Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 8/1/2007
Publication Date: 11/15/2007
Citation: Loyo-Rosales, J., Corsi, S., Rice, C., Torrents, A. 2007. Fate of the Alkylphenol Ethoxylate Components of ADAF in Airport Runoff. Meeting Abstract. p. 117.
Interpretive Summary: .
Technical Abstract: Aircraft deicing and anti-icing fluids (ADAF) contain toxic compounds that are often released without treatment and in relatively high concentrations to water bodies. The main components in ADAF, propylene glycol and ethylene glycol, are toxic; but in some instances, other constituents, such as alkylphenol ethoxylates (APEOs), might be responsible for most ADAF-related toxicity. The present study addressed the fate of the APEOs in outfalls and receiving waters from General Mitchell International Airport (GMIA). Flow-weighted composite runoff and receiving water samples were collected during ADAF application events from 2003 to 2006. Sampling sites included a reference site upstream from the airport, a downstream site to assess impact in receiving waters, and the two airport outfalls. The primary outfall combines flow from the reference site with flow from the storm sewers in the terminal and runways; whereas the secondary outfall serves the air-cargo section of the airport. Results show that the primary outfall contains higher concentrations of nonylphenol ethoxylate related compounds (NPE), whereas octylphenolic compounds (OPE) are more abundant in the secondary outfall. This is probably a result of the use of different ADAF in the cargo and passenger areas. In general, NPE concentrations are higher than OPE’s, possibly reflecting the contents of the ADAF formulations used, and also the lack of OP6-16EO data. Although NPE and OPE concentrations in the outfalls were very high, reaching low mg/L levels in some cases, dilution during these sampling events seemed to be high also, resulting in receiving water concentrations similar to those in the reference site and up to two orders of magnitude lower than the concentrations in the outfalls. Ratios of total NPE concentrations in receiving waters versus the reference site were between 0.2 and 1.5, implying that NPE levels were lower or only 50% higher in the receiving waters than in the upstream site. In contrast, ratios for the OPEs were higher than the ratios for the NPEs in all instances, and only 2 of the 6 events had ratios under 1.5; suggesting a more rapid elimination of the NPEs. Although the actual mechanism is not clear at this point, previous observations support elimination by sorption to solids, which would be favored for the NPEs because of their higher Kow values. Additionally, decrease of the APEO/APEC concentration ratios from outfalls to receiving waters in all sampling events suggests that biotransformation is possible in spite of the relatively low temperatures.