Enhanced styrene removal in a two-phase partitioning bioreactor operated as a biotrickling filter: Towards full-scale applications

Styrene vapor abatement was investigated in a two-phase partitioning bioreactor operated as a biotrickling filter (TPPB-BTF). The removal performance of the TPPB-BTF was simultaneously compared with a conventional BTF, which served as a control. Industrial-grade silicone oil was used as the non-aqueous phase in the TPPB-BTF due to its high affinity for styrene. Both bioreactors were operated at styrene inlet concentrations ranging from 55 to 323 mg C m(-3) and empty bed residence times (EBRT) of 15-30 s, corresponding to pollutant loading rates of 13-77 g C m(-3) h(-1). Both bioreactors exhibited styrene removal efficiencies (REs) higher than 90% at an EBRT of 30 s. Nevertheless, the TPPB-BTF showed a superior removal performance than that recorded in the control BTF at EBRTs shorter than 30 s. REs of 89%, 84% and 57% were recorded in the TPPB-BTF at EBRT of 15 s and loading rates of 13, 22 and 77 g C m(-3) h(-1), respectively, while the control BTF supported removal efficiencies of 64%, 42% and 18-42% under the same experimental conditions. The resilience and robustness of the TPPB-BTF over styrene shock loadings and transient inlet concentration was also confirmed, the TPPB-BTF being able to recover a stable RE of 89% one day after such operation disturbances. The potential of the TPPB-BTF towards full scale applications was also critically discussed based on the experimental determination of silicone oil loses through aqueous phase renewal, which accounted for 0.4% of the initial volume of oil added to the TPPB-BTF after 87 days of operation. (C) 2016 Elsevier B.V. All rights reserved.