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Bioclogging of Sand due to Biodegradation of Aircraft Deicing Fluid |
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| Authors: | Angela R. Bielefeldt Tissa Illangasekare Rosanna LaPlante |
| Affiliation: | 1Associate Professor, Dept. of Civil, Environmental, & Architectural Engineering, Univ. of Colorado, 428 UCB, Boulder, CO 80309-0428. 2AMAX Distinguished Chair of Environmental Science and Engineering, Colorado School of Mines, 1500 Illinois St., Golden, CO 80401-1887. 3Engineer I, EA Engineering, Science, & Technology, 15 Loveton Circle, Sparks, MD 21152. |
| Abstract: | The biodegradation of propylene glycol (PG) and PG-based aircraft deicing fluid (ADF) at initial concentrations of 400–100,000?mg/L was investigated in saturated sand columns operated under nitrogen-limited conditions that are expected occur in the environment. PG biodegradation resulted in the accumulation of 0.4–1.4?mg volatile solids/g sand, which decreased the hydraulic conductivity of the sand by 23–99.8%. At loading up to 0.27?mg ADF or PG/g sand/d, greater than 99% PG removal and 88% soluble chemical oxygen demand (COD) removal were achieved. At higher loading, removal efficiency decreased but the removal rate increased to 11.2?mg?PG/g sand/day and up to 10.7?mg COD/g sand/day. As ADF or PG loading increased causing more nitrogen-limited conditions and likely a greater amount of PG fermentation, cell yields decreased and a greater fraction of incomplete mineralization of the ADF and PG were noted as measured by higher residual soluble COD. The results indicate that natural attenuation of PG in groundwater is likely to occur in association with potentially significant bioclogging. |
| Keywords: | Biodegradation Hydraulic conductivity Sand Airports Water pollution |