Disinfection of Paramoebae perurans with UV and ozone In situ dose-response testing

Summary

Lab cultures of the amoebae Paramoebae perurans was exposed to UV irradiance at varying durations or ozonated seawater with varying residual oxidant (TRO) concentrations. The response to the treatment was observed as both changes in morphology and the ability to reproduce. UV exposures were performed with both a low and a medium pressure UV lamp in a collimated beam set-up. The amoebae lost their ability to reproduce even at the shortest UV exposure time (5 sec), both with low and medium pressure UV lamps (UV254-doses of 4 and 2 mJ/cm2, respectively). The amoebae had much higher resistance towards ozonated seawater than expected. They retained their ability to reproduce and seemed unaffected by the treatment even at the highest dose tested (25 mgCl2*min/L).