Advanced Semiconductor Laboratory
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UV water purification

Hamad Al-Otaibi

August 29, 2016 - Posted in Discussion
​Water supplies in Saudi Arabia are very scarce due to the lack of rains and rivers in the kingdom. 50% of the drinking water comes from seawater desalination and around 40% comes from the non-recovered underground water. The agricultural sector in the country consumes 83% of the water usage, and 8% is consumed in industry. This consumption encourages the government to build around 33 wastewater treatment plants across the country for the recycled water to be used for irrigation and industrial purposes. In water treatment, there are different treatment levels based on the water usage. Primary and secondary treatments of wastewater are acceptable for irrigation of non-food crop plants, but for other applications such as fruit and vegetable irrigation, bathing and maybe drinking, further treatments are required. 
Figure 1: Only 8% of water supplies are from the recycled water

In the process of water purification, in particular in the step of water disinfection (which is essential for drinking water), ultraviolet(UV) lights are very crucial, and necessary component since UV light has a very high energy to break DNA/RNA structures or genetic bonds. Thus, it can destroy 99.9% of microorganism in the water in a reliable, safe and cost-effective way. In developed countries (Canada, USA, Germany, etc.), UV light has been adopted for effluent water disinfection. 
On the other hand, UV light technology is still at its early stage and has many challenging problems (low power output, low efficiency, etc.).

Figure 2: AlGaN (UV light) efficiency (left) vs InGaN (Visible light) efficiency (right)

Here at KAUST, UV optoelectronic device is a hot topic for researchers, to develop and improve UV emitters that can purify the water and rescue the kingdom’s water future. Saudi Arabia had become the leader in seawater desalination because it needed it, and it can lead the world again in UV technology because it is not less important.

1- Chichibu, et al., Origin of defect-insensitive emission probability in In-containing (Al,In,Ga)N alloy semiconductors. Nature Materials (2006)
2- Anant K, “The Elixir of Life WATER” . April 29th, 2010 ‐ Chicago 1
3- Water supply and sanitation in Saudi Arabia. (2016, August 26). In Wikipedia, The Free Encyclopedia.
4- "UV Water Purification". ESP Water Products. Web. 3 Sep. 2013.

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August 30, 2016 at 3:30 PM
September 22, 2016 at 1:41 AM
" UV water purification" , It was an exceptionally well-written article. I particularly liked the fact that it was an objective look at the issue, pointing out the advantages and disadvantages of ultraviolet lights and how its in early stages. I would like to thank you for both a well researched and well-written article.
September 22, 2016 at 4:49 PM
Nice work Mr.Hamad, Keep it up ;)