Optimizing Ozone-Biofiltration Systems for Organic Carbon Removal in Potable Reuse Applications

ABSTRACT

This study presents a framework for simultaneously evaluating ozone dose and empty bed contact time in ozone-biofiltration systems when aiming to optimize or maximize total organic carbon (TOC) removal in potable reuse applications. Ozone:TOC ratios of 0.35, 0.62, and 1.12 resulted in ΔTOC_max values of 17–19%, 21–24%, and 26–30%, respectively, during pilot scale biofiltration with anthracite or biological activated carbon. The corresponding first-order rate constant for the biodegradation of TOC was similar for both media types (0.25 ± 0.06 min⁻¹). In addition to bulk organic transformation, ozone was effective in reducing the concentrations of many trace organic compounds.

KEYWORDS:

• Biofiltration
• biological activated carbon (BAC)
• Ozone
• potable reuse
• total organic carbon (TOC)
• trace organic compound (TOC)

Acknowledgments

This publication was made possible by U.S. EPA grant R835823 (Early Career Award – Framework for Quantifying Microbial Risk and Sustainability of Potable Reuse Systems in the United States) and U.S. Geological Survey grant G16AP00069. Its contents are solely the responsibility of the grantee and do not necessarily represent the official views of the U.S. EPA or USGS. Further, U.S. EPA and USGS do not endorse the purchase of any commercial products or services mentioned in the publication. We would also like to thank the participating utility and the following individuals for their assistance: Peter Faught, Eric Dickenson, Brett Vanderford, and Janie Zeigler-Holady.

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Additional information

Funding

This publication was made possible by U.S. EPA grant R835823 (Early Career Award – Framework for Quantifying Microbial Risk and Sustainability of Potable Reuse Systems in the United States) and U.S. Geological Survey grant G16AP00069.