Vol. 7 – No. 233
Ozone Disinfection : Municipal Water Distribution Pipelines
Benicia, CA — Water quality leaving treatment plants of North American water utilities is exceptional. Unfortunately, on the way to customers this safe and high quality potable water may become contaminated in miles of distribution system.
After two years of research by Denver Water and Camp Dresser and McKee (CDM) a new process to disinfect pipelines using ozone as the disinfectant is being employed in real world daily operation. The patent-pending Rapid Pipeline Disinfection system uses mass transfer and degas technology from Mazzei Injector Corp.-GDT™ and Floating Plate™ air-cooled ozone generating technology from Pacific Ozone Technology.
The new trailer mounted Rapid Pipeline Disinfection ozone system receives water from a local fire hydrant using a fire hose. Ozone is produced from pressurized oxygen cylinders by an air-cooled 180 g/h Pacific Ozone Technology ozone generator and is added to the hydrant water using a packaged pressurized GDT™ ozone mass transfer system. More than 90% of the ozone gas is dissolved in the GDT process with off-gas discharged through an ozone destruct unit also from Pacific Ozone Technology.
The new ozone system can disinfect a pipeline in one hour, compared to traditional methods using chlorine that can take up to 24 hours. The summary of benefits recognized using ozone disinfection includes:
1. No dechlorination step – chemical and labor cost reduction.
2. No hazardous chemical storage or transportation – permitting ozone to be generated on site.
3. Effective and rapid disinfection – minutes not hours/day before flush and sampling.
The Rapid Pipeline Disinfection ozone trailer is typically operated for 30 minutes. The residual ozone in the pipeline is allowed to naturally convert to oxygen (less than 1 hour) as compared to chlorination – dechlorination that can take up to 24 hours.
Denver Water has been tracking operational results of both the ozone and chlorination-dechlorination disinfection systems on 6 to 12 inch mains with runs up to 6,000 feet for almost two years. They have found first pass success rates to be virtually identical at 87%.
For more information on the Rapid Pipe Disinfection ozone system, contact:
Paul K. Overbeck
Pacific Ozone Technology Inc.
6160 Egret Court
Benicia, CA 94510
Web site: http://www.pacificozone.com/