Treatment kinetics of aircraft deicing fluid in an anaerobic baffled reactor

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 U-overall 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 U-overall 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 (k(1)-k(4)) or k(avg) 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.