Ozone revisited again

[In Canada eh]

First of all aI don,t know if I should even comment with what Vermonter has said and the info he/she has given, but here goes.

It took along time but I was able to dig though manuals, training books on disinfection, internet and talked to a couple senior operators at other plants.  I was able to find that a brand new, 120 volt UV bulb can supply about 100mg/hour of ozone.  So to Chas and Vinny you guys were right, I stand corrected.  This represents a amount very small to the water industry but should be enough for a hot tub,given the following assumptions  1  ph 7.5
                     2  75 % absorption of the gas
                     3  6 gpm or flow rate
                     4  10 feet of 3/4" tube for contact chamber
                     5 brand new bulb
                     6 4 log removal (99.99%)
                     7 25 degrees C water

Well all be a monkeys uncle! It will work.

 Vermonter, I don't mean to high jack your post it was very good and felt that this should be separated from it.

  I was not familiar with UV ozone due to the low output and the fact that it would not be cost effective on a large scale i.e. drinking water.

 Vermonter. I hope you will continue to add your expertise in the future.
           

[Vermonter]

given the following assumptions  1  ph 7.5
                      2  75 % absorption of the gas
                      3  6 gpm or flow rate
                      4  10 feet of 3/4" tube for contact chamber
                      5 brand new bulb
                      6 4 log removal (99.99%)
                      7 25 degrees C water

 Well all be a monkeys uncle! It will work.

Eh...

First - UV and ozone.  You may come from a background in which you have heard that UV will destroy ozone.  And now you see somebody saying it produces ozone.  That must be more confusing than why you ever let Pedro come to my Red Sox (of course, we let him go, too)!  It actually does both - but it is wavelength dependent.  

UV, at a wavelength of 254 nanometers (nm) is a highly effective form of treatment for most microorganisms (it is highly dependent on the UV dose and the quality of the water you are treating).  It kills - but leaves no residual.  At that wavelength, it also quantitatively DESTROYS OZONE - and is used in many applications for that purpose.  If you buy a UV system for your house, it will produce UV at 254 nm.

Ozone, at a wavelength of 184 nm (actually, I think it is 183.7 nm) PRODUCES OZONE and, as UV, is much, much less efficient at disinfection (perhaps you could say "not effective").  

So - ozone can be both produced and destroyed by UV; it all depends on the wavelength.

Second - the "monkey's uncle" statement that it will work!

The key here is the word "assumptions".  Given their assumptions, sure, for some microbes it will give even more than the 4-log reduction than they reference.  But in the "real world" - it won't happen.  Look at their own "assumption" of 25'C.  That is equal to 77'F (if I did the correct mental conversion) - and I know it gets cold in Canada, but I doubt you would be satisfied soaking in 77'F water and feeling nice and warm!  Even without focusing on the temperature, whatever reference you found appears to be lacking on empirical data.  It is all "could, assume, can, etc." but no documented, valid results.  I ran into the same thing when researching ozone in hot tubs; and for that matter, for enzymes and some of the other alternative treatments.

Best,

Vermonter

[Lori]

Ok, side bar....

Vermonter, good to see you around!  I've been a little out of touch lately!!!

Hope the star is doing well (along with all of the family)!!!

Ok, side bar over!

;-)

[In Canada eh]

The 25 degrees  C was as high as a drinking water chart can go, Lake water  very rarely get anywhere near that temp.  The assumptions made where the only way I could make the CT formula work.  I had to assume ( I know never to do that ) that UV can create ozone based on much debate on this forum.  While trying to find reference to it actually doing so, I found one small blurb about it.  I than used that assumption to plug in values.  I had previously argued that UV did not poduce ozone and was given enough info that said it might.

Another assumption   won't happen again!!!

[Vermonter]

Hope the star is doing well (along with all of the family)!!!

Ok, side bar over!

;-)

Hi Lori,

Thanks.  Minimal work - although a GPA of 4.47 in her Sophomore year and awarded "top Sophomore".  But, too restrictive on the dorm (run by nuns, God Bless Them), tough roommate situation and other considerations (family, etc.).  Change in plans and she will be going to a school here for at least the Junior year - coed and living at home.  I'm thrilled.  We'll be working at getting some top representation for both NY and LA; NY is a 6 hour drive or a 45 miute flight; much better than LA.

Thanks for asking!  I hope you are doing well.

Best,

Vermonter

[Chas]

Ozone, at a wavelength of 254 nanometers (nm) is a highlyng).  It kills - but leaves no residual.  At that wavelength, it also quantitatively DESTROYS OZONE - and is used in many applications for that purpose.  If you buy a UV system for your house, it will produce UV at 254 nm.
 effective form of treatment for most microorganisms (it is dependent on the UV dose and the quality of the water you are treati
Ozone, at a wavelength of 184 nm (actually, I think it is 183.7 nm) PRODUCES OZONE and, as UV, is much, much less efficient at disinfection (perhaps you could say "not effective").  

Typo - I think you meant, "UV light" instead of Ozone in the first sentence of these two paragraphs.

[Vermonter]

Chas,

Right you are.  I made the change in the original post - thanks!  Guess I should proof my posts before hitting "post"!

Vermonter

[Lori]

Vermonter,

All is well here!  Sounds like she is going to be a star, no matter where she goes!  Glad she will be closer to home (know that is rough on all of you)!!!  Thanks for the update!!!

I changed jobs last year, and I just heard this week that my previous employer has sold the business, so I got out just in time!  I just feel for my friends that are still there!  It hasn't been officially announced, so they are not sure about their jobs, but I'm sure he negotiated them a chance to save their employment for at least a year!  

Anyway, so I'm really doing well in my new position.  I'm now a benefits adjuster for a disability insurance carrier.  I recently had my 1st year review, and was promoted (I was a trainee to begin with since I didn't have any experience) to a full adjuster & got a nice raise along with it!!!  I'm just not able to hang out on the boards as much as I used to!  

Talk to you soon!  Take care!!!

[Steve]

Congrats Lori and it's so nice to see ya 'round these parts!   Glad you're doing well!

Steve

[Lori]

Thanks Steve!!!  I'm sorry to hear that you are looking to make a change!  But, as I always say, everything happens for a reason, and what is meant to be will be!!!  

I'm usually around on the weekends now!!!   [smiley=2vrolijk_08.gif]