BIOLOGICAL METHODS OF WATER TREATMENT A STUDY OF THE VARIOUS PROCEDURES OF WATER DISINFECTION BY O_3/UV

摘要

Different modes of ultraviolet irradiation were studied in conjunction with ozonization of a model water containing Escherichia coli test microorganisms. These included irradiation in the initial period of ozonization and continuous and intermittent exposure during the entire process with different ozone concentrations in the ozone-air mixture feed. To obtain an additive effect from the action of the two disinfectants it was necessary to use low combined total doses of UV-radiation in O_3/UV-treatment - in our case not higher than 14.8 mJ/cm~2. The most efficient disinfection was achieved by exposing water in the process of ozonization to high dosages of UV-radiation during the initial time period, which was equal to the latent phase on the kinetic curve describing the dying-off of bacteria under the effect of ozone alone.