CEE 200-2 Seminar: Daniel L. McCurry presents “Understanding and Minimizing Disinfection-Associated Carcinogens in Drinking Water and Recycled Wastewater”

Speaker: Dr. Daniel McCurry
Affiliation: USC

 

Dr. Daniel McCurry, Assistant Professor of Civil and Environmental Engineering at the University of Southern California, presents: Understanding and Minimizing Disinfection-Associated Carcinogens in Drinking Water and Recycled Wastewater’.

Summary:
Disinfection of potable water is one of the great public health victories of the twentieth century, responsible for the avoidance of millions of deaths due to waterborne illness. However, application of disinfectants, typically chemical oxidants, leads to formation of hundreds of trace contaminants, often carcinogens, and consumption of chlorinated water has been epidemiologically linked to bladder cancer and certain birth defects. Eleven of these compounds are federally regulated in drinking water, but certain non-regulated disinfection byproducts (DBPs) are orders of magnitude more toxic than currently regulated compounds. Two specific DBPs, chloropicrin and N-nitrosodimethylamine (NDMA), are under current regulatory scrutiny and are associated with nitrogen input, often from wastewater discharges, into drinking water supplies. Wastewater-impacted drinking water and recycled wastewater are enriched in the precursors of these compounds, and their formation during potable water treatment is likely to grow, as wastewater increasingly contributes to the water supply. This presentation will focus on applying the tools of environmental organic chemistry to identify the chemical precursors and formation mechanism of these compounds, leading to strategies for their control during water treatment.

In particular, ozonation of primary and secondary amine compounds, leading to formation of nitro compound intermediates, was found be responsible for chloropicrin formation during water treatment. Molecular features of certain particularly potent precursors were identified, and control strategies developed based on this chemical understanding. Strategies for controlling NDMA formation, a major concern during wastewater recycling, were developed based on an understanding of the chemical composition of NDMA precursors (typically aromatic amines), and chloramines, the primary disinfectant applied during wastewater reuse. Minor modifications to wastewater recycling operations, in particular switching from low-pressure to medium-pressure mercury lamps for ultraviolet light treatment, and minor adjustments in the application of chloramines, were shown to dramatically reduce NDMA concentrations in final effluent. These chemical insights provide options for substantially reducing the chronic health risk associated with consumption of (intentionally or unintentionally) recycled wastewater.

Biography:
Dr. Daniel McCurry is an Assistant Professor of Civil and Environmental Engineering at the University of Southern California. Dr. McCurry completed his Ph.D. in Civil and Environmental Engineering at Stanford in 2016. Prior to Stanford, he earned an M.S. in Environmental Engineering from Yale and a B.S. in Civil Engineering from the University of Cincinnati, and worked in the EPA Office of Research and Development.  Dr. McCurry’s research focuses on protecting public health by improving the long-term safety of engineered water sources. He applies the tools of environmental organic chemistry to water quality problems arising from chemical and ultraviolet disinfection of wastewater and drinking water.

Date/Time:
Date(s) - Jun 01, 2017
11:00 am - 12:00 pm

Location:
Boelter Hall 4275
4275 Boelter Hall Los Angeles CA 90095