• Pharmaceutical Applications
• Sugar Syrup Treatment
• Ozone Destruction

UV is also an effective tool in pond algae control. UV can be used in homes, cottages, hotels, motels, buildings, factories, rinse processes, bottling plants, food processing, cooling towers, breweries, hospitals, fisheries, farms, wineries etc etc