1. Perquat ™ technology Enhanced biocide and biofilm removal chemistry

2. Biofilms –What and Why Natural habitat for microorganisms
Complex ecosystem where bacterium work synergistically.
Allows microorganisms to withstand adverse conditions
Protects microorganisms from biocide – 1000x normal dosage
Facilitate nutrient and gaseous exchange
“Most engineered aquatic systems – especially those that are complex – have areas containing biofilms, even when that system is well maintained” (WHO, 2007)
“Preventing biofilm development can be difficult, particularly in dynamic water systems such as cooling towers and spas, where the water flow is disrupted and large amounts organic nutrients may enter “ (WHO, 2007)
The availability of complex nutrients in biofilms has led some researchers to propose that biofilms support the survival and multiplication of Legionella outside a host cell.

3. Biofilm - The Pathogen Reservoir
Biofilms more likely in wet, inaccessible areas and on corroded and soiled surfaces
Not sufficient to kill the surface organisms – must remove the reservoir
Failure to remove means repopulation in 48 hours

4. Biofilms In the Real World4

5. CDC 2010 (Operating Public Hot Tubs)
Extracted Recommendations
Appropriate pH and chlorine or bromine levels should be maintained at recommended levels.
Disinfection and pH levels should be monitored regularly
Filtration and recirculation systems should be designed and maintained according to manufacturer recommendations.
Spas should be scrubbed and super-shocked regularly to remove any biofilms
Water should be drained and replaced on a regular basis.

6. Options for Biofilm Control and Removal?
Oxidizing Biocides
Chlorine
Bromine
ClO2
Other halogen releasers
Non-Oxidizing Biocides
Glutaraldehyde
Quaternary Ammonium Compounds
THPS
DBNPA
This should be a very quick topic, and it can be simply stated that these are examples of commonly used biocides for microbe control in cooling towers. No details here.
Used to make biofilms more susceptible to biocides
Not approved by the EPA to have any effect on biofilm (removal or kill)
Biodispersants

7. Oxidizing Biocides Sodium Hypochlorite Chlorine Hypochlorous Acid
Advantages
Proven effective disinfection technique
Relatively cheap
Burns biofilm layers
Relatively easy to use
Disadvantages
Handling issues
Stability
Increased corrosion
Only attacks top layers of biofilms
Higher levels needed to burn biofilms can lead to accelerated corrosion
Formation of trihalomethanes and haloacetic acid
The concentration of Hypochlorous Acid is dependent on pH.
At pH of 7.0 about 90% of the Hypochlorous exists.
At pH of 7.5 only about 50% of the Hypochlorous exists.
At pH of 8.0 only about 24% of the Hypochlorous exists.
(Association of Water Technologies)
CDC recommends spa be maintained between pH of

8. Oxidizing Biocides Chlorine Dioxide Disadvantages Generated on site
Stabilized chlorine dioxide
Sodium chlorite added to hydrochloric acid (batch generation)
Electrochemical generation
Electrochemical decomposition of sodium chlorite
Reaction of sodium chlorite with sodium hypochlorite and hydrochloric acid
Advantages
Chlorine dioxide more selective than other chlorine.
Less issues of trihalomethanes and haloacetic acid
Biocide effectiveness not dependant on pH
Disadvantages
Depend on method of generation
Electrochemical generation
Method simple and safe
Can contain up to 25% unreacted sodium chlorite
Cells may need frequent replacement
Initial capital investment
Stabilized chlorine dioxide
Batch process
Not cost effective for continuous use
Chemical Handling
Burns biofilm

9. Non-Oxidizing Biocides
Quaternary Ammonium Compounds (Quats)
Positive charge binds to surfaces of the biofilm
Do not lift biofilm
Do not penetrate biofilm
Gluteraldehyde
Counter indicated for biofilm removal
Crosslinking agent
Not appropriate for pools and spas
THPS (Tetrakish(hydroxymethyl) phosphonium sulfate
Excellent safety and environmental discharge profile
Poor algae and biofilm removal properties
Not appropriate for pools
Widely used technique for controlling bacteria in Cooling Water Towers
Many different kinds of non-oxidizing biocides available
Disadvantages
Most are not applicable to Spas
Often used in conjunction with other biocides in a rotation

10. Biofilm Treatment with Different Sanitizers
Bleach/oxidizing
- Biofilm layers are burned but not removed
QAC
-Binds to surfaces
-Biofilm not removed
Gluteraldehyde
-Makes biofilm removal even harder 10

11. Traditional Biocides
Shown to be ineffective or require prolonged/high dosages of actives to “burn” layers of biofilm
Not always effective
Incomplete biofilm removal leaves reservoir of pathogens
“Biofilm Removal” – “Penetrates Biofilm” – “Kills Biofilm Bacteria” are EPA regulated claims
None of the previously mentioned techniques have approved public health and non-public health claims for these terms (or anything similar)

12. PerQuatTM Technology Hybrid Technology
Technology has EPA approved biofilm claims for public and non-public health sites
Multiple mechanisms of action
Oxidation
Hydrolysis
Microbubbling (oxygen pump)
Attacks adhesions that glue biofilm
Collapse polymer structure
Removes biofilm
Kills sessile population
Penetrates biofilms 12

13. PerQuat Chemistry
Novel hybrid biocide and biofilm removal agent characterized by a neutral ion pairing between the Hydroperoxide Anion (OOH-) and a cationic phase transfer agent (HPI-PTC)
Water phase
Oxidative and hydrolytic OOH- anion transported by Phase Transfer Catalyst
Tell them what it is!
Attack Pathogen
Attack Biofilm
Biofilm

14. PerQuat Chemistry
Once inside the biofilm, the anion of hydroperoxide reacts with acetyl esters to form peroxy-acids, which produces “strong hydroxyl radicals that are very reactive and decompose cell material efficiently”
Explain why it works, and why it is different than other non-oxidizers.
Before PerQuat
After PerQuat
iZinn, M., Zimmerman, R. C., & White, D. C. (2000). Environmentally Acceptable Control of Microbial Biofilms. In L. V. Evans (Ed.), Biofilms: Recent Advances in their Study and Control (p. 365). Amsterdam: Harwood Academic Publishers.

15. Biofilm Removal
The chart is very good. The pictures will need to be explained.

16. Biofilm Removal

17. Maintenance Guidelines
At least twice yearly
Higher frequency for systems:
High organic load
Poorly designed (dead spots)
Extremely high bather loads
Have frequent out-of-control occurrences
Typical concentration is 3.9 gallons of Solution 1&2 per 1000 gallons
Must be drained and flushed from the system

18. Conclusion
Control and removal of biofilms from spas key to controlling pathogens in water
Biofilms are reservoir for pathogens including Legionella
Bulk water counts can reach pre-treatment levels in 48 hours
Biofilms in the system will contribute to higher chemical demand
CDC and other World Organizations recommend that Spas be “Super-shocked” to remove biofilms
Hybrid technology (Perquat) has been effective (and has EPA approved claims) to “Penetrate Biofilms and Kill Biofilm Bacteria”