Empirical Model for Biofiltration of Toluene

In this study the toluene removal efficiency of a composted pine bark biofilter was determined at loading rates ranging from 9.04 to 54.21 g m-3 h-1, retention times of 0.25-3.0 min, and at various bed heights. Toluene removal efficiencies exceeding 90% were obtained when the biofilter was subjected to a gas retention time in excess of 0.32 min (19.2 s) and loading rates below 42 g m-3 h-1. The data obtained were used to develop an empirical model. The empirical model successfully described the overall removal efficiency with an R2 value of 0.98. The influence of oxygen concentration on the removal efficiency was also evaluated. Reduced biofilter performance was observed at oxygen concentrations below 5%. A wide range of microorganisms were isolated from the biofilter, which included Corynebacterium jeikeium A, Corynebacterium nitrilophilus, Micrococcus luteus, Pseudomonas mendocina, Sphingobacterium thalphophilum, and Turicella otitidis.