The biocidal efficacy of oxidizing (halohydantoin) and non-oxidizing (isothiazolones) biocide combinations against filamentous biofilms was compared to the efficacy of these biocidea alone under well defined Iaboratoy conditions. Synergistic efficacy of halohydantoins and isothiazolones was indicated. The halohydantoin/ isothiazolones combination programs provided optimized cost performance with respect to biofilm control. The simultaneous addition of oxidizing and non-oxidizing biocides is the preferable mode of biocide treatment.
Keywords: biocides, halohydantoin, isothiazolones, synergy, control, biofilms, filamentous bacteria, Sphaerotilus natans, heat transfer resistance, dissolved oxygen