Mineralization of propylene glycol in root zone soil

Propylene glycol is a common component on aircraft deicing fluids. Runoff from airports may contain high concentrations of propylene glycol, leading to a high biological oxygen demand (BOD) in the runoff. Root zone soils support a diverse microbial community and have been shown to enhance biodegradation of numerous compounds. Root zone soils from several grasses and legumes were tested for their ability to enhance mineralization of propylene glycol. Propylene glycol (1000 ppm) was applied to root zone soils incubated at either 22 or 7°C under darkened conditions. Root zone soils from legumes showed the highest rate of mineralization, however, soils from various grasses did not show consistently different mineralization rates from each other. Mineralization rates decreased 2.2 to 4.2-fold at the lower temperature; however, treatment soils still mineralized propylene glycol faster than autoclaved controls.