Evaluation of Antimicrobial Coatings for Cloth Media Filtration: Case Study

The results of an investigation of the effect of antimicrobial coatings on inactivating microbes on and within the media used in cloth media disk filtration systems are presented herein. Four filter fabrics were evaluated using a modified form of the American Association of Textile Chemists and Colorists Test Method 100 in 1996. The fabrics had been treated with two antimicrobial agents by two coating vendors. Treated fabrics were subjected to backwash cycles to examine whether the antimicrobial properties were retained during normal filter operation. Initially, the fabrics treated with Zoonocide exhibited significant microbial reduction whereas fabrics treated with AlphaSan exhibited little microbial reduction. Once the fabrics treated with Zoonocide were subjected to a backwash cycle, the biocidal properties of the fabrics were depleted. Lack of durability of the coating was either because it washed off easily or the antimicrobial properties were chemically depleted, rendering the treatment ineffective.