What is UV?

UV is an abbreviation of the term ‘Ultra Violet’ and refers to an electromagnetic radiation with a wavelength of between 400nm – 100nm. Ultra Violet light is invisible to the naked eye but is concealed within a powerful violet light and if strong enough, can disable and neutralise known pathogens and viruses, preventing them from causing harm and making them safe for ingestion.

How is UV used for water treatment?

Today, UV sterilisation is an extremely common and industry accepted method of sterilising a water source. Typical applications for a UV sterilisation include –

  • Swimming pools
  • Drinking water
  • Ultra pure water
  • Fish farming and aquatics
  • Food, beverage and bottled water industries
  • Municipal waste water treatment

UV is favoured about other methods of water treatment because it is a gentle and involves no hazardous substances.

UV sterilisation can be used on water that is visually clean. Murky or cloudy water would need to go through a pre filter to ensure the most effective results. If UV were to be used on cloudy or murky water, the UV rays would not be able to adequately penetrate through the water leaving areas untreated rendering the process meaningless.

The physical process involves clear water then passes through the UV system into the chamber containing the UV bulb. The flow rate is dictated by the amount of contact time required and the water then passes through the camber and to the outlet.

UV works as a method of sterilisation as it attacks the DNA within microorganisms, pathogens and viruses making them unable to reproduce and rendering them harmless is consumed. If the water is perfectly clear, the UV rays can penetrate the water without any obstruction. As light is unable to bend around objects, water with particulates makes a perfect place for microorganisms, pathogens and viruses to hide from rays.

Is water treated using UV safe to drink?

Yes! Provided your water has undergone adequate pre treatment and the UV system itself is in good working order and the bulbs are changed regularly as required.

Applying UV sterilisation to your water has no negative impact on your water at all. It adds nothing and removes nothing. No chemicals are used and no radiation stayes contained within the water. UV sterilisation is simply a case of emitting a powerful beam through your water.

Is UV a filter?

No. UV sterilisation does not remove anything from you water and in no way acts as a filter. UV sterilisation simply destroys the DNA of the microorganisms, pathogens and viruses contained within the water making them incapable of reproducing and causing any harm if consumed.

Why water still looks cloudy after UV treatment is it safe to drink?

If this is the case, the likelihood is that the pre-treatment stage of this process was not completed successfully. If your water is Cloudy before entering the chamber, the UV light will be unable to permeate all of the water. There will be in effect shadows whereby the light could not pass. It is within these ‘shadows’ that microorganisms, pathogens and viruses will continue to thrive and multiply and therefore your water will remain harmful. Dependant of that is causing the water to be cloudy, the contaminant may also settle on the quartz sleeve effectively masking the rays and rendering them ineffective.

How much does it cost to have a UV system installed?

Costs vary dependant on your condition of water, your flow rate and the volume of water that you require treating on a daily basis.

Domestic UVs can be purchased from as little as £33, depending on your intended usage and the size of your dwelling this can go up to £350

Commercial or industrial units are generally more expensive due to the increased flow rates and volumes required. Standard systems usually range between £152 and £3900. More robust and bespoke systems are available with prices given upon enquiry.

Is a UV system suitable for domestic use?

Absolutely! We supply very small UV systems that are specifically designed for single tap usage. We also have systems that a suitable for small homes and flats, cottages, medium sized homes and large homes. Flow rates and capacity are important factors to consider when purchasing a UV system. If the demand on a system it too great, the contact time between the water and the UV light may not be adequate and therefore will leave your water inadequately treated.

Is UV suitable to industrial use?

Yes. UV systems are used very commonly within industry. Large scale UV’s are available and are very effective. There are many benefits for using UV rather that other methods including –

  • No hazardous chemicals on site
  • No adverse effect once consumed or comes into contact with eyes/skin.
  • Clean and environmentally friendly
  • Don’t have to worry about waste disposal
  • Low cost and efficient

How reliable is UV sterilisation?

As long as all relevant pre treatments and maintenance advice is followed correctly, UV sterilisation is very reliable and very effective at removing 99.9999% of all microorganisms, pathogens and viruses.

In order to retain your systems reliability, it is paramount that basic maintenance instructions are followed-

Bulbs, as a rule of thumb should be chanced annually. A very common mistake that people make is to look at their UV bulb, see that it is still emitting a strong purple ray and to establish that the UV bulb is still going strong and doesn’t require replacement. Firstly, you must never look directly at a UV bulb without visual protection as the intensity of these bulbs can burn away your retina. Secondly, people often confuse the bluish purple ray emitted from the bulb as the UV ray itself. This is incorrect. The UV rays are actually invisible to the naked eye and the bluish purple ray will continue to burn long after the UV rays have been diminished. Most manufacturers of UV bulbs state that a UV bulb has between 8,500 – 9,500 hrs of effective use in them. If you are running your system continuously, these bulbs should last 12 months. If you are using the systems intermittently, the bulbs will last longer. UV radiation monitors can be purchased from IWE if you are required to continually monitor your systems effectiveness.

Pre treatments

For UV sterilisation to be effective, the microorganisms, pathogens and viruses need to be exposed to minimum levels of the UV radiation. T o ensure reliability of the system, all particulates that may negatively impact on UV transmission or that can collect on the quartz sleeve must be removed. For effective running of the UV system, there are minimum standards, which the water must achieve. These are as follows –

Turbidity < 1NTU

Suspended Solids <10mg/L

Colour None

Total Iron < 0.3mg/L

Manganese < 0.05mg/L

Hardness < 7gpg

Regardless of your starting water quality, it is recommended that as a minimum, there should be a 5-micron pre filter in situ before the UV system itself. If your starting water does not meet the water quality standards as above, pre-treatments will be requires to ensure your water supply reaches these basic standards.

What does UV sterilisation treat?

UV sterilisation is able to treat a wide range of different organisms including –

  • Bacteria
  • Mould spores
  • Alge/ Protoza
  • Viruses
  • Yeast

The level of UV radiation required for the treatment of each microorganism differs. To discuss further, speak to one of our water treatment engineers to ensure you find what you are looking for.

What spares and parts will be required throughout the life of the UV?

We have many different spares and consumables available for a range or UV systems including –

  • Lamps
  • Quartz Sleeves
  • Gland Nuts
  • Seal Kits inc. O-rings and backing nuts
  • Power Supplies
  • Wall mounting brackets

Do you supply spares and parts?

Yes. We supply a large range of spares, parts and consumables for various different UV systems. If you can’t see what you are looking for, give out team a call and if it exists, we should be able to help you find it.

Which manufacturers do you supply spares and parts for?

The systems we supply, along with their spares and parts include –

  • Cintropur Centrifugal Systems
  • IWE UV Systems
  • Silverline UV Systems
  • Watts UV Systems
  • Trojan UV Systems
  • Hannovia UV Systems
  • Sita UV Systems
  • Liff UV Systems
  • Aquada UV Systems
  • Luminor UV Systems
  • Aquafine UV Systems
  • Viqua UV Systems
  • Weedeco UV Systems
  • Pentek UV Systems