521-OM0108.88
Copyright
2009 Nalco Company
6-23
Technical Help
(630) 305-CHEM
3D TRASAR
5500 - Installation & Operation Manual
12. Does 3D TRASAR Bio-Control control Legionella?
No
biocide program ensures
Legionella
-free towers.
Legionella
influx is unpredictable.
There are
no
Biocides that are
specific
for
Legionella
. 3D TRASAR Bio-Control applies conven-
tional oxidizing biocides
Legionella are only a small fraction of microbial population in cooling tower. 3D TRASAR Bio-
Control monitors the general planktonic and sessile microbial activity in the tower and applies
biocide as a response. 3D TRASAR Bio-Control does NOT apply Biocides specifically for
Legionella
.
Use of 3D TRASAR Bio-Control can’t guarantee a Legionella-free tower. Although there is no
statistical correlation between general microbial control and Legionella detection, it is widely ac-
cepted within the industry that controlling microbial proliferation and biofilm formation reduces the
risk of Legionella proliferation. Numerous case studies have shown that 3D TRASAR Bio-Control
is effective in controlling biofilm and general microbial populations.
Application of an oxidizing biocide is only one component of an effective Bio-Manage program.
Other, equally important aspects of a properly administered Bio-Manage program include: ad-
dressing mechanical and operational issues (dead-legs, recirculation problems), routine tower
cleaning and disinfection, proper oxidizing biocide selection, routine application of an appropriate
non-oxidizing biocide at proper dosage and coordinated with detergent slugs.
For systems where control of
Legionella
and health related risks is a water treatment program goal,
Nalco Environmental Hygiene Services should be contacted for risk assessment and management.
13. Does 3D TRASAR Bio-Control control SRB’s (Sulfate Reducing Bacteria)?
The bio-reporter can respond to anaerobic bacteria such as SRB’s.
Numerous case studies have shown that 3D TRASAR Bio-Control is effective in controlling biofilm
and general microbial populations. SRB’s are typically found under deposits and biofilm. Control of
biofilm can help control SRB proliferation in the system.
SRB’s are only a small fraction of microbial population in cooling tower. 3D TRASAR Bio-Control
monitors the general planktonic and sessile microbial activity in the tower and applies oxidizing
biocide as a response. 3D TRASAR Bio-Control does NOT apply Biocides specifically for SRB’s.
SRB’s are typically found under deposits, which are inaccessible to the bio-reporter and oxidizing
biocide. It is effective to use a biodetergent and a non-oxidizing biocide to better disperse and treat
the deposits in the system.
If high SRB counts are encountered in the system consider supplementing 3D TRASAR Bio-Control
with regular Oxidizing biocide slugs. You may also consider using 3D TRASAR Bio-Shock mode for
a period in order to bring the system under good microbial control.