AWWA WQTC55179

The objective of this research was to investigate the impact of selected water quality parameters and initial ozone dose on the inactivation of Bacillus subtilis spores. Batch inactivation experiments were conducted on synthetic surface waters containing alkalinity (3mM HCO3 - ) and varying in their dissolved organic carbon and turbidity content. To observe the impact of initial ozone concentration on B. subtilis CT inactivation responses, initial ozone concentrations were varied over the range between 1-6 mg/L. When turbidity was present in synthetic surface waters, all initial ozone doses yielded similar responses as judged by log-normalized inactivation and associated CT. When turbidity was not present however, different initial ozone doses did not yield similar effective CTs. When water quality conditions were varied without the presence of turbidity, increasing initial ozone doses resulted in extended (CT) lag phases. Includes 9 references, figures.