BACKGROUND: Painting and wood finishing is one industrial sector affected by the European Union environmental regulations on volatile organic compound (VOC) air emissions. The painting process typically results in high flow rates with low VOC concentrations, so biotrickling filtration could be an economical alternative for controlling air emissions. This study analyses the operation of a pilot unit installed in a furniture facility, and compares its performance with the removal efficiency obtained in the laboratory using a synthetic feed composed of n-butyl acetate, toluene and m-xylene to simulate industrial air emissions. RESULTS: Laboratory studies showed that fluctuating and oscillating VOC feeding adversely affected the performance of the bioreactor in comparison with stationary feeding. The operation of the pilot plant at 35 s of empty bed residence time (EBRT) remained within the legal limits. The installation of an activated carbon prefilter improved considerably the removal efficiency, with emissions kept below 40 mg C m(-3) working at 24s of EBRT. CONCLUSION: Biotrickling filtration has been shown as effective for controlling air emissions from a closed booth operated for automatically painting furniture pieces. Laboratory study can provide valuable data for the scale-up. (C) 2010 Society of Chemical Industry