Water Reclamation – IOA 2019

Behind the scenes at the Atlanta Aquarium. Filtration and ozone equipment in the background.

Ozone use to control odor and pollutants in large water treatment plants is well documented and growing. In addition to disinfection benefits, the ozone breaks down pollutants so that they are better removed with bacteria and filtration. The research and testing for these large plants provides a rich resource for developing a variety of small scale water treatment systems for applications like aquariums, car-washes, building water reclamation, and water condensate treatment.

The IOA convention this year provided an opportunity to visit the Atlanta Aquarium. This aquarium is the largest in the western hemisphere and is home to four whale sharks and over 100,000 other aquatic residents. The filtration system recycles the 10 million gallon capacity in approximately 1.5 hours. The filtration system incorporates ozone to maintain water clarity and disease control. The stunning display of aquatic life and continual maintenance of its health speaks well for the power of ozone.

Many of the presentations at the 2019 IOA convention presented research and studies relating to water treatment plants that treat over 500 million gallons of water per day. The aquarium was a great example of this process on a smaller scale. One of the presenters shared a project of implementing ozone to treat water-reuse for a train-car wash facility. Ozone was used to address a concern of biological contaminants picked up by the vehicles and entering the wash water. Ozone eliminated the danger of pathogens making the operators sick.

Ozone works well by itself for destroying pathogens, but needs help with filtration methods to clean up the left-over scraps. Many studies conducted for large waste water facilities demonstrate that ozone is often most effective for odor and pollutant removal when combined with filtering and/or hydrogen peroxide. Ozone alone will break down many pollutants, but some compounds require more energy. Hydrogen peroxide in the presence of ozone generates powerful oxidizing molecules
Hydroxyl Radical (OH-) which are even more effective. Ozone often breaks pollutants down to the point where they are more easily digested by bacteria in a biologically active filter (BAF). The ozone causes some molecules such as dissolved iron to coagulate so they are larger and can be filtered out.

Our team at Oxidation Technologies has worked with various food and recycling industries looking for ways to reclaim water for further process use. We are dedicated to understanding your process so that we can provide the equipment and resources you need and stay within your budget. We offer rental systems  that can be used for experimentation before committing to a permanent system designed to fit your application.

Letter – New water filtration system good for Walla Walla’s future

Letter – New water filtration system good for Walla Walla’s future

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I‘d like to point out a silver lining in the June 22 Union-Bulletin story about the $20 million filtering system the city of Walla Walla will be building at our water plant.

About 15 years ago I was a member of the city Water Committee when it discussed how to deal with the cryptosporidium cysts found occasionally in our area’s untreated water. We considered two alternatives: ozone and filtration.

A few committee members advocated for filtration because of its ability not only to catch the crypto but also to reduce sediment levels in the water. Our final recommendation, though, was to construct the less-expensive ozone plant. Ozone was then thought to be completely effective in disabling crypto, which was the specific problem before us.

Since then, experience has revealed that ozone doesn’t work well when water is too cold, as it often is during winter months. Also, no disinfection system, including ozone, works well when water is full of sediment.

In addition to assuring that those of us on city water won’t have to endure, or even pronounce, cryptosporidiosis, our new plant will also remove sediments so we can make use of water that would otherwise be too turbid because of wind, storms and floods, or rain following fires in the watershed.

As climate continues to change, we face greater uncertainties in our water supply. We’ll likely see less snowpack, more large storms, more droughts and more wildfires.

Because of its ability to remove part of the sediment in the water, our new filtration system should allow us to use more of the surface water we do have, and that will leave us and our children better prepared to handle some of the many changes ahead.

Barbara Clark

Walla Walla City Council member