Fate of polybrominated diphenyl ethers during wastewater treatment process

Background: Polybrominated diphenyl ethers (PBDEs), a flame retardant, are widespread in home and office consumer goods, electronics, furnishings, and textiles, and may pose health risks. Those health risks include developmental and nervous system toxicity, as well as endocrine disruption. Due to the ubiquitous nature of PBDEs, there is a need to identify the waste streams containing PBDEs that release into the environment. One such source is wastewater treatment plants (WWTP). The purpose of this study is to investigate the fate and transport of PBDEs within the WWTP by examining the ambient air, wastewater, and sludge throughout the WWT process. Methods: Ambient air, wastewater, and sludge were collected over a 3-month period from a large, tertiary WWTP in West Central Florida which discharges effluent into the Bay, and produces sludge for land application. All extraction and analysis of samples followed pilot-tested EPA standard methods. Results: Ambient air concentrations were highest at the carbonaceous tanks, with a total concentration of 9 ng/m3 of the eight PBDEs of interest. Pilot study results of the wastewater found a total concentration range from 8.23E-04 to 247.04 pg/uL, with the largest PBDE reduction occurring at the nitrification reactors. Final results of wastewater and sludge analysis will be available May 2013. Mass loading of PBDEs will also be discussed. Conclusions: By examining total releases of PBDEs from the WWTP, a complete picture of the fate and transport of these emerging pollutants of concern can be created. This will allow researchers, engineers, and WWTP operators to discuss how best to reduce the impact of PBDE discharges to the environment.