QUESTION - Re: Ozonation and HPC/Coliform Bacteria

Enigl enigl at aol.com
Wed Mar 20 02:07:13 EST 1996

Subj:	Ozone Problems
Date:	03/17/96
To:	zippy at mlode.com

>>My question is: how effective is ozonation, in dosages of 0.4-0.6
mg/L for several minutes, in the inactivation of the aforementioned
bacteria? Should we not expect a total kill-off of these organism with
ozone. In my past experience pre-chlorination has reduced the counts to
nil. <<

Heat is far more effective.  I have two ozone water sanitized systems. 
What a pain...  any biofilm and the O3 is totally ineffective.  Apparently
the O3 does not penetrate biofilm and only slices off the top  layer. 
This is the same problem as Chlorine according to an_ ASM News_ article.

I wanted a heat sanitized system and my piping is all stainless steel
316L, so heat could be added instead of O3 in the future.  I had one small
(3 inches long) sample valve that got a biofilm last week and I tried
sanitizing it with O3 for an hour each day to no avail.  This was a
purified water, USP pharmaceutical system brand new as of February15.  I
used 0.34 mg/L daily for a week and the HPC went UP!  The O3 generator
company said:  " 0.08 mg/L will kill anything,......... except biofilm."  

Davin C. Enigl, MS, MEAS
Senior Microbiologist, Consultant

HACCP Validations-sm
Hazard Analysis and Critical Control Point Validations
For the Food, Cosmetic and Pharmaceutical Industry

March 17, 1996
4:01 pm

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