Performance and feasibility of biotrickling filtration in the control of styrene industrial air emissions

The performance and feasibility of a pilot unit of biotrickling filter (BTF) for the treatment of industrial emissions polluted by styrene was investigated for one year at a fiber reinforced plastic industrial site. The pilot unit was packed with a structured material with a volume of 0.6 m3. Monitoring results have shown successful treatment of the industrial styrene emissions working at empty bed residence times (EBRT) between 31 and 66 s. The best performance was obtained after 300 days when a more stable biofilm had been developed, obtaining the highest elimination capacity of 18.8 g m−3 h−1 (removal efficiency of 75.6%) working at 31 s of EBRT. In addition, a photocatalytic reactor was evaluated as pretreatment of the biological process, but results have shown very low capacity for improving the BTF performance due to catalyst deactivation. The economic feasibility of the BTF was evaluated. The total direct cost, excluding capital recovery, of the biotrickling filter technology was estimated in 0.71 year−1 per Nm3 h−1 of treated air whereas 2.27 year−1 per Nm3 h−1 was obtained for the regenerative catalytic oxidizer equipped with a zeolite pre-concentrator. Results show that this technology is economically and environmentally competitive in comparison with thermal treatment