Talk:Ultraviolet germicidal irradiation

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Untitled[edit]

Article merged: See old talk-pages here and here


Propaganda[edit]

This article is mere propaganda, and does not deserve to be on Wikipedia's Main Page. UV's main drawback is its lack of a residual, meaning that any germ that by chance survives the radiation, can begin to reproduce happily in the piping system once this single hurdle of UV radiation is taken. The odds of survival are in fact quite high, because the radiation intensity decreases exponentially an a straight path, being further attenuated fpr spatial reasons (radial rather than parallel light beams), so that many commercial systems contain lines through which germs could theoretically pass rather unharmed. In fact, I have seen commercial systems where after the UV system the germ count was higher than before, owing to biofilm development at the exit parts that are not exposed to radiation, and where because of tha lack of a residual, there is no disinfection at all. In addition, "real" water contains lots of material that can scatter light, further attenuating UV intensity. Because of Rayleigh's scattering law (scattering depends on wavelength to the fourth power!!!), the popular absorbance measurements to determine UV teatability are just window dressing, and not based on thorough science. To make things worse, UV destroys all common chemicals that may have been used prior to the water being irradiated. The biased praise of UV in this article is unwarranted. (PeterH, 2006-09-12)

If you can verify your arguments, why don't you add them to the article? Melchoir 16:09, 12 September 2006 (UTC)
With pleasure, as soon as I have time, but right now I am preparing for a job where the health officer has shut down a UV system because it has contaminated a previously clean hospital piping system, as I predicted, for exactly the reasons outlined above. This and some other similar jobs will keep me busy over the next few weeks, so please bear with me. (PeterH 2006-09-12)
Could PeterH kindly consider completing his commentary as this would prove invaluable guidance on design restrictions and considerations to empower interested readers in avoid the oversights he has outlined? I believe much of what he has highlighted can be mitigated through considered integrated systems design once a full understanding of these factors is achieved. If no verification for his assertions is forthcoming, could they be considered as biased opinion?(Tobyvanreenen (talk) 15:57, 13 August 2013 (UTC))

Propaganda Redux:[edit]

As the author of this let me state for the record: I wrote this based on an article I read in regards to ultraviolet used to remove allergens from circulating air. I wanted to check the article against Wiki and was surprised there was limited information about it in the Ultraviolet section. I had no agenda and I certainly don't advocate it. Just being bold. Please update the article with any information that corrects my errors. -- PDream

EEPROM times[edit]

I changed "10's of seconds" to "under a minute." Originally I was going to just fix the "10's" (http://www.grammarbook.com/punctuation/apostro.asp) but that still sounded awkward.

ChrisKurtz (talk) 06:06, 3 December 2009 (UTC)

Merger proposal[edit]

The following discussion is closed. Please do not modify it. Subsequent comments should be made in a new section. A summary of the conclusions reached follows.
The result was merge. -- zazpot (talk) 03:51, 8 August 2011 (UTC)

There are two articles with substantially overlapping content. I propose they be merged with this one. zazpot (talk) 22:59, 18 July 2011 (UTC)

For information, since the merge proposal templates will be deleted once the merge is complete, the two articles referred to above are the ones currently present on Wikipedia as Ultraviolet disinfection and UV water disinfection. zazpot (talk) 03:51, 8 August 2011 (UTC)

The above discussion is closed. Please do not modify it. Subsequent comments should be made in a new section.


Advantages[edit]

This paragraph is a mismash of semi-related ideas. UV have nothing to do with making water hard. The boiling does not have to be done on a biomass stove. It is not clear what is meant by chlorine treating "larger organisms." The connection with UV and expensive drill rigs is non-existent. And UV does not make wells "immobile." The advantages section does not really give the advantages of UV. KudzuVine (talk) 13:39, 29 February 2012 (UTC)

"Bandwith" of the 254nm line[edit]

This line is a chemical property of the mercury plasma and does not shift or widen with regard to power fluctuations. Article was updated accordingly. — Preceding unsigned comment added by 24.96.249.3 (talk) 20:55, 10 August 2012 (UTC)

Please Add[edit]

I wish this article said why reflective linings has the greatest positive effect on the SODIS method. I had figured out that by applying it onto the SODIS method, and testing my water samples. I'm still having trouble finding the answer to my question. — Preceding unsigned comment added by 24.225.121.218 (talk) 21:44, 14 December 2013 (UTC)

reply[edit]

I agree with PeterH, this is propaganda. The author just used scientific words. 24.225.121.218 (talk) 16:39, 15 December 2013 (UTC)g