Ozonated water in cooling towers eliminates the need for biocide chemicals, reduces anti-scalent use and blowdown, and it acts as a pH buffer. Cooling Towers also help with Biological control with Legionella and Listeria.
|COOLING TOWERS - CASE STUDY|
|OZONE FOR THE CONTROL OF LISTERIA|
SITE HISTORY-- The Meat Plant has Evaporative Condense Cooling with three individual water sumps which can be isolated, or operated as a collevtive unit. The sumps are currently operated collectively, with a total volume of approximately 3,000 gallons and a cross flow between the sumps of 30 to 40 gpm.
The sumps are located on a second floor level over the top of a "finished product" area on the first floor. The physical location of the sumps provide a unique food safety issue because any equipment failure at the sump location has the potential to contaminate finished products, and/or the production area on the first floor below.
Listeria is a type of bacteria commonly found in the environment, and consequently commonly found in condensor sump water. Because of the physical location of the sumps, there is a need for much tighter biological control at this production facility. Since the cost of Listeria outbreak or for that matter any other product contamination incident, can be in the millions of dollars, there is a high demand on zero tolerance for bacteria.
Late in 1999, an analysis of the sump water showed positive for Listeria, using a standard ELISA test. An aggressive liquid biocide program was immediatly implemented, in conjunction with a biomass dispersant. Although a decrease in the total bacteria count occured, Listeria was still present in sump water. The goal was, and still is, a zero count for Listeria. Because there is no treatment program specific for Listeria, sterile water conditions now became the goal.
RESULTS--The use of Ozone showed an immediate reduction in total bacteria counts of 50% within a 2-day period. Viable Listeria counts were eliminated within 4 days of operation, and no presence of Listeria (dead or alive) was detectable after 6 days. Listeria bacteria have not been detected in the condense water since the employment of Ozone.
The system is currently running 24 hours per day, providing continuous protection against the unusually high bacteria loads scrubbed out of the air, in the Metro Detroit area.
CEC the Ozone Company • Phone 630-964-1200 • Fax 630-964-1282 • Email