Skip to main content
Log in

Ultraviolet light-emitting diodes in water disinfection

  • Published:
Environmental Science and Pollution Research Aims and scope Submit manuscript


Background, aim, and scope

The novel system of ultraviolet light-emitting diodes (UV LEDs) was studied in water disinfection. Conventional UV lamps, like mercury vapor lamp, consume much energy and are considered to be problem waste after use. UV LEDs are energy efficient and free of toxicants. This study showed the suitability of LEDs in disinfection and provided information of the effect of two emitted wavelengths and different test mediums to Escherichia coli destruction.

Materials and methods

Common laboratory strain of E. coli (K12) was used and the effects of two emitted wavelengths (269 and 276 nm) were investigated with two photolytic batch reactors both including ten LEDs. The effects of test medium were examined with ultrapure water, nutrient and water, and nutrient and water with humic acids.


Efficiency of reactors was almost the same even though the one emitting higher wavelength had doubled optical power compared to the other. Therefore, the effect of wavelength was evident and the radiation emitted at 269 nm was more powerful. Also, the impact of background was studied and noticed to have only slight deteriorating effect. In the 5-min experiment, the bacterial reduction of three to four log colony-forming units (CFU) per cubic centimeter was achieved, in all cases.


When turbidity of the test medium was greater, part of the UV radiation was spent on the absorption and reactions with extra substances on liquid. Humic acids can also coat the bacteria reducing the sensitivity of the cells to UV light. The lower wavelength was distinctly more efficient when the optical power is considered, even though the difference of wavelengths was small. The reason presumably is the greater absorption of DNA causing more efficient bacterial breakage.


UV LEDs were efficient in E. coli destruction, even if LEDs were considered to have rather low optical power. The effect of wavelengths was noticeable but the test medium did not have much impact.

Recommendations and perspectives

This study found UV LEDs to be an optimal method for bacterial disinfection. The emitted wavelength was found to be an essential factor when using LEDs; thus, care should be taken in selecting the proper LED for maximum disinfection.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Subscribe and save

Springer+ Basic
EUR 32.99 /Month
  • Get 10 units per month
  • Download Article/Chapter or Ebook
  • 1 Unit = 1 Article or 1 Chapter
  • Cancel anytime
Subscribe now

Buy Now

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1

Similar content being viewed by others


  • Cantwell RE, Hofmann R, Templeton MR (2008) Interactions between humic matter and bacteria when disinfecting water with UV light. J Appl Microbiol 105:25–35

    Article  CAS  Google Scholar 

  • Crawford AH, Banas MA, Ross MP, Ruby DS, Nelson JS, Boucher R, Allerman AA (eds) (2005) Final LDRD report: ultraviolet water purification systems for rural environments and mobile applications. Sandia National Laboratories, Albuquerque

    Google Scholar 

  • Hjinen WAM, Beerendonk EF, Medema GJ (2006) Inactivation credit of UV radiation for viruses, bacteria and protozoan (oo)cysts in water: a review. Water Res 40:3–22

    Article  Google Scholar 

  • Hu X, Deng J, Zhang JP, Lunev A, Bilenko Y, Katona T, Shur MS, Gaska R, Shatalov M, Khan A (2006) Deep ultraviolet light-emitting diodes. Phys Stat Sol 203:1815–1818

    Article  CAS  Google Scholar 

  • Jeong J, Kim JY, Yoon J (2006) The role of reactive oxygen species in the electrochemical inactivation of microorganisms. Env Sci Tech 40:6117–6122

    Article  CAS  Google Scholar 

  • Khan MA (2006) AlGaN multiple quantum well based deep UV LEDs and their applications. Phys Stat Sol 203:1764–1770

    Article  CAS  Google Scholar 

  • Koivunen J, Heinonen-Tanski H (2005) Inactivation of enteric microorganisms with chemical disinfectants, UV radiation and combined chemical/UV treatments. Water Res 39:1519–1526

    Article  CAS  Google Scholar 

  • Polcaro AM, Vacca A, Mascia M, Palmas S, Pompei R, Laconi S (2007) Characterization of a stirred tank electrochemical cell for water disinfection processes. Electrochim Acta 52:2595–2602

    Article  CAS  Google Scholar 

  • Soloshenko IA, Bazhenov VY, Khomich VA, Tsiolko VV, Potapchenko NG (2006) Comparative research of efficiency of water decontamination by UV radiation of cold hollow cathode discharge plasma versus that of low- and medium-pressure lamps. IEEE Trans Plasma Sci 34:1365–1369

    Article  CAS  Google Scholar 

  • Taniyasu Y, Kasu M, Makimoto T (2006) An aluminum nitride light-emitting diode with a wavelength of 210 nm. Nature 441:325–328

    Article  CAS  Google Scholar 

Download references


This work was financially supported by the Finnish Environmental Science and Technology graduate school (EnSTe), EU, and city of Mikkeli. The authors greatly thank Ms. Taija Holm for laboratory assistance.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Sari Vilhunen.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Vilhunen, S., Särkkä, H. & Sillanpää, M. Ultraviolet light-emitting diodes in water disinfection. Environ Sci Pollut Res 16, 439–442 (2009).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: