Abstract
BACKGROUND: The performance of two biotrickling filters (BTFs) was evaluated for styrene removal from gas streams at the start-up period and at a pseudo-steady-state under various operating conditions. RESULTS: The BTFs exceeded 99% removal efficiency within 19 days when the average inlet styrene concentration was 250 mg m-3 and gas empty bed retention time (EBCT) was 30.0 s. The effect of a surfactant, Triton X-100, on styrene removal was examined by comparative experiments in which one biofilter was fed with nutrient solution with the surfactant while the other without the surfactant, and the average organic loading rate of styrene was set at 65.3, 100.9 and 201.7 g styrene m-3 h-1, respectively. Results showed that the corresponding average removal efficiency was 87%, 70% and 50% for the BTF without surfactant, while the average removal efficiency for the BTF with surfactant was 96%, 92% and 82%. Excessive biomass accumulation was observed in the medium when the styrene loading rate was high. However, the biomass density within the BTF medium when the surfactant was added remained stable during the whole period of the operation. CONCLUSION: These results demonstrated that the use of Triton X-100 can improve the degradation of styrene and control the excessive biomass accumulation. Copyright (c) 2012 Society of Chemical Industry