PLANT-ENHANCED REMEDIATION OF GLYCOL-BASED AIRCRAFT DEICING FLUIDS

To ensure passenger safety during flight operations, the Federal Aviation Administration demands the use of glycol-based aircraft deicing fluids (ADFs) at airports. However, from the deicing process a significant amount of ADF runoff enters storm-water collection systems and/or finds its way to soil and ground-water ecosystems. The environmental impact of the ADF mixture is a combination of the extremely high biological oxygen demand from glycols and the toxicity to bacteria, aquatic organisms, and plants of the corrosion inhibitor tolyltriazole. The present paper discusses some alternatives that have been proposed to manage ADF waste and the need for an environmental management technology able to deal with both kinds of contaminants. Phytoremediation has been explored because a rhizosphere effect improves the efficiency of land treatment for many substances and only fungi and vegetation have been reported to be able to degrade the corrosion inhibitor (Wu et al. 1998). Below a toxic threshold of about 100 mg of methyl benzotriazole/L in the aqueous phase, plants can degrade approximately about 2 mg of methyl benzotriazole/ (g dry root.day). Some of the advantages, difficulties, and conditions to apply the technology are outlined.