Analysis of Ultraviolet Disinfection on Microbial Activity and Validation of Rapid Testing Methods

Abstract

A faster testing method for quantifying microbiological contamination in wastewater is proposed and validated in this research. ATP analysis, in conjunction with incubation in a nutrient broth to is used to better represent the inactivation of the UV processes. The average disinfection efficiency for the Dartmouth WWTP using the HPC method was 84%. ATP testing gave an average disinfection efficiency of -10%, a false negative that shows immediate analysis is a poor approach but applying the proposed incubation method gives an average disinfection efficiency of 77%. NOM concentrations of 2 mg/L gave an acceptable 4.22 log reduction in E. coli concentration; but 20 mg/L yielded no reduction. Turbidity at 100 NTU and 1000 NTU yielded 3.67 and 3.58 log reduction in E. coli concentrations respectively. Amino acid at 2 mg/L and 20 mg/L saw reductions in E. coli concentrations of 3.94 log and 3.89 log respectively.