Florida Plant Reduces Color from RO Concentrate

April 3, 2018
Initial results of the ozone treatment system have met & exceeded performance goals

In the fall of 2014, the city of Palm Coast, Fla., installed a new Pinnacle Summit Series ozone system. The purpose of the system is to reduce the organic based color of the low-pressure reverse osmosis (RO) system concentrate stream. In a unique treatment application, this ozone pretreated concentrate stream is directed to the city’s lime softening facility and processed as an alternative water source. This process allows the recovery and treatment of up to 750,000 gal per day of alternative water supply that otherwise would have been discharged to waste.

Pinnacle technology was selected based on its ability to offer the greatest functionality and lowest total lifetime cost. In the fall of 2012 several oxidative treatment processes were piloted in an effort to reduce concentrate color. The city saw immediate results and chose Pinnacle following the pilot testing. The new system allows ozone production to precisely match real-time demand via seamless automatic control of three ozone generator platforms and three injection process trains using Pinnacle’s Ozone-On-Demand controls.  Initial testing indicates the new ozone system has exceeded performance goals and expectations.

Project Background

The city of Palm Coast was experiencing elevated color in the concentrate stream being directed to the lime softening facility to recover as drinking water. In an effort to meet secondary color standards at the lime plant, this water quality issue limited the volume of the concentrate able to be recovered. City staff and CPH Eng. identified O3 as a potential method to reduce color from the concentrate stream. Pilot testing was conducted in fall 2012/spring 2013. The testing demonstrated that O3 could effectively address color issues and improve concentrate quality to the lime plant and was the lowest cost alternative for treatment. Budget and schedule issues were significant challenges in the project in order for the city to receive Florida Department of Environmental Protection and St. Johns River Water Management District grant funding.

Treatment Approach

Pinnacle worked closely with city staff and the engineers at CPH to develop a comprehensive ozone system for this project. Pinnacle provided pilot equipment and process optimization services to prove design specifications for the application. Then, Pinnacle provided an integrated design approach for the entire ozone process. The final design included an onsite oxygen generator, Pinnacle’s modular Summit ozone generator, closed loop chiller system, venturi based ozone injection system, and ozone off gas destruct system. 

A unique aspect of the project is controlling ozone dose using both dissolved ozone and dissolved color. The dissolved ozone probes provide control of the ozone injection process, however, the dissolved color meter provides the final compliance point and allows for automatic adjustment of the ozone dose. The integrated system automatically adapts and compensates for changes in concentrate water quality from the plant.

Another significant challenge to the project was budget and schedule. In order to qualify for available Florida Department of Environmental Protection and St. Johns River Water Management District grant funding, the city needed to complete the entire ozone project in less than six months. Pinnacle was able to manufacture and deliver all of the equipment for the ozone process within six weeks of receiving the purchase order. By working closely with the contractor Sawcross Inc., Pinnacle was able to deliver the project within the schedule needed to receive grant funding.

In preliminary startup and testing, initial results of the ozone treatment system have met and exceeded performance goals. Pinnacle provided a complete and fully integrated ozone system including an onsite oxygen generation system, side stream injection, closed loop chiller and an off gas ozone destruct unit. The entire system was delivered and substantially completed in less than 12 weeks in order to meet the deadlines for project funding.

Louis LeBrun, P.E., is vice president of Pinnacle Ozone Solutions. LeBrun can be reached at [email protected].

About the Author

Louis LeBrun