Mineralization of Propylene Glycol in Root Zone Soil

Propylene glycol is a common component on aircraft deicingfluids. Runoff from airports may contain high concentrations ofpropylene glycol, leading to a high biological oxygen demand(BOD) in the runoff. Root zone soils support a diverse microbialcommunity and have been shown to enhance biodegradation of numerous compounds. Root zone soils from several grasses andlegumes were tested for their ability to enhance mineralizationof propylene glycol. Propylene glycol (1000 ppm) was applied toroot zone soils incubated at either 22 or 7 °C underdarkened conditions. Root zone soils from legumes showed thehighest rate of mineralization, however, soils from variousgrasses did not show consistently different mineralization ratesfrom each other. Mineralization rates decreased 2.2 to 4.2-foldat the lower temperature; however, treatment soils stillmineralized propylene glycol faster than autoclaved controls.