AAAR 36th Annual Conference October 16 - October 20, 2017 Raleigh Convention Center Raleigh, North Carolina, USA
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Transport and Characterization of Particulate Emissions from Three Wastewater Treatment Plants in Southern California
Pedro Piqueras, Md Robiul Islam, Fengying Li, Leigha Meredith, Mark Matsumoto, Elizabeth Stone, AKUA ASA-AWUKU, University of California, Riverside
Abstract Number: 588 Working Group: Bioaerosols
Abstract Wastewater treatment plants (WWTP) are proliferating in urban environments and their aerosol emissions have been associated with local and regional health burden. Known toxic compounds and pathogens have been detected in neighborhoods surrounding the plants but their concentration and classification are still dubious. The airborne exposure route is also still poorly established due to the lack of information on aerosol characterization and transport.
This study presents a WWTP particulate dispersion analysis through the AMS/EPA Regulatory Model (AERMOD) and establishes a relationship between basin coverage, source emission flux and dispersion: Three coverage scenarios (fully covered basin, semi-covered and covered) were modeled with annual, monthly and daily meteorological data. In addition, filter samples were collected from three WWTP along the Santa Ana River Watershed in Southern California: Orange County Sanitation District (OCSD) in Fountain Valley, Western Municipal Wastewater Treatment Plant (WMWWTP) in Riverside, and the City of Redlands Wastewater Treatment Plant (RWWTP). These specimens were collected at the WWTP source, 100 m upwind and 50 m, 100 m and 200 m downwind for quantification and characterization of organic compounds, endotoxins, fungal glucans and proteins. Filter data was later compared with particulate concentrations obtained from a laboratory bioreactor.
Results suggest that biological materials that are being generated through bubble bursting in WWTP are transported away from the source. Fecal sterols and some PAH were found in the WWTP samples with concentrations as high as 200 ng/m3 (cholesterol). Endotoxins were also observed (maximum of 130 EU/m3 at WMWWTP, 20 EU/m3 at OCSD and 2.17 EU/m3 at RWWTP). Protein levels reached 1.10 μg/m3 and glucan concentrations ranged from 0.01 to 1.07 μg/m3. It was also determined that partial coverage of the basins does not efficiently reduce the particulate emissions as previously thought. This indicates that aerosols may cause disease in neighborhoods and public spaces as far as 200 meters away from the source. Therefore a full coverage of the basin is advised to mitigate WWTP aerosols.