Date of Award

Winter 2009

Project Type


Program or Major

Civil Engineering

Degree Name

Master of Science

First Advisor

James P Malley


This research focused on what accelerates or hinders virus-particle association, how the addition of turbidity affects both chlorine and ultraviolet light disinfection, and if sonication can disrupt virus-particle associations exposing viruses to disinfection methods.

A decrease in pH, from 7--4, was found to accelerate association by 2-logs. Calcium increased association by 2.74-logs, and total organic carbon decreased association by 0.36-logs.

An addition of 5 NTU, the maximum turbidity level allowed by USEPA for unfiltered drinking water supplies, affected both chlorine and UV light disinfection showing differences in the rate of kill per dose. The association of viruses and particles can hinder inactivation. These effects must be considered when disinfecting unfiltered drinking water sources because the rate of inactivation is reduced at higher turbidities.