Perquat ™ technology Enhanced biocide and biofilm removal chemistry

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.

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

Biofilms In the Real World 4

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.

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

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 7.2-7.8

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

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

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

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)

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

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

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.

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

Biofilm Removal

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

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”