Treatment kinetics of aircraft deicing fluid in an anaerobic baffled reactor

Abstract

A four compartment anaerobic baffled reactor (ABR) operated with and without recycle treated aircraft deicing wastewater. Without recycle a minimum hydraulic retention time (HRT) of 27 h (organic loading rate, OLR, of 6.2 g·L–1·d–1) with a chemical oxygen demand (COD) removal efficiency of 89% and a Uoverall of 0.25 g·g–1·d–1 was achieved. With recycle the minimum HRT was 17 h (OLR of 9.9 g·L–1·d–1) with 93% COD removal efficiency, achieved at a Uoverall of 0.32 g·g–1·d–1. Anaerobic baffled reactor compartments served to naturally separate acidogenic and methanogenic activities longitudinally through the reactor, with acidogenic activity highest in compartment 1. A first order compartment model for substrate removal could not describe ABR performance. The rate coefficients (k1–k4) or kavg were inconsistent and no predictive correlation of k values with substrate concentration, HRT or OLR could be achieved in describing the naturally attenuated two-phase phenomenon.Key words: anaerobic, baffled reactor, deicing fluid, ethylene glycol, treatment.