Natural, cost-effective, and sustainable alternatives for treatment of aircraft deicing fluid waste

The waste generated by aircraft deicing operations represents a threat to the environment arising from the high biological oxygen demand of propylene and ethylene glycols and the toxicity associated with some of the additives, such as the corrosion inhibitor benzotriazole. To date, there have not been any reports of waste-water treatment alternatives that completely degrade the toxic triazole components in the deicing waste. Constructed wetlands and land application can potentially take advantage of vegetation in two different ways: enhancement of biodegradation of glycols by the root-bacteria symbiosis and transformation of benzotriazoles by plant enzymatic activities. In a plant treatment system, phytotransformation of the triazoles can follow a conventional biological wastewater treatment, which can be used for glycol degradation. This paper reviews the main aspects of aircraft deicing waste treatment, outlines the results from successful applications of constructed wetlands to treat glycol-rich waste, and summarizes the experimental basis that demonstrates the benefits of using vegetation for decontamination of the main components of deicing waste. (c) 2004 American Institute of Chemical Engineers Environ Prog