THE KINETICS OF BATCH ULTRAVIOLET INACTIVATION OF BACTERIOPHAGE-MS2 AND MICROBIOLOGICAL CALIBRATION OF AN ULTRAVIOLET PILOT-PLANT

Batch ultraviolet (UV) inactivation of bacteriophage MS2 in water or w astewater effluent using low pressure mercury lamps exhibits a tailing effect, which could be modeled by assuming that the rate constant, k, decreases with the logarithmic reduction, LR, according to the relati on: k = aLR + b with a = 0.00044 +/- 0.00012 m(2)/J and b = 0.0152 +/- 0.0010 m(2)/J. It is not clear why k decreases with the LR. Possibili ties are differences in sensitivity between individual phages within t he population or the formation of clusters of organ isms by aggregatio n with each other or with suspended solids present in the water. A ful l scale pilot plant could be characterized hydraulically by microbiolo gical calibration using the batch kinetic constants. Ultraviolet disin fection units must be modeled as a number of completely mixed tanks in series.