WQTS, Inc.
   
 
Home
space
About WQTS
space
Services & Projects
space
Staff
space
Facilities & Equipment
space
On-Line Models
space
Important Links
space
Publications
space
Presentations
space
Regulatory Documents
space
Employee Opportunities
space
Contact Us
Water Research Foundation
Validating Disinfection in Ozone Contactors

 


 

The method of calculating the CT product through an ozone contactor is a critical concern for utilities using ozone to meet the disinfection requirements of the Surface Water Treatment Rule (SWTR) and the Long-Term 2 Enhanced SWTR. The typical CT calculation method, the CT10 method, while relatively simple and easy to use, contains a high degree of conservatism, which translates into higher-than-necessary ozone doses and higher-than-necessary bromate formation. WQTS developed and conducted a tailored-collaboration project with four ozonating utilities from across the U.S. that sought to achieve two objectives: 1) confirm that the disinfection CT10 calculation under-predicts the actual disinfection achieved in an ozone contactor; 2) determine whether less-conservative disinfection calculation methods more accurately predict actual disinfection through the contactor. These alternative methods included the Integrated Residual method and the Segregated Flow Analysis (SFA) method. WQTS led the study involving bench- and pilot-scale disinfection testing and computer modeling to demonstrate that of the four CT calculation methods evaluated, the SFA method most accurately predicted the actual disinfection of Bacillus subtilis spores in a multi-chamber under/over ozone contactor.

 
Copyright WQTS, Inc 2006 | Los Angeles, CA | All rights reserved | info@WQTS.com
Site Design: JM Design