Comparison of the Anti-Legionella Fill Material against Standard Polypropylene Fill Material in Model Cooling Tower Water System

Abstract

Objective: Cooling towers are heat exchangers which are utilized in specific industrial devices. They possess the potential to support Legionella bacteria. The objective was to evaluate the efficacy of biocide impregnated polymer against regular polypropylene polymer in terms of anti-Legionella features during a 120-day period. Materials and Methods: To reduce the bacterial colonization in towers, anti-Legionella splash fill and regular polypropylene splash fill material were tested to compare anti-Legionella activity and biofilm formation potential within a 120-day period using a lab-scale recirculating cooling tower model system. The system was experimentally infected with Legionella suspension and operated continuously for 120 days. Results: Legionella colonization occurred on both test material surfaces beginning at the first month. Legionella counts on surfaces were increased over time on standard polypropylene surfaces. The product with anti-Legionella activity showed significantly lower Legionella colonization in comparison to standard polypropylene fill. Conclusion: The product with anti-Legionella activity has a significant biocidal effect against surface-associated Legionella under the above-mentioned conditions which mimics cooling tower water systems. Product seems to facilitate effective control program criteria against Legionella colonization in cooling towers.