P6: Laboratory Studies of Biofilm and Scale Mitigation by Sphagnum Moss

The accumulation of biofilm and scale in man-made water systems creates numerous challenges including health/infection issues, increased maintenance expenses, and significant operating inefficiencies. Sphagnum moss is a plant with many unique properties (i.e. cation binding) and acts as a natural water conditioner. We evaluated extracts of Sphagnum moss (MX) for their ability to inhibit or remove biofilm in a standard, laboratory biofilm assay (MBEC) and for the potential of Sphagnum moss to remove scale in an experimental laboratory system. For biofilm inhibition studies, MX and Pseudomonas were added simultaneously, incubated up to 24hrs, and the amount of biofilm quantified. For removal studies, Pseudomonas was incubated for 24hrs to establish a biofilm, then MX was added, incubated up to 24hrs, and the amount of biofilm quantified. The results demonstrated a dose dependent ability of Sphagnum moss extracts to inhibit biofilm formation up to 80% and to effect biofilm removal up to 70%. These effects were maximal 12-24hrs after addition of MX to the MBEC. Scale studies were performed by creating scale on the inside surface of beakers, treating the beakers for 7 days with Sphagnum moss, and quantification of the remaining scale (as Ca). Scale remaining in moss-treated beakers (16.05mg) was reduced 70% from the untreated beakers (54.15mg, p<0.001). The pH in the beakers remained stable over the 7 days and within 0.1-0.2 units of each other. The results of these laboratory studies demonstrate the ability of Sphagnum moss to mitigate biofilm formation, remove established biofilm, and to remove surface scale.