Biofiltration of a styrene/acetone vapor mixture in two reactor types under conditions of acetone overloading

BACKGROUND: Evaluation of the biodegradation interactions between styrene and acetone, two typical paint solvents and vapor phase pollutants differing in water solubility and biodegradability, was conducted both in a trickle bed reactor (TBR) and a biofilter (BF). The loading rate experiments were performed by increasing the acetone concentration in the inlet air while keeping the styrene concentration and loading rate constant. RESULTS: At acetone loading rates (OLAC) between 25 and 35 gc m−3 h−1, the BF featured greater steady state performance characteristics for styrene degradation. At OLAC between 35 and 48 gc m−3 h−1, a decline of removal efficiency (RE) was observed for both pollutants, due to the system's overloading with acetone. Increasing OLAC above 52‐55 gc m−3 h−1 in both reactors resulted in drifts of RE and EC over time to much lower values. A step‐drop of acetone loading rate back to OLAC of 3 gc m−3 h−1 (gc denotes grams of carbon) resulted in lag periods lasting for several hours. CONCLUSIONS: Two important issues inherent for acetone biofiltration, e.g., from paint booths or polystyrene production, were identified: (1) poor performance at high loadings of this aggressive solvent and (2) acetone back‐stripping into the air following periods of high overloading.