UV Technology
UV Treatment is a fast, chemical-free and cost-effective way to disinfect water from harmful bacteria, viruses, mould spores, algae and yeast, making drinking and wastewater safe.
Bacteria and viruses have known, but limited repair mechanisms, that are easily overwhelmed. Exposure to UV photons (light) prevents cell replication and inactivates bacteria and viruses.
Bacteria and viruses, crucially, can develop resistance to antibiotics and chemicals but have not been shown to develop any resistance to UV.
Ultraviolet (UV) light is a natural process and does not produce harmful chemicals in water disinfection. It’s a safe, effective and environmentally friendly disinfection method that inactivates waterborne bacteria, viruses and protozoa to make water safe.
UV has been internationally recognised for over 100 years and is widely used in applications for water companies, industrial, commercial and residential globally.
As an applied disinfection technology, UV disinfects water to make it safe to drink or as a process medium, it may eliminate odours and does not impact on colour or pH of water treated.
For most households by the time the water we use reaches our homes it has been suitably treated for our safe consumption. Failing to remove or inactivate microorganisms from drinking water may cause people to fall ill.
There are several ways to disinfect water. UV treatment does not use chemicals, and is a safe, effective and environmentally friendly disinfection method, that inactivates waterborne bacteria, viruses and protozoa, often found in water. UV water disinfection treatments are commonly used for domestic and industrial applications world-wide.
The ultraviolet light that is used in Daro UV Systems’ water treatment products is a natural component of sunlight that falls just below the visible light region in light spectrum. For monochromatic UV lamps, the wavelength utilised for the use of water disinfection is 253.7nM. This is very close to the optimum wavelength, approaching 265 nM for cell inactivation.
UV is effective in inactivating a wide range of microorganisms such as
- Algae
- Bacteria
- Microorganisms
- Mould spores
- Protozoa
- Viruses
- Yeast
including chlorine resistant pathogens.
Doses Required
The resistance to different micro-organisms to ultraviolet radiation varies. The approximate doses of energy required to inactivate a range of microorganisms is shown in the table below.
Doses of UV -254nm in m/Wsec/cm² (mJ/cm²) is required for the inactivation of 90% of pathogens.
Per one log reduction
| Type
| Fluence mJ/cm2
| Type
| Fluence mJ/cm2
| |
| Algae | Organisms continued | |||
| Diatoms | 360.0-600.0 | Micrococcus piltonencis | 8.10 | |
| Green algae | 360.0-600.0 | Micrococcus sphaeroides | 10.0 | |
| Blue algae | 360.0-600.0 | Neisseria catarrhalis | 4.40 | |
| Phytomonas tumefaciens | 4.40 | |||
| Mould Spores | Proteus vulgaris | 2.64 | ||
| Aspergillus amstelodami (meat) | 66.70 | Pseudomonas aeruginosa | 5.50 | |
| Aspergillus flavus | 60.00 | Pseudomonas fluorescens | 3.50 | |
| Aspergillus glaucus | 44.00 | Salmonella typhimurium | 8.00 | |
| Aspergillus niger (bakeries) | 132.00 | Sarcina luta | 19.70 | |
| Cladosporium herbarum | 60.00 | Serratia marcescens | 2.40 | |
| Mucor mucedo | 65.00 | Dysentery bacilli | 2.20 | |
| Mucor racemosus A | 17.00 | Shigella dysenteriae | 1.68 | |
| Mucor racemosus B | 17.00 | Spirillum rubrum | 4.40 | |
| Oospora lactis | 5.00 | Staphylococcus albus | 1.84 | |
| Penicillium digitatum | 44.00 | Staphylococcus aureus | 2.60 | |
| Penicillium expansum | 13.00 | Streptococcus hemolyticus | 2.16 | |
| Penicillium chrysogenum | 50.00 | Streptococcus lactis | 6.15 | |
| Penicillium roqueforti | 13.00 | Streptococcus viridans | 2.00 | |
| Rhizopus nigricans | 111.00 | Tubercle bacillus | 10.00 | |
| Scopulariopsis brevicaulis | 80.00 | |||
| Organisms | Protozoa | |||
| Bacterium coli in water | 5.40 | Paramecium | 64.0-100.0 | |
| Bacillus anthracis | 4.52 | |||
| Salmonella Enteritidis | 4.00 | Viruses | ||
| Bacillus megaterium (veg) | 1.13 | Most viruses | 1.0-10.0 | |
| Bacillus megaterium (spores | 2.73 | |||
| Bacillus paratyphoid | 3.20 | Yeasts | ||
| Bacillus subtilis | 7.10 | Baker’s yeast | 3.90 | |
| Bacillus subtilis (spores) | 12.00 | Brewer’s yeast | 3.30 | |
| Corynebacterium diphtheriae | 3.37 | Common yeast (cake) | 6.00 | |
| Eberthella typhosa | 2.14 | Saccharomyces ellipsoideus | 6.00 | |
| Escherichia coli (e.coli) | 3.00 | Saccharomyces sp. | 8.00 | |
| Micrococcus candidus | 6.05 | Saccharomyces cerevisiae | 6.00 | |
| Legionella pneumophila | 3.80 | Torula sphaerica (milk & cream) | 2.30 | |
WRAS Approvals
The Water Regulations Approval Scheme is an independent UK certification body for plumbing products and materials, helping business and consumers choose compliant products that keep water safe.
Any water fitting, which when installed, will carry or receive water from the public mains water supply in the UK, must comply with the Water Supply (Water Fittings) Regulations or Scottish Byelaws. These require that a water fitting should not cause waste, misuse, undue consumption or contamination of the water supply and must be ‘of an appropriate quality and standard’.
Selecting WRAS Approved products is an easy way to demonstrate compliance with water fittings regulations.
About Daro UV Systems
British designer and manufacturer Daro UV Systems has been delivering ultraviolet (UV) disinfection systems in the UK for over 40 years.
Please contact us on +44 (0) 1787 370187 or email sales@darouv.com
To find out more about Daro UV solutions please get in touch. Our experts would be delighted to advise you which solution would be best suited to your needs, please call +44 (0) 1787 370187
