Mitigation of biofilm colonization on various surfaces in a model water flow system by use of UV treatment

Medium-pressure (MP) ultra violet (UV) disinfection was suggested as a pre-treatment to control biofouling in a semi-scale flow-through model water system. Water, spiked with Pseudomonas aeruginosa, nutrients, and carbon source, was flowed through the system and biofilm formation on glass, PVC, and stainless steel 316 slides was examined following 24 h runs. Following UV exposure a 99 % reduction in biovolume and average thickness of the biofilm was observed on all surfaces examined, despite clear differences in the virgin surface characteristics analyzed using contact angle, zeta potential, and atomic force microscopy (AFM). The findings support the stochastic behavior of biological systems in relation to predictions derived from conventional theories. The reduction of viable microbial counts seems to be the major mechanism in reducing the actual biofilm formation rate and the overall effect UV provides could indeed render it an effective tool in mitigating biofilm formation in water distribution systems.