Tuesday 8:00 AM
[Presentation PDF]

Room: Governor

Balancing Ozone Oxidation with Disinfection By-Product Mitigation Strategies

Ozone has typically been used in water treatment for disinfection and treatment of color, taste and odor. Ozone has recently gained attention for its ability to oxidize emerging contaminants, including endocrine disrupting compounds (EDCs), pharmaceutical and personal care products (PPCPs), and algal toxins. Meeting the disinfectant and disinfection by-product rules is a balancing act for water utilities as they are required to decrease microbial risk with disinfectants, while simultaneously reducing the chemical risk caused by disinfection by-products (DBPs). The use of ozone may cause the formation of bromate (BrO3-) through a series of interactions between bromide, ozone, and hydroxyl radicals. Recent studies by Burns & McDonnell were conducted to balance ozone disinfection and oxidation while minimizing bromate formation. This paper presents the results from several bromate mitigation studies. Practical guidelines will be presented to address the operational limitations for balancing ozone dose and bromate formation to achieve disinfection requirements, color reduction, taste and odor abatement, and emerging contaminants treatment.

Moderator:  Lara Biggs


Nathan Dunahee, P.E. - Burns & McDonnell

Mr. Nathan Dunahee is a project manager with Burns & McDonnell Engineering Co (Kansas City) in its Water Technology Group. He graduated from the University of Illinois with a BS in Civil Engineering and MS in Environmental Engineering as a Gradate Research Fellow.  He then attended the University of Michigan where he conducted three years of post-graduate laboratory research through an EPA Fellowship. Since leaving academic research, he has 10 years of experience as a drinking water engineer. He provides expertise at the national level and serves on two AWWA technical committees overlooking Emerging Water Quality Concerns and Taste & Odor.
Mr. Dunahee has a wide range of technical capabilities with expertise in water treatment optimization, disinfection, taste and odor, and emerging contaminants. His expertise in physical and chemical processes, coupled with his strong background in academic research, helps bridge the gap between fundamental research and practical engineering solutions. He has performed water treatment process optimization and testing for clients in more than twelve states. Bench and pilot testing has included filtration, disinfection, advanced oxidation, conventional treatment, lime softening, and other plant processes.

Randy Patchett - Burns & McDonnell

Randy Patchett is the Regional Water Global Practice Manager for the Burns & McDonnell Chicago and Downers Grove, Illinois offices.  Randy is a senior civil with extensive experience providing consulting engineering services on wastewater treatment and collection system projects for municipal, industrial and federal clients.  His responsibilities have included  include developing and managing projects involving a wide range of services in the areas of wastewater including  studies, modeling, master planning, design and construction management.